bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aufnahme von Wasserdampf aus ungesättigter Atmosphäre und ihre ökologische Bedeutung bei mesostigmaten Milben
Authors: Gaede K. , Knülle W. 
Published: October 2003

ZusammenfassungViele mesostigmate Milben mit unterschiedlicher Lebensweise und Habitatbeziehung absorbieren Wasserdampf aus ungesättigter Atmosphäre. Eingeschlossen sind hämatophage, räuberische, saprophage und polyphage Arten. Die niedrigste relative Feuchte, bei der Wasserdampfaufnahme möglich ist, reicht in Abhängigkeit von der Species von 76% bis 97% rel. Feuchte. Die Transpirationsraten der verschiedenen Arten unterscheiden sich um den Faktor 50. Durch Sorption und Transpiration folgt der Wassergehalt der Milben den Schwankungen der Umgebungsfeuchte ziemlich unvermittelt. Durch atmosphärische Wasserdampfaufnahme kompensieren die Milben Wasserverluste. Die kritische Gleichgewichtsluftfeuchte der Milben bezeichnet die relative Feuchte der umgebenden Luft bei der sich Sorption und Transpiration die Waage halten und bei der die Milben in der Lage sind, den Körperwassergehalt aufrecht zu erhalten. Die Versuche deuten auf einen oralen Sorptionsort hin. Sorption und Transpiration sind physiologische Parameter von ökologischer Bedeutung hinsichtlichWachstum von Populationen, Überleben und Habitatpräferenz. Eine Reihe von Arten sind als Parasiten und Agenzien der biologischen Schädlingsbekämpfung von grösserer wirtschaftlicher Bedeutung.
Behavioural induction in Drosophila: timing and specificity
Authors: Barron Andrew B. , Corbet Sarah A. 
Published: October 2003

AbstractExperiments reported in this paper investigate the properties of a change in the responsiveness of adult Drosophila melanogaster induced by exposure to different rearing media. This effect has previously been described as habituation or associative learning. Exposure to food medium containing 0.08% menthol induced a positive response to menthol odour in a T‐maze olfactometer. A brief (one hour) exposure to mentholic food just before testing was sufficient to induce a change in responsiveness. The effect did not persist through periods of more than an hour of separation from mentholic medium.Effects induced by exposure to a single compound were not specific to that compound alone. Menthol‐reared flies (MRFs) differed from plain reared flies (PRFs) in their responsiveness to the odours of benzaldehyde and ethyl acetate, as well as menthol, and exposure to ethyl acetate induced a change in response to menthol odour.That there was an induced positive response to menthol in MRFs suggests that conventional habituation is insufficient to explain the induced change in responsiveness, but the generalised nature of this behavioural induction in MRFs is hard to explain in terms of associative learning. The mechanism underlying the induction remains elusive.
Glandular trichomes of Solanum berthaultii and its hybrids with potato deter oviposition and impair growth of potato tuber moth
Authors: Malakar Raksha , Tingey Ward M. 
Published: October 2003

AbstractGlandular trichomes on foliage of the wild potato species, Solanum berthaultii Hawkes, deter oviposition by the potato tuber moth (PTM), Phthorimaea operculella Zeller and negatively affect other important performance parameters. Oviposition deterring factors are localized in the glandular trichomes of S. berthaultii. When mechanically transferred to foliage of a susceptible potato cultivar, trichome contents reduced egg laying by 97%. Removal of glandular trichomes from S. berthaultii foliage using a combination of chemical and mechanical procedures increased oviposition rates ca. 210‐fold. Removal of trichomes also led to increased mobility of larvae on the leaf surface, more leaf feeding, shorter larval development and larger pupae. The resistance conferred by glandular trichomes of S. berthaultii provides an important genetic trait potentially useful for management of PTM.
Statistical analysis of amounts and ratios in pheromone composition: a mixed model approach
Authors: Van Dongen Stefan 
Published: October 2003

AbstractAnalysis of variation in pheromone amounts and ratios between individuals is usually performed separately for amounts and ratios of the different components. Non‐parametric tests are regularly applied. This way of analysis is statistically correct, yet, limited for several reasons. The use of a parametric linear mixed model approach to analyze both amounts and ratios of different components at the same time is proposed. This method appears to be very flexible and may facilitate the analysis of pheromone data.
Laboratory and field experiments towards the development of an attract and kill strategy for the control of the codling moth, Cydia pomonella
Authors: Lösel Peter M. , Penners Gunter , Potting Roel P.J. , Ebbinghaus Dirk , Elbert Alfred , Scherkenbeck Jürgen 
Published: October 2003

