bluuebunny/crossref_metadata_2025 huggingface dataset:
Mass rearing Ceratitis capitata: reuse of the finisher larval diet
Authors: Bruzzone N. D. , Economopoulos A. P. , Wang Hua‐Song
Published: April 2011

The standard finisher larval diet used at Seibersdorf for rearing the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), was reused following autoclave heat‐treatment to kill larvae or pupae remaining from its first use. Only when the spent diet was mixed with water (about 40% of final diet, w/w) to reconstitute fresh‐diet texture, and combined with fresh starter, a similar, but still inferior in respect to larval duration and pupal recovery and size, to the fresh finisher diet production of flies was achieved. Enrichment of the autoclaved spent finisher with small quantities of nutrients gave inconclusive results. Although spent‐diet pupae were significantly smaller than fresh‐diet control pupae, their adults survived significantly longer than control adults.

Zur Massenaufzucht von Ceratitis capitata: die Wiederverwendung der Endkomponente der Larvendiät

Die in Seibersdorf zur Aufzucht der Mittelmeerfruchtfliege, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), verwendete Standardend‐komponente der Larvendiät konnte nach Abtötung der von der Erstverwendung verbliebenen Larven oder Puppen mittels Autoklavensterilisation wiederverwendet werden. Eine zur frischen Kontrolldiät vergleichbare, jedoch bezüglich der Länge des Larvenstadiums, der Entwicklung der Puppen nach dem Schlüpfen sowie der Größe der Puppen noch immer schlechtere Fliegenproduktion wurde erreicht, wenn die wiederverwendete, autoklavierte Diät mit Wasser (ca. 40% der Enddiät, w/w) zwecks Rekonstitution zur frischen Diättextur gemischt und mit frischem Starter kombiniert wurde. Eine Anreicherung der wiederverwendeten Diätendkomponente mit geringen Mengen von Nährstoffen ergab keine schlüssigen Resultate. Obwohl Puppen der wiederverwendeten Diät signifikant kleiner als Puppen der Frischdiät‐Kontrolle waren, überlebten deren Erwachsene signifikant länger als die Erwachsenen der Kontrolle.
Structural damage to oak leaves alters natural enemy attack on a leafminer
Authors: Faeth Stanley H.
Published: April 2011

A field experiment was conducted to test the role of structural changes in oak leaves caused by folivory on natural enemy attack of leafmining larvae and pupae of Cameraria sp. nov., while controlling for induced chemical responses. Damaged and intact leaves of Quercus emoryi were sealed with a fluorocarbon telomer in 1988–1989 to prevent release of long‐range or contact chemical cues that might be perceived by searching parasitoids and predators. These leaves were attached to Q. emoryi leaves harboring first instars of Cameraria, but otherwise were undamaged. Rates of attack by natural enemies of leafminers in leaves with sealed, damaged leaves attached were significantly greater than those in control leaves, indicating that structural damage alone influences attack by natural enemies. Survival of leafminers in leaves with attached damaged leaves was significantly less than that of controls, suggesting that structural changes in leaves due to folivore feeding affect population dynamics of Cameraria via increased attack by the third trophic level.

Modifications des attaques contre une mineuse des feuilles provoquées par les altérations structurales des feuilles

Des expériences ont été faites dans la nature pour évaluer l'influence des modifications structurales provoquées par la défoliation sur les attaques des ennemis naturels des chenilles mineuses et des chrysalides de Cameraria sp. nov. En 1988–89 des feuilles saines et endommagées de Quercus emoryi ont été enduites de télomère de fluorocarbone pour empêcher l'émission d'indicateurs chimiques à distance ou de contact pouvant être utilisés par les parasitoïdes et les prédateurs lors de leur prospection. Ces feuilles ont été attachées à des feuilles apparemment intactes de Q. emoryi mais hébergeant des Cameraria du premier stade. Les attaques par les ennemis naturels des mineuses étaient plus importantes sur feuilles associées à des feuilles endommagées mais enduites de fluorocarbone que sur feuilles témoins, ce qui montre que les dégâts structuraux seuls influent sur les attaques par les ennemis naturels. La survie des mineuses dans les feuilles associées à des feuilles endommagées était plus faible que chez les témoins, ce qui suggère des changements structuraux dans les feuilles provoqués par les phytophages affectant la dynamique de population de Cameraria via une attaque accrue par le troisième niveau trophique.
The effect of two proteinase inhibitors, E‐64 and the Bowman‐Birk inhibitor, on the developmental time and mortality of Acanthoscelides obtectus
Authors: Hines M. E. , Nielsen S. S. , Shade R. E. , Pomeroy M. A.
Published: April 2011

An artificial bean seed system was used to evaluate the effects of a cysteine proteinase inhibitor (E‐64) and a serine proteinase inhibitor (Bowman‐Birk inhibitor) on the developmental time and mortality of the common bean weevil, Acanthoscelides obtectus (Say). These inhibitors were incorporated into artificial bean seeds on which the insect fed. To better understand the mode of action of these inhibitors, free amino acids were also added to the seeds, alone and in combination with the inhibitors. E‐64 was found to be highly effective in delaying development and increasing mortality of the insect. Both effects were directly related to the concentration of E‐64. Bowman‐Birk inhibitor had little effect on these parameters. Assays of gut proteolytic activity of insects reared on artificial seeds with various levels of E‐64 demonstrated a direct relationship between E‐64 concentration in the diet and reduction of gut proteolytic activity. Free amino acid supplementation to the diet did not prevent inhibition of gut proteolytic activity by E‐64, but did reverse its effects on developmental time and mortality, strengthening the hypothesis that E‐64 operates by inhibition of essential digestive proteinase activity.

