bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of mineral oil on stylet activities and potato virus Y transmission by aphids
Authors: Powell G.
Published: April 2011

Mineral oil sprayed onto potato virus Y (PVY) infected tobacco plants reduced acquisition of this potyvirus by Myzus persicae (Sulz.). Although the pre‐penetration activities of aphids were longer on oil treated leaves, the inhibitory effect of the oil could not be attributed to differences in the duration of stylet penetration. Aphids were therefore made part of a DC circuit in order to investigate their stylet activities during penetration of PVY infected source plants and healthy test plants. Both acquisition and inoculation of the virus were reduced by the presence of oil on the plant surface, but these reductions could not be related to electrically recorded differences in plant penetration behaviour. In particular, stylet punctures of plant cell membranes were not reduced by mineral oil. Non‐behavioural reasons are suggested to explain the mode of action of the oil.
The role of honeydew as an ovipositional stimulant for two species of syrphids
Authors: Budenberg W. J. , Powell W.
Published: April 2011

The influence of honeydew contamination on egg laying by the syrphids Episyrphus balteatus (Deg.) and Platycheirus albimanus (F.) on ears of wheat was investigated in a large laboratory flight cage. Artificially‐applied honeydew elicited oviposition by E. balteatus but not by Platycheirus albimanus. Episyrphus balteatus females landed more frequently on ears contaminated with honeydew than on clean ears, suggesting a response to honeydew volatiles. Honeydew from the rose‐grain aphid Metopolophium dirhodum and from the pea aphid Acyrthosiphon pisum stimulated E. balteatus to lay eggs, whereas honeydew from the nettle aphid Microlophium carnosum did not. The number of eggs laid by E. balteatus increased with increasing honeydew concentration. At low honeydew concentrations the presence of aphids increased oviposition by E. balteatus, but aphid presence had little effect on the number of eggs laid at high honeydew concentrations.
Resistance in certain maize cultivars to first and third‐instar Chilo partellus larvae
Authors: Kumar H. , Saxena K. N.
Published: April 2011

The resistance/susceptibility levels of ten maize (Zea mays L.) cultivars to neonates and 3rd‐instar larvae of Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae) were measured in the field and screenhouse experiments. The maize cultivars tested were: Inbred A, Mp 704, V‐37, Population 10, Hybrid 511, Katumani Composite B, ER‐29 SVR, Poza Rica 7832, ICZ2‐CM, and MMV 400. Most cultivars were found susceptible to 3rd‐instar larvae based on the incidence of dead heart symptoms, foliar feeding and stem tunnelling caused by stem borers in both the field and screenhouse experiments. However, the maize cultivars V‐37, MMV 400 and Poza Rica 7832 sustained significantly lesser damage than the other cultivars when infested with neonates or 3rd instar larvae.

The screenhouse experiments conducted with five maize cultivars, i.e. Inbred A, Mp 704, V‐37, ER‐29 SVR, and Poza Rica 7832 showed that neonates fed less on the resistant than the susceptible maize cultivars but feeding by the 3rd instars was equally high on all the maize cultivars except Mp 704 on which the larvae fed less than the others. In the cultivars infested with neonates, the mean period for 50% moth emergence P50 was longest on Mp 704 followed by Poza Rica 7832, ER‐29 SVR, V‐37 and Inbred A. In the cultivars infested with 3rd‐instars, P50 was longest for Poza Rica 7832 followed equally by the remaining cultivars.

On the basis of the evidence presented we here conclude that neonates of C. partellus are sensitive to the growth inhibiting effects of the resistant maize cultivars Mp 704, V‐37, and Poza Rica 7832 but the older larvae are insensitive to these effects of Mp 704 and V‐37 but not of Poza Rica 7832.
Influence d'une alimentation préalable et du jeûne sur l'apparition de la recherche intensive des proies chez Semiadalia undecimnotata
Authors: Ettifouri M. , Ferran A.
Published: April 2011

Les prédateurs qui vivent aux dépens de ressources alimentaires groupées, modifient leur mode de déplacement après la capture et l'ingestion d'une proie. Ils passent de la recherche extensive (déplacements rapides et linéaires) à la recherche intensive (déplacements lents et sinueux). Chez les adultes et les larves de dernier stade de la coccinelle Semiadalia undecimnotata Schn. (Col., Coccinellidae), dans les premières heures qui suivent leur naissance ou leur mue, l'ingestion d'un premier puceron ne modifie pas les caractéristiques locomotrices individuelles: les déplacements restent de type extensif. Au début de chaque stade, cette coccinelle présente une période de sensibilisation à la proie rencontrée. Durant ces laps de temps, elle doit consommer plusieurs proies avant d'ětre capable d'adopter la recherche intensive. L'existence d'une période de jeûne avant cette première prise alimentaire favorise, au contraire, l'adoption de la recherche intensive.

