bluuebunny/crossref_metadata_2025 huggingface dataset:
Diurnal change of adult behaviour, daily oviposition and influence of temperature on adult emergence and light trapping data of the beech caterpillar, Quadricalcarifera punctatella (Motsch.) (Lep., Notodontidae)
Authors: Kamala N. , Igarashi M.
Published: August 2009

Ecological properties of Quadricalcarifera punctatella adults needed in population studies were investigated. Diurnal changes of behavior were recorded by video camera. Adults emerged from dusk to midnight (1700–2400) with the peak between 2200–2300. Females copulated the 1st night, though most males began to copulate from the 2nd night. Almost all females began to lay eggs the 2nd night and oviposition continued for several days, with the peak being the 2nd–4th days after emergence. Since females laid several egg‐masses a day, time of oviposition varied greatly from dusk to dawn. Females laid several eggs before flying to a trap because they were not active the 1st night and because most of the trapped females had fewer eggs than the estimated fecundity. Adult emergence lasted for more than 1 month even in the laboratory and there was no difference in emergence curve between males and females. The number of emerged adults in the laboratory and that of adults trapped in the field both fluctuated greatly. Temperature influenced the numbers: many adults were caught on warm nights and only a few on cold nights. This was because high temperatures promoted the emergence and flight activity of the adults. Adults were caught in the field for about 2 months from late May to late July with a peak in mid‐ to late June; more than 75% of the total were caught during this period. Total number of trap catches from 11–30 June was concluded to be a good parameter for comparing annual changes in adult densities in future studies.
Effets d'un extrait de neem (Azadirachta indica A. Juss) sur le développement de Forficula auricularia L (Dermaptera)
Authors: Sauphanor B. , Lenfant C. , Sureau F.
Published: August 2009

Abstract: Effects of a neem seed extract (Azadirachta indica A. Juss) on the development of the Dermaptera, Forficula auricularia L.: Young nymphs and adults of the European earwig, Forficula auricularia L., were exposed in the laboratory and in the field to an extract from seed kernels of the neem tree, Azadirachta indica A. Juss. No effect was observed on mortality, weight, food intake or fecundity of adults when treated directly in the laboratory with 50 ppm of azadirachtin. None of the second instar nymphs treated by contact with the fresh residue or fed on medium treated with 25, 50, or 250 ppm of the product could achieve their development. The nymphs exhibited a decrease of food intake and of ponderal growth a few days after the treatment, as well as an increase of the intermoulting delay. Behavioural tests revealed no repellent or antifeedant effect of the product. Applications in peach tree orchards resulted in a 70% reduction of nymphal population of earwigs. Neem products could be used to reduce earwig populations if applied when young instars are present. They should therefore be avoided during this period on crops where these insects need to be preserved because of their predation on aphids.
Aphid‐parasitoid interactions in a winter cereal crop: field trials involving insecticide application
Authors: Giller P. S. , Ryan B. , Kennedy T. , Connery J.
Published: August 2009

Large scale field trials were conducted to investigate aphid‐parasitoid interactions in winter wheat following spring applications of contact or systemic insecticides. Percentage parasitism was also investigated in the dominant aphid species using acrylamide‐gel electrophoretic methods. Sitobion avenae (F.) Metopolophium dirhodum (Walk.) and Rhopalosiphum padi (L.) were the commonest aphids and showed typical patterns of abundance through the growing season. Six parasitoid species were found: Aphidius rhopalosiphi de St.‐Per., A. ervi Hal., A. picipes (Nees) and Praon volucre (Hal.) being the most common primary parasitoids that attack the three main aphid species. The present work demonstrated a degree of temporal separation of these dominant cereal aphid parasitoid species which has rarely been documented. There was also evidence of earlier female activity in the crop in four of the six species. Parasitoid populations increased into June and peaked in July, coinciding with and continuing after peak aphid populations, before rapidly declining into August.

