bluuebunny/crossref_metadata_2025_split huggingface dataset:
An analysis of an outbreak of the woodwasp, Sirex noctilio F. (Hymenoptera, Siricidae), in Pinus radiata
Authors: Madden J. L. 
Published: July 2009

AbstractThe development of an outbreak of the woodwasp, Sirex noctilio F., in a 30-year-old population of Pinus radiata in Tasmania was traced by growth ring analysis of killed trees. The outbreak probably developed from small foci; it reached its peak when the trees were 18–19 years old and then declined rapidly. Attack per tree was directly related to the density of emergents from trees killed in the previous season and the intensity of oviposition drilling was modified by the rainfall during the emergence season; the frequency of treble oviposition drills was directly related to summer rainfall. Survival of insects within trees declined with the years; this was related to the greater vigour and resistance of the surviving trees, but was apparently modified by spring rainfall. Resinosis and polyphenols associated with growth rings in stems living in 1964 indicated an increase in the proportion of trees resisting attack during the outbreak. The growth patterns of attacked and unattacked trees, and the obvious susceptibility of the weaker understorey trees, are discussed and due attention to site quality and plantation management are recommended to reduce Sirex attack in future.
Field trials with a nuclear polyhedrosis virus and Bacillus thuringiensis against larvae of Heliothis armigera (Hb.) (Lepidoptera, Noctuidae) on sorghum and cotton in Botswana
Authors: Roome R. E. 
Published: July 2009

AbstractSix trials with an unpurified suspension of Heliothis armigera nuclear polyhedrosis virus (NPV) against Heliothis armigera (Hb.) larvae on sorghum (five trials) and on cotton (one trial) during 1971–73 are described. Commercial preparations of H. zea NPV and of Bacillus thuringiensis were included in two of the trials. H. armigera NPV was as successful as a standard insecticide in preventing losses of sorghum in one trial. Lowering the rate of NPV reduced the control of H. armigera larvae. There was no difference in control achieved by spraying in the morning or in the evening. Spraying every second or every third row (relying on natural spread of the virus) reduced control. Low concentrations of molasses (0·6%) made control by 100 larval equivalents (L.E.) per hectare as good as that by 200 L.E. per hectare without molasses. Neither the commercial H. zea NPV nor the Bacillus preparation was as effective as the local virus. The local virus was reasonably effective against H. armigera on cotton at very high rates and with molasses. It was not as damaging as carbaryl to populations of egg parasites and predators, but the predators did not control damaging populations of aphid and Jassid on the virus-sprayed plots.
Activity of adult Heliothis armigera (Hb.) (Lepidoptera, Noctuidae) with reference to the flowering of sorghum and maize in Botswana
Authors: Roome R. E. 
Published: July 2009

AbstractNight-time observations on adults of Heliothis armigera (Hb.), and data from light-trap and hand net catches in irrigated and dryland crops, showed that both sexes flew and fed and females oviposited between 20.00 and 23.00 h. From then until 02.00 h both sexes were inactive, but. from 02.00 to 04.00 h the males flew above the crop in a ‘purposeful’ manner, while the females were stationary and releasing pheromone. During this period of high male and low female activity, copulation in cages, assembly of males to females in cages and copulating pairs on crop plants were all observed. Inseminated female H. armigera were collected in crops which were at a stage suitable for oviposition, while traps away from crops or near mature crops collected mainly virgin females. It is suggested that susceptible crops attract H. armigera adults and that, once within the crop, inseminated females are ‘trapped’ by suitable physiological cues from the plants. Identification of such cues could assist in the breeding of crop varieties resistant to H. armigera attack.
Observations on the free larval stage of Glossina morsitans morsitans Westw. (Diptera, Glossinidae): the possibility of a larval pheromone
Authors: Nash T. A. M. , Trewern M. A. , Moloo S. K. 
Published: July 2009

