bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of tree host and beetle density on reproduction and survival of Ips typographus japonicus Niijima (Col., Scolytidae) in Hokkaido, Japan
Authors: Lawson S. A. , Furuta K. , Katagiri K. 
Published: August 2009

AbstractReproduction and survival of I. typographus japonicus at non‐outbreak densities in relation to two tree species, its natural host, Picea jezoensis, and an introduced host, Picea abies, was investigated in 1990 and 1991 in the natural mixed forest zone of Hokkaido, Japan. Beetles did not discriminate between logs of the two species during the attack phase, however, female beetles produced significantly longer egg galleries in P. jezoensis logs than in P. abies logs, particularly in 1990. Regression analysis showed that egg galleries were on average 2 cm longer in P. jezoensis in both years. A consistent trend toward higher larval survival in P. jezoensis logs was also observed. It is postulated that these differences were caused by a combination of differences in tree ages used in the studies and therefore their physiological status and inherent differences in the suitability of each tree species as breeding resource. Intraspecific density dependent effects on reproduction and survival were similar to those previously reported for outbreak or post‐outbreak populations, with the strongest effects being on reductions in egg gallery length and larval survival as beetle density increased. These factors were important even at the relatively low densities found in this study. The relevance of these results to the management of I. typographus in the spruce forests of Japan and the importance of native insects exploiting non‐native host plants as new resources is briefly discussed.
Are aphid mean relative growth rate and intrinsic rate of increase likely to show a correlation in plant resistance studies?
Authors: Wojciechowicz‐Zytko E. , van Emden H. F. 
Published: August 2009

AbstractIn a study of the performance of Aphis fabae Scop. on 6 British and 3 Polish cultivars of Vicia faba L., the aphid showed a poor mean relative growth rate (mrgr) on the Polish cultivar Hangdown Bialy (p = < 0.05). Measurements of fecundity, the intrinsic rate of natural increase (rm) and mrgr were obtained on a large number of individual plants. Correlations between mrgr and both rm or fecundity for individual plants across cultivars were not significant. Although within cultivars, individual plants of Aquadulce and Relon showed significant positive correlations of aphid mrgr on fecundity and rm respectively, the two correlations accounted for less than 20% of the variation in mrgr and no such correlations were found for the other seven cultivars. Although mrgr showed the highest residual variance (in relation to the mean) of the three performance indicators assessed, it nonetheless proved to provide the best discrimination between the cultivars tested. It is suggested that this is because mrgr is less subject to ‘maternal influence’ than fecundity or rm.
Variation du potentiel biotique de l'auxiliaire parasite Encarsia formosa G. (Hym., Aphelinidae) en fonction du stockage au froid: I. Du point de vue du taux d'emergence
Authors: Ganteaume A. , Tabone E. , Poinsot‐Balaguer N. 
Published: August 2009

Abstract: Encarsia formosa biotic potentialities variation after black pupae cold storage: I. Rate of hatching variationImproving the method of black pupae storage at low temperatures was necessary in order to improve their commercialization and different combinations of temperature‐length of storage were tested.To obtain good hatching results, Encarsia black pupae cold storage can be extended to 20 days at 9°C, the best results being given with 15 days at 9°C. The rate of hatching decreases with decreasing temperatures and increasing lengths of storage.RésuméL'optimisation d'une méthode de stockage à basse température des pupes noires d'Encarsia formosa étant nécessaire afin d'améliorer leur commercialisation, différentes combinaisons température‐durée de stockage ont été testées.Les meilleurs résultats concernant les émergences sont obtenus pour 15 jours à 9°C (76,58%), mais le stockage au froid d'Encarsia peut être prolongé jusqu'à 20 jours à 9°C. Le taux d'émergence diminue avec l'abaissement des températures et l'augmentation de la durée de stockage au froid.
Morphometric, biological and behavioural differences between Hemiptarsenus varicornis (Hym., Eulophidae) and Opius dissitus (Hym., Braconidae) parasitoids of Liriomyza trifolii (Dipt., Agromyzidae)
Authors: Bordat D. , Coly E. V. , Roux‐Olivera C. 
Published: August 2009

