argonauta argo , also known as the greater argonaut , is a species of pelagic octopus belonging to the genus argonauta .

the female of the species , like all argonauts , creates a paper-thin eggcase that coils around the octopus much like the way a nautilus lives in its shell , hence the name paper nautilus .

the chinese name for this species translates as " white sea-horse 's nest " .

a. argo was the first argonaut species to be described and is consequently the type species of the genus .

a. argo is the largest species in the genus and also produces the largest eggcase .

live animals have a characteristic blue sheen on the first arm pair and around the eyes .

the eggcase is characterised by two rows of small , sharp tubercles running along a narrow keel , smooth ribs across the walls of the shell , and a thickening along the shell aperture , which forms distinct protrusions or ' horns ' on either side .

argonauta cygnus monterosato , 1889 was described based on a shell which lacked these protrusions , although it is now considered a junior synonym of a. argo .

the greatest recorded size of an a. argo eggcase is 300.0 mm .

a. argo is cosmopolitan , occurring in tropical and subtropical waters worldwide .

a dwarf form exists in the mediterranean sea , which was described as argonauta argo mediterranea monterosato , 1914 , although this taxon is now regarded as invalid .

a. argo is thought to feed primarily on pelagic molluscs .

the species is preyed on by numerous predators .

it has been reported in the stomach contents of alepisaurus ferox from the south-western pacific .

males of this species reach sexual maturity at a mantle length ( ml ) of 8 mm .

females mature at about double the size of argonauta bottgeri and argonauta hians .

they begin to secrete an eggcase at 6.5 – 7 mm ml .

eggs are usually laid when females reach 14 – 15 mm ml , although the size at which this takes place differs across the animal 's range .

a small a. argo residing in an 88 mm long eggcase was estimated to be carrying 48,800 embryos .

females grow to 100 mm ml , while males do not exceed 20 mm ml .

in the open ocean , a. argo has been observed attached to jellyfish .

this behaviour has been known for a long time , although little was understood about the relationship prior to the work of heeger et al. in 1992 .

in " predation on jellyfish by the cephalopod argonauta argo " , heeger et al. describe their observations of a female a. argo found atop a host jellyfish .

the argonaut was seen holding on to the aboral ( exumbrellar ) surface of the jellyfish using its lateral and ventral arms .

the authors found that about half of the animal 's aboral surface was damaged and large pieces of mesoglea were missing , presumably removed by the argonaut .

additionally , two holes , apparently bite marks , were found in the center of this area with channels leading from these holes into the gastral cavity of the jellyfish .

the argonaut presumably used these channels to suck food particles from the gastral cavity .

heeger et al. suggested that " the association provided shelter or camouflage for the argonaut " .

observations of captive a. argo females suggest that the expanded webs of the dorsal arms may aid the animal in feeding .

mark norman mentions that " when food was touched against the spread webs , an arm shot out of the shell in a sweeping action , grabbing the prey " .

it is speculated that argonauts do not actively hunt , but employ this method to catch animals that bump into them in the open ocean .

a. argo is occasionally involved in mass strandings along the south african and southern australian coastlines .

the strandings are seasonal and generally occur between april and august , towards the end of the animals ' spawning season .

a damaged beak of a female a. argo ( ml = 40.0 mm ; caught at 20 ° 56 ′ n 175 ° 33 ′ w ) , measuring 4.30 mm in hood length and 7.80 mm in crest length , is mentioned in a handbook for the identification of cephalopod beaks .

the type specimen of a. argo was collected in the mediterranean sea and is deposited at the linnean society of london .