Effect of a prior feeding period and of fasting on the appearance of intensive search of preys with S. undecimnotata

The ladybird, Semiadalia undecimnotata, like all other entomophagous insects feeding on relatively sedentary prey, exhibits two types of walking pattern during the search for prey: extensive and intensive search. The latter is engaged following detection of visual or chemical cues. Changes in the ladybird search pattern: extensive search ‐ a single prey capture ‐ intensive search, were investigated in relation to experience of prior feeding‐periods (experienced coccinellids) or to lack of such experience (naïve coccinellids) and with respect to changes in duration of fasting. The analysis of their pathways was performed initially by comparison of three locomotory paramètres: the number of stops (number/s), the walking speed (mm/s) and the turning‐rate (degrees/s), and subsequently by statistical classification (principle components analysis). Unlike experienced coccinellids, observations of naïve coccinellids, indicate that a single feeding session during the three to five hours after emergence of an adult, or ecdysis of the larva, will change the walking pattern slightly. These animals will maintain extensive search or adopt a particular, intermediate locomotory pattern which is a development of extensive search but do not adopt intensive search. Fasting, for periods over twelve hours, favoured intensive search in populations studied. It is probable that the requirement to feed on more than one prey item before adopting intensive search involves concepts such as forms of learning (sensitization).
Host acceptance behaviour of the jack pine tip beetle, Conophthorus anksianae and the red pine cone beetle, C. resinosae
Authors: de Groot P. , Borden J. H.
Published: April 2011

The jack pine tip beetle, Conophthorus banksianae McPherson (Coleoptera: Scolytidae) and the red pine cone beetle, C. resinosae Hopkins, are doubtful sibling species. However, it is possible that these two taxa are valid species that maintain reproductive isolation because they accept different hosts. In a series of laboratory and field cage experiments, the host acceptance behaviours of these two species under choice and no choice conditions were compared. The field experiments demonstrated that the two species have a similar propensity to accept jack pine cones and shoots for feeding, but differ consistently in their acceptance of red pine cones, and variably in their acceptance of red pine shoots. However, the laboratory experiments did not indicate a difference between the two species in their propensity to accept red pine cones for feeding. In field cages, C. resinosae accepted significantly more red pine cones for oviposition than C. banksianae; the situation was reversed for jack pine shoots. In comparison to C. banksianae, C. resinosae is a more generalist feeder. The results from this study suggest that host acceptance behaviour is a permeable barrier unable to ensure reproductive isolation between the two species. Although there are differences in the host acceptance behaviours between C. banksianae and C. resinosae, we conclude that these differences do not necessarily support their designation as distinct species.
The role of trophallaxis in the distribution of Perizin in a honeybee colony with regard to the control of the Varroa mite
Authors: van Buren N. W. M. , Mariën A. G. H. , Velthuis H. H. W.
Published: April 2011

It is claimed that Perizin, a pesticide to control the mite Varroa jacobsoni, acts systemically and is distributed by trophallaxis of the bees. We studied the role of trophallactic interactions in the distribution of coumaphos, the active ingredient, among the colony members and whether coumaphos can reach all mites by systemic activity. Colonies were divided into three compartments by a screen, one receiving a Perizin treatment by sprinkling, the others receiving no Perizin. In this way it was possible to trace the amount of coumaphos transferred between bees through the screen from the treated part to the untreated one by trophallaxis. After different periods of time the number of fallen mites was counted and the amount of coumaphos in bees was determined for all hive compartments. We found that trophallactic interactions are of minor importance in the distribution of Perizin between the two compartments. The recommended method of sprinkling Perizin over the bees was shown to be very inefficient; only 24% of the applied amount reaches the alimentary canal of the bees; the rest must therefore remain at other places: on the outside of the bees, in the combs and on the hive‐parts.
Dispersion pattern of the medfly from its geographic centre of origin and genetic relationships of the medfly with two close relatives
Authors: Kourti A. , Loukas M. , Sourdis J.
Published: April 2011

We used three different approaches, a phylogenetic analysis, the principal component analysis, and Gabriel Graphs, to study the dispersion of the medfly from its geographic centre of origin. Our analysis was based on 13 enzyme polymorphisms detected electrophoretically in 15 natural populations coming from distinct geographic areas. The results indicate that (i) there is a clear‐cut separation of the native African from the introduced populations, (ii) the population from Spain seems to connect the African and the Mediterranean or American populations, and (iii) the Mediterranean populations as well as the American ones comprise two distinct groups of closely related populations.

We have also estimated a phylogenetic tree for 3 species of the genus Ceratitis: C. capitata, C. rosa and C. nigra, based on electrophoretic data under the assumption of a molecular clock. The results suggest that C. capitata and C. rosa are more closely related to each other than either is to C. nigra.
Development and application of an integrated pest management programme for the psyllid, Ctenarytaina thysanura on Boronia megastigma in Tasmania
Authors: Mensah R. K. , Madden J. L.
Published: April 2011

An integrated pest management programme for control of the psyllid, Ctenarytaina thysanura (Ferris & Klyver) (Hemiptera: Psyllidae) in commercial boronia plantations was developed and implemented from 1986–1989. The programme involved spraying boronia stems only with the systemic organophosphate mevinphos at peak incidence of late stage nymphs. At this time, the majority of parasitoids were pupating within mummified hosts. Consequently, actively feeding nymphs were potentially susceptible to mevinphos but the parasitoids were not. Stem application negated any contact effect on parasitoids and predators. The conservation of natural enemies subsequently reduced psyllid numbers and no insecticide has been required since 1989. In economic terms the benefit to cost ratio of the IPM programme was 22.40: 1.0 and this was 40 times greater than the conventional 10 demeton‐S‐methyl sprays used by growers prior to the study.
Antimetabolic effects of plant lectins and plant and fungal enzymes on the nymphal stages of two important rice pests, Nilaparvata lugens and Nephotettix cinciteps
Authors: Powell K. S. , Gatehouse A. M. R. , Hilder V. A. , Gatehouse J. A.
Published: April 2011