Effets de 2 inhibiteurs de protéinases, E‐64 et inhibiteur Bowman‐Birk sur la durée de développement et la mortalité d' Acanthoscelides obtectus

Des grains artificiels de haricot ont été utilisés pour évaluer les effets sur la durée de développement et la mortalité d' Acanthoscelides obtectus. Say d'inhibiteurs de la protéinase de la cystéine (E‐64) et de la protéinase de la sérine (l'inhibiteur de Bowman‐Birk). Ces inhibiteurs avaient été incorporés dans les grains artificiels. Pour mieux comprendre leur voie d'action, des acides aminés libres étaient ajoutés à ces graines, seuls ou combinés aux inhibiteurs. E‐64 a très efficacement retardé le développement et accru la mortalité; ces 2 effets étaient liés à sa concentration. L'inhibiteur de Bowman‐Birk a eu peu d'effets sur ces paramètres. Des expériences sur l'activité protéolytique du tube digestif d'insectes élevés sur des graines artificielles avec différentes concentrations de E‐64 ont montré une relation directe entre la concentration en E‐64 et la réduction de l'activité protéolytique. L'addition d'acides aminés libres dans l'aliment n'a pas empêché l'inhibition de l'activité protéolytique par E‐64, mais a inversé ses effets sur la durée de développement et la mortalité, renforçant l'hypothèse que E‐64 agit en inhibant l'activité protéinase digestive essentielle.
Effects of lead and cadmium on chemical composition and total water content of the pupal parasitoid, Pimpla turionellae
Authors: Ortel J.
Published: April 2011

The parasitoid Pimpla turionellae L. (Hymenoptera, Ichneumonidae) was fed on Cd, Pb and Cd + Pb‐contaminated food (33 μg Cd, 82 μg Pb and 33 μg Cd + 82 μg Pb per gram food fresh weight, respectively). Significant decrease in the total lipid and protein content was found along with an increase in the water content particularly in Cd‐contaminated parasitoids.
Effects of temperature and diet on oviposition rate and development time of the New Zealand flower thrips, Thrips obscuratus
Authors: Teulon D. A. J. , Penman D. R.
Published: April 2011

The life history of New Zealand flower thrips (Thrips obscuratus (Crawford), Thysanoptera: Thripidae) was studied using a simple laboratory rearing method. The effects of temperature and diet on oviposition rate and development time were examined. Oviposition rate increased with increasing temperature between 10°C and 25°C. Development time for individual instars and for total development decreased with increasing temperature between 10°C and 27°C. Total development time ranged from 50 days at 10°C (female) to 10 days at 27°C (male). The relationship between temperature and development rate was expressed as a straight line such that lower thresholds of development of between 4.2°C and 6.3°C were established for life stages. Adult lifespan increased with decreasing temperature between 10°C and 25°C and females lived longer than males. At 10°C and 25°C females lived for an average of 34 and 3 weeks respectively. Thrips supplied with pollen exhibited highest and sustained levels of egg production in comparison to other diets. Larval mortality was lowest and development time fastest on diets of pollen and sucrose or fruit juice in comparison to other plant tissues. Larval development time was similar on four species of pollen.
Interaction of fertilizer regime with host‐plant resistance in tomato
Authors: Barbour J. D. , Farrar R. R. , Kennedy G. G.
Published: April 2011

The effect of fertilizer regime on trichome‐ and lamellar‐based resistance in the wild tomato species, Lycopersicon hirsutum f. glabratum C. H. Mull accession PI 134417, to three insect pests of tomato, the tobacco hornworm, Manduca sexta (L.), the Colorado potato beetle, Leptinotarsa decemlineata (Say), and the tomato fruitworm, Heliocoverpa zea (Boddie), was examined. Increasing the rate at which NPK fertilizer was applied, from 1.8 to 19.6 g/plant/week, reduced the trichome‐based resistance of PI 134417 to M. sexta and L. decemlineata by lowering both the density of type VI (sensu Luckwill, 1943) glandular trichomes and the amount of 2‐tridecanone contained in the tips of these trichomes. 2‐Tridecanone is a toxic methyl‐ketone responsible for glandular trichome‐mediated resistance in PI 134417 to M. sexta and L. decemlineata. A similar increase in the application rate of NPK fertilizer reduced the lamellar‐based resistance of PI 134417 to L. decemlineata and H. zea. The meachanisms for this reduction of resistance are unknown, but may be related to improved nutritional quality of hosts at higher fertilizer regimes.
Selection for pesticide resistance in Aphytis
Authors: Havron A. , Kenan G. , Rosen D.
Published: April 2011

High levels of azinphosmethyl resistance, ca × 10 of a laboratory stock, were discovered in a field population of Aphytis lingnanensis Compere (Hymenoptera: Aphelinidae) parasitizing the California red scale, Aonidiella aurantii (Maskell) (Homoptera: Diaspididae), in a heavily sprayed citron orchard. Nine selections for increased resistance led to an initial loss of variability with no significant gains in resistance. Eight additional selections increased resistance to ca 4 times that of the source population, and variability to an extent indicating potential for further progress.