argonauta argo

forma argonauta argo f . agglutinans martens , 1867 accepted as argonauta argo linnaeus , 1758
forma argonauta argo f . aurita martens , 1867 accepted as argonauta argo linnaeus , 1758
forma argonauta argo f . mediterranea monterosato , 1914 accepted as argonauta argo linnaeus , 1758
forma argonauta argo f . obtusangula martens , 1867 accepted as argonauta argo linnaeus , 1758
variety argonauta argo var . americana dall , 1889 accepted as argonauta argo linnaeus , 1758
figure . two views of argonauta argo atop the jellyfish , phyllorhiza punctata . photographs copyright © , thomas heeger , university of san carlos , philippines .
figure . hectocotylus of argonauta argo . top - oral view . middle - aboral view . bottom - side view . drawings from naef , 1921 - 3 .
figure . left - lateral view of an argonauta argo shell , hawaii . photograph by r . young ) . right - a collection of argonauta nodosa shells from a swarm that washed ashore , australia . photograph by mark norman .
to cite this page : virden , t . 1999 .
argonauta argo
( on - line ) , animal diversity web . accessed july 09 , 2018 at urltoken
heeger , t . , u . piatkowski and h . möller . 1992 . predation on jellyfish by the cephalopod argonauta argo . marine ecology progress series 88 : 293 - 296 .
figure . view of a portion of the radula of a . argo . drawing from naef ( 1921 - 1923 ) .
okutani , t . and t . kawaguchi . 1983 . a mass occurrence of argonauta argo ( cephalopoda : octopoda ) along the coast of shimane prefecture , western japan sea . venus 41 : 281 - 290 .
figure . side - oblique views of an argonauta argo , photographed in a ship - board aquarium . left - arm i web expanded over shell . right - arm i web retracted . photographs by m . vecchione .
( of argonauta argo f . obtusangula martens , 1867 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta argo f . aurita martens , 1867 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta argo f . agglutinans martens , 1867 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta argo var . americana dall , 1889 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta argo f . mediterranea monterosato , 1914 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta ferussaci monterosato , 1914 ) monterosato t . a . ( di ) ( 1914 ( 30 giugno ) ) . sur les argonauta de la méditerranée . journal de conchyliologie 61 ( 4 ) : 385 - 390 , tabs . x - x3 [ details ]
( of argonauta corrugata humphrey , 1797 ) check list of european marine mollusca ( clemam ) . , available online at urltoken [ details ]
( of argonauta haustrum wood , 1811 ) check list of european marine mollusca ( clemam ) . , available online at urltoken [ details ]
( of argonauta papyria conrad , 1854 ) check list of european marine mollusca ( clemam ) . , available online at urltoken [ details ]
( of argonauta monterosatoi coen , 1915 ) coen g . ( 1915 ) . delle forme adriatiche di argonauta ed in particolare dell ' a . monterosatoi n . sp . . annali del museo civico di storia naturale di genova ( 3 ) 6 ( 46 ) : 261 - 275 , pl . 5 [ details ]
figure . lateral view of a juvenile female ( 6 . 5 mm ml ) argonauta hians showing the web on arms i , equatorial south atlantic . drawing from chun , 1910 .
figure . side and ventral views of the funnel and mantle locking - apparatus of argonauta hians , juvenile male , 5 . 0 mm ml , equatorial south atlantic . drawing from chun , 1910 .
figures . lateral and oral views of male argonauts . left , center - a 5 mm ml , apparently immature , male argonauta hians from the equatorial south atlantic . drawings from chun , 1910 . in oral view the male looks like a 7 - arm octopus . right - a male argonauta nodosa , off australia , with the hectocotylus in a much larger sac is apparently mature . photograph by mandy reid ; provided by mark norman .
( of argonauta minor risso , 1854 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta ferussaci monterosato , 1914 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta monterosatoi monterosato , 1914 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta cygnus monterosato , 1889 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta pacificus dall , 1871 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta corrugatus humphrey , 1797 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta papyraceus röding , 1798 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta sulcatus lamarck , 1801 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta grandiformis perry , 1811 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta haustrum dillwyn , 1817 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta monterosatoi coen , 1915 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta dispar conrad , 1854 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta compressus blainville , 1826 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta papyrius conrad , 1854 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta naviformis conrad , 1854 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta bulleri kirk , 1886 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
( of argonauta sebae monterosato , 1914 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
banas , p . t . , d . e . smith and d . c . biggs . 1982 . an association between a pelagic octopod , argonauta sp . linnaeus 1758 , and aggregate salps . fish . bull . u . s . 80 : 648 - 650 .
embryonic development begins in the oviducts . older embryos are attached to the inner region of the shell where they are brooded . the elongate egg stalks ( extensions of the egg chorion ) are woven together and attached to the shell apex on its inner surface . a female a . argo with a shell length of 88 mm was estimated to be carrying 48 , 800 embryos ( okutani and kawaguchi , 1983 ) . the eggs are very small ( 0 . 6 - 1 . 0 mm ) . spawning is intermittent , and the brooding embryos can be seen to be in different stages of development .
figure . side view of argonauta sp . , showing the expansion of the web ( web presence indicated by their chromatophores ) of the first arm , past the horn of the shell and over most of the shell surface , gulf of aqaba , red sea . photograph of living argonaut by shai enbinder ; provided by nadav shashar .
( of argonauta cygnus monterosato , 1889 ) monterosato t . a . ( di ) ( 1889 ( 1 gennaio ) ) . coquilles marines marocaines . journal de conchyliologie 37 ( 1 ) : 20 - 40 ; 37 ( 2 ) : 112 - 121 . , available online at urltoken page ( s ) : 120 [ details ]
( of argonauta cygnus monterosato , 1889 ) gofas , s . ; afonso , j . p . ; brandào , m . ( ed . ) . ( s . a . ) . conchas e moluscos de angola = coquillages et mollusques d ' angola . [ shells and molluscs of angola ] . universidade agostinho / elf aquitaine angola : angola . 140 pp . ( look up in imis ) [ details ]
( of argonauta minor risso , 1854 ) adam , w . ( 1942 ) . notes sur les céphalopodes : 21 . a propos d ' une publication peu connue de a . risso 1854 [ notes on the cephalopods : 21 . on a hardly known publication from a . risso 1854 ] . bull . mus . royal d ' hist . nat . belg . / med . kon . natuurhist . mus . belg . 18 ( 25 ) : 1 - 36 ( look up in imis ) [ details ]
argonauts are pelagic in tropical and subtropical surface waters of all oceans and seas . sometimes they are found in large swarms , but only rarely are they encountered nearshore . in the open ocean they are commonly found attached to jellyfish ( david , 1965 ) . while this unusual association between argonauta spp . and jellyfish has long been known ( kramp , 1956 ; david , 1965 ) it was uninvestigated prior to the work of heeger et al . ( 1992 ) . the latter authors describe argonauta astride the aboral ( = exumbrellar ) surface of a swimming jellyfish that it held with its lateral and ventral arms . upon examination of the jellyfish they found about half of its aboral surface was damaged and large pieces of mesoglea were missing . two holes , apparently bite marks were found in the center of this area and channels led from these holes into the gastral cavity of the jellyfish . they presumed the octopod used these channels to suck particles ( food ) from the gastral cavity . they also suggest that the association provided shelter or camouflage for the argonaut .
the female lives in a thin , calcareous , laterally compressed shell secreted by its dorsal arms . the shell is paper - thin and the animal is commonly called the
paper nautilus .
the latter part of the name comes from similarly - shaped shell of nautilus . the shell of the pearly nautilus , however , is the true cephalopod shell ( i . e . , the homologue of the molluscan shell ) and not a unique evolutionary innovation like the
shell
of argonauta ( naef , 1921 - 23 ) .
( of argonauta cygnus monterosato , 1889 ) finn j . k . ( 2014 ) . family argonautidae . pp . 228 - 237 , in p . jereb , c . f . e . roper , m . d . norman & j . k . finn eds . cephalopods of the world . an annotated and illustrated catalogue of cephalopod species known to date . volume 3 . octopods and vampire squids . fao species catalogue for fishery purposes [ rome , fao ] . 4 ( 3 ) : 353 pp . 11 pls . page ( s ) : 230 [ details ]
( of argonauta pacificus dall , 1871 ) finn j . k . ( 2014 ) . family argonautidae . pp . 228 - 237 , in p . jereb , c . f . e . roper , m . d . norman & j . k . finn eds . cephalopods of the world . an annotated and illustrated catalogue of cephalopod species known to date . volume 3 . octopods and vampire squids . fao species catalogue for fishery purposes [ rome , fao ] . 4 ( 3 ) : 353 pp . 11 pls . page ( s ) : 230 [ details ]
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thank you for taking the time to provide feedback on the iucn red list of threatened species website , we are grateful for your input .
have been described . a full list is given by mangold , vecchione and young ( 2008 ) . taxonomic work on this genus is required , but
is undoubtedly a good species and is the type species of the genus . we treat
has been assessed as least concern because , although little is known about this species , its wide distribution , oceanic lifestyle and low interest to fisheries suggest that it is not threatened .
this species is found in surface tropical and subtropical waters of the world ' s oceans . in the atlantic , it extends north to cape cod in the west and portugal in the east and south to brazil in the west and southern africa in the east . it also occurs in the mediterranean sea . in the pacific , its northern limits appear to be california in the east and southern hokkaido in the west . it extends southwards to subtropical waters around australia and new zealand . it is found throughout the indo - west pacific ( nesis 1987 , norman 2000 ) .
