bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of an optimum sampling plan for the population of Aphis gossypii (Hom., Aphididae) on cotton in Greece
Authors: Kapatos E. T. , Stratopoulou E. T. , Sahinoglou A. , Tsitsipis J. A. , Lycouresis D. P.
Published: August 2009

Abstract: A sampling plan was developed for the study of the population dynamics of Aphis gossypii, Glover on cotton. The distribution of the population of A. gossypii within the plant is not randomly distributed in relation to height. At the beginning (end of May‐June) and at the end (October) of the season, the upper part of the plant is more heavily infested than the lower but this relationship changes in mid‐summer (July‐August). Therefore, the samples for estimating mean population density should be taken proportionally in respect to the height of the plant. The optimum size of the sampling unit was found to be 10 leaves but at the beginning of the season, when the number of leaves per plant is low, a smaller sampling unit could be adopted or even the whole plant can be considered as the sampling unit. The number of samples required to attain a certain precision (i.e. a 10% standard error of the mean) was found to be a strong function of density, fewer samples are required at the higher densities. This is the result of the relationship between the mean and the variance of the population density as it is expressed by the value of the coefficient b in the expression of Taylor's power law. At the low densities, the adoption of the above level of precision leads to a very high number of samples and, therefore, a lower level of precision should be accepted.
Intensity of forest management and bark beetles in non‐epidemic conditions: a comparison between Finnish and Russian Karelia
Authors: Martikainen P. , Siitonen J. , Kaila L. , Punttila P.
Published: August 2009

Abstract: The population levels of bark beetles in non‐epidemic conditions were compared between intensively managed forests in Finnish Karelia and extensively managed forests in Russian Karelia. Thirty randomly chosen sample plots with five window flight traps in each were established in both countries. The numbers of species and individuals of bark beetles did not differ between the countries. This indicates that extensive forest management has not increased the general level of bark beetle populations. Species assemblages were, however, different between the countries and between the forest site types. Hylastes brunneus and Pityogenes bidentatus, which are common in stumps or in logging residue of Scots pine, were more abundant in Finland. Crypturgus subcribrosus, Polygraphus punctifrons, and Hylurgops glabratus, which prefer dead spruce trees in shady conditions, and Trypodendron signatum, which live in dead deciduous trees, were more common in Russia. Bark beetles were most abundant in old mesic forests. The amount of decaying wood on the ground did not correlate with the numbers of bark beetles caught.
Functional response of Encarsia formosa (Gahan) parasitizing castor whitefly, Trialeurodes ricini Misra (Hom., Aleyrodidae)
Authors: Shishehbor P. , Brennan P. A.
Published: August 2009

Abstract: Laboratory experiments were conducted to measure the functional response of Encarsia formosa parasitizing castor whitefly, Trialeurodes ricini. Parasitoids were isolated singly for 24 h in 10 cm Petri dishes with either 4, 8, 16, 32, 64 or 128 prepupal stages of T. ricini. Results showed a typical Type II response, with up to 12 prey attacked when 128 were provided. The rate of attack and handling time were 1.43 and 0.077 (days), respectively. Theoretically, one T. ricini prepupa could be parasitized by E. formosa every 111–115 minutes (0.077–0.080 days), and an adult E. formosa could parasitize a maximum of 13 castor whitefly prepupae per day.
Different parasitism patterns of two hymenopterous parasitoids (Ichineumonidae and Ibaliidae) depending on the development of Sirex nitobei (Hym., Siricidae)
Authors: Fukuda H. , Hijii N.
Published: August 2009

Abstract: For the two parasitoid wasps, Ibalia leucospoides and Megarhyssa praecellens emerging together with their host woodwasp, Sirex nitobei, from trees of Pinus densiflora, the seasonal trends in number of emerging adults, their body size characteristics and fecundities were recorded to evaluate the life histories and parasitism patterns.

The mean female body mass of M. praecellens was about 1.8 times (fall population) or about 4.1 times (spring population) larger than that of I. leucospoides. The difference in body size was remarkable also between sexes in both species. The spring population of M. praecellens was about 3.7 times (male) or 2.3 times (female) larger in mean body weight than the fall population. The mean egg length of M. praecellens was about 10 times larger than that of I. leucocpoides, whereas I. leucospoides produced about 50 times greater numbers of eggs than M. praecellens. The percentage of parasitism on S. nitobei by both parasitoids was considerably large, accounting for more than 60%. Our results suggested that two parasitoid species could utilize larvae of S. nitobei in wood as their hosts at different development stages of woodwasp in different manners: egg and/or 1st instar larvae parasitized by I. leucospoides and maturated larvae by M. praecellens.
Influence of parasitism by Glyptapanteles liparidis (Hym., Braconidae) on the haemolymph carbohydrate and glycogen content of its host larva, Lymantria dispar (Lep., Lymantriidae)
Authors: Schopf A. , Nussbaumer C.
Published: August 2009