AbstractUnder simulated natural conditions the anal orifice of the larva of Glossina morsitans morsitans Westw. appears to open either at or soon after parturition. The larva burrows on average within two minutes of deposition; pupariation is completed 10–15 min later. Using methods that prevent burrowing and prolong the crawling period, certain larval movements were related to the pre-pupariation anal discharges and to the rapid spread of the fluid. Although the anus is not generally thought to be connected with the hind gut during the whole of larval life, the presence of uric acid in the discharges indicates that the fluid is a product of Malpighian tubule excretion. In a two-choice chamber in an incubator, flies larviposited significantly more often in the experimental pot if it contained a water- or ether-soluble extract of larval excretion in addition to any pupariating larvae. This points to the presence of a larval phero-mone which may attract gravid females to a breeding site.
Ecological studies of ixodid ticks (Acari, Ixodidae) in Zambia. I. Cattle as hosts of the larvae ofAmblyomma variegatum(F.) andRhipicephalus appendiculatusneum.
Authors: MacLeod John , Colbo M. H. 
Published: July 2009

AbstractThe roles of cattle and alternative hosts in maintaining the immature stages ofAmblyomma variegatum(F.) andRhipicephalus appendiculatusNeum. are unknown. Weekly collections of ticks from cattle in two herds in Zambia indicated an apparently higher nymph-adult ratio in the annual totals forA. variegatumthan forR. appendiculatus. The larva-nymph ratios for these herds were estimated by a patch-sampling method in which all larvae and nymphs on 100 cm2areas on the cheek, neck, dewlap, shoulder, ribs, abdomen and lower-foreleg were collected. The overall annual ratios of larvae to nymphs on the two herds were:A. variegatum5:1 and 14:1,R. appendiculatus1·5:1 in both herds. The ratios suggest that cattle themselves feed larvae ofA. variegatumin sufficient numbers to maintain their nymphal infestation level. The numbers of cattle-fed larvae ofR. appendiculatusmay not be adequate for this, and alternative hosts may play an important part in maintaining the population at existing levels. There was negligible evidence of significant shift of distribution of the immature stages over the body with advancing season, and it is suggested that patch-sampling affords a method of quantitative comparison of the relative infestations by the immature stages of ticks.
Diapause of the southwestern corn borer,Diatraea grandiosellaDyar (Lepidoptera, Pyralidae): effects of a juvenile hormone mimic
Authors: Chippendale G. M. , Yin C.-M. 
Published: July 2009

AbstractTopical applications of a juvenile hormone (JH) mimic induced and prolonged the mature larval diapause of the southwestern corn borer,Diatraea grandiosellaDyar. The onset of this diapause is marked by an ecdysis from a spotted to an immaculate morph. A high percentage of spotted non-diapause larvae treated with a single dose of a JH mimic moulted into the immaculate morph and became dormant. Similar treatments of diapause larvae led to a reversion to the spotted morph, but the larvae remained dormant. These results imply that diapause larvae contain an intermediate JH titre. A use for JH mimics in disrupting the seasonal phenology of pest insects with larval dormancies is suggested.
Experimental observations of food-aversive responses in larvae of Spodoptera exempta (Wlk.) (Lepidoptera, Noctuidae)
Authors: Ma Wei-Chun 
Published: July 2009

AbstractThe oligophagy of the African armyworm, Spodoptera exempta (Wlk.), was investigated experimentally. The resistance to feeding on cassava, a non-food plant, declined at a faster rate if the larvae had been reared on artificial diet. If diet-reared larvae were allowed to feed on maize for increasing periods of time the subsequent rejection of cassava increased accordingly. This effect could still be induced after removing the labral or palpal sensilla but not after removing both pairs of stylo-conic sensilla. The left and right pair of styloconic sensilla are supplementary to each other. In so far as aversive responses to non-food plants are concerned, the rearing on artificial diet can be considered as a case of pseudomaxillectomy. It is suggested that during feeding on maize the larva receives a specific input pattern which influences central acceptance-rejection decisions in a time-dependent manner. This specific information is absent from artificial diet and can no longer be perceived by larvae without styloconic sensilla.
Studies on some ornithophilic mosquitoes (Diptera, Culicidae) of the Kano Plain, Kenya
Authors: Chandler J. A. , Highton R. B. , Boreham P. F. L. 
Published: July 2009