albania ; algeria ; american samoa ; angola ; anguilla ; antigua and barbuda ; aruba ; australia ; bahamas ; bangladesh ; barbados ; belize ; benin ; bermuda ; bonaire , sint eustatius and saba ; bosnia and herzegovina ; brazil ; british indian ocean territory ; brunei darussalam ; cambodia ; cameroon ; cape verde ; cayman islands ; china ; christmas island ; cocos ( keeling ) islands ; colombia ; comoros ; congo ; congo , the democratic republic of the ; cook islands ; costa rica ; côte d ' ivoire ; croatia ; cuba ; curaçao ; disputed territory ; djibouti ; dominica ; dominican republic ; ecuador ; egypt ; el salvador ; equatorial guinea ; eritrea ; fiji ; french guiana ; french polynesia ; gabon ; gambia ; ghana ; gibraltar ; greece ; grenada ; guadeloupe ; guam ; guatemala ; guinea ; guinea - bissau ; guyana ; haiti ; honduras ; hong kong ; india ; indonesia ; iran , islamic republic of ; iraq ; italy ; jamaica ; japan ; kenya ; kiribati ; korea , democratic people ' s republic of ; korea , republic of ; kuwait ; liberia ; libya ; macao ; madagascar ; malaysia ; maldives ; malta ; marshall islands ; martinique ; mauritius ; mayotte ; mexico ; micronesia , federated states of ; monaco ; montenegro ; montserrat ; morocco ; mozambique ; myanmar ; namibia ; nauru ; new caledonia ; new zealand ; nicaragua ; nigeria ; niue ; norfolk island ; northern mariana islands ; oman ; pakistan ; palau ; panama ; papua new guinea ; peru ; philippines ; pitcairn ; portugal ; puerto rico ; qatar ; réunion ; russian federation ; saint barthélemy ; saint helena , ascension and tristan da cunha ; saint kitts and nevis ; saint lucia ; saint martin ( french part ) ; saint vincent and the grenadines ; samoa ; san marino ; sao tomé and principe ; saudi arabia ; senegal ; seychelles ; sierra leone ; singapore ; sint maarten ( dutch part ) ; solomon islands ; somalia ; south africa ; spain ; sri lanka ; sudan ; suriname ; taiwan , province of china ; tanzania , united republic of ; thailand ; timor - leste ; togo ; tokelau ; tonga ; trinidad and tobago ; tunisia ; turks and caicos islands ; tuvalu ; united arab emirates ; united states ; united states minor outlying islands ; vanuatu ; venezuela , bolivarian republic of ; viet nam ; virgin islands , british ; virgin islands , u . s . ; wallis and futuna ; western sahara ; yemen
female argonauts secrete a shell using glands on their dorsal arms into which they lay their eggs . they produce the shell early in life ( before maturation ) and use it as a home . males are dwarf and have been reported living within salps ( banas et al . 1982 ) . they have a modified third arm which detaches during mating and carries the spermatophores to the females . female argonauts are often found associated with jellyfish , which they use as a source of food and possibly as camouflage ( heeger et al . 1992 ) . eggs are small ( 50 , 000 ) and are brooded in the shell until they hatch ( laptikhovsky and salman 2003 ) . up to five developmental stages can be present in one shell , which is neutrally buoyant due to the female trapping air at the surface ( jereb et al . 2014 ) . the species is assumed to be semelparous and likely has a lifespan of around one year as is common for other cephalopod species . females probably spawn continuously releasing a batch of around 2 , 000 - 4 , 000 eggs per day over a period of a month or more ( laptikhovsky and salman 2003 ) .
the shells are of interest to the shell trade and the flesh is edible . this species is of limited interest to fisheries but is reported occasionally in indian , japanese and taiwanese ( jereb et al . 2014 ) markets , occasionally with landings of several hundred kilograms ( de bruin et al . 1995 ) . jereb et al . ( 2014 ) state that between the 17th of june and 3rd of july 1982 , around 6 , 300 females were caught in the sea of japan .
there is a potential threat from the shell trade , but mostly trade appears to be of shells that wash up on shores so this cannot be considered a current threat .
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yes , it ' s a cephalopod ! this squid and other cephalopods are featured in the cephalopod pages maintained at the national museum of natural history , department of invertebrate zoology ! see the following links for more information on cephalopods .
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the list of species featured in the videos , arranged as a taxonomic list , only relevant taxa included .
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expedition journals from the search for the giant squid off new zealand , 1999 .
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katharina m . mangold ( 1922 - 2003 ) , michael vecchione , and richard e . young
the family contains at least four species ( nesis , 1982 / 7 ) .
argonauts are muscular , pelagic octopods . females secrete a thin calcareous
shell
in which they reside . shells may reach a length of 30 cm ( nesis , 1982 ) . the dorsal arms of females are modified with large , flag - like membranes that expand over the shell and are responsible for the secretion of the shell . eyes are very large and webs very small . the mantle - funnel locking apparatus consists of knob - like cartilages ( mantle ) and matching depressions ( funnel ) . males are dwarfs .
females with distal flag - like expansion of the web of the dorsal arms that contain shell - secreting glands .
presence of external
shell
in females secreted by the dorsal arms . the true molluscan shell ( i . e . , stylets in most incirrates ) is absent .
a list of all nominal genera and species in the argonautidae can be found here . the list includes the current status and type species of all genera , and the current status , type repository and type locality of all species and all pertinent references .
an unusual feature of argonauts is the secreted shell that functions as a brood chamber . the
shell
is not homologous with the true molluscan shell as evidenced by its unique site of formation : the dorsal arms of the female rather than the internal shell sac as in other coleoids . naef ( 1921 / 3 ) noted the remarkable resemblance of the argonaut shell to the shells of some of the abundant cretaceous ammonoids and suggested that the argonaut shell evolved in the following way : ancestral argonauts occupied empty ammonoid shells during the late cretaceous . [ occupancy of molluscan shells by octopodids is common in the present day . ] the octopod evolved glandular structures on the arms to repair the shell of the ammonoids after the latter had become extinct at the end of the cretaceous . eventually , the ammonoid shell was completely replaced by a secreted structure whose shape had been evolutionarily molded by the ammonoid shell . however , as pointed out by young et al . ( 1998 ) , a gap of about 40 million years exists between extinction of ammonoids and the earliest fossil record of an argonaut , and they suggest that the mold for the shell was from some other type of mollusc and that the resemblance to ammonoids is coincidental . the origin of the argonaut shell is a challenging problem and has important implications for understanding the relationships amoung groups of the argonautoidea ( young , et al . , 1998 ) .
the male argonaut is a dwarf , about 10 % of the length of the female . the entire third right arm is hectocotylized and carried in a special sac . at mating , the hectocotylus , which carries one large spermatophore , breaks out of its sac and then from the male body . the free hectocotylus invades , or is deposited in , the female ' s mantle cavity , where it remains viable and active for some time . the hectocotylus was first described as a worm parasitic on the female ( delle chiaje , 1825 ) .
the argonaut paralarva has a distinctive appearance as seen in the photo . the arms are very short and equal in length and are surrounded in their proximal half by a membranous collar or cuff ( barely recognizable in the photograph ) formed by the interbrachial membrane . the latter feature is found also in tremoctopus hatchlings . the life - span is unknown .
- ventrolateral view captured in a plankton tow , hawaii . photograph by r . young .
- side view . drawing from naef ( 1921 - 230 . note the lock and pit of the funnel / mantle locking - apparatus at the bottom of the photograph and drawing .
males have been reported living within salps ( banas et al . , 1982 ) .
chun , c . 1910 . die cephalopoden . oegopsida . wissenschaftliche ergebnisse der deutschen tiefsee expedition auf dem dampfer
valdivia
1898 - 1899 , 18 ( 1 ) : 1 - 401 .
david , p . m . 1965 . the surface fauna of the ocean . endeavour ( oxf . ) 24 : 95 - 100 ) .
delle chiaje , s . 1825 . memorie sulla storia e notomia degli animali . senza verlebre del regno di napoli . i .
kramp , p . l . 1956 . pelagic fauna . p . 65 - 86 . in : ( a . bruun , sv . greve , h . mielche and r . spärck , eds . ) the galathea deep sea expedition 1950 - 1952 .
naef , a . 1921 / 23 . cephalopoda . fauna und flora des golfes von neapel . monograph , no . 35 .
nesis , k . n . 1982 / 7 . abridged key to the cephalopod mollusks of the world ' s ocean . 385 , ii pp . light and food industry publishing house , moscow . ( in russian . ) . translated into english by b . s . levitov , ed . by l . a . burgess ( 1987 ) , cephalopods of the world . t . f . h . publications , neptune city , nj , 351pp .
young , r . e . , m . vecchione and d . donovan . 1998 the evolution of coleoid cephalopods and their present biodiversity and ecology . south african jour . mar . sci . . , 20 : 393 - 420 .
page copyright © 2016 katharina m . mangold ( 1922 - 2003 ) , , and
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mangold ( 1922 - 2003 ) , katharina m . , michael vecchione , and richard e . young . 2016 . argonautidae
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linnaeus , c . ( 1758 ) . systema naturae per regna tria naturae , secundum classes , ordines , genera , species , cum characteribus , differentiis , synonymis , locis . editio decima , reformata . laurentius salvius : holmiae . ii , 824 pp . , available online at urltoken page ( s ) : 708 [ details ]
description mantle globular , as wide as long ; surface of mantle , head , arms , and web covered with conspicuous , closely - set , large , . . .