Abstract: Parasitism of the gregarious endoparasitic braconid, Glyptapanteles liparidis, reduced markedly the hae‐molymph trehalose level of its host larva, Lymantria dispar, when the parasitoid larvae had reached their final endo‐phageous second instar. The extent of the trehalose decrease was dependent on the time of parasitization and therefore on the host stage in which the second instar parasitoids developed. The haemolymph glucose content amounted to 5–10% of the trehalose level during the feeding period of unparasitized larvae and only rose before moulting. The level was significantly reduced in hosts at the end of the endophageous development of the parasitoid larvae as well as in hosts which contained parasitoid larvae moulting from the first to the second instar. Only in newly moulted third instar hosts parasitized during premoult to the second instar a markedly lower glycogen content was found than in unparasitized gypsy moth larvae. On the other hand, the mean glycogen level of final fifth midinstar hosts was significantly elevated compared to unparasitized larvae, when they were parasitized one stage later, during the premoult period to the third instar. The number of parasitoids per host, however, did not significantly influence the host's carbohydrate level.
The predation of Chrysoperla carnea (Neurop., Chrysopidae) on eggs and larvae of Mamestra brassicae (Lep., Noctuidae)
Authors: Klingen I. , Johansen N. S. , Hofsvang T.
Published: August 2009

Abstract: In the present study the predation rate of Chrysoperla carnea (Stephens) on eggs and larvae of the lepidopterous species Mamestra brassicae (L.) was investigated including the prey's influence on survival and development. The experiments were done at 20 ± 1°C and L:D = 16:8. C. carnea larvae were fed on eggs and first instar larvae of M. brassicae, respectively. In both cases the daily predation rate of C. carnea increased slowly during the two first instars and reached a peak in the third larval instar. During the third instar 87% and 85% of the total numbers of M. brassicae eggs and larvae, respectively, were consumed. C. carnea preyed on a mean total of 312 M. brassicae eggs and 232 M. brassicae larvae during its larval development. The mean daily predation rate of C. carnea reached a maximum of 106.6 eggs of M. brassicae and 46.1 larvae of M. brassicae. C. carnea consumed a total of 32 mg of M. brassicae eggs and 70 mg of M. brassicae larvae during its larval development. The developmental time of C. carnea fed on M. brassicae eggs and larvae was 27.4 and 21.5 days, respectively. Almost 10% of C. carnea died when reared on M. brassicae eggs and 15% died when reared on M. brassicae larvae. The quality aspect of the prey is discussed.
Theoretical approaches to forensic entomology: I. Mathematical model of postfeeding larval dispersal
Authors: von Zuben C. J. , Bassanezi R. C. , dos Reis S. F. , Godoy W. A. C. , von Zuben F. J.
Published: August 2009

Abstract: An overall theoretical approach to model phenomena of interest for forensic entomology is advanced. Efforts are concentrated in identifying biological attributes at the individual, population and community of the arthropod fauna associated with decomposing human corpses and then incorporating these attributes into mathematical models. In particular in this paper a diffusion model of dispersal of postfeeding larvae is described for blowflies, which are the most common insects associated with corpses.
Feeding deterrence of verbenone to the pine weevil, Hylobius abietis (L.) (Col., Curculionidae)
Authors: Lindgren B. S. , Nordlander G. , Birgersson G.
Published: August 2009

Abstract: Exposure to verbenone vapours did not cause any acute toxicity symptoms in the pine weevil, Hylobius abietis, whereas weevils exposed to higher doses of both limonene and α‐pinene exhibited signs of poisoning within a few h. Verbenone consistently suppressed feeding, while symptom‐free weevils exposed to limonene or α‐pinene fed as much as controls. Feeding in verbenone‐exposed weevils remained suppressed 20 h after the insects had been transferred from the exposure vials, whereas weevils exposed to limonene and α‐pinene resumed normal feeding soon after transfer. Feeding deterrence by verbenone was lost after 48 h, and starved weevils were less deterred than fed weevils. Feeding was also reduced by weevils offered food contaminated by verbenone, indicating that acute toxicity effects were not responsible for the reduced feeding observed in weevils exposed to verbenone vapors. Feeding deterrence by verbenone is hypothesized to be due to its association with microbial breakdown of host tissues, indicating sub‐optimal food quality.
Larval dispersal in Chrysomya megacephala, Chrysomya putoria and Cochliomyia macellaria (Dipt., Calliphoridae): Ecological implications of aggregation behaviour
Authors: Godoy W. A. C. , von Zuben C. J. , dos Reis S. F.
Published: August 2009

Abstract: In this study we investigate aggregated patterns as a consequence of post‐feeding larval dispersal in three blowfly species, based on the frequency distribution of sampling units in the substrate having 0, 1, 2,…,n pupae. Statistical analysis revealed that aggregated patterns of distribution emerge as a consequence of larval dispersal, and Cochliomyia macellaria has higher levels of aggregation when compared to Chrysomya megacephala and C. putoria. Aggregation during dispersal is associated with a spatial pattern where most larvae in the species tend to pupariate near the food source. The possible consequences for the population ecology of these species are discussed.
Compounds repellent to Delia radicum (L.) (Dipt., Anthomyiidae)
Authors: den Ouden H. , Bulsink A. , Theunissen J.
Published: August 2009

Abstract: By means of two non‐preference test methods a number of pre‐selected repellents of Delia radicum has been examined. Dosage increase efficiency of repulsion to larvae and adults has been determined for five and three compounds, respectively. Salicylaldehyde and toluquinone appeared to be promising new repellents. Data from literature about repellents involved are mentioned.
Morphometric analyses of the males of Quadraspidiotus species (Hom., Diaspididae) found in European orchards or their vicinity
Authors: Kozár F. , Hippe C. , Mani E.
Published: August 2009