AbstractThe study of two parasitoids of the leaf‐miner Liriomyza trifolii (Burgess), Opius dissitus Muesebeck and Hemiptarsenus varicornis (Girault), was conducted in the laboratory. It focused on the morphological and biological differences between the two species, and the production of females when confronted with a population of leaf‐miner larvae at different stages and sizes.RésuméDifférences morphométriques, biologiques et comportementales entre Hemiptarsenus varicornis (Hym., Eulophidae) et Opius dissitus (Hym., Braconidae) parasitoïdes de Liriomyza trifolii (Dipt., Agromyzidae).Opius dissitus et Hemiptarsenus varicornis sont deux parasitoïdes naturels de Liriomyza trifolii, mouche mineuse des feuilles. Des études en laboratoire montrent que O. dissitus peut, à l'inverse d'H. varicornis, se multiplier dans des stades Ll de L. trifolii. Par contre, sur de faibles populations de larves hôtes et lorsque les deux espèces de parasitoïdes sont en compétition, seul H. varicornis parvient à se multiplier.
Effects of the insect growth regulator cyromazine on the fecundity, fertility and offspring development of Mediterranean fruit fly, Ceratitis capitata Wied. (Dipt., Tephritidae)
Authors: Jimenez‐Peydro R. , Gimeno‐Martos C. , Lopez‐Ferrer J. , Serrano‐Delgado C. , Moreno‐Marí J. 
Published: August 2009

AbstractAddition of cyromazine to adult diet affected negatively the development of Ceratitis capitata Wied. (Dipt., Tephritidae) offspring. Five concentrations of cyromazine (0.00001 mg/ml, 0.01 mg/ml, 0.1 mg/ml, 1 mg/ml and 10 mg/ml) have been tested. A reduction of Mediterranean fruit fly populations has been found mainly due to the effects of fertility and larval development. At these concentrations, cyromazine does not affect Ceratitis capitata fecundity.
Mortality and predation efficiency of Coleomegilla maculata lengi Timb. (Col., Coccinellidae) following application of Neem extracts (Azadirachta indica A. Juss., Meliaceae)
Authors: Roger C. , Vincent C. , Coderre D. 
Published: August 2009

AbstractThe toxicity of two neem (Azadirachta indica) extracts and of the chemical insecticide malathion was evaluated on adults of the predacious coccinellid C. maculata. Bioassays were carried out with both neem formulations at 1,5,10, 20 and 50% concentration. The azadirachtin quantities contained in neem oil (v/v) and neem seed kernels (w/v) were 13.7 ppm AZA and 91.0 ppm AZA respectively. Malathion was tested at field rate (2.85 g (AI)/L). The mortality rate was evaluated in the laboratory after topical applications on the ventral side of the coccinellids. Adult mortality rate after 72 h was 100% following malathion treatments. Only one dose of neem oil (10%) resulted in significantly greater mortality than in the control group. No toxicity was observed after the treatments with the aqueous suspension of ground neem seeds. Predation efficiency of C. maculata was also evaluated after topical application of these three insecticides at sublethal doses. Fifteen min after treatments, adult coccinellids were presented 30 aphids for 24 h. The aqueous suspension of ground neem seeds caused a 50% reduction in the number of aphids consumed.
Selection for monocrotophos resistance in pear psylla, Cacopsylla pyri (L.) (Hom., Psyllidae)
Authors: Berrada S. , Nguyen T. X. , Merzoug D. , Fournier D. 
Published: August 2009

AbstractPear psylla, Cacopsylla pyri (L.), adults collected from commercial pear orchards around Toulouse (France) were selected in the laboratory for resistance to monocrotophos. Resistance was obtained only when the insecticide selection pressure was continuous, but when some generations were not selected, resistance did not develop or even reverted. Resistance appeared to be stable after 30 generations of selection and stabilized at a level of 140‐fold. The monocrotophos‐selected strain was highly cross‐resistant to the organophosphate phosmet (155‐fold) and cross‐resistant to the formamidine amitraz (14‐fold).
Seasonal variation in local abundance of adults of the large pine weevil, Hylobius abietis L. (Col., Curculionidae)
Authors: Leather S. R. , Small A. A. , Bøgh S. 
Published: August 2009

AbstractThe abundance of adult H. abietis was studied over a 6‐month period at a clear‐fell site in Kielder Forest, Northumberland, UK. Numbers varied markedly over the study period, peaking in August. Using enclosure and exclosure techniques it was estimated that most of the beetles captured at the study site emerged from the soil or from the stumps present at the site. Weevil abundance declined from September onwards and by the end of November, no more weevils were trapped, presumably due to movement away to hibernation sites. The implication of these findings for pest management strategies is highlighted.
Winter dormancy in Ernobius abietis F.(Col., Anobiidae) studied in relation to cold hardiness
Authors: Luik A. 
Published: August 2009