description mantle globular , as wide as long ; surface of mantle , head , arms , and web covered with conspicuous , closely - set , large , stellate tubercles ; a narrow , tuberculate , fold of skin encircles the lateral surface of the mantle ; funnel organ , 4 separate longitudinal pads . [ details ]
( of ocythoe antiquorum leach , 1817 ) leach w . e . ( 1817 ) . synopsis of the orders , families and genera of the class cephalopoda . the zoological miscellany ; being descriptions of new or interesting animals . 3 ( 30 ) : 137 - 141 . , available online at urltoken page ( s ) : 139 [ details ]
finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
finn j . k . ( 2014 ) . family argonautidae . pp . 228 - 237 , in p . jereb , c . f . e . roper , m . d . norman & j . k . finn eds . cephalopods of the world . an annotated and illustrated catalogue of cephalopod species known to date . volume 3 . octopods and vampire squids . fao species catalogue for fishery purposes [ rome , fao ] . 4 ( 3 ) : 353 pp . 11 pls . page ( s ) : 230 [ details ]
roper , c . f . e . , m . j . sweeney & c . e . nauen ( 1984 ) . fao species catalogue . vol 3 . cephalopods of the world . an annotated and illustrated catalogue of species of interest to fisheries . fao fish . synop . ( 125 ) , vol 3 : 277 p . [ details ]
branch , g . m . et al . ( 2002 ) . two oceans . 5th impression . david philip , cate town & johannesburg . , available online at urltoken [ details ]
gofas , s . ; afonso , j . p . ; brandào , m . ( ed . ) . ( s . a . ) . conchas e moluscos de angola = coquillages et mollusques d ' angola . [ shells and molluscs of angola ] . universidade agostinho / elf aquitaine angola : angola . 140 pp . ( look up in imis ) [ details ]
spencer , h . g . , marshall , b . a . & willan , r . c . ( 2009 ) . checklist of new zealand living mollusca . pp 196 - 219 . in : gordon , d . p . ( ed . ) new zealand inventory of biodiversity . volume one . kingdom animalia : radiata , lophotrochozoa , deuterostomia . canterbury university press , christchurch . [ details ]
judkins , h . l . , m . vecchione , and c . f . e . roper . 2009 . cephalopoda ( mollusca ) of the gulf of mexico , pp . 701–709 in felder , d . l . and d . k . camp ( eds . ) , gulf of mexico–origins , waters , and biota . biodiversity . texas a & m ; press , college station , texas . [ details ]
rosenberg , g . 1992 . encyclopedia of seashells . dorset : new york . 224 pp . page ( s ) : 178 [ details ]
liu j . y . [ ruiyu ] ( ed . ) . ( 2008 ) . checklist of marine biota of china seas . china science press . 1267 pp . ( look up in imis ) [ details ] available for editors [ request ]
lu , c . c . & chung , w . s . ( 2017 ) . guide to the cephalopods of taiwan . national museum of natural science , taichung , taiwan , 560 pp . isbn 978 - 986 - 05 - 2569 - 4 . page ( s ) : 516 [ details ]
( of ocythoe argonautae cuvier , 1829 ) check list of european marine mollusca ( clemam ) . , available online at urltoken [ details ]
( of ocythoe antiquorum leach , 1817 ) finn j . k . ( 2013 ) taxonomy and biology of the argonauts ( cephalopoda : argonautidae ) with particular reference to australian material . molluscan research 33 ( 3 ) : 143 - 222 . [ details ]
gleadall , i . g . ( 1997 ) . hong kong cephalopada : a brief review of current knowledge and identification of specimens collected in 1995 . in : morton b , editor . proceedings of the eighth international marine biological workshop : the marine flora and fauna of hong kong and southern china . the marine flora and fauna of hong kong and southern china iv . hong kong university press , hong kong . 503 - 513 . [ details ]
to museum of new ze . . . [ hosted externally ; from synonym ]
likes to be near the surface of the water . it is an epipelagic oceanic species .
the maximum length of shell is 30 cm in females , but only 1 . 5 - 2 cm in males . the shell is coiled and laterally compressed with a narrow keel and numerous sharp nodules . nodules toward the center of the coil are brown , but most of the shell is white .
the male uses a specialized arm called a ' hectocotylus ' to fertilize the eggs . the hectocotylus is inserted into the females pouch and breaks off during mating . the female forms a
nacelle ,
a thin calcareous shell , with two of her legs ( the others are used for swimming ) . this structure holds the eggs throughout development .
the female is up to twenty times larger than the male . normally these animals are solitary .
can be found in fish markets in india and japan . the shell is praised by collectors because of its beauty , coloration , sculpture , and fragility .
this animal is very common but is rarely spotted by humans . every once and a while many of them may be washed up by a change in currents or chased into shallow waters by predators , allowing people to observe and catch them .
the body of water between africa , europe , the southern ocean ( above 60 degrees south latitude ) , and the western hemisphere . it is the second largest ocean in the world after the pacific ocean .
body of water between the southern ocean ( above 60 degrees south latitude ) , australia , asia , and the western hemisphere . this is the world ' s largest ocean , covering about 28 % of the world ' s surface .
having body symmetry such that the animal can be divided in one plane into two mirror - image halves . animals with bilateral symmetry have dorsal and ventral sides , as well as anterior and posterior ends . synapomorphy of the bilateria .
the area in which the animal is naturally found , the region in which it is endemic .
structure produced by the calcium carbonate skeletons of coral polyps ( class anthozoa ) . coral reefs are found in warm , shallow oceans with low nutrient availability . they form the basis for rich communities of other invertebrates , plants , fish , and protists . the polyps live only on the reef surface . because they depend on symbiotic photosynthetic algae , zooxanthellae , they cannot live where light does not penetrate .
lane , frank . 1960 . kingdom of the octopus . sheridan house , new york .
roper , c . 1984 . cephalopods of the world . national museum , washington .
abbot , r . t . 1954 . american seashells . d . van nostrand co . , inc .
cousteau , jacques . 1973 . octopus and squid . doubleday and co . , new york .
disclaimer : the animal diversity web is an educational resource written largely by and for college students . adw doesn ' t cover all species in the world , nor does it include all the latest scientific information about organisms we describe . though we edit our accounts for accuracy , we cannot guarantee all information in those accounts . while adw staff and contributors provide references to books and websites that we believe are reputable , we cannot necessarily endorse the contents of references beyond our control .
this material is based upon work supported by the national science foundation grants drl 0089283 , drl 0628151 , due 0633095 , drl 0918590 , and due 1122742 . additional support has come from the marisla foundation , um college of literature , science , and the arts , museum of zoology , and information and technology services .
html public
- / / w3c / / dtd xhtml 1 . 0 transitional / / en
urltoken
argonauts occur in all tropical and temperate waters of the world . the exact number of species is not known . four species are currently recognised . the species are mainly distinguished by shell shape .
by well - developed connective apparatus conspicuous even in larvae . body firm , muscular ,
long , 1st much longer than others , 4th and 2nd shorter , 3rd are the shortest . fourth
10 - 20 % longer than 2nd , 1 . 5 - 2 times the length of 3rd . in maturing and mature females
present , photophores absent . twenty eight lamellae per demibranch in females . female builds characteristic thin , fragile calcareous
approx . 5 - 7 mm ; during subsequent life , beginning from approx . 8 mm ,
length . eggs very small ( 0 . 6 - 0 . 8 mm ) , laid and incubated in rear part of
wall . newborn larvae liberated by female probably every night . female begins to reproduce shortly after building
and continues to spawn eggs during entire life . males dwarfed , their 3rd left
everts and becomes much longer than male itself , detaches during mating . part of the
and remains there ; male dies after mating and is probably devoured by female . up to 3 hectocotyli may be found in one female . color of females purple - blue to wine - red from above , light from below ; extended 1st
not numerous ( < 35 ) , set far apart , nodules brown . fourth
much shorter than 2nd - 3rd , length in large females approx . 60 % of 2nd . egg size 0 . 7 - 0 . 8 mm . 20 lamellae per demibranch . a third
systema naturae per regna tria naturae , secundum classes , ordines , genera , species cum characteribus , differentiis , synonymis , locis .
sweeney , m . j . and c . f . e . roper / n . a . voss , m . vecchione , r . b . toll and m . j . sweeney , eds .
systematics and biogeography of cephalopods . smithsonian contributions to zoology , 586 ( i - ii )
turgeon , d . d . , a . e . bogan , e . v . coan , w . k . emerson , w . g . lyons , w . pratt , et al .
turgeon , d . d . , j . f . quinn , jr . , a . e . bogan , e . v . coan , f . g . hochberg , w . g . lyons , et al .
common and scientific names of aquatic invertebrates from the united states and canada : mollusks , 2nd ed .
taxon validity : [ fide robson ( 1932 : 181 ) ] . repository : ls syntypes . type locality :
pelago , m . indico , mediterrane
disclaimer : itis taxonomy is based on the latest scientific consensus available , and is provided as a general reference source for interested parties . however , it is not a legal authority for statutory or regulatory purposes . while every effort has been made to provide the most reliable and up - to - date information available , ultimate legal requirements with respect to species are contained in provisions of treaties to which the united states is a party , wildlife statutes , regulations , and any applicable notices that have been published in the federal register . for further information on u . s . legal requirements with respect to protected taxa , please contact the u . s . fish and wildlife service .
this page was last edited on 16 may 2017 , at 00 : 41 .
text is available under the creative commons attribution - sharealike license ; additional terms may apply . by using this site , you agree to the terms of use and privacy policy .