Both contact and systemic insecticides sprayed in spring produced only a slight initial trend of suppression of aphid populations compared to control treatments; no influence on late summer populations was found. However, significant between‐field differences occurred. Neither contact nor systemic insecticides had any effect on population sizes, species composition or life history of aphid parasitoids (Braconidae; Aphidiinae, Aphelinidae) compared to control plots in the present study. Percentage parasitism was likewise unaffected by insecticides and reached a peak, based on electrophoretic methods, of 40% at peak aphid densities at the end of June. Estimates of parasitism based on presence of mummies were up to 10 times lower.

Possible reasons for the lack of effect of insecticide application in the present study include timing of application (prior to main immigration period of aphids and parasitoids), mobility of populations and insecticide‐induced stimulation of reproduction in aphids.
Effect of pesticide residues on mortality of Aphytis melinus DeBach (Hym., Aphelinidae) in Munger cells and larger containers
Authors: Bellows T. S. , Morse J. G. , Gasto L. K.
Published: August 2009

An experimental study was designed to test the reliability of field‐usable bioassays in determining the toxicity of previously treated foliage to natural enemies. Lemon trees were treated at commercial rates with carbaryl‐oil, chlorpyrifos and methidathion. Residues on leaves and twigs were quantified weekly for 50 days after treatment. Bioassays of treated and control foliage to Aphytis melinus DeBach were conducted at similar intervals in Munger cells, 3.8 1 glass jars, and 2 1 paper cartons. Pesticide residues on twigs dissipated at approximately the same rates as residues on leaves. Bioassay mortality was high immediately following treatment. Subsequent mortality was reduced to near pre‐treatment and control levels quickly (3–8 days) in the cells, less quickly in the cartons, and slowest in the jars (up to 10 weeks). The mortality in the jars did not appear closely related to pesticide residue levels, but was possibly due to other contributing factors.
Within‐tree vertical pattern in Bactrocera oleae Gmel. (Dipt, Tephritidae) infestations and optimization of insecticide applications
Authors: Gaouar N. , Debouzie D.
Published: August 2009

The vertical pattern in olive fruit fly infestations was studied in the Tlemcen region (western part of Algeria) in 1990. The infestation rate of olives, measured by punctures, eggs, larvae, exit holes and pupae, was always higher in the lowest stratum (up to 2 m) than in the upper (3 m), the middle stratum being infested at an intermediate level. Differences were largest in October. In 1992 this result was used by spraying insecticide in an orchard half as intensely in the two higher strata as in the lower stratum. This led to relatively good protection in comparison with unsprayed orchard.
Phase variation—a possible adaptive character for the false spider mite, Brevipalpus phoenicis (Geijskes 1939)
Authors: Kennedy J. S.
Published: August 2009

The phenomenon of phase variation brought about by crowding has been proven to be an adaptive character for insects like locusts. Observations made on a cohort of Brevipalpus phoenicis (Geijskes) in groups of 50 individuals revealed that grouping shortens the developmental time and total life span and reduces the capacity for oviposition. This enables one to postulate a new hypothesis that during an epidemic outbreak and in the initial phase of colonisation the mites live longer and produce more eggs when the density of the population is lower until the population reaches a threshold level of crowding and vice versa. This phenomenon of phase variation brought about by the group effect is an adaptive character in the sense that when the density of the population is higher, the mites develop faster before the available food is exhausted.
Effects of the gregariousness of larvae in galls on the reproductive success of the pine needle gall midge, Thecodiplosis japonensis Uchida et Inouye (Dipt., Cecidomyiidae)
Authors: Soné K.
Published: August 2009