Additional selections of this stock by the male selection method resulted in further improvement and field releases of the resistant strain.

Initial levels of permethrin tolerance were ca 1.9 times higher than those of the susceptible population. LC50 values were only marginally increased by 13 selections, but a marked increase in the proportion of highly resistant individuals pointed to potential for further progress.

Exposure to the insecticides had no observable sub‐lethal after‐effects on rates of progeny production by survivors and on the sex ratio and developmental period of offspring.
Effects of nitrogen and foliar biomass on population parameters of cabbage insects
Authors: Jansson R. K. , Leibee G. L. , Sanchez C. A. , Lecrone S. H.
Published: April 2011

The effects of different nitrogen (N) fertilization rates (0, 45, 90, and 168 kg N/ha), plant nitrogen concentration, and plant biomass on abundance and population growth of diamondback moth, Plutella xylostella (L.), cabbage looper, Trichoplusia ni (Hübner), cabbage budworm, Hellula phidilealis (Walker), imported cabbageworm, Artogeia rapae (L.), and cross‐striped cabbageworm, Evergestis rimosalis (Guenée), were investigated in Homestead and Sanford, Florida in 1987. The effects of these factors on the parasitization of P. xylostella were also examined. In Homestead, abundance of most insect pests and parasitized P. xylostella increased with an increase in the level of N applied and with an increase in plant biomass. Similar results were found in Sanford, although results were not consistently significant. Abundance of most insect pests was significantly positively correlated with plant N concentration. Multiple regression analyses indicated that foliar biomass was significantly more important than N fertilization rate and subsequent plant N concentration at predicting abundance of insect pests and parasitized P. xylostella on cabbage.
Changes in calling behaviour and mating success in the European corn borer (Ostrinia nubilalis), caused by relative humidity
Authors: Royer L. , McNeil J. N.
Published: April 2011

We examined the calling behaviour of O. nubilalis virgin females, held at three different constant conditions of relative humidity from the time of emergence through their sixth night of calling, as well as the incidence of mating over time at low or high relative humidity conditions. The mean age at which females initiated calling in their life was independent of relative humidity conditions, although more variable at low humidity. On successive nights of calling, fewer virgin European corn borer females called under low compared with high humidity conditions, and those that did began later in scotophase, had fewer calling bouts, and spent less time calling. These changes in the female prereproductive behaviour were reflected on the incidence of mating which, in the first two days following emergence, was significantly less at low than at high humidity conditions. The ecological significance of these results is discussed in relation with the susceptibility of O. nubilalis to desiccation.

Modification du comportement d'appel et du succès d'accouplement de la pyrale du maïs (Ostrinia nubilalis) causées par les conditions d'humidité relative

Nous avons étudié le comportement d'appel des femelles vierges d'Ostrinia nubilalis maintenues sous trois conditions constantes d'humidité relative, depuis l'émergence jusqu'à la sixième nuit d'appel, ainsi que l'incidence d'accouplement d'individus placés en milieu sec ou humide pour diverses périodes de temps. Les conditions d'humidité n'ont pas significativement affecté l'âge moyen auquel les femelles ont commencé à appeler au cours de leur vie, bien qu'il ait été plus variable à 53% h.r. Les nuits subséquentes, le comportement d'appel des femelles maintenues à basse humidité a débuté plus tard dans la nuit, s'est exprimé pour une période de temps plus courte avec moins de séquences d'appel que celui de leurs congénéres placés en milieu humide, et la proportion de femelles en appel a toujours été plus faible à 53% h.r. Ces changements du comportement préreproducteur des femelles se sont répercutés sur l'incidence d'accouplement qui, les deux premiers jours suivant l'émergence, a été significativement plus faible à basse humidité qu'elle ne l'a été en milieu humide. Ces résultats seront discutés en relation avec l'écologie de O. nubilalis et associés à sa susceptibilité à la dessication.
The influence of azadirachtin on the feeding behaviour of cereal aphids and slugs
Authors: West A. J. , (Luntz) A. J. Mordue
Published: April 2011

The probing behaviour of Rhopalosiphum padi (L.) and Sitobion avenae (F.) and the feeding behaviour of several slug species, (Deroceras reticulatum (Müller), Arion distinctus Mabille, Agriolimax caruanae Pollonera, Maximus sp.) were assessed on seedlings of winter barley (Hordeum marinum) treated with different concentrations of azadirachtin. Settling behaviour of both aphid species was strongly biased towards the untreated seedlings or those treated with low concentrations of azadirachtin. Concentrations of <500 ppm were effective with topical application and probing activity was reduced for at least 4 days after application. Systemic activity of azadirachtin against cereal aphids was also demonstrated. Feeding behaviour of the slug species, as seen by the amount of leaf eaten compared to the controls, was not affected by the presence of azadirachtin at those concentrations which deterred aphids from feeding. The relevance of these results to crop protection is discussed.
Rearing of two predators, Thanasimus dubius and Temnochila virescens, for the biological control of Ips grandicollis in Australia
Authors: Lawson S. A. , Morgan F. D.
Published: April 2011