a leafhopper is the common name for any species from the family cicadellidae .

these minute insects , colloquially known as hoppers , are plant feeders that suck plant sap from grass , shrubs , or trees .

their hind legs are modified for jumping , and are covered with hairs that facilitate the spreading of a secretion over their bodies that acts as a water repellent and carrier of pheromones .

they undergo a partial metamorphosis , and have various host associations , varying from very generalized to very specific .

some species have a cosmopolitan distribution , or occur throughout the temperate and tropical regions .

some are pests or vectors of plant viruses and phytoplasmas .

the family is distributed all over the world , and constitutes the second-largest hemipteran family , with at least 20,000 described species .

they belong to a lineage traditionally treated as infraorder cicadomorpha in the suborder auchenorrhyncha , but as the latter taxon is probably not monophyletic , many modern authors prefer to abolish the auchenorrhyncha and elevate the cicadomorphs to a suborder clypeorrhyncha .

members of the tribe proconiini of the subfamily cicadellinae are commonly known as sharpshooters .

leafhopper

the following leafhopper is a very common type of leafhopper known officially as graphocephala coccinea but common names include : “candy - striped” leafhopper , “red - banded” leafhopper , “scarlet and green” leafhopper and “red and blue” leafhopper . this is a very common type of leafhopper in north and central america .
adult female wasp , anagrus spp . , is a parasite of leafhopper eggs .
relationship of the white apple leafhopper typhlocyba pomaria mcatee and the rose leafhopper edwardsiana rosae ( l . ) , on apple in the hudson valley region of new york
. general information on leafhopper biology with links to other sites containing more detailed information .
control of the potato leafhopper ( empoasca mali le b . ) and prevention of “hopperburn”
systematics of the leafhopper genus draeculacephala ball ( homoptera : cicadellidae ) - bugguide . net
checklist of leafhopper species : 1758 - 1955 [ s . h . mckamey ] .
early - instar potato leafhopper with piercing - sucking mouthpart , or stylet ( st ) .
when it comes to getting rid of them , it doesn’t matter what type of leafhopper you have , because the remedies will work on all species . if you have leafhopper damage , it means you have some type of leafhopper and the remedies below will get rid of them !
adult potato leafhopper ; note the six white spots located on top of the head behind the eyes .
the leafhopper vectors of phytopathogenic viruses ( homoptera : cicadellidae ) . taxonomy , biology , and virus transmission
this page contains general information on leafhopper biology with photos and links to keys and a list of specialists .
the white apple leafhopper attacks apple , cherry and prune but has also been found on peach and hawthorn . it does not usually damage pear , although the rose leafhopper has been noted in sizable numbers on this crop .
note : there are more leafhopper species worldwide than all species of birds , mammals , reptiles and amphibians combined .
late - instar potato leafhopper with wing pads ( wp ) and specialized legs ( sl ) used for jumping .
this web site provides general information on leafhopper classification , evolution , behavior , ecology , conservation , and pest status .
leafhopper offers web based solutions for your business or organisation , including solar , web design and support and it training .
potato leafhopper resistance in alfalfa : recent improvements , p . 101 . in proceedings , 36th north american alfalfa improvement conference
leafhoppers are one of the most abundant groups of plant feeding insects in the world with leafhopper and planthopper species outnumbering that of all species of birds , mammals , reptiles , and amphibians combined ! many species are host specific with their names indicating their preferred host ; e . g . rose leafhopper , grape leafhopper , potato leafhopper , etc . leafhoppers are wedge shaped and vary in color depending on species . their name references leafhoppers ' affinity for hopping off of leaf surfaces when disturbed .
glasshouse leafhopper is a small 3mm long , pale green sap - feeding insect which can jump of leaves and fly short distances .
safer® brand offers a variety of leafhopper control products to help control and eliminate this garden pest and revive your plants . please check out our leafhopper control products for more details about how they work and how , when , and where they should be applied .
ross , h . h . , and cooley , t . a . , 1969 , a new nearctic leafhopper of the genus
glasshouse leafhopper can cause a pale mottling on the foliage on a wide range of glasshouse and garden plants , including tomato and fuchsia .
ross , h . h . , and hamilton , k . g . a . , 1970 , phylogeny and dispersal of the grassland leafhopper genus
young , d . a . , jr . , and beirne , b . p . , 1958 , a taxonomic revision of the leafhopper genus
raatikainen , m . , and vasarainen , a . , 1976 , composition , zonation and origin of the leafhopper fauna of oat fields in finland ,
in kent leafhopper works closely with the kent and medway social enterprise network , kentcan , case kent and the kent equality cohesion council council and many others .
after several weeks or months of feeding and several moltings , they will develop into adults . the length of time for development depends upon the species of leafhopper .
as with other cold - blooded organisms , potato leafhopper development is dependent on environmental temperatures . potato leafhopper development ceases when temperatures drop below a lower developmental threshold of 45°f ( 7 . 6°c ) , and the rate begins to decline when temperatures consistently exceed an upper developmental threshold of 86°f ( 30°c ; hogg 1985 ) .
called f . whitcombi , the leafhopper was named after the author ' s
extraordinary
mentor , colleague and friend , dr . robert whitcomb .
among many other accomplishments ,
in the fields of microbiology and ornithology , mr . hicks points to whitcombs '
major contributions
to leafhopper taxonomy and ecology .
parasitic wasps lay their eggs inside the leafhopper ' s body eventually killing the host insect . lure parasitic wasps to your garden by planting nectar or pollen producing plants .
this is a different type of leafhopper that attacks cannabis plants . although it looks very different , it acts exactly the same and makes the same type of damage .
white apple leafhopper is native to north america and occurs throughout the fruit growing areas of the united states and canada , but its pest status varies from region to region .
leafhopper directors have a wealth of knowledge and expertise with many years practical experience in setting up and running business and social economy organisations with links to national and regional organisations .
dietrich , c . h . 1994 . systematics of the leafhopper genus draeculacephala ( homoptera : cicadellidae ) . transactions of the american entomological society 120 : 87 - 112 .
blocker , h . d . , and reed , r . , 1976 , leafhopper populations of a tallgrass prairie ( homoptera : cicadellidae ) : collecting procedures and population estimates ,
genung , w . g . , and mead , f . w . , 1969 , leafhopper populations ( homoptera : cicadellidae ) on five pasture grasses in the florida everglades ,
glandular - haired alfalfa varieties with > 50 % resistance offer a valuable trait to potato leafhopper ipm programs . it is important to note that although alfalfa varieties bred for resistance to the potato leafhopper no longer demonstrate visual hopperburn , this does not necessarily indicate that there is no yield or quality damage to the alfalfa ( kindler et al . 1973 , shockley et al . 2002 ) . under moderate to heavy potato leafhopper infestations , glandular - haired varieties still benefit from timely scouting and insecticide treatment when leafhopper populations have exceeded thresholds established for susceptible alfalfa varieties . the first crop of seeding - year stands of glandular - haired varieties should be treated for potato leafhopper using the same economic thresholds established for susceptible alfalfa ( lefko et al . 2000b ; tables 1 and 2 ) , although rice et al . ( 1999 ) recommend increased economic thresholds for resistant alfalfa stands in subsequent crops and years .
insecticidal soaps ( potassium salts of fatty acids ) penetrate the soft outer shell of the leafhopper , causing its cells to
leak
and resulting in the death of the insect .
leafhoppers are one of the largest families of plant - feeding insects . there are more leafhopper species worldwide than all species of birds , mammals , reptiles , and amphibians combined . leafhoppers feed by sucking the sap of vascular plants , and are found almost anywhere such plants occur , from tropical rainforests , to arctic tundra . several leafhopper species are important agricultural pests .
leafhopper can customise its support and solution to meet your enterprise ' s needs . whether you are an individual , a small business or a large enterprise we are here to help .
the current pest management strategy in alfalfa for the potato leafhopper is to monitor the pest throughout the season with a sweep net and treat with foliar insecticide when economic threshold populations are reached ( degooyer et al . 1998 , cullen et al . 2012 ) . a fully developed integrated pest management ( ipm ) program is composed of multiple strategies for a given pest or pest complex in a cropping system incorporating host plant resistance , biological , cultural , and physical controls when available and chemical control when necessary ( pedigo 1999 ) . several integrated management strategies have been developed for the potato leafhopper in alfalfa . for example , alfalfa cultivars bred for resistance to the potato leafhopper were first available to farmers in 1997 ( miller 1998 ) . despite advances in pest management for potato leafhopper in alfalfa , it continues to be considered the most important economic pest of alfalfa through much of its range . as the market value of alfalfa hay has nearly doubled over the past decade ( gould 2012 ) , the potential for economic loss from potato leafhopper has also increased . thus , a more thorough understanding of potato leafhopper biology and ipm is a timely subject . in this pest profile , we summarize knowledge of potato leafhopper life history , ecology , scouting procedures , and management options in alfalfa .
nakamura , k . , ito , y . , miyashita , k . , and takai , a . , 1967 , the estimation of population density of the green rice leafhopper ,
lacewings , lady beetles and parasitic wasps will appear shortly after the leafhoppers invade your garden . they can be purchased at any time during the growing season when a leafhopper infestation is present .
parasitic wasps and predatory flies can help control leafhoppers . other predators include birds , lizards , spiders and lacewings . these insects are great partners to help control leafhopper infestations in your organic garden .
maramorosch , k . ; harris , k . f . ( eds . ) . 1979a . leafhopper vectors and plant disease agents . academic press , new york . xvi + 654 pp .
young , d . a . , jr . 1957c . the leafhopper tribe alebrini ( homoptera : cicadellidae ) . proc . u . s . natl . mus . 107 : 127 277 .
as well as early identification errors , the relationship between the potato leafhopper and crop damage was originally not well understood . although the effect of potato leafhopper on alfalfa was noted as early as 1907 , plant damage symptoms known as alfalfa “yellows” were initially attributed to abiotic factors such as weather and soil nutrient deficiency . greenhouse experiments at the university of wisconsin agricultural research station confirmed that alfalfa “yellows” was caused by the potato leafhopper ( granovsky 1928 ) . in potatoes , farmers and researchers originally believed that potato leafhoppers were the vector for a pathogen leading to the characteristic yellowing of leaves ( dudley 1920 ) . although closely related to some known insect vectors of phytoplasma infecting agriculturally important plants ( galetto et al . 2011 ) , there are no known records of disease transmission to plants by potato leafhopper .