Insect feeding trials were carried out to determine the effects of incorporating a range of plant derived proteins into artificial diets fed to leafhopper and planthopper pests of rice. The lectins Galanthus nivalis agglutinin (GNA) and wheat germ agglutinin (WGA), and the enzyme soy bean lipoxygenase (LPO) were shown to exhibit significant antimetabolic effects towards first and third instar nymphs of rice brown planthopper (Nilaparvata lugens Stål) when incorporated into artificial diet at 0.1% (w/v), 0.1% (w/v) and 0.08% (w/v) levels respectively. The lectin GNA was also shown to exhibit a significant antimetabolic effect towards third instar nymphs of the rice green leafhopper (Nephotettix cinciteps Uhler). A number of inert proteins, lectins, protein inhibitors and enzymes also tested showed relatively little or no effect towards both insects.
The behaviour of 9 stored product beetles at pitfall trap arenas and their capture in millet
Authors: Obeng‐Ofori D.
Published: April 2011

Pitfall trap capture for Sitophilus oryzae (L.), S. zeamais (Motschulsky), S. granarius (L.), Tribolium confusum (Duval), T. castaneum (Herbst); Oryzaephilus surinamensis (L.), Cryptolestes pusillus (Schonherr), Rhyzopertha dominica (Fabr.), and Prostephanus truncatus (Horn) in millet was assessed by visual and time‐lapse video recordings. The behaviour of different beetle species in arenas containing millet was monitored over 24 h and the frequency of encounters with the trap rim resulting in capture recorded. The capture efficiency of four types of pitfall traps (i.e. polystyrene, polythene, glass and tin‐plated steel can) with rims exposed or submerged below the millet surface level were compared. Capture was related to beetle size, locomotory rate, and beetle behaviour at the trap rim as well as trap design and placement. The lighter and smaller species were least captured. Glass jars were more effective than plastic and metal containers. Traps placed with their rims submerged below the grain surface level were more efficient than those with rims exposed. Capture rate was unrelated to trap size. The frequency of encounters with trap rims was not correlated with capture rate. Three types of avoidance behaviours at the trap rims i.e. probing, skirting and spontaneous retreat, were related to capture rate, spontaneous retreat being the most effective escape mechanism and probing least.
The occurrence of translocations in insecticide resistant and susceptible field‐collected strains of the German cockroach
Authors: Ross M. H. , Crouch J. H.
Published: April 2011

Insecticide resistant and susceptible field‐collected strains of the German cockroach were surveyed for the occurrence of chromosome polymorphisms. Analyses were on meiotic cells of males that hatched from oothecae with unusual numbers (>5) of incompletely developed eggs (aberrant oothecae). Three males were reciprocal translocation heterozygotes. A spontaneous translocation was noted in one cell of a fourth male. The males were from insecticide resistant strains. Partially developed eggs in oothecae from outcrosses of two of the translocation herozygotes ceased development in early stages and were characterized by gross morphologic abnormalities. Chromosome abnormalities other than translocations occurred in a low percentage of males from aberrant oothecae in both resistant and susceptible strains. The only general differences between susceptible and resistant strains were that, in pooled data, the frequencies of unhatched oothecae and of aberrant oothecae were higher in the resistant than susceptible strains.
Influence of larval dietary supply on the food consumption, food utilization efficiency, growth and development of the lacewing Chrysoperla carnea
Authors: Zheng Y. , Hagen K. S. , Daane K. M. , Mittler T. E.
Published: April 2011

Larvae of the common green lacewing, Chrysoperla carnea (Stephens)(Neuroptera: Chrysopidae), were fed either an optimal or a suboptimal number of eggs of the moth Anagasta kuehniella (Zeller) in the first and/or second larval instar, or in all three larval instars. Parameters for the duration, growth, and the efficiency of conversion of ingested food to body substance (ECI) of each instar were established for seven different dietary regimes. Larvae that had a suboptimal food supply in the first instar had a significantly longer developmental time, gained significantly less weight, and had a slightly lower ECI in that instar larvae. Suboptimally‐fed second less, but remained only slightly longer in that instar and had a similar ECI to optimally‐fed second instar larvae. The developmental time of suboptimally‐fed third instar larvae was similar to that of optimally‐fed larvae of that stage. Whereas the growth of the former was significantly less than that of larvae optimally fed in that instar, the ECI of the former was significantly higher. Despite the relatively smaller size of larvae fed suboptimally in the first and/or second instar, when such larvae were subsequently supplied with an overabundance of prey eggs, they consumed approximately the same number of eggs during the remainder of their larval life as did larvae whose food supply had not been restricted previously. When larvae were allowed to consume different numbers of eggs in their third instar, their gain in weight and therefore the weights attained by the resulting adults (based on the weights of 3‐day‐old cocoons) had a highly significant positive correlation with the number of eggs consumed in this instar.
Mating disruption to control damage by leafrollers in Virginia apple orchards
Authors: Pfeiffer D. G. , Kaakeh W. , Killian J. C. , Lachance M. W. , Kirsch P.
Published: April 2011

