bluuebunny/crossref_metadata_2025_split huggingface dataset:
Olfactory antennal responses of the vine weevil Otiorhynchus sulcatus to plant volatiles
Authors: van Tol R.W.H.M. , Visser J.H. 
Published: October 2003

AbstractElectroantennograms (EAGs) were recorded from the vine weevil, Otiorhynchus sulcatus F. (Coleoptera: Curculionidae) to a broad range of volatile plant compounds. The response profile is restricted to a small number of volatiles that evoke substantial EAGs. Large EAG responses were particularly found among green leaf volatiles (GLV) such as (E)‐2‐hexenol‐1, (Z)‐3‐hexenol‐1, hexanol‐1, hexanal, and heptanal. Other plant volatiles eliciting responses in the weevils' antenna are 2,5‐dimethylpyrazine, hexylamine, benzylalcohol, 1,2‐dimethoxybenzene, o‐cresol, myrtenol, 3‐methylcyclohexanol, γ‐hexalactone, and γ‐heptalactone. EAG responses to terpenes were generally weak. Many of the monoterpenes are characteristic for the odour of conifers, a group of plants which tend to be avoided by adult vine weevils. The EAG response to several GLV and benzene derivatives in three geographically distinct populations of the vine weevil differed, suggesting between‐population variation in receptor sensitivities for several compounds under test. The GLV‐composition of the odour profile of potential food plants may be an important criterion for a polyphagous insect like the vine weevil to be used in host‐plant selection, since compounds in this odour group dominate so strongly the EAG response profile. In multiple food‐choice situations the weevils are known to prefer certain plant species and we hypothesize that they combine GLV information with that of more specific plant volatiles, thereby promoting attraction or avoidance.
Adaptation of the gypsy moth to an unsuitable host plant
Authors: Lazarević J. , Perić‐Mataruga V. , Stojković B. , Tucić N. 
Published: October 2003

AbstractThe pattern of adaptation with regard to life history traits and traits thought to be important in feeding habits of caterpillars in two populations of the gypsy moth (Lymantria dispar L.; Lepidoptera: Lymantriidae) originating from the locust tree (Robinia pseudoacacia; Fabaceae) and oak (Quercus petrea; Fagaceae) forests were investigated in the laboratory. The Robinia population has experienced unsuitable locust tree leaves as an exclusive food resource for more than 40 years. Since Quercus species are the principal host plants of the gypsy moth, the specific objectives of this study have been to measure the extent of differentiation between ancestral and derived populations in several life history traits (egg‐to‐adult viability, duration of larval and pupal stages, and pupal weight) and nutritional indices – relative growth rate (RGR), relative consumption rate (RCR), assimilation efficiency (AD), gross growth efficiency (ECI), and net growth efficiency (ECD). Significant differences between the Quercus and Robinia populations were detected in pupal duration, RGR, RCR, and AD. The presence of a significant population × host interaction in traits such as preadult viability, duration of pupal stage, RGR, and ECI suggests that adaptation of the gypsy moth to the unsuitable host might be ongoing. Using a full‐sib design, we screened for genetic variation in life history traits within both populations, and examined the genetic correlations of performance across oak and locust leaves within both populations. The genetic variances for analyzed life history traits were lower under conditions that are commonly encountered in nature. Our data show that positive cross‐host genetic correlations preponderate within both populations.
Life history of Bicyclus anynana mutants: Can they serve as internal controls?
Authors: Zijlstra Wilte G. , Zwaan Bas J. , Brakefield Paul M. 
Published: October 2003