Abstract: Morphological characteristics (antenna, scutellum) of the males of Quadraspidiotus gigas, Q. marani, Q. ostreaeformis, Q. perniciosus, Q. pyri and Q. zonatus were studied and analysed. The length of the scutellum and the width of the third antennal segment proved to be the most distinct characters for the differentiation of certain species. They allow to identify individual males of Q. gigas and Q. pyri. When large samples of males are studied, the average and the frequency distribution of the data are typical and different for most of the species.
Bionomics of the four‐eyed spruce bark beetle, Polygraphus rufipennis (Kirby) (Col., Scolytidae) in Newfoundland II. Host colonization sequence
Authors: Bowers W. W. , Borden J. H. , Raske A. G.
Published: August 2009

Abstract: The four‐eyed spruce bark beetle, P. rufipennis, is a phloeophagous bark beetle restricted to Abietineae hosts in northern and mountainous area of North America. Projected wood shortages in Newfoundland have focused attention on the bark beetle and its role in contributing to black spruce mortality. Our findings disclosed that colonization on felled and standing trees by P. rufipennis followed the typical host selection sequence of scolytids, notably, emergence, dispersal, selection and establishment. All brood stages except eggs overwintered in black spruce, however, the majority of overwintering stadia consisted of larvae and callow adults. Adult mortality was significant during winter, especially in standing severed and felled trees. In Newfoundland, P. rufipennis had 1 generation and produced a spring and summer brood. Four weeks after establishing a first brood, parent adults re‐emerged to establish a second brood. Development from egg to adult took ≅2 months. P. rufipennis of either sex initiated attack at mean densities per 100 cm2 of 8.1 and 9.3 on felled and standing‐severed trees, respectively. Densities were significantly lower at 4.7 per 100 cm2 on standing unsevered trees. Following copulation, males stayed with the females and exhibit guarding behaviour by occupying the entrance hole. Significantly higher numbers of galleries were established on trees felled in shade than in full sunlight. Black spruce attacked by P. ruipennis were often secondarily attacked by Dryocoetes affaber and Crypturgus borealis. Other associates included Medetera sp. and the cylindrical bark beetle, L. intricatus.
Identification of female‐produced sex pheromones and their geographical differences in pheromone gland extract composition from click beetles (Col., Elateridae)
Authors: Yatsynin V. G. , Rubanova E. V. , Okhrimenko N. V.
Published: August 2009

Abstract: Female sex pheromone of click beetles represent multicomponent systems. From 1980 to 1993 pheromones of Agriotes, Sinaptus and Melanotus genera were examined. The esters of geraniol, 8‐hydroxygeraniol, 8‐hydroxynerol (E,E)‐farnesol and all‐trans geranylgeraniol were identified as the components of the sex pheromones. In the pheromone glands some species of click beetles contain up to 24 substances. This study confirms the existence of pheromone dialects in Agriotes sputator L. and Agriotes obscurus L. populations.
Female calling behaviour and response of males to synthetic pheromone and virgin females in spring and summer generations of Hyphantria cunea (Lep., Arctiidae) (Drury) in Northeastern China
Authors: Zhang Q.‐H. , Schlyter F. , Chu D. , Ma X.‐Y. , Ninomiya Y.
Published: August 2009

Abstract: The Chinese population of Hyphantria cunea (Drury) was investigated regarding female calling, male flight, and male response to synthetic and natural pheromone. Special attention was given to the little studied spring generation. In the spring, (1st) generation females called in the beginning of the night, 19:30‐01:30, and the older females started calling earlier and calling lasted longer. During the summer, (2nd) generation females called in early morning, 03:45–04:50, with a 20 min peak just before sunrise. Pumping rate of the ovipositor ranged between 0.8–1.0 Hz and 1.1–1.2 Hz in spring and summer generation, respectively. Calling longevity of females was 4.7 ± 0.6 days (mean ± SEM) in spring and 3.6 ± 0.6 days in summer, respectively, and females 2–3 days old attracted most males. Synthetic baits (1,3Z,6Z‐9,10‐epoxyheneicosatriene: 3Z,6Z‐9,10‐epoxyheneicosadiene: 9Z,12Z,15Z‐octadecatrienal, at 1:1:8, total 5–6 mg/dispenser) had the same or higher catch than virgin females as baits. A bait with 2 mg loading was not competitive, while a 5 mg bait had good activity even when used during both generations. Change in dose of synthetics (1–3 ×) or number of females (1–6 ×) did not give a clear increase in response, while the coefficient of variation decreased with female number. Smaller sticky traps caught less than Uni‐traps (covered buckets with DDVp as killing agent), while a large cross‐barrier sticky trap caught equal to Uni‐trap but proved impractical. Height of trap placement was important in summer generation, when traps at 4 and 7 m caught 2 × and 4 × more than those at 2 m. The spring generation had a more uniform distribution of catch with height. Light intensity and air temperature affected male flight cativity, with temperature drop at dusk in 1st gen. and light increase at dawn in 2nd gen., repsectively, judged to be the most important for onset of male activity.
Some biochemical effects of plant extracts in the black cutworm, Agrotis ipsilon (Hufnagel) (Lep., Noctuidae)
Authors: El‐Ghar G. E. S. Abo , Khalil M. E. , Eid T. M.
Published: August 2009