Mating disruption for control of variegated leafroller (VLR), Platynota flavedana (Clemens), tufted apple bud moth (TBM), P. ideausalis Walker, and redbanded leafroller (RBL), Argyrotaenia velutinana (Walker), was studied in Virginia apple orchards in 1989 and 1990. In 1989, each dispenser (1000/ha) contained 190 mg of 67.2% E11–14:Ac, 28.8% Z11–14:Ac, 1.4% E11–14:OH, 0.6% Z11–14:OH, and 2% Z9–12:Ac (a putative generic leafroller disruption blend). Trap captures of VLR, TBM and RBL were reduced by 97%, 51% and 55%, respectively. Average leafroller injury in the interior and edge of the pheromone block was 3.8% and 2.7%, respectively. The conventional control and abandoned blocks had 0.05 and 27.5% injury, respectively. Dispensers containing E11–14:OH (70%) and Z11–14:OH (30%) (close to the natural blend of VLR), more effectively disrupted orientation to pheromone traps by both Platynota spp. than did the generic blend. In 1990, dispensers containing 150 mg of E11–14:OH (70%) and Z11–14:OH (1000/ha) were placed in two 2‐ha blocks and one 4‐ha block. One pheromone‐treated block was sprayed in August with phosmet for codling moth, not timed for leafrollers. Trap captures of VLR and TBM were reduced by almost 100% and 69%, respectively. RBL captures were not reduced by VLR pheromone permeation. Injury from Platynota spp. in pheromone block middles and edges ranged from 0.3–1.7% and 0.3–2.3%, respectively. Injury in conventional blocks ranged from 0–1.1%. RBL injury in pheromone block middles ranged from 0–6.1%, and in edges, 1.7–4.8%. Injury in control blocks ranged from 0–1.1%. Combined leafroller injury in an abandoned block was 18% (s.e. 0.3). Release rates averaged 30 and 32 mg/ha/h for the VLR and generic pheromone dispensers, respectively.
Field cage performance of two tachinid parasitoids of the tomato fruitworm on insect resistant and susceptible tomato lines
Authors: Farrar R. R. , Kennedy G.
Published: April 2011

Rates of parasitism of Helicoverpa (= Heliothis) zea (Boddie) (Lepidoptera: Noctuidae) by two tachinid parasitoid species differing in larviposition habits were measured in field cages on tomato plant lines with or without methyl‐ketone (2‐tridecanone and 2‐undecanone)‐mediated insect resistance. Hosts were placed on resistant or susceptible plants, exposed to parasitoids for 24–48 h, then held on artificial diet for parasitoid emergence. Rates of parasitism by Archytas marmoratus (Townsend) (Diptera: Tachinidae), which larviposits on its host's food plant, were significantly reduced on the resistant plants, relative to those on the susceptible plants. Parasitism by another Tachinid, Eucelatoria bryani Sabrosky, which larviposits directly into its host and does not directly contact the foliage of its hosts' food plant as a small larva, was not affected by the methyl‐ketone mediated resistance.
Adaptation of a Ceratitis capitata population Diptera, Tephritidae to an animal protein‐based diet
Authors: Zucoloto F. S.
Published: April 2011

A population of Ceratitis capitata (Wiedemann) (Diptera, Tephritidae) reared in the laboratory on a diet based on brewer's yeast (BY) was studied in terms of adaptation to another diet based on cow's meat flour (MF). After a population fed the MF diet was established, the two populations were compared in terms of nutritional values of the diets and sexual choice. The results indicate that there was adaptation of the population to the MF diet, probably by directional selection. Assortative mating between individuals of the two populations was also observed.

It is suggested that the capacity of this species to adapt to a diet based on animal protein may be maintained by the occasional practice of cannibalism during periods of competition for food.
Acid phosphatase activity in hemolymph of the migratory grasshopper, Melanoplus sanguinipes, during Beauveria bassiana infection
Authors: Vincent M. J. , Miranpuri G. S. , Khachatourians G. G.
Published: April 2011

The distribution and abundance of acid phosphatase (AP) in hemolymph (HL), plasma (PM) and hemocyte lysate supernatant (HLS) of the migratory grasshopper, Melanoplus sanguinipes infected with Beauveria bassiana (strain GK 2016) has been examined. AP activity was determined at intervals from 30 min to 60 h postinjection of 2 μl of 1 times 108conidia/ml per grasshopper. The enzyme was detected with the substrate β‐glycerophosphate in sodium acetate acetic acid buffer form hemocytes (HC) and with p‐nitrophenol phosphate sodium salt for HL, PM and HLS. In results of experiment 1 proportion of HC showing AP activity increased 1–2 h, then returned to normal after 4 h. However, in B. bassiana‐injected grasshoppers, a second increase was noted 24 h later which was not seen in the Tween‐80‐injected insects. Uninjected controls showed no change with time in the proportion of HC with AP activity.

Studies were also made of the distribution of AP activity in the HL, PM, and HLS. AP activity in HL appeared to vary with the sex of the grasshoppers. Females showed increase in AP activity in HL 18–24 h after injection with B. bassiana, whereas males only showed an increase 1 h after injection. Assay of HLS showed that the level of AP activity did not change significantly throughout the experiment. Changes in AP activity in PM, in both B. bassiana – and Tween‐80‐injected insects (both sexes) paralleled those of the HL, indicating that the enzyme is released from the HC. The observations are discussed in terms of the possible role of AP in the immune response of M. sanguinipes.
Influence of microbe‐associated parthenogenesis on the fecundity of Trichogramma deion and T. pretiosum
Authors: Stouthamer R. , Luck R. F.
Published: April 2011