AbstractA viscous formulation based on castor oil containing the pyrethroid insecticide cyfluthrin and E8, E10‐dodecadienol, the main component of the codling moth sex pheromone, (Cydia pomonella L.: Tortricidae, Olethreutinae) was developed. The insecticidal performance of the formulation was evaluated in the laboratory using a tarsal‐contact bioassay. The pheromone dosage required to attract male moths to the formulation was determined in behavioural tests performed in a wind tunnel. The efficacy of formulations applied to seedlings of the host plant was further investigated in glasshouse experiments conducted with male moths in small wire‐gauze cages. The laboratory tests resulted in a formulation for preliminary field trials containing 4% cyfluthrin and 0.1% pheromone. During the 1995 growing season, experiments were conducted in apple orchards at three locations in Germany. The formulation was first applied to the bark of apple trees (Malus domestica) in mid May and then again in late July. A good level of control, comparable with a spray treatment using the insect growth regulator Alsystin was achieved. The potential of the attract and kill strategy, combining selective attraction of a pest species with the efficacy associated with a pyrethroid insecticide treatment, as a means of controlling the codling moth in commercial apple growing, is discussed.
Can chemical cues from blossom buds influence cultivar preference in the apple blossom weevil (Anthonomus pomorum)?
Authors: Kalinová Blanka , Stránský Karel , Harmatha Juraj , Čtvrtečka Richard , Žd'árek Jan 
Published: October 2003

AbstractThe post‐hibernating adults of the apple blossom weevil, Anthonomus pomorum (L.), show preferences for certain cultivars in mixed apple tree orchards. The degree of infestation of various cultivars was positively correlated with the density of flower buds at a comparable phenological stage, but the numbers of collected beetles were not linearly proportional to the bud density of different cultivars. Hence other possible factors, namely chemical ones, were investigated. Chromatographic analysis of apple tree bud emanations showed that volatiles from two different apple cultivars that show a different attractiveness to the beetles, differed in chemical composition. Several less volatile components of the bud emanation bouquet elicited antennographic responses in both male and female antennae. Four terpene hydrocarbons, namely 3‐carene, perillene, caryophyllene and (E,E)‐α‐farnesene, were identified among the components that produced distinct electrophysiological responses in the antennae. These findings support a hypothesis that the adult weevils use chemical cues for olfactory discrimination during host‐searching behaviour.
Host suitability of two biotypes of Bemisia tabaci on some common weeds
Authors: Muñiz M. 
Published: October 2003

AbstractSignificant differences in some reproductive parameters of the B and Q biotypes of Bemisia tabaci (Gennadius) with regard to four species of winter weeds were determined in a no‐choice assay. The highest fecundity (eggs) and fertility (pupae and adults) were obtained with Malva parviflora L. as host, followed by Capsella bursa‐pastoris L., Brassica kaber (DC) and Lactuca serriola L. The percentage of adult emergence (from egg to adult) was significantly higher (P < 0.001) with M. parviflora, C. bursa‐pastoris and B. kaber than with L. serriola. Except on L. serriola, the mean values of the reproductive parameters for the Q‐biotype were significantly (P < 0.05) greater than those for the B‐biotype. On the other hand, in choice experiments with summer weeds, both B‐ and Q‐biotypes preferred Datura stramonium L. and Solanum nigrum L. to Amaranthus retroflexus L., Chenopodium album L. and Echinochloa crus‐galli L. Significantly more males and females, and more pupae and empty pupal cases per plant were found on D. stramonium than on S. nigrum. Adult abundance on A. retroflexus, C. album and E. crus‐galli plants was very low. At a constant temperature of 26 ± 1 °C, the Q‐biotype developed significantly faster than the B‐biotype on S. nigrum and D. stramonium. Both biotypes required, for this development, significantly more days on D. stramonium than on S. nigrum. These results suggest that it is important to suppress the growth of M. parviflora, C. bursa‐pastoris, B. kaber, D. stramonium and S. nigrum in order to avoid the risk of further expansion of whitefly populations where these weeds and both B‐ an Q‐biotypes are present.
Biology and oviposition behavior of the phorid Apocephalus attophilus and the response of its host, the leaf‐cutting ant Atta laevigata
Authors: Erthal Milton , Tonhasca Athayde 
Published: October 2003