Abstract: Changes in the nutrient content and in the activities of carbohydrate digestive enzymes in the haemolymph of 6th‐instar Agrotis ipsilon (Hufnagel) larvae were determined after feeding of larvae for 96 h on castor bean leaves treated with selected plant extracts, at a concentration of 5%. Feeding of larvae on the petroleum ether extracts from Ammi majus and Apium graveolens, and acetone or/and ethanol extracts from Melia azedarach and Vinca rosea [Cartharanthus roseus] resulted in a considerable reduction in the total nutrient content, i.e. proteins, lipids and carbohydrates, of larval haemolymph as compared to that found in the controls. However, slight changes in the nutrient content were found in case of larval feeding on leaves treated with water extracts from the selected plants. Moreover, the activities of haemolymph carbohydrate digestive enzymes, especially amylase and invertase, were significantly decreased as a result of larval feeding on the selected ethanol extracts from M. azedarach and V. rosea. On the other hand, a considerable increase in the activity of trehalase was found after larval feeding on most selected plant extracts. It seems that the obserserved disturbances of nutrient content and carbohydrate digestive enzyme activities might affect larval growth.
Insecticidal activity of Aglaia odorata extract and the active principle, rocaglamide, to the European corn borer, Ostrinia nubilalis Hübn. (Lep., Pyralidae)
Authors: Ewete F. , Nicol R. W. , Hengsawad V. , Sukumalanand P. , Satasook C. , Wiriyachitra P. , Isman M.B. , Kahn Y. , Duval F. , Philogène B.J.R. , Arnason J.T.
Published: August 2009

Abstract: A standardized twig extract of the Asian shrub, Aglaia odorata Lour. (Meliaceae), and rocaglamide, a purified active principle of the extract, were evaluated for potential to control the European corn borer (Ostrinia nubilalis Hübn.), via incorporation into meridic diet fed to larvae. Life cycle bioassays using the extract revealed that it inhibited larval growth at all concentrations tested (12.5–100 p.p.m./fresh wt.) and delayed mean time to pupation from 24.1 days (control) to 83.8 days (50 ppm). Other effects include reduced pupal and adult weights and an increase in the frequency of deformed pupae. Investigation of consumption rates and dietary utilization in larvae feeding on diet containing the extract suggested that it acts via a combination of antifeedant and postingestive (toxic) actions. Life cycle bioassays using rocaglamide demonstrated that this compound is an extremely potent inhibitor of larval growth, with concentration dependent activity observed at dietary concentrations from 0.05‐0.02 ppm. Effects at these levels include severe reductions in growth and pupal weight, and increases in larval mortality and time to pupation. Rocaglamide appears to be as, or even more active, than the very effective botanical pesticide azadrachtin from the neem tree.
Demecology of the false spider mite, Brevipalpus phoenicis (Geijskes) (Acari, Tenuipalpidae)
Authors: Kennedy J. S. , Van Impe G. , Hance Th. , Lebrun Ph.
Published: August 2009

Abstract:A life and fecundity table has been constructed forBrevipalpus phoenicis, a serious pest of plantation crops, and various demographic parameters have been calculated. Although this mite has been found to possess a low growth rate (rm= 0.127), it possesses high rates of survival even in its senescence. Under constant experimental conditions the net reproduction rate is 33.2 eggs/mite, the generation time is 27.6 days and the population doubles once in 5.5 days. The stable age profile of the population is distributed as 74.9%, 19.24% and 6.07% of eggs, immatures and adults, respectively. Another aspect considered in this paper is the evolution of the population in function of an effective initial population of 10 individuals. This mite takes a longer time to reach constant growth rate and stable age distribution (156 days), however, the population growth is astronomical. The damage caused by them passes beyond the economic injury level within 34 days by an effective initial population of 10 mites in a tea bush having 100 leaves. This suggests an earlier intervention to check the population. The demographic analysis reveals that the following five aspects of its life history, namely high survival and fertility rates, reproductive intensity in the prime youth, lack of diapause, parthenogenetic mode of reproduction and euryphagy on perennial crops, are of major importance. Reasons for the importance of these characteristics are also discussed.
Non‐target insects in unsprayed cereal edges and aphid dispersal to the adjacent crop
Authors: de Snoo G. R. , de Leeuw J.
Published: August 2009

Abstract:In 1992 and 1993 6 m wide edges of a winter wheat crop were not sprayed with herbicides and insecticides to investigate the impact on the abundance of insects inhabiting the upper parts of the crop and on farmland flowers. To this end, a total of 19 fields were sampled using sweep nets. It was demonstrated that the number of insect groups as well as the insect density increases in the unsprayed edges, by a factor of 1.4 and 3.5, respectively. At the level of the 21 insect groups studied, too, a significant increase in numbers was found for most groups. This held true for aphid predators (mainly Coccinellidae), flower visitors (mainly adult Syrphidae) and insects that form the staple diet of the bird speciesMotacilla flava flava.Although there was an increase in aphid abundance in most unsprayed edges, the aphids did not spread to the rest of the field, improving the compatibility of unsprayed edges with farm management.
Strip‐management in rape crop: is winter rape endangered by negative impacts of sown weed strips?
Authors: Hausammann A.
Published: August 2009