Rearing methods for two coleopterous predators, Thanasimus dubius and Temnochila virescens, imported into Australia for the biological control of Ips grandicollis, were developed. Bionomic data obtained from laboratory rearings between 1982–1987 showed that T. dubius eggs took about 7 days to hatch and that duration of the larval stage was about 42 days. Observations showed that T. dubius had a prolonged prepupal stage (x̄ = 56.4 days, range 14–274 days), which was probably non‐diapausal in nature. Mean adult longevity was 50 days (range 1–358 days). Temnochila virescens eggs took almost 9 days to hatch, and a lengthy larval stage (x̄ = 155.4 days, range 73–333 days) was observed. Mean duration of the pupal stage was 14 days (range 7–28 days). A long preoviposition period (x̄ = 141 days, range 47–206 days) was observed, and adults were very long‐lived (x̄ = 232.7 days, range 14–667 days). Capacity for increase (rc) calculated from rearing data suggested that numbers of T. dubius could be increased faster than T. virescens. Mortality between 1982–1987 averaged about 70% for both species. However, mortality of T. dubius in 1987 increased significantly, suggesting that inbreeding or other methodological factors could be responsible. A mass‐rearing method using Ips‐infested pine billets was developed as a cheaper alternative to laboratory rearing, and was shown to be effective in producing large numbers of insects for release.
Geocoris punctipes as a predator of Bemisia tabaci: a laboratory evaluation
Authors: Cohen A. C. , Byrne D.N.
Published: April 2011

Geocoris punctipes (Say), a predaceous lygaeid not previously documented as a whitefly predator, was tested in the laboratory as a natural enemy of the sweet potato whitefly, Bemisia tabaci (Genn.). Its stalking behavior with whiteflies as prey was similar to that observed with aphids. A previously unobserved behavior was noted that involves the predators using salivary secretions to fasten the wings of prey to various surfaces, allowing labial probing and feeding. Prey consumption as a function of prey number appeared to follow the pattern of the Holling type II functional response. Handling time per prey item ranged from about 180 to 240 seconds. No changes were observed in handling time devoted to earlier versus later catches. Nutritional quality of whiteflies was measured using crude protein, lipids and carbohydrates as criteria. Performance, in terms of predator behavior, total daily handling time, functional response, energy budget and nutritional quality all support the hypothesis that G. punctipes is a promising candidate for biological control of sweet potato whiteflies.
Use of learned visual cues during habitat location by Brachymeria intermedia
Authors: Drost Y. C. , Cardé R. T.
Published: April 2011

Like many other parasitoids, Brachymeria intermedia (Hymenoptera: Chalcididae) uses olfactory cues to find its host, but in addition it appears to use learned visual cues to focus its searching efforts at the macrohabitat level. In laboratory experiments, females were held in cages where Lymantria dispar pupae were hidden either in a vertical, tree‐like structure or on the floor. After four days females had learned to search for hosts in the structure in which they previously had found pupae. Such training was reversible. During similar tests in a semi‐natural situation, in which pupae were hung from a tree trunk or were hidden under leaf litter, females also tailored their subsequent searching to favour the macrohabitat where hosts previously had been found. This parasitoid most likely uses a combination of visual and olfactory cues during host searching.
Population genetic studies of leafhopper (Empoasca) species
Authors: Loukas M. , Drosopoulos S.
Published: April 2011

Seven populations of the genus Empoasca Walsh 1864 (Homoptera, Typhlocybinae) collected from six different host‐plants were electrophoretically analyzed for thirteen enzyme loci. By using both the allozymes and the morphological characters of the male genitalia we found that these populations consisted of only two Empoasca species; E. decedens and E. decipiens. The use of allozymes proved to be the faster and more efficient method for discrimination; nine out of thirteen enzyme loci were diagnostic. E. decedens was found to be the most abundant species in all populations studied. There are no genetic differences between E. decedens populations associated with different host‐plants. The total genetic variability was mainly organized within E. decedens populations, explaining more than 95% of the total variability.
The resistance of lettuce (Lactuca sativa L.) to Nasonovia ribisnigri: bionomics of N. ribisnigri on near isogenic lettuce lines
Authors: VAN Helden M. , Tjallingii W. F. , Dieleman F. L.
Published: April 2011

The intrinsic rate of increase (rm‐values), mean relative growth rates and mortality of Nasonovia ribisnigri (Mosley) (Homoptera, Aphididae) on different lines of lettuce (Lactuca sativa L.) were determined. Near isogenic resistant and susceptible lines, plus their ancestors, were used. Bionomics of N. ribisnigri on the resistant lines (NrNr) with the dominant Nasonovia resistance gene (Nr‐gene) differed clearly from the susceptible lines (nrnr). Mortality was high, no larvae reached adulthood, and no reproduction nor honeydew production was seen on the resistant lines. Transfer of aphids to susceptible plants after a period of 2 days on the resistant lines showed no signs of intoxication of aphids. Apparently there is no feeding on the resistant lines. It is not clear whether the aphids can not reach the phloem or do not accept it on the resistant line.
Populations of Sitobion avenae and Aphidius ervi on spring wheat in the northwestern United States Spatial distribution and sequential sampling plans based on numerical and binomial counts
Authors: Feng M. C. , Nowierski R. M. , Zeng Z.
Published: April 2011