Abstract Atta laevigata (Smith) (Hymenoptera: Formicidae) foragers collected in the field and parasitized by Apocephalus attophilus Borgmeier (Diptera: Phoridae) (1.2% of sampled ants) were larger and had lower survival rates than similar non‐parasitized foragers. Moreover, the size of parasitized ants was significantly correlated with the number of A. attophilus puparia and percentage of adult emergence. These results suggest that host size is important for the reproductive success of A. attophilus. Different from most ant‐parasitizing phorids, A. attophilus exhibits a pre‐oviposition behavior that involves walking towards the host and inspecting it, and this careful approach may be responsible for a relatively low percentage of parasitoid detection by A. laevigata. When an exotic resource (Acalypha sp. leaves) was placed on ants' foraging trails, more foragers were recruited, which resulted in the attraction of A. attophilus. The number and recruiting rates of small workers (minima) were significantly higher on leaves visited by A. attophilus, but larger foragers showed no response to phorids. These results demonstrated that minima react to the presence of A. attophilus and suggest a defensive role of these ants against phorid parasitism.
Integrating pesticide effects with inundative biological control: interpretation of pesticide toxicity curves for Anaphes iole in strawberries
Authors: Udayagiri Sujaya , Norton Andrew P. , Welter Stephen C. 
Published: October 2003

AbstractWe examined pesticide residue effects on the egg parasitoid Anaphes iole Girault (Hymenoptera: Mymaridae), an inundative biological control agent for Lygus hesperus Knight (Heteroptera: Miridae) in strawberries (Fragaria×ananassa Duchesne). Our objectives were to identify compatible pesticides, determine appropriate parasitoid release timings for minimizing harmful effects, and develop an approach for interpreting pesticide toxicity curves. Six insecticides, 2 acaricides and 6 fungicides were tested, and survivorship of adult A. iole exposed to foliar residues for 48 h, at 4–6 different times after pesticide application, was examined. A logistic function was developed for incorporating control mortality at each test date. Values for LT50 (Lethal Time for 50% mortality) and mortalities on day 1 (initial mortality) and day 13 (estimated maximum time parasitoid releases can be delayed under extreme summer conditions) were estimated. In the study, insecticide residues proved to be the most toxic, followed by those from acaricides while most fungicides were least toxic. Among insecticides, fenpropathrin, bifenthrin and carbaryl caused the greatest mortality (estimated mortality on day 13 > 75%). Residues of naled resulted in the least mortality (LT50LT50=3.2 days) followed by methomyl (LT50=8.3 days) and malathion (LT50=13.2 days). Estimated mortality = 12.3% on day 13 for the acaricide propargite and < 1% for abamectin. For the fungicides benomyl, captan, myclobutanil and thiram, estimated mortality on day 1 was < 1%, and for iprodione it was < 6%, indicating compatibility with A. iole releases. For sulfur, LT50=0, but the mortality decay curve was relatively flat (estimated mortality on day 13=13.6%). These results suggest possibilities for integrating A. iole releases with certain pesticide programs by appropriate timing of pesticide applications to minimize negative impacts.
Do Maculinea rebeli caterpillars provide vestigial mutualistic benefits to ants when living as social parasites inside Myrmica ant nests?
Authors: Wardlaw J.C. , Thomas J.A. , Elmes G.W. 
Published: October 2003