Abstract: With crop rotation as a fundamental element of the IPM and organic production, crop plants and their pests change beside permanent sown weed strips. Rape pests which are known to populate the fields from the edges might be augmented by sown weed strips. To evaluate whether weed strips have a negative impact on rape crop, insect pests and their antagonists were studied in a winter rape field near Berne, Switzerland, divided into two parts by a sown weed strip. They were registered at different distances from the weed strip and from the opposite field boundary in 1993. The pollen beetle Meligethes sp. and the cabbage weevils Ceutorhynchus assimilis Payk., C. napi Gyll. and C. pallidactylus Marsh and the brassica pod midge Dasineura brassicae Winn. were significantly more frequent near the field boundary than in the middle of the field and close to the sown weed strip. This could be because a sown weed strip does not act as a real field edge. For the investigated rape pods, little difference was observed as to the rate of infestation of C. assimilis. It was astonishing that only a few predators were caught by sweep netting in the whole field as well as close to the weed strip. A higher number of parasitoids near the sown weed strip could not be found either, which was probably due to their high mobility. The low rate of parasitization of the rape pests was only once assessed clearly higher near the weed strip than in the rest of the field. Therefore, flower visiting predators and parasitoids might not have been efficiently increased the weed strip. Generally, no negative impact of the weed strip on rape crop was found and therefore sown weed strips could be suitable areas in a farming with crop rotation to diversity an agroecosystem.
Life cycles of five eriophyid mites species (Eriophyoidea, Acari) developing on trees and shrubs
Authors: Vanêčková‐Skuhravá I.
Published: August 2009

Abstract: Life cycles of five eriophyid mite species developing in galls on the leaves of trees and shrubs were studied, viz. Eriophyes liosoma on Tilia cordata, Phytoptus tiliae and Aceria exilis on Tilia platyphyllos, Artacris macrorhynchus on Acer campestre and Epitrimerus trilobus on Sambucus nigra. Only one generation of eriophyid mites develop inside galls on the leaves of their host plants during one year in Middle Europe. In autumn eriophyid mites move from leaves into the leaf buds where they hibernate till spring of the following year. The morphology and anatomy of Eriophyes fraxinivorus is given.
Host‐associated strains within Ugandan populations of the whitefly Bemisia tabaci (Genn.),(Hom., Aleyrodidae)
Authors: Legg J. P.
Published: August 2009

Abstract: Studies were undertaken to investigate host relationships of populations of Bemisia tabaci taken from the major crop hosts in Uganda. B. tabaci adults taken from cotton and sweet potato did not colonize cassava. None survived for longer than two days and nymphs emerging from eggs laid on cassava died. Cassava B. tabaci in contrast showed limited colonization on cotton and sweet potato and adults emerging from cotton retained the ability to colonize cassava, confirming the genetic basis of the distinction between ‘strains’ suggested by previous isozyme studies. The implications of these findings with regard to the role of B. tabaci in the epidemiology of African cassava mosaic geminivirus are discussed.
Role of hydroxamic acids in the resistance of wheat to the Russian Wheat Aphid, Diuraphis noxia (Mordvilko) (Hom., Aphididae)
Authors: Givovich A. , Niemeyer H. M.
Published: August 2009

Abstract: Wheats and triticales resistant to Russian wheat aphid (RWA), Diuraphis noxia, contained medium to very high concentrations of hydroxamic acids. Feeding behaviour and performance of RWA in wheat seedlings differing in hydroxamic acid (Hx) levels, were determined by electrical penetration graphs, and mean relative growth rates, respectively. Higher Hx levels in the seedlings produced a delay in attaining a sustained phloem ingestion, and tended to produce lower mean relative growth rates. These facts support Hx as resistance factors in wheat towards RWA.
Effect of cowpea cultivar, plant part and growth phenology on oviposition behaviour of the legume pod borer, Maruca testulalis Geyer (Lep., Pyralidae)
Authors: Oghiakhe S.
Published: August 2009

Abstract: Abstract: The effect of cultivar, plant part and three phenological growth stages of cowpea, Vigna unguiculata (L.) Walp., genotypes on oviposition behaviour of the legume pod borer, Maruca testulalis Geyer, was studied in free‐choice and no‐choice tests in screen cages. The three growth stages were: pre‐flowering, flowering and podding, respectively. Oviposition pattern by M. testulalis gravid females was similar between the three cultivars, and all the various plant parts were oviposited upon at the different growth stages. TVNu 72 was the least preferred for oviposition while IT82D‐716 was the most. At the three growth stages and on the cultivars, abaxial leaf surface and flowers were consistently the most and least preferred oviposition substrates. Significantly more eggs were obtained in no‐choice oviposition tests than in free‐choice tests. Ovipositional non‐preference due to the presence of trichomes was found to be one of the mechanisms of resistance of cowpea to M. testulalis. Results from the study show the need to protect cowpea crop against M. testulalis oviposition at the different growth stages in order to significantly reduce grain yield losses.
Effect ofBacillus thuringiensisendotoxin onApanteles litaeNixon andBracon instabilisMarsh. (Hym., Braconidae), two parasitoids of the potato tuber mothPhthorimia operculellaZeller (Lep., Gelishiidae)
Authors: Salama H. S. , Zaki F. N. , Sabbour M. M.
Published: August 2009

Abstract:Treatment of the host larvae,P. operculella, withB. thuringiensisdid not change their susceptibility to being parasitized by eitherB. instabilisorA. litae. The longevity of adults of both parasitoids, as well as their egg production, were not markedly affected as a result of the treatment, while the duration of immature stages was prolonged. Also, emergence of the adult parasitoids was significantly reduced. The longevity of emerged adult parasitoids was significantly shortened when fed on honey containingB. thuringiensisand the fertility of the resultant females was significantly reduced.
A sampling technique to estimate within‐tree populations of pre‐emergent Ips typographus (Col., Scolytidae)
Authors: Gonzalez R. , Grégoire J.‐C. , Drumont A. , De Windt N.
Published: August 2009