During a three‐year field survey of the English grain aphid, Sitobion avenae (F.) (Homoptera: Aphididae) and the parasitoid, Aphidius ervi Haliday (Hymenoptera: Aphidiidae; represented by aphid mummies) on spring wheat, data sets were generated which consisted of 47 estimates of mean density (m aphids per tiller), variance (s2), and the proportion of empty tillers (P0) for S. avenae and 22 estimates of the same statistics for A. ervi, respectively. Each estimate of the aphid and parasitoid populations was based on counts per individual tiller on each sampling occasion. Taylor's power law was found to fit the data sets better than Iwao's m* ‐ m regression model. Taylor's slope for S. avenae (1.3076) was significantly higher than that for A. ervi (1.1519), indicating that S. avenae was more aggregated than A. ervi. Based on temporal changes in spatial aggregation represented by an index, 1/k [where k was estimated as m2/(s2 ‐ m)], S. avenae was most aggregated at low densities during the early infestation period and tended to be less aggregated as density increased, whereas A. ervi was more likely to be randomly distributed. A common k was detected for neither S. avenae nor A. ervi because the slopes from the linear regression of k on m significantly exceeded 0. Sequential sampling plans, based on numerical (complete) and binomial (presence or absence) counts, for the aphid and parasitoid species were developed using Taylor's parameters and those estimated from the linear regression of ln(m) on ln[‐ ln[P0)], respectively. Suggestions are made concerning the use of the sampling plans and the levels of precision that may be attained.
Diapause development in the chestnut weevil Curculio elephas
Authors: Menu F.
Published: April 2011

Larval diapause development in the chestnut weevil Curculio elephas (Coleoptera, Curculionidae) was studied in the laboratory at different temperatures. The results proved that exposure to low temperatures (3–6 °C) in the period December–February is not required to complete diapause. The diapause is terminated in December and from January on, the larvae can initiate post‐diapause morphogenesis in the laboratory, if temperatures allow it. In the field developmental rates are negligible during winter cold (4–6 °C) and only after March morphogenesis can proceed with no interruption until adult emergence. Diapause and post‐diapause quiescence contribute to individual synchronization for initiation of development. The observed spread of adult emergence was 30 days in the laboratory. This variability produced during post‐diapause development may be a response to annual variation in the phenology of the chestnuts.

Des expériences menées au laboratoire à différentes températures ont montré que chez le balanin de la châtaigne Curculio elephas (Coleoptera, Curculionidae) des basses températures (3–6 °C) entre décembre et février ne sont pas nécessaires au développement de la diapause larvaire et que cette dernière est levée en décembre. Bien que les larves soient potentiellement capables de reprendre leur morphogenèse à partir de janvier, dans la nature, les vitesses de développement entre décembre et mars sont négligeables en raison des basses températures dans le sol (4 à 6 °C). Après mars, les températures autorisent une morphogenèse continue jusqu'aux émergences des adultes. La diapause et la quiescence hivernale contribuent à synchroniser le début du développement des larves. La dispersion des émergences a été d'en moyenne 30 jours au laboratoire. Cette variabilité, produite durant le développement post‐diapause, serait un exemple de répartition du risque en réponse à la variation annuelle de la phénologie des châtaignes.
Grapevine leaf gas exchange, plant growth, yield, fruit quality and carbohydrate reserves influenced by the grape leafhopper, Empoasca vitis
Authors: Candolfi M. P. , Jermini M. , Carrera E. , Candolfi‐Vasconcelos M. C.
Published: April 2011

The impact of the grape leafhopper, Empoasca vitis, on leaf gas exchange, plant growth, yield, fruit quality and carbohydrate reserves of the grapevines, Vitis vinifera L., was studied. Gas exchange was measured on the discolored (red) and the green parts of infested main leaves and on leaves from uninfested vines. Photosynthesis and mesophyll conductance were severely reduced on main leaves showing leafhopper feeding symptoms. The stomatal conductance of the red leaf section of infested main leaves was lower than on undamaged control leaves. Additionally, the red leaf section of infested main leaves showed lower transpiration rates when compared to the green parts of the same leaves and to undamaged control leaves. Gas exchange processes of lateral leaves were not affected by leafhopper feeding. Leafhopper‐load on main leaves was correlated to visual damage symptoms. At 71.8 leafhopper‐days per leaf up to 40% of the main leaf area of the infested plants was discolored from the borders towards the center. Lateral leaves showed no feeding symptoms. Shoot diameter, pruning weight and carbohydrate reserves in the wood were not affected by leafhoppers. Lateral leaf area growth was significantly stimulated on plants infested by leafhoppers. No decrease in yield and fruit quality with leafhopper‐loads up to 71.8 leafhopper‐days per leaf were observed.
Glandular trichomes of Solanum berthaultii alter host preference of the Colorado potato Beetle, Leptinotarsa decemlineata
Authors: Yencho G. Craig , Tingey Ward M.
Published: April 2011

Choice and no‐choice studies were conducted to determine how the glandular trichomes of the wild potato, Solanum berthaultii Hawkes, affect host preference of the Colorado potato beetle, Leptinotarsa decemlineata (Say). Given a feeding choice between S. tuberosum and S. berthaultii, larvae and adults preferred the foliage of S. tuberosum, but adults were more discriminating. When foliage of S. berthaultii was appressed to S. tuberosum leaflets, fewer adults fed on the appressed leaflets. When given a choice between ‘trichome‐intact’ and ‘trichome‐removed’ S. berthaultii foliage, adults preferred to feed on the latter. The preference for ‘trichome‐removed’ foliage and the percent of adults initiating feeding, increased with the degree of trichome removal. These studies provide evidence that the resistance of S. berthaultii is associated with feeding deterrents localized in the glandular trichomes, that S. berthaultii possesses more than one mechanism of resistance to the Colorado potato beetle, and that the expression of resistance is dependent on the developmental stage of the insect.
Fluctuating asymmetry and survival ability in the forest tent caterpillar moth Malacosoma disstria: implications for pest management
Authors: Naugler Christopher T. , Leech Susan M.
Published: April 2011