throughout the summer , insect population growth and plant vigor are regulated by abiotic factors such as precipitation and temperature . on moisture - stressed alfalfa , development time of potato leafhopper eggs , nymphs , and adults slows , mortality increases , and fecundity decreases ( hoffman et al . 1990 , 1991 ) . however , hopperburn seems to appear more frequently during summer droughts ( hoffman et al . 1991 ) . this may be due to an additive effect of leafhopper feeding and drought stress on alfalfa ' s physiological response ( schroeder et al . 1988 ) . moreover , drought stress interspersed with bouts of rain throughout the summer may increase potato leafhopper performance , which has been proposed as a theory that could explain discrepancies in leafhopper population growth in field observations versus laboratory studies ( huberty and denno 2004 ) .
the potato leafhopper is a polyphagous insect herbivore that can achieve pest status in many agricultural crops throughout the united states . however , it is most frequently a pest of economic concern in alfalfa fields in the midwest and northeast united states . owing to the migratory nature of the potato leafhopper , intensity of infestation cannot be predicted from year to year throughout its geographic range . although models have been developed to aid in predicting development of migrant source populations from southern states ( taylor and shields 1995b ) , these have not been incorporated into management . this lack of incorporation is likely owing to the fact that timing of initial migrant arrivals is not a reliable predictor of infestation or damage severity ( maredia et al . 1998 ) . the most valuable management recommendation is to establish a regular scouting program for the potato leafhopper and to apply foliar insecticides if and when economic threshold populations are found . in addition , in geographic regions that experience economically damaging potato leafhopper populations more consistently , farmers should consider planting leafhopper - resistant alfalfa cultivars .
grass intercrop . lamp ( 1991 ) showed that alfalfa–oat mixtures have fewer potato leafhopper adults , both per area as well as per alfalfa stem . several forage grass–alfalfa mixtures have had similar effects on potato leafhopper density . alfalfa stands containing 9 % forage grass , either smooth bromegrass ( bromus inermis leyss ) or orchardgrass ( dactylis glomerata l . ) , had 4–37 % reduction in potato leafhopper densities compared with alfalfa monocultures ( roda et al . 1997 ) . degooyer et al . ( 1999 ) similarly observed significantly fewer leafhoppers in alfalfa stands intercropped with smooth bromegrass or orchardgrass compared with alfalfa monocultures . these patterns may be due to higher leafhopper emigration out of plots containing grass ( roda et al . 1997 ) , as well as inability of potato leafhoppers to reproduce on monocots such as grass ( lamp et al . 1994 ) .
the white apple leafhopper is the most common leafhopper found on apple in the pacific northwest . until it became a pest of significance in washington in the mid - 1970s , specific control measures were rarely needed . resistance to organophosphates is the most likely cause of increased populations . since about 2000 , it has again become an uncommon pest in most orchards , likely because of the shift away from pesticides toxic to its primary parasite .
dietrich , c . h . 2004 . phylogeny of the leafhopper subfamily evacanthinae with a review of neotropical species and notes on related groups ( hemiptera : membracoidea : cicadellidae ) . systematic entomology 29 : 455 - 487 .
if immediate control is necessary , use fast - acting insecticides like pyrethrins or azadirachtin to suppress leafhopper populations . insecticides can offer you immediate control and enough of a knockdown that beneficials may be introduced later for more lasting control .
the potato leafhopper is a tiny insect—barely half the size of a grain of rice—with a bright lime green color that helps it blend in against plant leaves . despite its unassuming appearance , this little pest causes big . . .
heavy potato leafhopper infestations on soybean can lead to plant stunting , smaller seed size , and decreased yield ( yeargan et al . 1994 ) . these negative impacts are more severe on seedling soybeans , whereas larger plants can better tolerate potato leafhopper feeding ( hunt et al . 2000 ) . yield loss from potato leafhopper damage is more severe when the plant is under moisture stress ( yeargan et al . 1994 ) . however , heavy infestations are not common on soybeans ( ogunlana and pedigo 1974 ) , except when nearby alfalfa fields are harvested ( poston and pedigo 1975 ) . economic thresholds for soybeans vary by plant age : early vegetative stages can be treated when there are two leafhoppers per plant , flowering fields can be treated when there is one leafhopper per trifoliate leaf , and while pods are developing , fields should be treated when there are two leafhoppers per trifoliate leaf ( krupke et al . 2013 ) .
hopperburn is the term used to describe symptoms associated with potato leafhopper feeding injury to host plants . hopperburn symptoms ( fig . 4 ) always include stunted plant growth . in addition , various leaf symptoms include tip - wilting and chlorosis in alfalfa , but leaf curling and marginal necrosis in other host plants , ultimately leading to premature leaf - drop ( backus et al . 2005 ) . theories regarding toxins in saliva have been proposed since the earliest years of potato leafhopper research . however , more recent research has shown that feeding injury is actually caused by varying plant responses to the complicated feeding behaviors of the potato leafhopper ( as well as its relatives in the e . fabae complex ) .
dietrich , c . h . and d . a . dmitriev . 2007 . revision of the new world leafhopper genus neozygina dietrich & dmitriev ( hemiptera : cicadellidae : typhlocybinae : erythroneurini ) . zootaxa 1475 : 27 - 42 .
zahniser , j . n . , and dietrich , c . h . 2008 . morphology - based phylogeny of the leafhopper subfamily deltocephalinae and related groups ( hemiptera : cicadellidae ) . systematics and biodiversity 6 : 1 - 24 .
jones , j . r . , and l . l . deitz . 2009a . phylogeny and systematics of the leafhopper subfamily ledrinae ( hemiptera : cicadellidae ) . zootaxa 2186 : [ 1 ] - 120 . [ available online ]
foliar insecticides registered for potato leafhopper control on alfalfa are effective against nymphs and adults . pyrethroids are the most commonly recommended and used insecticides for control of potato leafhopper . there are a limited number of insecticide active ingredients in the organophospate chemical class registered for potato leafhopper control in alfalfa . in addition , insecticide premix products are registered that combine two insecticide classes ( e . g . , organophosphate + pyrethroid ; chlorantraniliprole + pyrethroid ; neonicotinoid + pyrethroid ) . because potato leafhopper populations vary from year to year , and field to field , populations within a given year cannot be predicted , and fields must be monitored weekly to accurately determine damage potential before insecticides are applied . other pests and beneficial insects in the alfalfa field should also be considered before application of these broad - spectrum insecticides . for example , insecticides that control potato leafhopper at economic thresholds can also kill beneficial insects such as honey bees . to reduce hazards to honey bees in alfalfa , applicators can notify beekeepers before using insecticides , apply between 4 p . m . and nightfall , when bees are least likely to be foraging , and refrain from spraying alfalfa when in bloom ( cullen et al . 2012 ) .
nault , l . r . , and bradfute , o . e . , 1979 , com stunt : involvement of a complex of leafhopper - borne pathogens , in : k . maramorosch and k . harris ( eds . ) ,
observations regarding alfalfa host plant resistance to potato leafhopper date back to 1928 , when granovsky ( 1928 ) noted that “hairier” medicago spp . demonstrated greater tolerance to leafhoppers before exhibiting hopperburn . laboratory studies have shown greater potato leafhopper mortality and reduced reproduction on glandular - haired medicago spp . as well as leafhopper preference for smooth - stem alfalfa varieties in choice tests ( shade et al . 1979 , brewer et al . 1986 , ranger and hower 2002 ) . both physical and chemical traits associated with glandular - haired alfalfa have been reported as resistance mechanisms : entrapment of the first instars in trichome exudates ( ranger and hower 2001 ) and adult settling deterred by compounds in the exudate ( ranger et al . 2004 ) .
dietrich , c . h . , and d . a . dmitriev . 2003 . reassessment of the leafhopper tribes koebeliini baker and grypotini haupt ( hemiptera : cicadellidae ) . annals of the entomological society of america 96 : 766 - 775 .
dietrich , c . h . 2004a . phylogeny of the leafhopper subfamily evacanthinae with a review of neotropical species and notes on related groups ( hemiptera : membracoidea : cicadellidae ) . syst . entomol . 29 ( 4 ) : 455 - 487 .
optimum timing for control of the first generation is when most of the overwintering eggs have hatched but before the majority of the nymphs are in the last two instars , when they are harder to kill . a somewhat arbitrary target timing for this point in the leafhopper ' s phenology is when about 10 % of the population is in the fourth and fifth instars , with 90 % still in the first , second , and third instars . this is usually at or slightly after petal fall . the first cover spray , applied at the standard codling moth timing , will also reduce leafhopper populations somewhat , as will carbaryl when used as a fruit thinning material . in general , however , first cover timing is too late for optimum leafhopper control .
zahniser , j . n . & dietrich , c . h . ( 2010 ) phylogeny of the leafhopper subfamily deltocephalinae ( hemiptera : cicadellidae ) based on molecular and morphological data with a revised family - group classification . systematic entomology , 35 , 489–511 .
zahniser , j . n . and dietrich . c . h . 2010 . phylogeny of the leafhopper subfamily deltocephalinae ( hemiptera : cicadellidae ) based on molecular and morphological data with a revised family - group classification . systematic entomology 35 : 489 - 511 .
viraktamath , c . a . 1998a . a revision of the leafhopper tribe paraboloponini ( hemiptera : cicadellidae : selenocephalinae ) in the indian subcontinent . bull . natur . hist . mus . , entomol . ser . 67 ( 2 ) : 153 - 207 .
zahniser , j . n . ; dietrich , c . h . 2008a . phylogeny of the leafhopper subfamily deltocephalinae ( insecta : auchenorrhyncha : cicadellidae ) and related subfamilies based on morphology . syst . & biodiv . 6 ( 1 ) : 1 - 24 .
this article summarizes the knowledge to date on biology of the potato leafhopper , empoasca fabae ( harris ) , including its distribution , development , migration , agricultural host plants , and mechanics of injury to host plants . damage to alfalfa , potatoes , soybeans , and snap beans , and treatment guidelines , are summarized . particular attention is given to integrated pest management options in alfalfa , the host plant most frequently incurring economically damaging populations of potato leafhopper . alfalfa scouting and economic thresholds are discussed along with cultural controls and host plant resistance .
although pinebarren smokegrass is still relatively well - distributed in the pine barrens , the pine barrens themselves have already been seen to suffer the effects of a warming climate . various human activities could also pose a further threat to the leafhopper ' s host and the its habitat .
dietrich , c . h . , and d . a . dmitriev . 2006 . review of the new world genera of the leafhopper tribe erythroneurini ( hemiptera : cicadellidae : typhlocybinae ) . bulletin of the illinois natural history survey 37 ( 5 ) : 119 - 190 .
because they drink the juices of fruits and vegetable plantings , they can cause a variety of symptoms and problems . leaves may appear yellowed and curled or have brown tips . using a product like safer® brand fruit and vegetable insect killer will help you keep your garden leafhopper free !
the best way to prevent a leafhopper infestation ( or any bug infestation really ) is to catch them as soon as possible . leafhoppers will suck sap moisture out of cannabis leaves most often when it’s dry , because they get thirsty , so that’s a good time to check .
chen , f . y . & dai , w . ( 2015 ) bicoloratum dai and li , a new synonym of the leafhopper genus scaphoideus uhler ( hemiptera , cicadellidae , deltocephalinae ) , with description of two new species . zootaxa , 3985 ( 2 ) , 275–283 .