Microbe‐associated parthenogenesis (thelytoky) has been discovered in nine Trichogramma species, parasitoids of mainly lepidopteran eggs. Parthenogenetic and bisexual conspecifics co‐occur in many field populations. As an initial step to understand the dynamics of these two reproductive strategies we studied the effect of microbe‐associated parthenogenesis on fecundity. The fecundity of two parthenogenetic isofemale lines of T. pretiosum and one of T. deion was compared with bisexual lines derived from them by antibiotic treatment. In all three cases parthenogenetic females were less fecund over their lifetime than bisexual females. Also, parthenogenetic females produced fewer daughters in two cases and in one case a similar number of daughters as their respective bisexual counterparts. The lack of mating and insemination was excluded as an explanation for the reduced fecundity of parthenogenetic females, because mated and virgin parthenogenetic females produce the same number of offspring. Antibiotic treatment can also be excluded because females of field‐collected bisexual line treated with antibiotics produced the same number of offspring as untreated females. The reduced fecundity of parthenogenetic females was caused by a lower number of eggs being laid rather than by a greater developmental mortality. Parthenogenetic females produced less daughters than bisexual females when host availability was not limiting, but when host availability was severely limited, parthenogenetic females produced more daughters than the bisexual females.
Existence d'une phéromone sexuelle chez Caryedon serratus: attractivité des femelles et réactivité des mâles
Authors: Chaíbou M. , Pierre D. , Biémont J. C. , Pouzat J.
Published: April 2011

Les femelles de Caryedon serratus (Ol.) produisent, pendant la scotophase, une phéromone sexuelle volatile qui déclenche chez les mâles une chémoanémotaxie positive. Les effets de l'âge sur l'attractivité des femelles et sur la réactivité des mâles ont été étudiés. Plus de soixante‐dix pour cent des mâles commencent à réagir à la phéromone sexuelle dès les premières 24 heures qui suivent leur émergence. Une seule femelle sur 31 a été attractive à cet âge. A 48 heures, le pourcentage des femelles attractives est de 38,7%. Il existe une variabilité inter et intra femelles dans la production de phéromone sexuelle (début, régularité).

L'existence des récepteurs antennaires à la phéromone sexuelle chez le mâle est montrée par des études électrophysiologiques (EAG). La variabilité de la production de phéromone sexuelle est discutée.

Existence of sex pheromone in Caryedon serratus (OL): female attractiveness and male reactivity

The female of Caryedon serratus release, from the beginning of scotophase, a sex pheromone witch triggers a positive chemoanemotaxy in males. The effects of age on female attractiveness and on male reactivity are studied. About 70.37% of males begin to react to the sex pheromone within the first 24 h after emergence. At this age, only one female out of 31 is attractive. At 48 h, the percentage of attractive females is 38.7%. There is inter and intra‐female variation in sex pheromone production (beginning, regularity). The existence of receptors on male antennae for this pheromone is shown by electrophysiology (EAG). The variability in sex pheromone production is discussed.
Behavioural responses of three stored product Coleoptera species to extract of carob (Locust bean), Ceratonia siliqua
Authors: Obeng‐Ofori D.
Published: April 2011

The behavioural responses of Cryptolestes pusillus, Oryzaephilus surinamensis and Prostephanus truncatus to different doses of carob extract were assessed in a two‐choice pitfall bioassay and in plastic grain probe traps. The extract evoked a quick directional response and induced high beetle attraction to treated pitfall arenas compared with the controls. Overall, the extract improved probe trap efficiency by about 50% compared to unbaited probes. Beetle response was dose‐dependent with the medium dose of 10 μl probably eliciting optimum response.
Performance of nymphal and adult southern green stink bug on an overwintering host plant and impact of nymph to adult food‐switch
Authors: Panizzi Antônio R. , Saraiva Sílvia I.
Published: April 2011

Performance of nymphs and adults of the southern green stink bug, Nezara viridula (L.) (Heteroptera: Pentatomidae) feeding on immature fruits of radish, Raphanus raphanistrum L. (Brassicaceae) was poor compared with feeding on immature soybean [Glycine max (L.) Merrill] pods, but a change from radish to soybean from nymph to adult alleviated some of the detrimental effects of this food on adult performance. Over 50% of nymphs died on radish, while only 15% died on soybean. To complete nymph development (stadia 2 through 5), male and female nymphs required 9.5 and 13.3 days longer on radish compared to soybean. Fresh body weight of 1‐d‐old adult females and males was ⋍65% greater for those reared as nymphs on soybean than on radish, with females being significantly heavier than males on both foods. Survivorship and longevity of females, however, was greater for those fed on radish as nymphs and as adults, as compared to those that fed on soybean or radish followed by soybean. Males lived longer when fed exclusively on soybean. In general, reproductive performance and percentage gain in adult body weight was greatest for insects fed on soybean only, and were better for those whose food was switched from nymph to adult, as compared to those insects fed on radish solely.
Realized heritability of resistance to dicrotophos in greenhouse whitefly
Authors: Omer Amir D. , Tabashnik Bruce E. , Johnson Marshall W. , Leigh Thomas F.
Published: April 2011

Realized heritability (h2) of resistance to dicrotophos in greenhouse whitefly, Trialeurodes vaporariorum Westwood, was estimated from a laboratory selection experiment. Five generations of selection increased the LC50 approximately 13‐fold. Estimated h2 of resistance to dicrotophos was 0.40 when calculated with the method of Tabashnik (1992) and 0.35 with the method of Tanaka & Noppun (1989). These results suggest that 35 to 40% of the total phenotypic variation in resistance was caused by additive genetic variation. For thirteen previously reported estimates of h2 of insecticide resistance in other insect pests, the mean was 0.29. The relatively high h2 of dicrotophos resistance for T. vaporariorum is consistent with rapid resistance development in field populations.
Cold‐tolerance of the oriental cockroach Blatta orientalis
Authors: le Patourel G. N. J.
Published: April 2011