AbstractCaterpillars of the lycaenid butterfly Maculinea rebeli Hirschke (Lepidoptera: Lycaenidae) live for 11–23 months as social parasites in Myrmica (Hymenoptera: Formicidae) red ant nests, a trait that is believed to have evolved from mutualistic myrmecophilous ancestry. Although Maculinea rebeli caterpillars harm Myrmica larvae, they simultaneously produce copious secretions which the adult worker ants imbibe, perhaps representing a vestige of the ancestral mutualism. We report the results of laboratory experiments designed to test alternative hypotheses: (i) Maculinea rebeli caterpillars provide a beneficial source of sugar in return for being tended by Myrmica workers; (ii) Maculinea rebeli harms its host by stressing the workers by competing for available sugar. Comparisons were made of Myrmica worker fitness after 90–450 days under all possible combinations of three experimental treatments: ±M. rebeli caterpillars, ± sucrose and ± ant brood. Caterpillars always reduced the survival of both ant workers and their larvae, even when sugar was not provided, suggesting that M. rebeli is wholly parasitic on all stages in its host colony. The results also confirmed the importance of sucrose in the diet of Myrmica, and showed that M. rebeli caterpillars which eat ant brood to supplement their normal trophallactic feeding by workers develop more quickly ‐ but have the same survival and pupal weights – as caterpillars that are fed solely by worker ants.
Behaviour of male pine sawflies, Neodiprion sertifer, released downwind from pheromone sources
Authors: Östrand Fredrik , Anderbrant Olle , Jönsson Peter 
Published: October 2003

AbstractThis study investigated the behaviour of male European pine sawflies, Neodiprion sertifer Geoffroy (Hym., Diprionidae), that were released and observed downwind from pheromone traps baited with 100 μg of the sex pheromone, (2S,3S,7S)‐3,7‐dimethyl‐2‐pentadecyl acetate. Releases were done at three distances; either at 5 m from one trap, or at 50 or 200 m from five traps, placed in a line perpendicular to the current wind direction. As control, males were released identically but without any pheromone source present. The behaviour of the males prior to take‐off was studied. A total of 1729 males were released, and 80% of them took flight. Males took off significantly faster in the presence of pheromone. Grooming was significantly more frequent in presence of pheromone compared with control. In all pheromone experiments significantly more males displayed grooming, wing fanning and take‐off towards the wind compared with the control. Weather data was simultaneously collected at the study site. Wing fanning was negatively correlated with wind speed. Grooming was not influenced by wind speed. Reduced levels of incoming short‐wave radiation lowered the take‐off frequency significantly. Pheromone‐induced behaviour in diprionids seems to be less distinct than in other insects, e.g., Lepidoptera.
Specificity of chemical cues used by a specialist egg parasitoid during host location
Authors: Meiners Torsten , Westerhaus Christine , Hilker Monika 
Published: October 2003

AbstractPlant synomones and host kairomones are known to guide the egg parasitoid Oomyzus gallerucae to its specific host, the elm leaf beetle Xanthogaleruca luteola (=Pyrrhalta) (Muller) feeding upon elm leaves (Ulmus spp.). In this study, we investigated whether the activities of these plant synomones and kairomones are specific for the plant and herbivore species, respectively. Olfactometer and contact bioassays were used. In habitat location, O. gallerucae (Fonscolombe) is known to use synomones from Ulmus minor (Miller) that are induced by egg depositions of X. luteola. The attractiveness of such induced volatiles was shown to be specific both for the Ulmus species and the herbivore species depositing eggs. Neither leaves of U. glabra Hudson (=U. montana) carrying eggs of X. luteola nor leaves of U. minor (=U. campestris=U. procera) carrying eggs of the chrysomelid species Galeruca tanaceti L. emitted attractive synomones. O. gallerucae is also known to be attracted by volatile kairomones from faeces of X. luteola feeding on U. minor and to show prolonged antennal drumming when contacting substrates contaminated with these faeces. The kairomonal activity of the faeces was proved to be independent of the Ulmus species, since also faeces from elm leaf beetles feeding upon U. glabra emitted attractive volatiles. However, the faecal kairomones were specific for the herbivorous species, since faeces from a lepidopteran larva (Opisthograptis luteolata L.) feeding upon elm hardly elicited any antennal drumming in O. gallerucae. The egg parasitoid studied is known to recognize host eggs of X. luteola by contact kairomones extractable from the egg shell. O. gallerucae clearly differentiated between host eggs and eggs of another closely related chrysomelid species, Galerucella lineola L., as was shown by comparing duration of antennal drumming on host eggs and eggs of G. lineola.
Rearing of Prays citri on callus derived from lemon stigma and style culture
Authors: Carimi Francesco , Caleca Virgilio , Mineo Giovanni , De Pasquale Fabio , Crescimanno Francesco Giulio 
Published: October 2003