The effects of the gregariousness of larvae of the pine needle gall midge, Thecodiplosis japonensis Uchida et Inouye (Dipt., Cecidomyiidae), on the reproductive success of the midge were examined by field observations and laboratory experiments. The gregariousness of larvae in a gall did not cause the death of larvae in the gall, and the number of emerged adults per gall was expected to increase with the number of larvae per gall. Gregariousness decreased the size of larvae in galls. The decline in the larval size did not cause a simple decline in the number of eggs deposited per female. Females that emerged from medium size larvae deposited many more eggs than those from large and small larvae. The calculated number of eggs deposited per gall increased with an increase in the number of larvae per gall from one to five, but not when the number of larvae per gall was more than six. A simple model showed that if a female deposited about 10 eggs per egg cluster the number of eggs deposited by her daughters in the next generation would be maximum. The oviposition pattern and the gregariousness of larvae in galls in the field probably offer the midge the maximum reproductive success.
Thermal requirements ofDiaeretiella rapae(M'Intosh) on Russian wheat aphid (Diuraphis noxiaMordwilko, Hom., Aphididae) hosts
Authors: Bernal J. , González D.
Published: August 2009

Studies were undertaken to assess the effect of temperature on development, and to estimate the thermal requirements (tandK) and upper developmental thresholds of three developmental periods (i.e. egg–mummy, mummy–adult, egg–adult) inDiaeretiella rapae(M'Intosh) (Hym., Aphidiidae) from China onDiuraphis noxia(Mordwilko) (Hom., Aphididae) hosts. Experiments were conducted at 5 constant temperatures: 10.0, 15.5, 21.1, 26.7, and 29.4°C (±1.0°C). Photoperiod and humidity conditions were maintained at 14L: 10D and 50–70% R.H., respectively. In general, the developmental times and rates for the three developmental periods inD. rapaewere influenced by the temperature to which they were exposed. Developmental times for the egg–mummy period increased from 7.3 days at 29.4°C to 28.5 days at 10.0°C; for the mummy–adult period from 4.6 days at 29.4°C to 20.0 days at 10.0°C; and for the egg‐adult period from 11.3 days at 29.4°C to 48.3 days at 10.0°C. At all five temperatures, the developmental times for the egg–mummy period were longer than the developmental times for the mummy–adult period. There were no differences in developmental times between males and females at the temperatures tested except at 15.5°C where males developed slightly faster than females (P < 0.011), i.e. 23.2 and 24.0 days, respectively. The estimatedtandKvalues were, respectively, 2.47°C and 198.99 degree‐days for the egg‐mummy period; 3.89°C and 106.45 degree‐days for the mummy–adult period; and 3.56°C and 292.29 degree‐days for the egg‐adult period. The upper developmental threshold for the three developmental periods is considered to be above, but near 29.4°C since the developmental rate decelerated but did not cease at this temperature.
Disruption mechanisms of pheromone communication in the European grape moth Lobesia botrana Den. & Schiff. (Lep., Tortricidae) II. Influence of the population density and the distance between insects for males to detect the females in atmosphere impregnated by pheromone
Authors: Schmitz V. , Roehrich R. , Stockel J.
Published: August 2009

The main consequence of mating disruption in the European grape moth is a decrease of female active space. Two experiments were done in a vineyard in order to evaluate the effect of population density and initial distance between insects on female detection by males.

In the first experiment, two population densities corresponding to 10 and 20% infestation levels during the previous generation, were carried out in regard to two types of distribution of the population: low and high aggregates. Within these limits, population density had no influence on later attacks if the distribution was homogeneous, while, if the distribution was not homogeneous, attacks were more important.

In the second experiment, colored males were released in areas with dispensers (1 and 500 mg of pheromone) and traps baited with one virgin female in a small cage. It was confirmed that the number of males trapped by females decreased when the dose of pheromone increased. Without pheromone, males scattered and may be captured at all distances. With pheromone, the nearest female only may be located by a male.

Etude des mécanismes de la confusion sexuelle chez l'Eudémis de la vigne, Lobesia botrana Den et Schiff (Lep., Tortricidae). II ‐ Rôles respectifs de la densité de population et de la distance entre les insectes pour la détection des femelles par les mâles en atmosphère imprégnée de phéromone

Chez L. botrana, la confusion sexuelle a pour conséquence majeure la diminution de l'espace actif de la femelle. Dans ce travail, deux expérimentations ont été réalisées en vignoble en vue d'évaluer l'effet de la densité de population et de la distance initiale entre les insectes sur la détection des femelles par les mâles.