AbstractDuring 1972–74, 13 865 female mosquitoes of 25 species from eight genera were collected at the Kisumu heronry using light-traps, chicken-baited traps and battery-driven aspirators. A total of 3298 of these were engorged and 2169 were subjected to precipitin testing in order to determine their food sources. A high percentage of feeds on birds was recorded for Coquillettidia karandalaensis (Wolfs) (96%), Culex poicilipes (Theo.) (82%), and C. univittatus gp (65%); Mansonia uniformis (Theo.), M. africana (Theo.) and C. antennatus (Becker) were found to feed on birds occasionally. Results from catches in CDC light-traps set at various heights in trees with nesting birds indicated that C. univittatus gp, C. poicilipes and Aedomyia africana Nev.-Lem. were active in the upper levels of the canopy. Further analysis of blood-meals from birds indicated that C. univittatus gp mosquitoes were feeding principally on ciconiiform birds. Any mosquito which feeds regularly on birds and man must be considered as a potential vector of arboviruses; the results indicate that the most important vectors at Kisumu are probably C. univittatus gp mosquitoes.
Effects of groundnut sowing date and plant spacing on rosette virus disease in Malawi
Authors: Farrell J. A. K. 
Published: July 2009

AbstractIn a series of field trials at Chitedze, Malawi, groundnuts were sown at spacings of 30 cm, 7·5 cm and 2·5 cm within rows 90 cm apart. Contrasting sowing dates were approximately 1 December and 1 January. Immigration of alatae of Aphis craccivora Koch, monitored on observation plots, commenced 5–6 weeks after the emergence of early-sown groundnuts. Numbers of immigrant alatae were significantly greater on late-sown or open-spaced than on early-sown or close-spaced groundnuts, and were correlated with numbers of randomly distributed primary rosette virus infections. During observations, more alatae landed on 56–60-day-old plants than on 85–112-day-old plants. Similar numbers landed on 11–26-day-old plants at 30-cm and 2·5-cm spacing, but significantly more aphids settled on 30-cm spacing. The incubation period of rosette virus was consistently longer in 2·5-cm than in 30-cm spacing, and increased with plant age at inoculation. The virus was transmitted from a low proportion of infected plants before the appearance of rosette symptoms, and from a high proportion of plants snowing symptoms. The rate of spread of virus transmissions from inoculated sources within the crop varied significantly with spacing as 30 cm > 7·5 cm > 2·5 cm. Secondary spread of rosette varied, approximately, with the numbers of aphids per infected plant.
Description of the larva of Chalcosoma atlas (L.) (Coleoptera, Scarabaeidae, Dynastinae) from Malaysia
Authors: Bedford G. O. 
Published: July 2009

AbstractThe third-stage larva of Chalcosoma atlas (L.) collected in Malaysia is described, with illustrations, and a key is provided to distinguish larvae of this species from those of Oryctes rhinoceros (L.) and Xylotrupes gideon beckeri Schaufuss, all of which occur in similar breeding sites.
The immature stages of the Old-World screw-worm fly, Chrysomya bezziana villeneuve, with comparative notes on other australasian species of Chrysomya (Diptera, Calliphoridae)
Authors: Kitching R. L. 
Published: July 2009

AbstractThe eggs, three larval instars and puparia of Chrysomya bezziana Villeneuve are described and illustrated in detail by scanning electron micrographs. Particular attention is paid to the extent and nature of the median strip in the eggs and the spine bands and spiracular structures in the larvae and puparia.Eggs and third-instar larvae of five other species of Chrysomya, C. nigripes Aubertin, C. varipes (Macquart), C. rufifacies (Macquart), C. saffranea (Bigot) and C. megacephala (F.), are illustrated, described and compared with C. bezziana and each other by means of keys, which also permit their identification. In addition, notes on the puparia of these species are provided.
The effects of temperature and relative humidity on the development ofRhipicephalus appendiculatusNeumann (Acarina, Ixodidae)
Authors: Tukahirwa E. M. 
Published: July 2009