Abstract: A sampling method was designed to assess within‐tree pre‐emergent adult populations of Ips typographus in Belgium. In a first series of 6 standing, attacked trees, a large number of 1 dm2 samples (56–171 samples, according to tree) were collected and analysed. Sets of samples were selected at random with successive increments of one unit among the samples from each tree, and the mean numbers of beetles and standard deviations in each of these random sets were used to calculate changes in sampling precision as the number of samples in a set increased. For each tree, there was an excellent fit with a power function linking sampling error and number of samples in each set. Fifty random samples per tree allowed estimates of the mean with an error of 9–24%. Further analysis of sample variation along and around the trunks showed that beetle density did not vary around but along the trunks, suggesting that sampling should not be totally random but should take into account longitudinal changes in beetle populations on attacked trees. At each level of each tree, sets of samples were selected at random with successive increments of one unit to calculate changes in sampling precision. At any level along the trunks, taking four 1 dm2 samples yielded estimates with an error inferior to 10%. To validate the conclusions drawn from these results, eight other trees were then sampled at regular intervals along the trunk. A total of 43–56 samples were taken per tree, yielding estimates with a computed error of 9–13% of the mean. Beetle density along the trunks was found to increase linearly along the basal portions of the infested stems (15% of the infested stem), remain constant along the following 65% of the infested stems, and decrease linearly along the terminal 20%. Taking all this information into account, the total pre‐emergent beetle population in each tree was estimated. Total beetle production per tree ranged from 35 000–72000.
Defence reactions of Norway spruce (Picea abies Karst.) to controlled attacks of Ips typographus (L.) (Col., Scolytidae) in relation to tree parameters
Authors: Baier P.
Published: August 2009

Abstract: The defence reactions of 105 Norway spruce trees in response to controlled attacks of Ips typographus were analysed and five groups with different defence reactions were recognized. Growth‐ and vigour‐indices showed no significant correlation with the induced reactions, but parameters of bark anatomy were most important. Due to secondary radial growth, the formation of periderm was intensified. Thereby, the density and thickness of radial resin ducts in the phloem increased, the number of boring attempts decreased and the number of boring attempts, defended by primary resin exudation, increased. Seasonal changes in the defence reaction could partly be traced back to changes in starch reserves in the phloem. Temporary changes in carbohydrate and water balance may affect the defences, but structural and anatomical properties of the bark govern the basic conditions for the responses to invading bark beetles.
Evaluation of Triflumuron, a benzoylphenylurea derivative, on Tenebrio molitor pupae (Col., Tenebrionidae): effects on cuticle
Authors: Soltani N. , Soltani‐Mazouni N. , Delachambre J.
Published: August 2009

Abstract: Triflumuron (TFM), a benzoylphenylurea (BPU) derivative, exhibited insecticidal activity when injected to newly ecdysed pupae of Tenebrio molitor. Mortality occurs by defect in adult ecdysis. Treatment resulted in a significant increase in the duration of pupal stage and caused a reduction in both cuticle thickness and incorporation of 14C‐labelled precursor into chitin compared to controls. Moreover, TFM reduced the amount of cuticle chitin without any significant effect on protein level. Thus, TFM acts by preventing the chitin biosynthesis confirming the primary mode of action of the BPU insecticides.
Thermal requirements of Aphelinus albipodus (Hayat and Fatima) (Hym., Aphelinidae) on Diuraphis noxia (Mordwilko) (Hom., Aphididae) hosts
Authors: Bernal J. S. , González D.
Published: August 2009

Abstract: The thermal requirements, t and K, and upper developmental thresholds for three developmental periods in Aphelinus albipodus, a parasite imported to the USA for biological control of Diuraphis noxia, were investigated under laboratory conditions. Studies were conducted at constant temperatures in the range 10.0–29.4°C, 14 L:10D photoperiod, and 50–70% R.H. Total developmental time (from egg to adult) in A. albipodus increased from 10.1 days at 29.4°C to 27.9 days at 15.5°C. Adult parasites did not emerge from mummies at 10°C (although pharate adults were recovered by dissection). The thermal requirements for the egg‐mummy, mummy‐adult, and egg‐adult developmental periods were estimated, respectively, as t = 7.62, 9.15, and 8.56°C, and K = 100.30, 107.31, and 208.24 degree‐days. The upper developmental threshold was considered to be above 29.4°C because development did not cease and did not appear to be affected by that temperature. The possibility of hibernal dormancy or diapause as well as the potential for successful establishment in California, USA, in A. albipodus are discussed.
Seasonal changes in the infection of pupae of the beech caterpillar, Quadricalcarifera punctatella (Motsch.) (Lep., Notodontidae), by Cordyceps militaris Link (Clavicipitales, Clavicipitaceae) in the soil of the Japanese beech forest
Authors: Kamata N. , Sato H. , Shimazu M.
Published: August 2009

The entomopathogenic fungus, Cordyceps militaris, is considered to be an important factor in suppressing population explosions of the beech caterpillar, Quadricalcarifera punctatella. The number of fruit bodies produced by the fungus was counted in a natural beech forest and parasitism was evaluated by burying lab‐reared pupae of the insect in the soil. Seasonal changes in infection rate in the ground and the corresponding number of fruit bodies were compared. The emergence curve of fruit body production exhibited an L‐shape with a peak in late July. The fruit body of C. militaris lasts for about two weeks and appears from late July to early September. The rate of infection was found to change seasonally: it was highest in early August when the number of fruit bodies was at a peak, then decreased gradually until the following summer. From an epizootiological viewpoint, the results suggested that the fruit body plays a role in enhancing the infection rate of the fungus.
Développement automnal et hivernal de Trichogramma cacoeciae et de T. evanescens (Hym., Trichogrammatidae), en conditions naturelles dans le midi de la France
Authors: Rossi M. M. , Pizzol J.
Published: August 2009