Dans la première expérience, deux densités de population, correspondant à des attaques de 10 et 20% des grappes lors de la génération précédente ont été réalisées selon deux types de répartition en vignoble (agrégats faibles et agréggats forts). Dans ces limites, la densité n'intervient pas sur les attaques ultérieures si la population est bien répartie, alors que, dans le case contraire, les attaques sont nettement plus abondantes.

Dans la deuxième expérience, des lâchers de mâles d'élevage colorés étaient effectués en différents points des zones où étaient disposés des diffuseurs chargés de 1 ou 500 mg, face à des pièges englués appâtés d'une femelle vierge encagée. Il est confirmé que la proportion des mâles capturés par les femelles diminue quand la dose de phéromone augmente. En absence de confusion, les mâles se dispersent et peuvent être capturés à toutes les distances. En confusion, seule la femelle la plus proche peut être repérée par le mâle.
Potato tuber moth Phthorimaea operculella (Zeller) (Lep., Gelechiidae) and tuber infestation in Tunisian potato fields: analysis of the flight phenology
Authors: Roux O. , Baumgärtner J.
Published: August 2009

From 1986 to 1991, pheromone traps were placed in Tunisian potato fields to record weekly the number of male Phthorimaea operculella (Zeller). The data were subjected to a time‐series analysis. The coincidence of social events with harvest practices are considered responsible for the relatively high number caught in 1986. In the subsequent years, the pheromone catches gradually decreased, and a linear model was used to remove this trend. A study of seasonality revealed a peak at the beginning of June and another increase in mid‐June leading to high catches beyond the period of spring potato crops. After removal of the seasonality the correlogram indicated a stationary stochastic process. By means of a spectral analysis, a four‐week cycle, presumably influenced by the moon, and a 10‐week cycle, due to unknown causes, were identified. Furthermore, there is an annual cycle related to increasing population densities in spring, i.e. the harvest time of the main‐season potato crop.
Dispersal of the spruce beetle, Dendroctonus rufipennis Kirby (Col., Scolytidae) from an experimental log deck
Authors: Safranyik L. , Shore T. L. , Linton D. A. , Taylor S. P.
Published: August 2009

Dispersal of spruce beetles from a log deck composed of infested (brood) and uninfested spruce logs was assessed by trapping emerged beetles and sampling logs for fresh attacks. The brood logs were dusted with fluorescent powder in order to mark beetles as they emerged. Two other log decks, composed of uninfested spruce, were built 25 m distant on opposite sides of the brood log deck to provide alternative host material for the dispersing beetles. About 14% of the emerged beetles attacked uninfested logs in the central deck and 25% attacked logs in the other two decks. The balance of the beetles dispersed beyond the experimental area.
Investigations on the nuclear polyhedrosis of teak defoliator, Hybhea puera (Cram) (Lep., Hyblaeidae)
Authors: Ahmed S. I.
Published: August 2009

Laboratory and field studies on the nuclear polyhedrosis of teak defoliator caterpillars, Hyhlaeu pueru (Cram) were carried out to understand the insect‐virus relationship. The typical symptoms of nuclear polyhedrosis were observed in both naturally and artificially infected caterpillars. The natural incidence of the disease observed was 35.6%. The

number of polyhedral inclusion bodies (PIBs) per larva ranged from 1.12 times 10 to 2.37 times 10“ with an average of 1.973 times 10”.There was no correlation between the larval weight and number of PIBs estimated. The virulence of the NPV, measured in terms of total mortality and incubation period was reduced when PIBs of the virus were stored at room temperatur as a dry powder for a period of 6 years. The cross infectivity tests against the Achaea janata. Atteva fabriciella. Catopsilia crocale, Eligma narcissus, Euproctis fraterna and Eutectona machacralis proved negative. It was confirmed with the straining property of the polyhedra that the disease pathogen belonged to nuclear polyhedrosis virus (NPV)
Increased effectiveness and applicability of the sterile insect technique through male‐only releases for control of Mediterranean fruit flies during fruiting seasons
Authors: Hendrichs J. , Franz G. , Rendon P.
Published: August 2009

One of the main obstacles for a wider use of the Sterile Insect Technique (SIT) against the Mediterranean fruit fly (medfly) is the damage commercial fruit suffers due to sterile female stings. To overcome this obstacle, the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture has played a leading role in sponsoring and carrying out research to develop medfly genetic sexing strains that allow male‐only SIT releases.