AbstractHibernating larvae of E. abietis lowered their supercooling points from – 11.8°C in September to – 25.6°C in January and adults from –12.7 to – 25.7°C due to the state of winter dormancy which is mainly controlled by temperature. Only under low enviromental temperatures in autumn and winter did the overwintering specimens develop their cold hardiness. During favourable temperatures, hibernating larvae activate easily and continue their development despite the day length. Winter dormancy in adults seems to be induced by photoperiodical conditions.
Electroantennogram responses of the grain aphids Sitobion avenae (F.) and Metopolophium dirhodum (Walk.) (Hom., Aphididae) to plant odour components
Authors: Visser J. H. , Fu‐shun Yan 
Published: August 2009

AbstractElectroantennogram responses (EAGs) to a range of plant volatiles were recorded from alate summer forms of the English grain aphid Sitobion avenae and the rose‐grain aphid Metopolophium dirhodum. This bioassay screens for potential semiochemicals which are involved in host plant selection. EAGs of both species reveal pronounced receptivities of the antennal olfactory sensilla for the green leaf volatiles. In S. avenae (£)‐2‐hexenal and hexanal elicit larger responses than the corresponding alcohols, whereas in M. dirhodum only the mono‐unsaturated C6 aldehyde produces larger EAGs than the alcohol. In the remaining group of plant volatiles benzaldehyde, benzyl acetate, 2‐phenylethyl acetate, linalool, citronellal and β‐pinene elicit distinct EAGs from both species. Structure‐activity relationships are especially evident in the S. avenae olfactory responses. The response profiles of the aphid species are similar, although species‐specific traits occur.
Electrophoretic detection of dryinid parasitoids in Empoasca leafhoppers
Authors: Demichelis S. , Manino A. 
Published: August 2009

AbstractAdults of Empoasca decipiens Paoli 1930, E. solani (Curtis, 1846) and E. vitis (Göthe, 1875) (Hom.; Auchenorrhyncha, Cicadellidae) were collected by sweepings on potato (Solatium tuberosum L.) and grapevine (Vitis vinifera L.), but only E. decipiens was parasitized by dryinids, probably Lonchodryinus ruficornis (Dalman) (Hym.; Dryinidae, Anteoninae). Parasitized and unparasitized leafhoppers were assayed by polyacrylamide gel electrophoresis (PAGE) to identify isozymes for diagnosing dryinids. The α‐glycerophosphate dehydrogenase (α‐GPD) enzyme system proved to be a reliable tool for the detection of parasitized individuals.
Production of exclusively male progeny by mated, honey‐fed Trichogramma minutum Riley (Hym., Trichogrammatidae)
Authors: Leatemia J. A. , Laing J. E. , Corrigan J. E. 
Published: August 2009

AbstractMost mated, honey‐fed, female Trichogramma minutum, provided with host eggs of Ephestia kuehniella from eclosion, were shown to produce broods of exclusively male offspring as they aged. Females produced an average of 218.5 ± 69.9 offspring during a reproductive period of > 20 days. Of these offspring, 96.7 ± 59.5 were males that were produced after the mother had ceased to produce female offspring. Females that had shifted to all‐male production were capable of re‐mating and resuming production of female progeny, indicating that either sperm depletion or loss of sperm viability played a role in the shift to all‐male production. However, honey‐fed, mated females that were held without access to hosts for up to 16 days at 25° C or 28 days at 16° C were able to produce female offspring when allowed to parasitize. This indicates that sperm would remain viable in the females' spermatheca for extended periods of time and that sperm depletion was, at least partially, the cause of the shift to all‐male progeny production. Honey‐fed females held without host eggs for up to 8 days at 25° C or 28 days at 16°C had reductions in their initial, 2‐day offspring production of only 10% and 20%, respectively. This could allow for the build‐up of large numbers of effective parasitoids for mass culture or field release.
Drifting in populations of the alfalfa leafcutting bee, Megachile rotundata (Fab.) (Hym., Megachilidae)
Authors: Goerzen D. W. , Richards K. W. , Rank G. H. 
Published: August 2009