Fluctuating asymmetry of the first tarsal segment of the proleg of the forest tent caterpiller moth Malacosoma disstria Hbn. (Lepidoptera: Lasiocampidae) was significantly inversely related to survival ability in the lab. The monitoring of population levels of fluctuating asymmetry could have important implications in pest management of this and other species by providing an indication of the health of a population.
Effect of temperature on the termination of diapause in the univoltine almond seed wasp Eurytoma amygdali
Authors: Tzanakakis M. E. , Veerman A.
Published: April 2011

Diapausing larvae of Eurytoma amygdali Enderlein (Hymenoptera, Eurytomidae) were collected in early August and late September. They were subjected to various photoperiod and temperature regimens for up to 20 weeks, then kept at L16:D8 and 19 °C for another 14 to 26 weeks for diapause to be terminated and pupation to take place.

Photoperiod did not affect diapause completion. It was confirmed that the two morphologically distinct diapause stages have different temperature requirements for their completion. The first diapause stage was completed synchronously at temperatures between 16 and 19 °C. A higher temperature of 26 °C delayed diapause development. The second stage required lower temperatures between 4 and 10 °C. Spontaneous termination of diapause was observed at constant 19 °C.

When applied to the first diapause stage for 20 weeks, low temperatures made the larvae refractory to subsequent intermediate temperatures. The first stage was thus maintained until a higher temperature of 26 °C made the larvae regain their ability to respond to the intermediate temperatures and complete this stage. Larvae grown in Retsou almonds had a higher diapause intensity than larvae grown in Truoito almonds.

The results suggest that, in nature, the high temperatures of late summer and early autumn are likely to maintain the first diapause stage. Subsequently, the less warm temperatures of autumn allow the completion of the first stage by late autumn, and the low temperatures of late autumn and of winter allow the completion of the second diapause stage by mid winter.
Thermal responses in the citrus fruit fly, Dacus tsuneonis: evidence for a pupal diapause
Authors: Yasuda Tetsuya , Narahara Minora , Tanaka Seiji , Wakamura Sadao
Published: April 2011

Thermal responses controlling pupariation and adult eclosion in a citrus fruit fly, Dacus tsuneonis (Miyake), were studied to understand the winter biology of this species. When mature larvae were exposed to various temperature conditions, the highest percentage of pupariation was obtained at 15°C, although the variance at this temperature was greater than at 20C or 25°C. Pupariation occurred most rapidly at 20°C and an alternating temperature with a mean of 15°C. At constant 15°C, pupae failed to emerge as adults. Pupae were characterized by a reduced respiration rate, which is typical of a diapausing pupa. When insects were stored at different temperatures for 45 days after pupariation, and then transferred to 25°C, adult eclosion occurred earlier when the initial temperature was 10°C than when it was 5°C or 15°C. Adult eclosion occurred most synchronously and pupal mortality was lowest when insects were stored at 15°C for 90 days before incubation at 25°C. These results strongly suggest that D. tsuneonis enters a pupal diapause.
Environmental variation in physical and chemical cues used by the parasitic wasp, Aphytis melinus, for host recognition
Authors: Hare J. Daniel , Luck Robert F.
Published: April 2011

O‐caffeoyltyrosine is a host recognition kairomone for Aphytis melinus DeBach (Aphelinidae) found in the covers of its host, California red scale, Aonidiella aurantii (Maskell) (Diaspidae). This study tests the hypothesis that the concentration of O‐caffeoyltyrosine and scale cover size are reliable indicators of scale body size, an important component of host quality for A. melinus, over a range of scale rearing conditions. Both scale cover area and O‐caffeoyltyrosine concentrations were only qualitatively related to scale body size during the third instar, the scale life stage most suitable for A. melinus. Scale cover area and O‐caffeoyltyrosine concentrations were reduced, relative to scale body size, when scale were reared on bark and leaves compared to fruits. Scale cover area and O‐caffeoyltyrosine concentration were also relatively reduced when scales were reared in mid‐summer compared to spring and fall, and when reared on orange cultivars compared to lemon cultivars in the field. Finally, scale cover area and O‐caffeoyltyrosine concentration were reduced when scale were reared at 52% compared to 100% humidity in the laboratory. Scales appear to be chemically conspicuous to A. melinus for a short period of the time in which they are physiologically susceptible. Scales that minimize their cover size and maximize the incorporation rate of O‐caffeoyltyrosine into covers may minimize their conspicuousness to A. melinus. Minimizing scale cover size, but not necessarily incorporation rates, may make scales more vulnerable to predators, however.
Comparative field studies of various traps and attractants of the olive fruit fly, Bactrocera oleae
Authors: Broumas T. , Haniotakis G. E.
Published: April 2011