Recently, as a result of this continued FAO/IAEA effort, genetic sexing strains based on a temperature sensitive lethal (tsl) mutation have been developed at the IAEA Laboratories at Seibersdorf. Unlike previous pupal color sexing strains, these ‘second generation’ sexing strains allow female killing at an early (embryonal) stage. In addition, they are essentially stable under mass rearing conditions. This represents an important breakthrough because both of these attributes were considered indispensable for genetic sexing strains with any potential to replace conventional strains with both sexes in large scale sterile medfly production facilities. Besides the considerable savings in the costs of release and field monitoring, genetic sexing strains in field tests have shown severalfold increases in the effectiveness of the SIT as compared with the standard strains involving males and females. When releasing both males and females, sterile males are apparently not used effectively, because they use their limited sperm mostly to mate with sterile females and because they do not disperse widely in the presence of these females. When males only are released, however, they disperse much further in search of wild females and compete more intensely with wild males for wild females.

As a result of the availability of usable male‐only strains, and the demonstration of their increased effectiveness, the applicability of the SIT against medfly has increased in two different ways. Highly developed commercial fruit growing regions, that previously had excluded application of SIT because of the fruit damage due to sterile female stings, are now reconsidering such free area/exclusion programs. More‐importantly, sterile male releases can now also be used for routine control purposes, rather than only for eradication programs, partially or fully replacing chemical bait‐sprays during the fruiting seasons.
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

Reproduction 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

In 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 variation

Improving 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.

L'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

The 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.

Différences 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

Addition 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

The 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

Pear 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

The 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

Hibernating 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

Electroantennogram 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

Adults 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

Most 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

The 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

Feeding 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

The 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

Studies 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

The 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

During 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.
Taxonomic characters for differentiating cohabitating larvae of Dendroctonus ponderosae and Ips pini (Col., Scolytidae)
Authors: Bentz B. J. , Vandygriff J. , Johnson K.
Published: August 2009

Abstract: Dendroctonus ponderosae Hopkins and Ips pini (Say) are often found cohabitating in Pinus spp. hosts, especially when D. ponderosae is in the endemic population phase. Although the adult stages are morphologically distinct, distinguishing between the species is difficult when only the larval stages are present. Using field collected specimens, several taxonomic characters of the larvae were identified which may be used to differentiate the two species. These results have application in studies of endemic D. ponderosae populations and competitive interactions between I. pini and D. ponderosae populations.
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.
The chemosterilizing activity of some mycotoxins and their influence on the development and survival of Spodoptera littoralis (Boisd.) (Lep., Noctuidae)
Authors: Sadek M. M. , Crailsheim K. , Azab S. G.
Published: August 2009

Abstract: The effects of four mycotoxins: aflatoxin B1 (AFB2), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1) and kojic acid (KA) on Spodoptera littoralis were investigated. Second instar larvae were allowed to feed on an artificial diet containing various concentrations of either AFB1 (0.5, 1, 2, 2.5, 3 and 3.5 ppm), AFB2 (2, 3 and 4 ppm), AFG1 (1, 2, 3 and 4 ppm), or KA (up to 100 ppm). Mortality, development time, fecundity, egg hatchability and adult longevity were determined for each treatment and compared to control values. AFB1 (2–3.5 ppm) and AFG1 (3 and 4 ppm) delayed the larval and pupal development and reduced the fecundity and hatchability. AFB2 (4 ppm) reduced fecundity and hatchability but did not affect the development rate. The highest mortality was caused by AFB1 (3.5 ppm). KA had no remarkable effect when given alone, even in concentrations up to 100 ppm. Yet it potentiated the toxicity and sterilizing activity of AFB1. A combination of AFB1 (3.5 ppm) and KA (75 ppm) caused more than 92% sterility among male and female moths. Sterilized males exhibited good, though not fully equal, mating competitiveness against control males. The possibility of making use of the chemosterilizing activity of these mycotoxins is discussed.
Field biology of Zapriothrica sp. Wheeler (Dipt., Drosophilidae), a pest of Passiflora spp. of high elevation possessing long tubular flowers
Authors: Casañas‐Arango A. D. , Trujillo E. E. , Friesen R. D. , de Hernandez A. M. R.
Published: August 2009