AbstractThe within‐field drifting of Megachile rotundata (Fab.) females was evaluated at three field sites in Saskatchewan and one site in Alberta, Canada. Marked females were released at field shelters and bee movement was monitored throughout the field season. High levels of bee drifting were observed at all locations. An average of 32.3% (Saskatchewan) or 51.8% (Alberta) of marked females were observed to have drifted away from their release site. The distance female bees drifted was predicted using exponential regression equations and expressed using contour reponse patterns. This high level of within‐field movement must be taken into account when evaluating field treatments in sub‐populations of alfalfa leafcutting bees.
Feeding patterns of the larch casebearer Coleophora laricella Hbn. (Lep., Coleophoridae) on European larch
Authors: Habermann M. , Ott A. 
Published: August 2009

AbstractFeeding patterns of the larch casebearer Coleophora laricella Hbn. were investigated for eggs, 2nd/3rd instars, 4th instars and pupae in a 21‐year‐old larch stand. No significant differences occurred between the infestation rates of border‐ and within‐stand‐trees; no preferences were found for cardinal points. Clear preferences were detected for distal twig sections. There seems to be a tendency to higher densities in the middle parts of larch crowns. Larch trees in the direct neighbourhood of beech showed significantly lower moth densities than larch in pure stands. This may be a result of different physiological interactions between moth and host tree in pure or mixed stands, respectively.
Interaction between Apanteles ruficrus Hal. and Meteorus rubens Nees on larvae on Agrotis ipsilon (Hufn.)
Authors: Awadallah K. T. , Zaki F. N. , Gesraha M. A. 
Published: August 2009

AbstractThe two internal gregarious parasitoids Apanteles ruficrus Hal. and Meteorus rubens Nees attack larvae of Agrotis ipsilon (Hufn.) and they naturally co‐exist during the period from end April to end May. The present paper deals with the interaction between these two parasitoids. First and late 6th instar (3‐day old) of A. ipsilon never attacked by either A. ruficrus or M. rubens. No sort of direct competition between the two parasitoids existed around 2nd, 3rd and early 6th instars, because of the unique instar attacked by each. Fourth instar larva is adequate for both parasitic species, but when being exposed simultaneously to females of both species, no progeny are obtained owing to the early death of the host. Fifth instar of Agrotis larva is highly preferable for Meteorus compared to Apanteles and thus, when being exposed simultaneously, the survivor is Meteorus. In nature the two parasitic species were never obtained together from a 4th instar larva, and no Apanteles individuals were secured from 5th instar larvae.
Efficiency of Scutellista cyanea Motsch. (Hym., Pteromalidae) and Tetrastichus cetoplastae (Gir.) (Hym., Eulophidae) in population suppression of Ceroplastes rusci L (Hom., Coccidae)
Authors: Ragab M. E. 
Published: August 2009

AbstractStudies on the relationship between the population fluctuations of the wax scale, C. rusci L., and its parasites on quince trees were carried out in the Mansoura district for a whole year starting April, 1993 until March, 1994. Two annual generations of C. rusci were recorded, the summer one from April to September and the winter one from September to the next April. The two hymenopterous parasites, C. cyanea Motsch. (Pteromalidae) and Tetrastichus ceroplastae (Gir.) (Eulophidae) emerged from C. rusci. The highest monthly percentages of parasitism with S. cyanea (15.6%) and T. ceroplastae (30%) were recorded in September and November, respectively. The rate of parasitism induced by the two parasites together reached its peak (33.4%) in September. The results assured the important role of these parasites as biotic mortality factors against the populations of C. rusci in Egypt.
Effect of sample size and number of doses for the determination of LD50
Authors: Moermans R. , Van Hecke P. 
Published: August 2009

AbstractThe effects of the LD50 value of the number of applied doses and the number of individuals submitted to each dose were studied. Simulated data were used and the lognormal distribution was assumed. Increasing the number of individuals submitted to the doses results in a much larger effect than increasing the number of doses. To obtain an accuracy of 50% of the true value, with a chance of .85 that this should happen, at least 20 individuals per dose should be used.
Postrelease dispersal of Trichogramma brassicae Bezdenko in corn fields
Authors: Greatti M. , Zandigiacomo P. 
Published: August 2009