dietrich , c . h . , r . f . whitcomb , and w . c . black , iv . 1997 . phylogeny of the grassland leafhopper genus flexamia ( homoptera : cicadellidae ) based on mitochondrial dna sequences . molecular phylogenetics and evolution 8 : 139 - 149 .
nielson , m . w . 1968b . the leafhopper vectors of phytopathogenic viruses ( homoptera : cicadellidae ) : taxonomy biology , and virus transmission . . u . s . dep . agric . tech . bull . 1382 : [ i - ii ] , 1 - 368 .
nault , l . r . , madden , l . v . , styer , w . e . , triplehorn , b . w . , and heady , s . e . , 1984 , pathogenicity of com stunt spiroplasma and maize bushy stunt mycoplasma to its leafhopper vector ,
elissa m . chasen , christopher dietrich , elaine a . backus , eileen m . cullen ; potato leafhopper ( hemiptera : cicadellidae ) ecology and integrated pest management focused on alfalfa , journal of integrated pest management , volume 5 , issue 1 , 1 march 2014 , pages a1–a8 , urltoken
this key will enable any leafhopper found in australia and neighbouring regions to be identified to subfamily or tribe . checklists of species in each country are provided for each group and identification keys are provided to enable identification to genus for those groups that are sufficiently well known for this to be possible .
the wild glandular - haired medicago spp . were integrated into breeding programs that eventually led to the first line of commercially available alfalfa cultivars with host plant resistance in 1997 ( miller 1998 ) . however , in the field , glandular - haired alfalfa cultivars have had varying levels of success . lefko et al . ( 2000b ) found that established stands of resistant alfalfa could tolerate greater than twice the potato leafhopper pressure as established susceptible stands , but this was not the case for the first cutting of seeding - year stands . established resistant stands also had greater yield ( sulc et al . 2001 ) as well as higher forage quality over susceptible cultivars when leafhopper pressure was high ( sulc et al . 2004 ) . however , under low potato leafhopper pressure , resistant alfalfa stands have no yield benefit and sometimes express a yield drag ( hogg et al . 1998 , hansen et al . 2002 ) .
leafhopper damage is characterized by light - colored speckling on plant leaves caused by the leafhoppers sucking sap and plant juices from within the plant tissue . left unchecked , this gradual feeding reduces the plant ' s vigor over time , browning the leaves . damage caused by leafhoppers is usually not severe enough to seriously harm mature plants ; however , young plants or new growth can be stunted and / or deformed by leafhopper feeding . transmission of disease is a concern with select species of leafhoppers and the honeydew produced by some can aid in the propagation of fungal diseases ; e . g . beet leafhoppers vector curly top virus .
mckamey , s . h . 2000a [ not dated , with periodic revisions ] . checklist of leafhopper species 1758 - 1955 ( hemiptera : membracoidae : cicadellidae and myserslopiidae ) with synonymy and distribution [ catalogue of the homoptera , fascicle 6 , abridged ] . online : urltoken [ pdf version ] ; urltoken [ html version ] .
the potato leafhopper feeds by inserting its piercing - sucking mouth parts ( stylets ; fig . 5 ) into host plant tissues , rupturing and ingesting nutrients from all types of mesophyll , parenchyma , and phloem cells , depending on the host plant ( backus et al . 2005 ) . unlike other leafhoppers , potato leafhoppers do not produce a true salivary sheath that encases the stylets during feeding . instead , the naked stylets repeatedly probe plant tissues , mechanically lacerating cells and simultaneously injecting watery saliva into the tissues . the watery saliva is composed of digestive , hydrolyzing , and cell wall - degrading enzymes , and to date , has not been found to contain any nonenzymatic “toxin . ” instead , hopperburn is caused by a combination of mechanical and salivary mechanisms ( ecale and backus 1995a ) , so it is termed a “saliva - enhanced wound response . ” unique to this species of leafhopper , the symptoms of feeding injury on different host plants are related to three different tactics of potato leafhopper stylet probing ( backus et al . 2005 ) .
a survey was conducted in the 2001 growing season to examine the leafhopper diversity and abundance among trees of 17 red maple ( acer rubrum ) clones . yellow sticky traps were used to qualify and quantify the number of aerial leafhoppers from 1 may 2001 until 4 september 2001 . a total of 45 species from eight different leafhopper subfamilies , for a total of 6055 individuals , were considered in this study . the mean number of leafhoppers collected , mean species richness , diversity and evenness were significantly lower on traps of trees for ‘october glory’ than for the other clones . yet , none of the leafhopper species dominated the weekly samples . species similarity among clones ranged from 56 to 90 % . no two clones had complete similarity . ‘franksred’ and trees of a controlled cross between ‘october glory’ × ‘autumn flame’ shared the highest degree of species similarity , while clones from pa , usa and ri , usa were the least similar . the development of new clones did not create new pest problems , but suppressed populations of damaging pests , and maintained the diversity of low abundance species .
whitcomb r . f . , kramer j . , coan m . e . , hicks a . l . ( 1987 ) ecology and evolution of leafhopper—grass host relationships in north american grasslands . in : harris k . f . ( eds ) current topics in vector research . current topics in vector research , vol 4 . springer , new york , ny
actually , it is exactly the ecology factor that could make it or break it for the
charismatic
new leafhopper . not only is pinebarren smokegrass , which the insect inhabits , a threatened species , but it is known that the rest of the leafhoppers from the genus flexamia , with a few exceptions , are each dependent on a very specific plant .
scouting for potato leafhoppers in alfalfa is standardized through the use of a 15 - inch - diameter sweep net . university extension recommendations are to monitor alfalfa fields weekly beginning mid - june or when potato leafhopper migrants have arrived in the area by taking five sets of 20 sweeps at various locations in a w - shaped pattern throughout the alfalfa field ( university of wisconsin - extension 2010 ) . adult potato leafhoppers may be found at the bottom of the sweep net , while nymphs can be found along the rim of the sweep net as well as throughout the net ( university of wisconsin - extension 2013 ) . insecticide recommendations are based on the average potato leafhopper number per sweep calculated from total samples taken across the field , including nymphs and adults ( cullen et al . 2012 ) . because taller alfalfa can tolerate more potato leafhopper feeding , established economic thresholds depend on the average height of the alfalfa stand . when scouting for potato leafhoppers , it is important to avoid taking sweep net samples at field edges , as potato leafhopper populations are typically higher along field margins and this is not representative of population density throughout the field ( emmen et al . 2004 ) . it is also important to avoid taking sweep samples while it is raining or when dew is present on the plants , and if possible , avoid sweeping when winds are > 10 miles per hour , as this reduces the sweep net sample efficiency ( cherry et al . 1977 ) .
leafhopper adults ( 1 / 4 inch long ) are slender , wedge - shaped insects that fly or disperse rapidly when disturbed . depending on species they may be green , brown or yellow in color and often have colorful markings . nymphs do not have wings and are generally lighter in color than adults . both adults and nymphs run sideways and are good jumpers .
leafhoppers are common and abundant insects worldwide . they are currently placed among two families : myerslopiidae , with only two genera , and the enormous family cicadellidae , which , with more than 22 , 000 described species and 2600 genera , ranks among the 10 largest insect families . phylogenetic analyses suggest that leafhoppers may have given rise to treehoppers , and it seems likely that additional families of leafhoppers will be recognized once the evolutionary relationships are better understood . indeed , a number of previously recognized leafhopper
families
( including eurymelidae , hylicidae , ledridae , and ulopidae ) are currently placed within cicadellidae . as noted below , numerous leafhopper species are considered serious plant pests , and those that vector plant diseases inflict untold economic loses in agricultural crops .
because leafhoppers are indirect pests , they should only be controlled when necessary . it is difficult to set treatment thresholds for white apple leafhopper since no fruit size , fruit quality , or return bloom reduction due to leafhopper damage has been observed . other factors must be taken into account when deciding whether control is needed . since the major form of biological control occurs during the egg stage , this mortality is already accounted for when nymphal populations are assessed . if the trees are very young , excessive damage to the relatively small leaf canopy could retard growth . in vigorous , mature trees with a high leaf - to - fruit ratio , moderate to heavy leafhopper damage will probably have little effect . similarly , if the crop is very light , more foliar damage can probably be tolerated than if the crop load is heavy . the potential for drought because of light soils , inadequate irrigation schedules , or extremely hot , dry weather could also serve as a reason to consider controlling leafhoppers or other indirect pests . if substantial foliar damage by mites or leafminers has already been incurred , further damage by leafhoppers should probably be avoided .
common name glasshouse leafhopper scientific name hauptidia maroccana plants affected many glasshouse vegetables and ornamental plants including tomato , peppers , aubergine , cucumber , fuchsia , pelargonium and streptocarpus . outdoor plants , such as polyanthus , foxglove and nicotiana are also attacked main symptoms coarse pale spotting on upper leaf surface . leafhoppers may be seen on the underside of leaves most active april to september but all year round in glasshouses
andrew hicks from the museum of natural history at the university of colorado and his team discovered a previously unknown leafhopper species in the new jersey pine barrens , located just east of the megalopolis that extends from new york city to washington , dc . this was the first time an insect has been reported from the state - listed threatened pinebarren smokegrass , muhlenbergia torreyana . the study can be found in the open - access journal zookeys .
dr . jaco le roux hopes to establish the number and identity of the leafhopper species introduced to hawaii so he can assess the threat that it poses to our local flora and fauna . this research effort includes molecular systematics and phylogeography of invasive leafhoppers and those from putative source regions . these data could potentially also assist in identifying native range regions where productive biological control agents are likely to be found , should this prove a viable control option .
like other types of foliar damage , that caused by leafhoppers may reduce leaf photosynthesis , which in turn can affect the tree ' s ability to set , size or mature a crop of fruit . however , no effect on fruit size or fruit quality has been found under washington conditions , even when extremely high leafhopper populations were present . in addition , no reduction in return bloom or set was noted following a single season of heavy damage with a peak of 3 nymphs per leaf , although only one cultivar , oregon spur red delicious , has been studied . it is assumed that multiple seasons ' damage could eventually deplete the tree ' s reserves , making effects of feeding damage more apparent , but this has not been studied . as with other indirect pest damage , factors such as tree vigor , tree age , drought stress , and damage by multiple pests could exacerbate the effect of leafhopper damage .