In the framework of an ongoing testing and refining process of a mass trapping method, using a combination of semiochemicals, for the control of the olive fruit fly, Bactrocera (Dacus) oleae, four trap designs, three trap colors, six different food attractants and two pheromone formulations were compared under field conditions. No differences were observed between the trap designs and the food attractants tested. Trap color had a significant effect in preference tests only. Traps combining food attractants and pheromones attracted higher numbers of both male and female flies but the differences became statistically significant only in cases of low trap densities. Pheromones enclosed in cyclodextrenes were not as attractive as standard pheromone formulations. The findings of these tests allow a choice among trap types and semiochemicals for cost reduction and convenience, but not for enhancement of the efficacy of the method.
Prey preference and egg production of the carabid beetle Agonum dorsale
Authors: Bilde Trine , Toft Søren
Published: April 2011

In order to elucidate whether the aphid Rhopalosiphum padi is low quality food for the carabid beetle Agonum dorsale, as it has previously been found to be for cereal spiders, we performed a series of experiments using fruit flies Drosophila melanogaster as a standard alternative prey (‘control prey’): 1) Prey preference, 2) Aphid consumption for satiated and starved beetles, 3) Egg production on different diets and 4) Preference experiments with fruit flies coated with a taste of different prey types. Other alternative prey types used were earthworms and sciarid midges, all potential prey in the field. A. dorsale has a low preference for aphids compared to fruit flies. Apparently there is an upper limit to the consumption of aphids independent of hunger and much below the beetles' total food demand. Egg production on a pure diet of aphids is lower than on a pure diet of fruit flies; it is extremely low on a pure diet of earthworms; the highest fecundity is found on a mixed diet. As fruit flies coated with a taste of aphids or sciarid midges are less prefered than flies covered with a taste of fruit flies there may be a chemical factor, acting through taste, involved in determining prey preference.
Dispersal of adult female fig wasps: 1. Arrivals and departures
Authors: Ware Anthony B. , Compton Stephen G.
Published: April 2011

Ficus burtt‐davyi, like most other fig species (Ficus, Moraceae), is exclusively pollinated by its own unique species of fig wasp, in this case Elisabethiella baijnathi (Chalcidoidea, Agaonidae). Because fig crop development on any one tree is usually synchronised, the small and short‐lived female wasps have to migrate and find other trees bearing figs which are at suitable stage of development for oviposition. However, the likelihood of successful location and subsequent arrival at a new host tree is dependent on distance and the effect of environmental factors such as wind and temperature. This study examines the relationship between ambient temperatures and the timing of fig wasps emergence from their natal figs and the commencement of their dispersal flight. The behaviour of the wasps arriving at figs which were ready to be pollinated was also examined. The female wasps did not appear to distinguish between the figs and other parts of the tree when in flight. However, after landing on the tree their search for figs was more directed as they visited more figs than leaves. Short‐range recognition of figs appears to be by contact chemo‐reception, but the wasps showed a preference for entering figs which did not already contain a female wasp.
Larval diet influence on oviposition behaviour in Spodoptera littoralis
Authors: Anderson P. , Hilker M. , Löfqvist J.
Published: April 2011

Females of Spodoptera littoralis Boisd. (Lepidoptera: Noctuidae) with different feeding experiences during their larval development were tested for their ovipositional response to methanol extracts of larval frass and semisynthetic diets. The effect of the following frass, diet and diet component extracts was tested: (a) frass from S. littoralis or Agrotis segetum larvae fed on a potato‐based diet; (b) frass from S. littoralis larvae fed on a wheat germ‐based diet; (c) potato and wheat germ‐based diets; and (d) potatoes and wheat germ.

Ovipositing females without prior experience of the potato diet were deterred by extracts of: (1) larval frass from either species fed on potato diet; (2) the potato‐based diet; (3) potato. Also females with experience of the potato diet during only a part of their larval development were deterred from oviposition by frass of larvae reared on the potato diet and by the diet itself. However, for females reared on the potato diet for their entire larval development, oviposition was no longer deterred by either of the three extracts listed above. Extracts of: (1) frass from larvae of either species reared on wheat germ diet: (2) the wheat germ diet; or (3) wheat germ did not significantly affect oviposition. Females with ablated antennae were still deterred by frass extracts from larvae fed on potato diet, when they had been reared on the wheat germ diet. In feeding experiments, larvae of larval stage one and of larval stage three‐four reared on either of the two diets preferred to feed on the wheat germ diet. However, the preference was significantly stronger for larvae with no prior contact with the potato diet. The effect of larval experience on the loss of oviposition‐deterring activity by extracts of larval frass, diets and diet components is discussed in view of induction and selection.
Endophytes of fescue grasses enhance susceptibility of Popillia japonica larvae to an entomopathogenic nematode
Authors: Grewal S. K. , Grewal P. S. , Gaugler R.
Published: April 2011

We evaluated tritrophic level interactions among fungal endophytes (Acremonium spp.) of fescue grasses (Festuca spp.), the root‐feeding Japanese beetle Popillia japonica Newman larvae, and the entomopathogenic nematode Heterorhabditis bacteriophora Poinar. Third‐instar P. japonica larvae were introduced into pots containing endophyte‐infected or endophyte‐free plants of tall fescue Festuca arundinacea Schreber (cultivars Kentucky 31 and Georgia Jesup Improved) and the Chewings fescue Festuca rubra commutata Guad. (cultivars F‐93 and Jamestown II). After two weeks, the surviving larvae were recovered, and their susceptibility to nematodes was evaluated in sand columns. Endophytes enhanced the rate of nematode‐induced mortality in all cultivars except Georgia Jesup Improved, and increased the proportion of dead larvae with nematodes in all cultivars except Jamestown II. Endophytes in the cultivar Kentucky 31 were associated with improved nematode establishment in the larvae. No effect on nematode reproduction was found.