Abstract: Blooms of Hawaii's banana poka, Passiflora tripartita var. tripartita, grown at Ipiales, Colombia were found suitable for the completion of the life cycle of the fly Zapriothrica sp. The tubular flowers were an ideal habitat for the mating and reproduction of this minute Andean fly. Oviposition occurred only on immature flowers 30‐20 days from bud opening. Eggs hatched 10–13 days after oviposition. Larvae averaged 1.3 × 0.3 mm at hatching, and 15 days after hatching at the end of the third larva instar averaged 5.2 × 1.0 mm. The light‐brown pupa averaged 3.6 × 1.3 mm and required 40–45 days for completion of this stage. Adult flies averaged 5.1 × 1.3 mm and their life span was 7–10 days in captivity and 5–8 days in field cages. Mating was inside the flower tube and a minimum of five pairs of adults were required for copulation. Other Passiflora spp. of high elevation with tubular flowers were host of the insect. However, campanulate flowers, e.g., P. edulis, P. ligularis, and P. alnifolia did not elicit any response whatsoever for feeding, aggregation, mating or oviposition. The dropping of immature flower‐buds caused by this insect in P. tripartita v. mollissima and P. tripartita v. tripartita was 60–80% in Colombian and Ecuadorian curuba farms with high pest populations.
Ant‐attendance as a critical factor in the biological control of the banana aphid Pentalonia nigronervosa Coq. (Hom. Aphididae) in Oceania
Authors: Stechmann D.‐H. , Völkl W. , Starý P.
Published: August 2009

Abstract: Colonies of the banana aphid Pentalonia nigronervosa Coq. were heavily attended by ants in banana plantations on Tongatapu Island, Kingdom of Tonga. Ant‐attendance reduced the density of indigenous predators of P. nigronervosa considerably. Most important was the reduction by ants of the parasitism of Aphis gossypii by the aphelinid wasp Aphelinus gossypii. The introduced aphid parasitoid Aphidius colemani was also heavily attacked by various ant species, and we conclude that ant‐attendance may limit the economic impact of this successfully introduced parasitoid species.
Seasonal difference in the abundance of the spruce beetle (Ips typographus japonicus Niijima) (Col., Scolytidae) within and outside forest in a bivoltine area
Authors: Furuta K. , Iguchi K. , Lawson S.
Published: August 2009

Abstract: In Hokkaido (Japan), the spruce beetle (Ips typograpaus japonicus) kills standing spruce trees after selection cutting. The seasonal change in the number of beetles captured in 18–21 traps within or outside forest was analysed, with reference to a control strategy for this species in a bivoltine area. The number of beetles captured in traps had two peaks: one, which was small, in early June, and the other, which was a large peak, in July. However, the number of beetles captured in traps outside the forest had only one small peak, in June. The difference between the inside and outside of the forest was caused by the difference in the number of newly emerged beetles captured in traps. Beetles were distributed contagiously within the forest and there was no remarkable change in distribution pattern throughout seasons. Beetles were distributed at random in June when beetle activity was high outside forest. Overwintered beetles must undertake long‐range dispersal irrespective of whether they are within or outside of forest for finding suitable breeding materials. Nevertheless, the most important point is that newly emerged beetles stayed inside the forest and only a few individuals dispersed outside the forest. This study recommends that different control methods are adopted according to the seasons for the control of spruce beetles.