Abstract: Development of Trichogramma cacoeciae and T. evanescens during autumn and winter under natural conditions in southern France. The development of two Trichogramma species, T. cacoeciae and T. evanescens (Hym., Trichogrammatidae), parasitoids of Lobesia botrana (Lep., Tortricidae) have been observed under natural conditions in Antibes‐France, during the fall and winter seasons, 1990/1991. It is clear that, T. cacoeciae and T. evanescens can stop their development by either quiescence or diapause, in these natural conditions. T. evanescens was more sensitive to low temperatures than T. cacoeciae.

Le développement de Trichogramma cacoeciae et T. evanescens, parasitoïdes provenant de pontes de Lobesia botrana, a été suivi en conditions naturelles à Antibes‐France, pendant l'automne et l'hiver 1990/1991. II a été montré qu'aussi bien T. cacoeciae que T. evanescens possèdent une capacité à entrer en arrêt de développement, soit une quiescence, soit une diapause, dans les conditions hivernales d' Antibes. T. evanescens est plus sensible que T. cacoeciae, aux conditions de basses températures.
Morphological prediction of worker size discrimination and relative abundance of sympartic species of Pseudacteon (Dipt., Phoridae) parasitoids of the fire ant, Solenopsis saevissima (Hym., Formicidae) in Brazil
Authors: Fowler H. G.
Published: August 2009

Patterns of attack for collected species of phorids are predicted using multivariate morphometries of female Pseudacteon species and worker size distributions of parasitized fire ants, Solenopsis saevissima. The model assumes that there is a direct correlation between phorid size and the size range of the worker ant attacked, and presumes that worker sizes are a resource that is divided by sympatric phorid species to minimize joint parasitism. These results suggest that the community of sympatric Pseudacteon species on only one host species coexists by restricting the size of workers attacked, and secondarily by differing diel patterns of ovipositional activity. When we compared relative abundance of species of Pseudacteon with the size distribution of foragers of S. saevissima, our observed distribution did not differ significantly from our predicted relative abundance of females of Pseudacteon. The activity of Pseudacteon may be a factor determining forager size distributions.
Etude du mécanisme de la confusion sexuelle chez l'Eudémis de la vigne, Lobesia botrana Den. et Schiff. (Lep., Tortricidae) IV – Quel est le rôle de la fixation de la phéromone par le feuillage?
Authors: Schmitz V. , Charlier L. , Roehrich R. , Stockel J.
Published: August 2009

Abstract: Disruption mechanisms of pheromone communication in the European grape moth Lobesia botrana Den. et Schiff. IV — What is the part of absorption of pheromone by foliage?

In three experiments using pheromone dispensers of Lobesia botrana, it was shown that the vine foliage was able to fix the pheromone and then to release it into atmosphere. Captures of males in sex traps are less numerous in a vineyard first submitted to confusion. The leaves pre‐exposed to pheromone may behave as baits in sex traps. Then, matings may be disturbed by the pheromone released by leaves first submitted to high doses of pheromone. This action should be able to regulate in time and space the confusion technique as control method.

Trois essais ont montré que le feuillage de la vigne pouvait fixer la phéromone de Lobesia botrana et, après le retrait des diffuseurs de celle‐ci, la relâcher dans l'air. Les captures aux pièges sexuels sont en effet moins nombreuses dans un vignoble préalablement soumis à la confusion. Les feuilles préexposées peuvent agir comme des appâts dans les pièges et les accouplements peuvent être fortement perturbés par la phéromone émise par des feuilles préalablement soumises à des doses très élevées. Cette action serait susceptible de régulariser dans le temps et l'espace l'application de la confusion sexuelle comme méthode de lutte.
Pathogenicity of Beauveria bassiana (Bals.) Vuill. to the larvae of diamondback moth, Plutella xylostella L. (Lep., Yponomeutidae)
Authors: Selman B. J. , Dayer M. Saaid , Hasan M.
Published: August 2009

The effects of the entomopathogenic fungus, Beauveria bassiana on the mature larvae of Plutella xylostella under two temperature regimes was studied. All the isolates were significantly pathogenic against P. xylostella larvae. Isolate 274 and 373 caused a higher mortality at 20 ± 5 and 24°C, respectively. These results also showed that the X2 for goodness of fit for the regression showed considerable homogeneity in most of the isolates.
Effect of neem (Azadirachta indica A. Juss) seed kernel extracts on the larval parasitoid Bracon brevicornis Wesm. (Hym., Braconidae)
Authors: Srivastava M. , Paul A. V. N. , Rengasamy S. , Kumar J. , Parmar B. S.
Published: August 2009