Since endophytes produce biologically active alkaloids, we tested the effects of an ergot alkaloid, ergotamine tartrate, on the feeding behavior and weight of P. japonica larvae in agar medium. The alkaloid caused feeding deterrence, and reduced the consumption of medium by the larvae, resulting in weight loss. These larvae were more susceptible to H. bacteriophora than the untreated larvae. Unfed ‘starved’ larvae were more susceptible to nematodes than those fed on untreated agar. Our results support the hypothesis that endophyte‐induced starvation of P. japonica would reduce larval vigor, and render them more susceptible to entomopathogenic nematodes.
Ant predation of Eriocrania miners in a polluted area
Authors: Koricheva Julia , Lappalainen Janne , Haukioja Erkki
Published: April 2011

We tested the hypothesis that air pollution may affect population densities of birch‐feeding leafminers via changes in ant predation. Foraging activity of three ant species (Formica rufa, F. fusca and F. lemani), predation rates and population densities of both solitary and gregarious Eriocrania (Lepidoptera: Eriocraniidae) miners were investigated at 13 sites around the Harjavalta copper‐nickel smelter, SW Finland. Ant species differed in their distribution patterns relative to pollution. However, the total percentage of birch trees foraged by ants (all species combined) showed no correlation with the distance from the factory complex. As a result, no clear trends in predation rates were apparent in relation to the distance from the pollution source for either solitary or gregarious Eriocrania species. Densities of the solitary Eriocrania species tended to increase with the distance from the pollution source whereas densities of the gregarious E. haworthi peaked close to the factory complex. No corresponding differences in predation rates between solitary and gregarious miners were found. Ant predation, thus, did not explain density patterns of Eriocrania miners in the polluted area.
Effect of methoxyphenols on grain aphid feeding behaviour
Authors: Leszczynski B. , Tjallingii W. F. , Dixon A. F. G. , Swiderski R.
Published: April 2011

Methoxyphenols might be important in the resistance of cereals to aphids. Electrical penetration graph (EPG) recordings were used to determine the effect of caffeic, ferulic and sinapic acids, and scopoletin on the feeding behaviour of the grain aphid Sitobion avenae (F.). Aphids on wheat seedlings treated systemically with these phenols showed reduced ingestion of phloem sap and salivation into sieve elements in most cases. The earlier pathway phases of probing were prolonged. Moreover increase in number of probes as well as reduction of total time of probing was observed. In addition, no O‐demethylase activity was found in homogenates of aphids fed on moderately‐resistant (phenolic rich) or susceptible (phenolic poor) wheat varieties. The significance of these results for understanding the resistance of cereals to aphids is discussed.
Suitability of the maize weevil and angoumois grain moth as hosts for the parasitoids Anisopteromalus calandrae and Pteromalus cerealellae
Authors: Smith Lincoln , Weaver David K. , Arbogast Richard T.
Published: April 2011

Two parasitoids, Pteromalus cerealellae (Ashmead) and Anisopteromalus calandrae (Howard) (Hymenoptera: Pteromalidae), were compared for their ability to parasitize two important internally‐developing insect pests of stored maize (Zea mays L.). Parasitism by P. cerealellae was greater on Angoumois grain moth, Sitotroga cerealella (Olivier), than on maize weevil, Sitophilus zeamais Motschulsky, in no‐choice experiments. Anisopteromalus calandrae parasitized more maize weevils than did P. cerealellae. The former parasitoid parasitized only a few Angoumois grain moths successfully in maize, but parasitized many in wheat if the hosts were younger than 3 weeks old. Thus, both host age and type of grain affect suitability for parasitism. The effects of parental host (species on which the female developed) and experimental host (species exposed to parasitism) on parasitism rate of P. cerealellae were tested in a host‐switching experiment. Parasitism by parasitoids reared on maize weevils was 23% lower than that of parasitoids reared on Angoumois grain moth. This effect was independent of which host the filial generation of parasitoids was tested on. However, the experimental host species had a much greater effect on parasitoid fecundity than the parental host species. Female progeny had smaller body sizes when emerging from maize weevil than from Angoumois grain moth, which may explain the parental host effect on fecundity. There was also a slight intergenerational effect of host species on parasitoid body size.
Do anthocorid predators respond to synomones from Psylla‐infested pear trees under field conditions?
Authors: Drukker B. , Scutareanu P. , Sabelis M. W.
Published: April 2011

Because Y‐tube olfactometer experiments in the laboratory showed a response of anthocorid bugs to odour from Psylla‐infested leaves, it was of interest to assess its relevance under field circumstances. This was done by measuring the density of predatory bugs on pear trees adjacent to Psylla‐infested or control trees that were covered with fine mesh gauze‐screens. In this way odours from these caged trees could spread through the screen, while contact with the Psylla prey in the cage was prevented. The density of anthocorid predators around cages with heavily infested trees was significantly higher than around uncaged control trees and around cages containing uninfested or little infested trees. Covering a cage with Psylla‐infested trees by an airtight plastic sheet led to an immediate drop in the density of anthocorid predators, whereas removal of the sheet led to predator aggregation again. The results of these field experiments strongly support the hypothesis that anthocorid predators respond to volatile chemicals emanating from Psylla‐infested pear trees.