AbstractA new method for rearing the citrus flower moth (Prays citri Mill.) (Lepidoptera, Yponomeutidae) on lemon [Citrus limon (L.) Burm.] callus is reported. In the present research callus (an undifferentiated mass of plant cells that can be grown under sterile conditions on an artificial medium in vitro) was induced from lemon stigma and style explants cultured on Murashige and Skoog (MS) medium supplemented with 500 mg l−1 malt extract, 13.3 μM 6‐benzylaminopurine, and 146 mM sucrose. Also somatic embryogenesis and plant regeneration were obtained from the cultures of styles and stigmas of lemon. Adults were obtained from larvae on infested flowers collected in the field. Different oviposition substrates were used: white oval pearls (WOP), black oval pearls (BOP), rooted shoots (RS) of lemon obtained in vitro, and artificial flowers containing lemon callus (AF). Larvae were reared on lemon callus. Adults oviposited on RS, on WOP, and on AF. BOP were rejected as oviposition substrates. The flower moth reared on callus oviposited fertile eggs. In our tests P. citri completed three generations on callus or on callus plus shoots. In the latter case the larvae preferred callus and fed on shoots only after callus was completely eaten. The life cycle on callus at 23 ± 1 °C lasted about 21 days. There were significant differences between oviposition substrates for what concerns the number of eggs laid. It was observed that females generally preferred WOP (about 25 eggs/female) to AF (about 20 eggs/female) or RS (about 12 eggs/female) as oviposition substrate. Nevertheless the percentage of eggs that developed into adults was higher when AF sealed with stretched Parafilm were used (about 70% of eggs developed into adults). The method of rearing P. citri with AF was labour‐saving and the feeding substrate (callus) had less tendency to become mouldy or decompose than when WOP and RS were used. Since such a diet is available for the insect all year round and callus can be produced in unlimited quantity, it could be possible to obtain a mass production of this moth.
The feeding behavior of Trichogramma brassicae: new evidence for selective ingestion of solid food
Authors: Wu Z.X. , Cohen A.C. , Nordlund Donald A. 
Published: October 2003

AbstractA descriptive study of the feeding behavior and structures of Trichogramma brassicae Bezdenko (Hymenoptera: Trichogrammatidae) was conducted. Based on direct observational and biochemical evidence, larvae feed predominantly on particulate materials, starting ca. 25 h post‐oviposition. Feeding lasted for ca. 9 h, at 25±1 °C. During this feeding period the shape of the larvae changed from vermiform to pyriform and then to sacciform, resulting in a ca. 40‐fold increase in body size. Larvae used elaborate feeding behaviors as they pulled solid food particles to their oral opening, broke small particles from larger ones, and took the particles into the stomodaeum, which is a powerful pump. In the stomodaeum, peristaltic movement further macerated the particles, which eventually passed through the cardiac valve into the midgut. As indicated by changes in fluorescently labeled casein, digestive enzymes aid in the extra‐oral chemical digestion of food. The contents of the gut, during and shortly after feeding, were almost entirely closely packed solid particles. The behavioral activity of feeding larvae centered almost exclusively on processing and ingesting solid food particles. The rapid larval growth is much more plausibly explained by their feeding on the highly concentrated nutrients found in solid foods, rather than the extensive concentration required if dilute liquids were the principal source of nutrients. The implications of these findings for the development of practical artificial diets are discussed.
Relationships between the occurrence of misshapen fruit on late‐season strawberry in the United Kingdom and infestation by insects, particularly the European tarnished plant bug, Lygus rugulipennis
Authors: Easterbrook M.A. 
Published: October 2003

AbstractIn experiments in which the European tarnished plant bug, Lygus rugulipennis, was caged on the developing flowers or young fruits of strawberry, the insects caused malformation of the fruits. Another species of capsid, Plagiognathus chrysanthemi, caused similar damage; this species is less numerous than L. rugulipennis on late‐season crops of strawberry in UK. Other insects which sometimes occur in large numbers in the flowers of late‐season strawberry, i.e. various species of thrips and pollen beetles, did not cause fruit malformation in caging experiments, though thrips sometimes caused discoloration of the fruit. In field experiments where numbers of L. rugulipennis were reduced by the use of insecticides, the amount of misshapen fruit was reduced greatly compared to untreated plots. Correlations between the numbers of L. rugulipennis present at the early stages of fruit development and damage scores for fruit deformity were highly significant. This capsid is likely to be the major cause of fruit malformation in late‐season crops of strawberry in the UK.