AbstractVariation in temperature affected the developmental periods of eggs, larvae and nymphs ofRhipicephalus appendiculatusNeum. and developmental periods were shortest at an optimum of 30°C. The periods increased as temperatures diverged from the optimum until upper and lower temperature limits were reached, when metabolism ceased. These limits were 16°C and 34°C for eggs, and 12°C and 41°C for larvae and nymphs.Generally, relative humidity did not affect the rate of development. It did, however, critically affect survival, particularly of eggs and larvae. The relative humidity range of 60–70% was critical, and below this range survival of the eggs and larvae was very limited. Nymphs and adults were more resistant, and natural tick populations probably survive hot and dry seasons in these stages.It was found that in a habitat with thick vegetation, temperature and humidity fluctuations were smaller than in one with sparse vegetation, and the former therefore supported a greater tick population. Denying cattle access to this thick vegetation or getting rid of it altogether seem to be possible methods of reducing the tick load of cattle in the area studied.
Effects of hempa on the gonads of Locusta Migratoria (L.) (Orthoptera, Acrididae)
Authors: Nath Vishwa , Mittal P. K. , Sheikher Chander 
Published: July 2009

AbstractOnly a very strong dose of 0·5 mg of hempa caused necrosis in testes of Locusta migratoria (L.). The apical cells, spermatogonia and primary spermatocytes became pycnotic and the germ cells were disorganised. Multinucleated cells also developed, due to failure of spindle formation, and a few hypertrophied spermatids occurred. In ovaries the chromatin of the follicular epithelial cell nuclei was abnormally fragmented; nuclei of the follicular epithelial cells became pycnotic; germinal vesicle was badly damaged; cytoplasm of the follicular epithelial cells was drawn into the peripheral empty space formed by the contraction of the ooplasm; the follicular epithelium degenerated later; and yolk formation was inhibited. With increased doses and post-treatment periods necrosis became more marked. Hempa was more effective in the ovary than in the testes of L. migratoria.
Communication disruption of adult Egyptian cotton leafworm Spodoptera littoralis (Boisd.) (Lepidoptera, Noctuidae) in Crete using synthetic pheromones applied by microencapsulation and dispenser techniques
Authors: Campion D. G. , McVeigh L. J. , Murlis J. , Hall D. R. , Lester R. , Nesbitt Brenda F. , Marrs G. J. 
Published: July 2009

AbstractCommunication between adult male and female Spodoptera littoralis (Boisd.) was disrupted by spraying microencapsulated formulations of pheromone inhibitor (IIA) (Z)-9-tetradecen-1-yl-acetate on lucerne plots in north-west Crete. Polyurea-based microcapsules applied at the rate of 100 g/ha active ingredient caused a 97% disruption for a period of seven days, as measured by the reduction of catches in the treated area in traps baited with the pheromone attractant (III) (Z)-9, (E)-11-tetradecadien-1-yl acetate, compared with catches in control areas. At lower rates of application both the level of disruption after seven days and the subsequent persistence of the effect were reduced. When applied at a rate of 100 g/ha active ingredient, disruption of 80% and above was achieved for a period of three weeks. Slower release microcapsules containing IIA based on polyurea/polyamide appeared more effective in that a level of disruption was achieved at one-tenth the amount of active ingredient required for the polyurea-based formulations.III dispensed in polythene vials caused 97% disruption when distributed at the rate of one vial per 9 m2, with lower levels of disruption at distributions of one vial per 25 m2 or 50 m2. IIA was much less effective in causing communication disruption at the same rates of distribution and no clear dose/response relationship was established.Inside enclosures of 10 100 and 1 000 m2 fenced by single-strand polythene impregnated with IIA at the rate of 1 mg/5 cm and maintained at a height of 0·5 m, a high level of disruption in excess of 93% was achieved for the first five days. The effect persisted in the smaller enclosures in that disruption in excess of 80% was maintained for a period of 40 days. In the 1 000 m2 enclosure the effect declined much more quickly.When IIA and III were dispensed together in WT traps the inhibitory effect persisted for at least 60 days. Similarly the polyurea-based microcapsules containing IIA together with III in WT traps maintained an inhibitory action for periods of 30–40 days. Polyurea/polyamide formulations of IIA were generally less effective, probably because loss from these slow releasing formulations became too low. Small numbers of mostly unmated female moths were attracted to the traps when IIA was exposed together with III, either when dispensed in the polythene vials or in microencapsulated formulations.
Ticks (Acarina, Ixodoidea) of the northern regions of the Somali Democratic Republic
Authors: Pegram R. G. 
Published: July 2009