The alcoholic and hexane extracts of 17 neem ecotypes of India have been found to be toxic to the egg, larval and pupal stages of the cosmopolitan, external gregarious larval parasitoid Bracon brevicornis (Wesm.). In general, the hexane extracts showed higher toxicity against the egg and pupal stages whereas the alcoholic extracts were more toxic against the larvae. Azadirachtin content of the neem ecotypes revealed no apparent correlation with the observed toxicity against different stages of the parasitoid.
Effect of NeemAzal, a natural azadirachtin‐containing preparation, on Periplaneta americana (L.) (Orthopt., Blattidae)
Authors: Richter K. , Böhm G.‐A. , Kleeberg H.
Published: August 2009

NeemAzal, a commercial neem preparation with an azadirachtin content of 20%, was proven to be a growth retardant for the cockroach Periplaneta americana. As shown in the reduction of food consumption, the effect of NeemAzal, ingested as food, is predominantly to interpret as a phagodeterrent effect. The decreased ingestion of food results in a retardation of growth of the larvae and finally in a reduction of the reproductivity of the adults. The results suggest that a long‐term decimation of a population with a small fluctuation until its breakdown by intensive and permanent offering a NeemAzal‐containing bait may be possible.
Egg distribution and survival of Cinara pilicornis (Hartig) (Hom., Lachnidae) on damaged and undamaged Norway spruce (Picea abies) (L.) Karst
Authors: Stadler B.
Published: August 2009

The spruce shoot aphid (C. piliconis) (Hartig) lives on Norway spruce (P. abies (L.) Karst.) and deposits its overwintering eggs on current year needles. Ovipara density and the distribution of their eggs on trees at two different sites of the Fichtelgebirge (north‐east of Bavaria), with host trees showing either heavy symptoms of needle‐yellowing (Oberwarmensteinach) or look green and healthy (Waldstein) is investigated. In addition, winter mortality of eggs and egg development until birth of the fundatrices is followed.

Host plant quality does not seem to influence the proportion of eggs surviving to spring. Also, the biomass of developing first instar larvae of the fundatrices was independent of the degree of needle yellowing. However, significantly more eggs/shoot and eggs/twig were found on hosts without growth disturbance which is due to a higher ovipara density and a higher fecundity of individual ovipara. Damaged or stressed trees do not seem to be better hosts for C. pilicornis. A significant correlation was found between the biomass of first instar larvae of fundatrices and the time of egg hatching. The high phenotypic plasticity of C. pilicornis on good quality plants is discussed and potential implications for forestry are assessed.
Densities of overwintering carabids and staphylinids (Col., Carabidae and Staphylinidae) in cereal and grass fields and their boundaries
Authors: Andersen A.
Published: August 2009

Abundances of carabids and staphylinids were measured during four winters in four fields with grass or autumn ploughed spring cereals, and in their boundaries. Most species were significantly more abundant in the boundaries than in the fields, indicating the high importance of boundaries in the agricultural landscape for these predator groups. Only the carabid Clivina fossor and staphylinids belonging to the genus Lathrobium were evenly distributed throughout the entire area. As none of the species with higher populations in the grass fields and their boundaries were among the important predators of insect pests in agricultural fields, it was concluded that the grass fields were of limited importance as a reservoir for the predatory beetles.
Influence of temperature on development, fecundity and survival of the cabbage moth Mamestra brassicae (L.) (Lep., Noctuidae) in relation to the improvement of forecasting and control methods
Authors: Johansen N. S.
Published: August 2009

Developmental time and survival of eggs, larvae, pupae and adult females of the cabbage moth, Mamestra brassicae (L.), were investigated at different temperatures within the range of 5–23°C. In addition, the influence of temperature during the larval period on the weight of the succeeding pupae was studied, as well as the effect of temperature on fecundity of adult females. The lower developmental thresholds (Tb) and thermal requirement (DD) were established for all developmental stages and the larval instars using linear regression analysis. Tb and DD were 8.6 C and 75 degree‐days for eggs, 5.4°C and 496 degree‐days for the total larval period, 7.2°C and 304 degree‐days for pupae, and 5.0°C and 56 degree‐days for the preovipositional period, respectively. Pupal mortality was low at all temperatures. The survival of eggs and larvae was highest at 18°C, whereas mortality was 100% at 8.5°C. Larval mortality was highest in the first instar and decreased with increasing age. Pupae gained the highest weight when the larvae were reared at 18°C, and the weight decreased with declining temperature. Temperature had no significant effect on total fecundity or fertility. Fecundity was basically unimodal distributed at all temperatures. At low temperatures the egg laying period was markedly prolonged.
Trichopria khandalus (Hym., Diapridae): a new biocontrol agent of the uzifly Exorista bombycis (Dipt., Tachinidae)
Authors: Jamil Kaiser , Jyothi K. N. , Prasuna A. L. , Murty U. S. N. , Persoons C. J.
Published: August 2009

Biological control of the silkworm pest (Exorista bombycis) was partly successful by using a new hymemopteran biocontrol agent Trichopria khandalus, recovered from the environs of a cocoon market in Hindupur district of Andhra Pradesh (India). T. khandalus is a tiny (1–1.5 mm) endoparasite, the females were found to parasitize the uzifly puparia. The progeny developed inside the uzi pupa, and the adults (140–160 individuals from a single pupa) emerged after about 18–25 days depending on the seasonal extrinsic factors. The lift cycle of T. khandalus averaged 32 days. Due to the favourable sex ratio (2:3 male/female) and high preference to parasitize uzi puparia it is qualified as a good biocontrol agent for the control of E. bombycis. Prospects for utilizing this hyperparasite to manage and eliminate the uzi populations are discussed in the light of its data on biology, and easily manageable mass multiplication in the insectary.