harvest timing . if economic thresholds are reached within 7 d of a planned harvest , early harvest is advised , rather than an insecticide spray ( undersander et al . 2004 ) . early harvest helps alfalfa stands to avoid further potato leafhopper feeding damage . in addition , potato leafhopper population dynamics can be influenced by harvest operations ( pienkowski and medler 1962 , simonet and pienkowski 1979 , cuperus et al . 1986 ) . cuperus et al . ( 1986 ) showed that greater populations of nymphs and adults were correlated with taller stubble or lodged growth left behind after harvest . cuttings at stubble height of 2–5 cm ( 1–2 inches ) with no remaining leaves or succulent stems can reduce populations up to 95 % in the next growth cycle ( simonet and pienkowski 1979 ) . these effects are due to high nymph and egg mortality from their lack of mobility and exposure to hot , drying conditions ( simonet and pienkowski 1979 ) and adult dispersal post harvest to neighboring fields ( poston and pedigo 1975 ) .
the potato leafhopper ' s diverse host plant list of more than 200 plant species includes alfalfa ( medicago sativa l . ) , soybean ( glycine max l . ) potato ( solanum tuberosum l . ) , and peanut ( arachis hypogaea l . ) , as well as roadside , weedy , and forest plants ( lamp et al . 1994 ) . as the key economic pest of alfalfa in the north central and northeast united states , yield losses have been documented up to $ 66 / ha ( $ 27 / acre ; lamp et al . 1991 ) .
a second parasitoid is a wasp in the family dryinidae ( probably aphelopus sp . ) , which is a parasitoid of both nymphs and adults . it develops internally in leafhopper nymphs , then appears on the adults as a pouch on the abdomen . this parasitoid has been collected from cherry and apple orchards in the mid - columbia area of oregon , although it may be much more widely distributed . while substantial rates of parasitism have been reported , the potential of this parasitoid species as a biological control agent is unknown . despite extensive examination of leafhoppers in washington , this parasitoid species has not been found .
snap beans ( phaseolus vulgaris l . ) are regularly infested by potato leafhoppers , and under intense feeding , this can result in complete leaf drop , whereas at moderate pressure , plant stunting and yield loss may occur ( gonzalez and wyman 1991 ) . duration and timing of infestation are important when making management decisions ; infestation on younger plants causes more significant yield loss than the equivalent pressure on older plants ( gonzalez and wyman 1991 ) . economic thresholds for green beans vary by plant age : for seedlings , the threshold is set at 0 . 5 potato leafhoppers per sweep , and for the third trifoliate to bud stage , the threshold is set at one per sweep . for dry beans , the thresholds are 0 . 5 potato leafhoppers per plant at the unifoliate stage and one potato leafhopper per trifoliate leaf once the plants have reached the trifoliate stage ( flood and wyman 2005 ) . neonicitinoid seed treatments are also commercially available and have been largely successful at controlling a suite of snap bean pests , including potato leafhoppers , especially for roughly the first 30 d of plant growth ( nault et al . 2004 ) . however , when potato leafhopper populations are exceptionally high , growers should still be mindful of scouting for economic threshold populations later in the summer .
interestingly , the three feeding tactics of e . fabae - complex species are mixed - and - matched on different host plants in relation to the degree of susceptibility or resistance of the plant . some genotypes of resistant snap bean cause less of the most - damaging tactics of feeding ( lacerate - and - flush and lacerate - and - flush ) to be performed , while more of the less - damaging tactic , lance - and - ingest ( serrano et al . 2000 , backus et al . 2005 ) . in addition to genetic mechanisms of resistance or susceptibility , drought or desiccation can enhance hopperburn symptoms because water and carbon transport are impaired after potato leafhopper feeding .
the results of studies performed by roda et al . ( 1997 ) and degooyer et al . ( 1999 ) show that potato leafhoppers are typically reduced in alfalfa–grass stands but that is not the case for every harvest . moreover , even when the population is reduced , it is not always reduced below economic threshold , so it is still important to monitor the population and use other management strategies when necessary . there is a great deal of variability in the response of potato leafhopper to the presence of grass in alfalfa stands , in part owing to the relative proportion of grass to alfalfa as well as the spatial arrangement of the grass in the alfalfa stand ( roda et al . 1997 ) .
members of the cicadellidae range in length from 2 to 32 mm and characteristically have four rows of enlarged , spine - like setae on the hind tibia . in this regard , they resemble treehoppers , which have up to three such rows of setae on the hind tibia , but most treehoppers have a posterior pronotal process that is absent in leafhoppers . among all insects , only cicadellids produce minute granules called brochosomes . these intricately shaped structures form in a specialized region of the malpighian tubules . the brochosomes are secreted and applied ( using the legs ) to the body as a hydrophobic coating . this curious anointing behavior is usually observed after each molt . members of the small leafhopper family myerslopiidae are peculiar flightless insects that have leathery forewings and vestigial ocelli .
white apple leafhoppers have piercing - sucking mouthparts and cause damage to leaves by piercing mesophyll cells and removing their contents . the resulting damage appears as a white or yellowish - white stippling of the leaves . leafhopper damage may superficially resemble mite feeding , but the individual spots are usually larger and there is no bronzing . damage can be so extensive that injured leaves appear nearly white . spur leaves in particular can be heavily damaged . initially , feeding tends to be concentrated near the midrib , then eventually covers most of the interveinal spaces of the leaf blade . leafhoppers generally prefer more mature leaves and will not infest shoots tips until the leaves have hardened off . both nymphs and adults feed on leaves , but most damage is probably done by the nymphs .
established economic thresholds are based on research done by cuperus et al . ( 1983 ) . they concluded that treatment was economic when 0 . 15 potato leafhoppers per sweep were present on 2 - inch alfalfa and when 0 . 42 potato leafhoppers per sweep were present on 7 - inch alfalfa . these conclusions have been adapted to current university recommendations of roughly one - tenth of a leafhopper per sweep per inch height of alfalfa growth ( table 1 ; fick et al . 2003 , townsend 2002 , university of wisconsin - extension 2013 ) . some university extension recommendations suggest a dynamic economic threshold based on varying costs of insecticide treatment ( rice et al . 1999 ; table 2 ) or fluctuating alfalfa hay market prices ( danielson and jarvi 2006 ) . under these threshold guidelines , as the treatment cost increases or the alfalfa hay market price decreases , a greater density of potato leafhoppers is required to cause economic yield loss equivalent to the treatment cost , and therefore the threshold is increased . hutchins and pedigo ( 1998 ) calculated economic injury levels for potato leafhopper on alfalfa , with an emphasis on management for nutritional value based on type of animal for which the feed is intended . incorporating variables of insect injury on forage quality characteristics ( hutchins and pedigo 1990 ) and different animal nutrition needs , they determined that the economic injury level is lowest for alfalfa hay intended for sheep or horses , medium for a beef or dairy cows , and highest for beef steer . however , economic thresholds were not calculated based on these economic injury levels , and thresholds based on livestock nutrient needs have not been adopted in practice .
second generation white apple leafhopper populations can greatly exceed the first , often surprising producers and consultants by the size of a late season infestation . adults are quite mobile , and during the first generation flight they can move into and rapidly reinfest a block that was treated for first generation nymphs . if a clean orchard is surrounded by infested ones , then second generation nymphs should be sampled . because of a prolonged egg hatch in the second generation , multiple stages occur at any one time , making control of this generation less likely to be satisfactory than that of the first generation . however , if picker annoyance reduction is the primary concern , then it may be more appropriate to control this generation . insecticide applications should be made before adult populations begin to rise sharply , which usually occurs in mid - to late august .
each year , the first potato leafhopper populations arriving in the north are largely female - biased ( medler and pienkowski 1966 ) and occur sometime in may ( maredia et al . 1998 ) . arriving females are typically mated ( medler and pienkowski 1966 ) and will oviposit for the duration of their lives ( delong 1938 , decker et al . 1971 ) . field studies indicate a female - biased sex ratio near 4 : 1 through most of the season , until it approaches 1 : 1 toward the end of the growing season ( medler and pienkowski 1966 , decker et al . 1971 , flinn et al . 1990 , emmen et al . 2004 ) . development from egg to adult can occur in as little as just over 2 wk or can take > 4 wk , depending on temperatures , which gives rise to three to five overlapping generations during summer months in the northern united states ( delong 1938 , hogg and hoffman 1989 ) .
the primary biological control agent of leafhoppers in the pacific northwest is an egg parasitoid , anagrus sp . ( probably a . epos ) , a mymarid wasp ( see section on anagrus ) . it attacks both overwintering and summer eggs of white apple leafhopper . in overwintering eggs , parasitism levels of up to 25 % have been found in the wenatchee area . the level of parasitism appears to be generally related to the intensity of pesticide use ( primarily that for codling moth ) the previous season , but no single application timing or material has been identified . research in michigan indicates that more than 90 % of the overwintering generation of eggs can be parasitized in unsprayed orchards so broad - spectrum pesticides undoubtedly suppress parasitoid populations . levels of parasitism found in conventionally managed orchards are generally too low to prevent substantial populations from developing . anagrus could potentially play a role in biological control of leafhoppers if broad - spectrum chemicals are reduced or removed from the spray program .
potato leafhoppers have five nymphal instars ( fig . 1 ) . instars can be distinguished by color , size , and presence of external wing pads . the first instar is pale white with red eyes , and extremely small . subsequent instars gain more of the vibrant yellow - green color typical of adults . wing pads ( fig . 2 ) begin developing in the third instar . sizes of the instars range from 1 mm for first instars to 3 mm ( in length ) for fifth instars ( hutchins 1987 ) . developmental time is more rapid in warmer temperatures and ranges from 9 to 18 d to complete all five instars ( hogg 1985 ) . all nymphal stages resemble the adult body shape in that the head segment is wider than the abdomen , which gives the body a wedge - shaped appearance . potato leafhopper nymphal movement is distinct from adults in that nymphs scuttle sideways . however , both nymphs and adults are able to use specialized legs ( fig . 2 ) for jumping .
on alfalfa , adult potato leafhoppers use the lacerate - and - sip tactic , which is also thought to be the most injurious , mostly on stems and petioles . adults insert their stylets perpendicular to the stem and proceed to arc the stylets back and forth , essentially cutting multiple channels through the vascular bundle ( all types of phloem cells ) for 1–2 min before removing the stylets , taking a couple of steps forward and repeating the action . the wounded but still living vascular cells then undergo saliva - enhanced wound responses over the next several days that result in temporary blockage of nutrient movement up the phloem ( nielsen et al . 1990 ) that is ultimately healed , but permanent blockage of xylem cells ( ecale and backus 1995b ) . both types of blockage cause systemic decreases in photosynthesis and decreased transport of sugars to growing areas of the plant , leading to both leaf chlorosis and plant stunting in all host plants ( backus et al . 2005 ) . potato leafhopper nymphs on alfalfa feed on both stems and leaves ; on leaves , their feeding is similar to adult feeding on nonalfalfa host plants ( see later text ) .