The cold‐hardiness of nymphal stages 1 to 5 and adult male and female Blatta orientalis was tested at 2°, −5° and −10 °C. The LT50 (time) of insects exposed to −5° ranged from 0.21 to 0.43 days. Acclimation at 10 °C for times varying up to 14 days progressively increased cold‐hardiness. A 14 day acclimation at 10° prior to exposure at −5°C increased LT50 (time) to 1.1–4.2 days for the various stages; prolonging the acclimation time to 28 days produced no further increase in LT50. All stages were rapidly killed at −10 °C (LT50<0.04 days) and survived prolonged exposures at 2 °C (LT50s from 16 to > 42 days) following acclimation. The potential for survival of outdoor populations of B. orientalis over winter is discussed.
Sex pheromone traps for monitoring the codling moth: effect of dispenser type, field aging of dispenser, pheromone dose and type of trap on male captures
Authors: Kehat M. , Anshelevich L. , Dunkelblum E. , Fraishtat P. , Greenberg S.
Published: April 2011

The effects of dispenser type, dispenser aging in the field, pheromone dose in the dispenser and trap type on trapping efficiency of codling moth, Cydia pomonella (L.), males were investigated in Israel. An Israeli‐manufactured rubber septum was significantly better than the CM Pherocon cap in attracting males to a Pherocon 1C cap trap or an IPS trap. The effect of aging of the dispenser in the field on trapping efficiency was significant in CM Pherocon caps and the Israeli septa. Captures in traps were negatively correlated with aging of septa. The effect of aging of dispensers was more marked during summer than during spring. The fairly rapid loss of attractancy indicates that the lures should be replaced after 2 weeks at the most. The release rate of the pheromone from the dispensers was measured in a flow system. The emission from the Israeli septa and Pherocon caps decreased sharply after 2 weeks and then was almost constant, which explains the lower attractancy of aged septa. However, there was a marked difference in the release profiles of the pheromone from the two types of dispensers, which may explain the different performance of the two dispensers. Within the range of 0.1 to 100 μg pheromone per dispenser, male response increased positively with the pheromone dose. Pheromone loadings of 100 or 1000 μg per dispenser did not differ significantly in their attractiveness for males. A load of 5000 μg per dispenser was significantly less attractive to males than was 100 or 1000 μg per dispenser. The non‐sticky IPS trap was significantly better in capturing codling moth males than was the sticky, commonly used Pherocon 1C trap, provided it was baited with the Israeli dispenser. The two traps were equally effective when baited with the CM Pherocon caps. The possibility of using the non‐sticky, nonsaturating and easy‐to‐handle IPS traps for monitoring codling moth is of great importance.
Locating a resistance mechanism to the cabbage aphid in two wild Brassicas
Authors: Cole R. A.
Published: April 2011

Feeding behaviour of the cabbage aphid, Brevicoryne brassicae, was monitored electronically on two resistant Brassica species, B. fruticulosa and B. spinescens, and compared with a susceptible control B. oleracea var. capitata cv. Offenham Compacta. Aphids, monitored for 10 h on the under side of leaves, performed recognizable feeding behaviour on all species. Electrical Penetration Graphs (EPGs) of aphids on resistant and susceptible plants showed no difference in behaviour for aphids on resistant Brassica species compared to susceptible until stylets penetrated the phloem sieve elements when a large reduction in the duration of passive phloem uptake (E2 pattern) on B. fruticulosa was indicated. Although feeding behaviour on 6 week‐old plants of B. spinescens was similar to the susceptible controls, behaviour on 10 week‐old plants was similar to that recorded for B. fruticulosa. The mechanism of resistance is thought to be located in the sieve element as the normal sieve element salivation (E1 signal was either quickly terminated by withdrawal of the stylets from the sieve element or continued as a disrupted E2 pattern. Analysis of secondary plant compounds in the three Brassica species only identified significant differences in the glucosinolate profile. No reproducible differences were detected in the concentration of phenolics or anthocyanins. The major glucosinolate component of B. fruticulosa and B. spinescens was gluconapin rather than glucobrassicin and glucoiberin as found in the susceptible host plant. However, both pure glucosinolates and glucosinolate extracts from all three species did not reduce aphid survival on chemically‐defined artificial diets. These results suggest that the mechanism of resistance may be a mechanical blocking of the sieve element or stylets rather than a difference in the secondary plant chemistry of glucosinolates and phenolics.
The effects of azadirachtin‐treated diets on the feeding behaviour and fecundity of the peach‐potato aphid, Myzus persicae
Authors: Nisbet A.J. , Woodford J.A.T. , Strang R.H.C.
Published: April 2011

Adult apterous Myzus persicae, which had fed for 26 h on diet containing azadirachtin at concentrations of 25–100 ppm, produced nymphs at less than half the rate of aphids on control diets. After 50 h on azadirachtin‐treated diets nymph production had virtually ceased. After this period, any nymphs produced by adults that had fed on azadirachtin‐treated diets were born dead with undeveloped appendages. Honeydew production on azadirachtin‐treated diets was unaffected during the first 26 h period but was approximately three times less than on control diets during the subsequent 24 h period.
Larvicidal activity of lectins on Lucilia cuprina: mechanism of action
Authors: Eisemann C. H. , Donaldson R. A. , Pearson R. D. , Cadogan L. C. , Vuocolo T. , Tellam R. L.
Published: April 2011