AbstractDuring the years 1992–93 a study on the dispersal of Trichogramma brassicae Bezd., an egg parasitoid of the European corn borer, Ostrinia nubilalis (Hbn.), was carried out in north‐eastern Italy. In 1992 an Italian strain of trichogrammatid wasp and in 1993 a French strain were used. During August in two different plots of corn, about 4 000 and 8 000 T. brassicae were released three times at one point per plot. Four checks of the O. nubilalis egg masses on corn plants were made weekly in August; six distances from the point of release, ranging from 0.75 to 10.6 m, were considered. The rate of parasitization was higher in 1993 when T. brassicae at different developmental stages (larvae and pupae) were released. The percentage of O. nubilalis egg masses parasitized by T. brassicae decreased with the distance from the point of release. In both years, wind seemed to have an important effect on the dispersal of the parasitoid. The dispersal of T. brassicae was lower in the upwind sectors whereas in the downwind sectors increasing the distance from the point of release no significant decrease of the rates of parasitization was observed; the performances of the Italian and the French strains of trichogramma appeared to be the same. The results obtained in this experiment indicate that there should be a high number of release points per hectare to reduce the effects of both distance and wind, and parasitoids at different developmental stages should be released to increase the rate of parasitization. The number of parasitoids released do not seem to effect the rate of parasitization.
Chromatomyia fuscula (Zett.) (Dipt., Agromyzidae) host plant, feeding and oviposition site preferences
Authors: Darvas B. , Andersen A. 
Published: August 2009

Abstract: In southern Norway, the grass Festuca pratensis supported the emerging overwintered population of the agromyzid Chromatomyia fuscula until the appearance of the primary host plant, spring barley (Hordeum vulgare). Oats (Avena sativa), rye (Secale cereale) and the grass species, Dactylis glomerata and Alopecurus paratensis were alternative secondary hosts.C. fuscula females preferred the upper surface of the two youngest barley leaves for feeding and oviposition. This behaviour is advantageous for the farmers when applying an insecticide spray because the distribution of a contact insecticide on the upper two leaves is the easiest possibility for plant protection practice. The earliest (1st and 2nd) leaves of barley died quickly due to unusually warm and dry weather conditions. Consequently, larval survival on these leaves was low. Leaf numbers 3–5 supported the greatest population of successful larvae. Overwintered caged, gravid females of C. fuscula made an average of 3–4 punctures and laid one egg per hour.
Substrate and food effects on biotic potentialities of Encarsia formosa (Hym., Aphelinidae)
Authors: Ganteaume A. , Tabone E. , Poinsot‐Balaguer N. 
Published: August 2009

Abstract: With the aim of improving the dispatches of Encarsia formosa to the agriculturist's greenhouses increasing wasp efficiency, a new method of conditioning by changing the substrate of black pupae was performed.Three groups of parasites to which pupae were glued with or without sugar and compared to a control were studied. This new method of conditioning (pupae were removed from the host‐plant then glued on a cardboard plaquette) did not disturb the wasp's biological potentialities (daily fecundity, longevity) and adding sugar increased the daily fecundity.
Influence of temperature and age of Nezara viridula L. eggs on the scelionid egg parasitoid, Trissolcus megallocephalus (Ashm.) (Hym., Scelionidae)
Authors: Awadalla S. S. 
Published: August 2009

Abstract: Laboratory experiments were carried out to study the influence of temperature and age of Nezara viridula eggs on the rate of parasitism by Trissolcus megallocephalus, the rate of emerged parasitoids, the duration of developmental stages, the adult longevity and the daily rate of oviposition.The results indicated that the highest rate of parasitism 55.4 ± 2.37/female (92.33%) and the highest number of emerged parasitoids 55.10 ± 2.60 individuals/female (91.83%) were obtained when the females were reared at a constant temperature of 25°C. At 30°C, egg‐larval stage, pupal stage and total developmental stages showed the shortest developmental time. Results showed also a negative response between adult parasitoids longevity and temperature. Females deposited the highest number of eggs during the first day at the highest temperature of 30°C, while the females which were reared at 25°C, 20°C and 21–36°C fluctuating temperature deposited the highest number of eggs during the second day.The results also indicated that the parasitoid females attacked host eggs at all developmental stages before hatching. The rate of parasitism and the number of emerged parasitoids were relatively high except for host eggs more than 3 days old. The shortest duration of developmental stages (14.2 ± 2.86 days) were obtained at host eggs of two days old, and increased to (17.8 ± 2.39 days) at 5 days old with a significant difference (P < 0.05). No significant differences were obtained between the adult longevity and the different ages of host eggs.