AbstractIn this survey of distribution and prevalence of adult ticks (Acarina, Ixodoidea) parasitising domestic animals in the northern regions of the Somali Democratic Republic, 26 species were identified. The ten most common species were widely distributed withHyalomma anatolicum anatolicumKoch,H. dromedariiKoch,H. erythraeumTonelli-Rondelli,H. impeltatumSchulze & Schlottke andRhipicephalus sanguineusgroup more common in the drier vegetation zones, andH. marginatum rufipesKoch,H. truncatumKoch,R. e. evertsiNeum.,R. pravusDön. andR. pulchellus(Gerst.) more common in the wetter woodland, evergreen and forested zones. Four species,Amblyomma gemmaDön.,A. variegatum(F.),Boophilus decoloratusKoch andR. simusKoch, were confined to the wooded zones above 1200 m altitude. Species collected less frequently wereArgas persicus(Oken),Amblyomma falsomarmoreumTonelli-Rondelli,H. anatolicum excavatumKoch,H. m. marginatumKoch,H. m. turanicumPom.,H. puntHoogst., Kaiser & Pedersen,Ornithodoros savignyi(Aud.),R. armatusPocock andR. longicoxatusNeum.Ambylomma lepidumDön. was represented only by a few specimens introduced on nomadic livestock.Nearly 60% of the total number of ticks collected wereR. pulchellus. This species is considered to be the main vector of Nairobi sheep disease (NSD) virus in northern Somalia. NSD is the most important tickborne disease in sheep and goats and causes considerable economic losses to the Somali livestock industry.A. gemmaandA. variegatumare probably the vectors ofCowdria ruminantium(heartwater) in sheep and goats in the western highlands. These two ticks are also incriminated in the spread ofDermatophilus congolensisinfection (streptothricosis).R. e. evertsimay be the vector ofBabesia motasiin sheep and goats.Boophilus decoloratusis probably the vector ofBabesia bigeminain cattle in the western highlands. Various tick species may be associated with bacterial abscesses of feet and lymph nodes in sheep and goats.
Rate of linear advance by Glossina morsitans submorsitans newst. (Diptera, Glossinidae) on a trade cattle route in south-western Nigeria
Authors: Riordan K. 
Published: July 2009

AbstractIndigenous cattle are trekked, along well defined routes, from the north of Nigeria to markets in the south of the country. A major route crosses the River Niger at Jebba and proceeds south through Ilorin, Ogbomosho and Oyo towns. In 1912 the tsetse fly Glossina morsitans submorsitans Newst. was absent from this route south of Jebba. The species appeared mid-way between Jebba and Ilorin in about 1935, reached Ilorin by about 1950 and Oyo by, or before, 1967. The rate of southwards advance, if linear, was about 5·4 km per year or 104 m per week.The Jebba-Oyo infestation may have originated, not as a southwards extension of a fly belt north of the River Niger at Jebba (now termed Belt 24), as generally believed, but by immigration of flies from Eastern Ilorin Province, known to be heavily infested as early as 1912. Several cattle routes from that area converged north of Ilorin before the present route became predominant.G. m. submorsitans was eradicated from the route south of Ogbomosho by insecticide spraying in January 1970. The rate of re-invasion of this section was measured for the next three years and found to be about 5·13 km per year or 99 m per week, proceeding faster during dry than during wet seasons.The calculated rates of advance, both long and short term, were about half the figure (180 m per week) proposed by other workers as the dispersal rate of individual flies, which is believed to determine rates of advance. The relative slowness of the present advance was probably related to the equability of the climate, in which seasonal increases and decreases in fly population were slight.
Larval habitats of common Culicoides Latreille (Diptera, Ceratopogonidae) in Kenya
Authors: Lubega R. , Khamala C. P. M. 
Published: July 2009

AbstractThe larval habitats of Culicoides species were determined by examining a total of 1 476 samples collected from different ecological environments in various parts of Kenya. Immature stages were collected from suspected breeding habitats and adults were reared. Adults were also captured in emergence traps and then identified. To determine species preferences, if any, the materials yielding Culicoides were analysed for pH, organic matter and water content.Fifty-seven percent of the samples yielded a total of 26 species of Culicoides. Sites in which Culicoides occurred were classified into eleven habitats grouped into four major systems, namely, aquatic, transitional, terrestrial and general systems. Most species were found breeding over a wide pH range in sites which were wet at least part of the time. A few species appeared to select breeding habitats with a high organic content.