Larvae of the blowfly Lucilia cuprina (Wied.) (Diptera: Calliphoridae) were grown in vitro on a serum‐free medium in the presence of a number of lectins. Lectins with specificities for β‐(1,4)‐N‐acetylglucosamine (wheat germ lectin) and α‐D‐mannopyranosyl and (α‐D‐glucopyranosyl residues (lentil lectin and Con A) caused strong concentration‐dependent inhibition of the growth of the larvae and substantial mortality. Wheat germ lectin had the strongest effects, showing 50% inhibition of larval growth at a concentration of 2 μM and 100% mortality at 25 μM. Other lectins with different sugar specificities had much less effect. The mechanism of the larvicidal action(s) of wheat germ lectin, lentil lectin and Con A was investigated. There were at least three effects of these lectins on L. cuprina larvae. First, these lectins bound to and reduced the permeability of the peritrophic membrane of the larvae. Second, they reduced ingestion of diet medium by larvae. Third, the lectins also bound to the apical membranes of larval gut epithelial cells although there were no obvious signs of damage to these cells. It is concluded that the combination of these effects probably results in the starvation of the larvae. The implications of these results in terms of possible control strategies for L. cuprina are discussed.
Interactive effects of rutin and constant versus alternating temperatures on performance of Manduca sexta caterpillars
Authors: Stamp N. E.
Published: April 2011

The effects of different concentrations of rutin and constant temperature (20 °C) versus alternating temperatures (23:15 °C) on growth, molting and food utilization efficiencies of third instar tobacco hornworms (Manduca sexta) were determined. Relative consumption rate (RCR) and relative growth rate (RGR) were significantly higher for larvae at the alternating thermal regime compared to those at the constant (representing the average) temperature. With increasing concentrations of rutin, the negative effect of rutin on RCR and RGR increased for the larvae in the alternating thermal regime; however, at the constant temperature, rutin had little effect. The alternating thermal regime promoted synchrony in the timing of spiracle apolysis (the earliest morphological marker of molt). Rutin disrupted that synchrony. I discuss how patterns of host plant resistance may be altered with a decrease in amplitude of diurnal temperatures (as has been documented recently for temperate regions) through the uncoupling of herbivore performance and allelochemical concentration. I conclude that simultaneous consideration of fluctuating temperatures and allelochemicals is advisable when assessing the effects of temperature and allelochemicals on performance of insect herbivores because interactive effects between temperature and dietary components occur and perhaps are common.
Temperature dependent functional response of Encarsia formosa parasitizing the Poinsettia‐strain of the cotton whitefly, Bemisia tabaci, on Poinsettia
Authors: Enkegaard Annie
Published: April 2011

The control efficiency and performance of Encarsia formosa Gahan (Hymenoptera: Aphelinidae) as influenced by the density of its host, the Poinsettia‐strain of Bemisia tabaci Gennadius (Homoptera: Aleyrodidae), were investigated by laboratory experiments on Poinsettia (Euphorbia pulcherrrima Willd.). E. formosa showed a Type II functional response to fourth instar larvae of B. tabaci, the response plateau increasing with temperature. A response model for randomly searching parasitoids incorporating temperature‐dependent handling time and temperature‐independent search rate was in accordance with the results, and gave an estimated search rate of 0.033 leaf·hour−1 and handling times of 1.54, 2.86 and 20.1 h at 28 °C, 22 °C and 16 °C, respectively. From the latter, the maximum number of hosts that can be parasitized at the three temperatures are 10.4, 5.6 and 0.8 larvae per day (provided the light period is 16 h). The number of hosts with ovipositor punctures was higher than the number of parasitized hosts, especially at 22 °C and 28°C, implying that E. formosa refrains from laying eggs in some of the hosts examined with the ovipositor. About 31% of the punctured larvae did not contain any eggs. Superparasitism occured during the experiment presumably originating from young, inexperienced parasitoids. Individual larvae were occasionally punctured several times, also by non‐superparasitizing E. formosa. The resulting distribution of ovipositior holes was random, indicating that E. formosa on the basis of antennal testing is unable to determine if a larva has previously been examined with the ovipositor. Almost fifty percent of the punctures were not followed by egg‐depositions. Besides parasitization E. formosa used hosts as food source. The number of hostfed larvae was independent of density, but varied with temperature being highest at 28 °C (0.12 hostfed larvae per parasitoid per day).
Diel activity pattern of a nocturnal moth, Zeiraphera canadensis, in nature
Authors: Quiring Dan T.
Published: April 2011

The spruce bud moth, Zeiraphera canadensis Mutt & Free. (Lepidoptera: Tortricidae), displayed a bimodal activity pattern in two young white spruce, Picea glauca (Moench) Voss, plantations. During the day, when temperatures were highest and relative humidities lowest, most moths remained in the lower crown, presumably in response to the risk of hygrothermal stress and/or predation. Flight activity peaks occurred near dawn and dusk. Moths moved higher in the crowns shortly after sunset and many were observed flying above the tree canopy. This activity peak was associated with oviposition and mating. Oviposition started at sunset and continued for approximately 3 h. Females probed oviposition sites with their ovipositor before ovipositing, suggesting that they use sensillae on the ovipositor to evaluate potential oviposition sites. Most mating occurred between 22:00 and 04:00 h. Males hovered adjacent to branches containing females before alighting. After alighting, males usually approached to within 2–5 cm of females and then remained motionless for a short time before attempting mounting, indicating that some short‐range communication usually occurs prior to mating. Reduced flight activity between midnight and dawn was not due to low temperatures, which were above the minimal temperatures for flight for males (10 °C) and females (12 °C) determined in the laboratory.
Toxicity of diflubenzuron and pyriproxyfen to the predatory bug Podisus maculiventris
Authors: De Clercq P. , De Cock A. , Tirry L. , Viñuela E. , Degheele D.
Published: April 2011

The susceptibility of the predatory pentatomid Podisus maculiventris (Say) to the insect growth regulators (IGRs) diflubenzuron and pyriproxyfen was investigated in the laboratory. Fifth‐instar nymphs were exposed to formulated materials of each compound via direct contact, residual contact and ingestion. Diflubenzuron was harmless to P. maculiventris by direct and residual contact, but was highly toxic when ingested via drinking water. Pyriproxyfen caused severe deformities at ecdysis whatever the method of exposure. Exposure of fifth instars to sublethal concentrations (around LC10) of both compounds had no adverse effects on reproduction of emerging adults. The data suggest that the use of these IGRs in the integrated management of insect pests should be evaluated with caution.
Influence of leaf epicuticular waxes from cerrado species on substrate selection by Atta sexdens rubropilosa
Authors: Sugayama R. L. , Salatino A.
Published: April 2011

The influence of leaf epicuticular waxes of nine woody species from cerrado (a savanna ecosystem of Brazil) on the foraging behavior of the leaf‐cutting ant Atta sexdens rubropilosa Forel, 1908 (Formicidae, Attini) was investigated. Some waxes showed neither inhibitory nor attractive effect over a series of tests, while a second group caused a delayed rejection. Waxes of two species were shown to be strongly deterrent to the ants. Since different waxes caused different responses, it is concluded that their chemical composition, rather than hydrophobicity or mechanical constraints, accounts for the observed effects. Plant species with leaves rejected by the ants did not necessarily have repellent waxes. On the other hand, no species with acceptable leaves yielded waxes with deterrent effects.
Development of mating disruption for control of pine sawfly populations
Authors: Anderbrant Olle , Löfqvist Jan , Högberg Hans‐Erik , Hedenström Erik
Published: April 2011

Mating disruption of the pine sawfly Neodiprion sertifer (Geoffroy) (Hymenoptera: Diprionidae) was strongly indicated by reduced male trap catches in pine plantations permeated with the sex pheromone, (2S, 3S, 7S)‐diprionyl acetate. The trap catch reduction was 95 to near 100% when dispensers every 10 m were used, giving a total release of about 3 mg per hectare and day. Two mg of pheromone per cotton roll dispenser maintained low catches for the whole season (about 2 months) without any renewal of disruption dispensers. An erythro‐mixture was as effective as the pure pheromone isomer. The effects of the experiments on population density and sex ratio were not possible to investigate, due to a general collapse of the population, also outside experimental plots, the year after the experiments.
Antifeedant effects of plant lectins and an enzyme on the adult stage of the rice brown planthopper, Nilaparvata lugens
Authors: Powell K.S. , Gatehouse A.M.R. , Hilder V.A. , Gatehouse J.A.
Published: April 2011

The feeding activity of adult rice brown planthopper, Nilaparvata lugens (Stal) on selected proteins incorporated into artificial diets was examined, based on quantitative analysis of honeydew excretion, in order to determine the mechanism of action of antimetabolic proteins towards homopteran pests. The lectins Galanthus nivalis agglutinin (GNA), wheat germ agglutinin (WGA) and the enzyme soybean lipoxygenase (LPO), previously demonstrated to be toxic to this insect, reduced honeydew excretion levels of adult Nilaparvata lugens over a 24 h period when incorporated into artificial diet at 0.1% {w:v}, indicating that these proteins acted as antifeedants. Of the proteins tested GNA was the most effective antifeedant, reducing honeydew droplet production by 96%, although after 24 h there was some recovery in the honeydew excretion levels and thus the insects appeared to tolerate the presence of the antifeedant with time. The lectin Pisum sativum agglutinin (PSA), previously demonstrated to be non‐toxic, showed no antifeedant properties.
Different antimetabolic effects of related lectins towards nymphal stages of Nilaparvata lugens
Authors: Powell K. S. , Gatehouse A. M. R. , Hilder V. A. , Van Damme E. J. M. , Peumans W. J. , Boonjawat J. , Horsham K. , Gatehouse J. A.
Published: April 2011

Insect feeding trials were carried out to determine the effects of a range of mannose‐specific lectins on third instar nymphs of the rice brown planthopper (BPH), Nilaparvata lugens. Stål. Dose response curves show that Galanthus nivalis agglutinin (GNA) has the strongest toxic effect of the lectins tested, and is effective at concentrations considerably lower than those previously reported. Narcissus pseudonarcissus agglutinin (NPA) and Allium sativum agglutinin (ASA) exhibit a significant antimetabolic effect towards the insect but were less effective (on a molar basis) than GNA. LC50 values for GNA, NPA and ASA are approximately 4 μM, 11 μM and >40 μM respectively. These mannose‐specific lectins are serologically identical, but differ in the number of subunits per protein molecule; ASA is a dimer, NPA is a trimer and GNA is a tetramer. The results obtained support the hypothesis, that the effectiveness of the mannose‐binding lectins as antimetabolites is determined by the number of subunits per molecule. Two N‐acetylglucosamine binding lectins, the dimeric Oryza sativa agglutinin (OSA) and the monomeric Urtica dioica agglutinin (UDA), were also tested but at a concentration of 0.1% w/v exhibited no significant antimetabolic effect towards BPH, although the related lectin wheatgerm agglutinin (WGA) has previously been demonstrated to be toxic towards the insect.