AbstractCorrection for environmental effects in quantitative genetics experiments is often achieved by use of separate control populations. However, this method may not always correct accurately for environmental fluctuations in rearing conditions. A more suitable approach could be rearing mutants together with experimental groups, provided that these mutants are clearly distinguishable phenotypically and have similar life histories. We tested whether two mutants (yellow and Spotty) available for the tropical butterfly Bicyclus anynana could serve as such true internal controls. The yellow butterflies had lower survival and longer development time than the wild type animals they were reared with, whereas Spotty individuals were equivalent in those respects to their wild type counterparts. Moreover, heritability estimates for development time in the Spotty stock were mostly significantly different from zero and fell within the range found for wild type butterflies. Therefore, we conclude that a backcrossed stock homozygous for the Spotty mutant of B. anynana can reliably serve as an internal control in life‐history studies and we discuss potential advantages of this method.
Influence of water‐stressed cassava on Phenacoccus herreni and three associated parasitoids
Authors: Calatayud P.A. , Polanía M.A. , Seligmann C.D. , Bellotti A.C. 
Published: October 2003

AbstractThe influence of cassava Manihot esculenta Crantz grown under condition of water‐stress on development and reproduction of the cassava mealybug, Phenacoccus herreni Cox & Williams, and levels of parasitism of three encyrtid parasitoids, Apoanagyrus diversicornis Howard, Aenasius vexans Kerrich, and Acerophagus coccois Smith, were studied in the laboratory. Two cassava cultivars were used: CM 507‐37 (drought‐tolerant) and CMC 40. A 30 day period of water stress, imposed by reducing the irrigation volume, led to a reduction in shoot development and stomatal conductance of leaves of both cassava genotypes. Phenacoccus herreni development and reproduction were favoured by cassava under water shortage. Parasitism decreased and water stress appeared to enhance the encapsulation of parasitoid eggs or larvae by the mealybug. In the case of the parasitoid A. diversicornis, there was a decrease in size of female progeny, suggesting a lower fitness in this species on cassava plants under water stress. All results indicated that cassava grown under low water availability favoured P. herreni development and reproduction, and affected the success of parasitism and, depending on the species, parasitoid development. The drought‐tolerance characteristic of cassava genotypes and parasitoid species most suitable for controlling P. herreni in drought‐stricken areas are discussed.
Variation in the effectiveness of abdominal shields of cassidine larvae against predators
Authors: Müller Caroline 
Published: October 2003

AbstractThe abdominal shields of the larvae of two tansy [Tanacetum (Chrysanthemum) vulgare L., Asteraceae] feeding species of Cassida (Coleoptera: Chrysomelidae) were tested for their ability to deter attacks by predatory insects. Cassida stigmatica Suffr. which carries an abdominal shield made of the exuviae only, and C. denticollis Suffr. which builds a compact faecal shield, were compared. Adult earwigs (Forficula auricularia L., Dermaptera: Forficulidae), adult ladybird beetles (Coccinella septempunctata (L.), Coleoptera: Coccinellidae), and larval lacewings (Chrysoperla carnea Steph., Neuroptera: Chrysopidae) were used as predators and tested in dual choice bioassays. Against earwigs, shields of both cassidine species acted as a protective device. Earwigs preferred to feed on larvae without shields over larvae with intact shields. Adult ladybirds did not differentiate between C. stigmatica larvae with and without exuvial shields. However, C. denticollis larvae with faecal shields were contacted at a higher frequency by ladybird beetles, even though they were less often consumed, i.e., their shield served as protection. In an olfactometer assay, faecal shields of C. denticollis were shown to have no attractive effect on the ladybird beetles. The protection for larvae with shields is likely to be caused by mechanical effects, namely the ability to move the shields. Control insects, where faecal shields of C. denticollis were glued on larvae of Galleria mellonella L. (Lepidoptera: Pyralidae), could not move their shields and were consequently consumed by the predator. Feeding by larvae of lacewings was not influenced by the presence or absence of the faecal shield. Thus, the effectiveness of the abdominal shields of tansy‐feeding cassidine larvae varies with predator species, and might be based more on mechanical, than on chemical modes of action.
Courtship in the medfly, Ceratitis capitata, includes tactile stimulation with the male's aristae
Authors: Briceño R. Daniel , Eberhard William G. 
Published: October 2003

AbstractMale Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) used their aristae to repeatedly tap the female, usually on her aristae, during the second stage of head rocking courtship. The male's antennae moved in an apparently exploratory manner earlier in head rocking. Reduced rates of copulation followed removal of male and female aristae, supporting the idea that tapping with the aristae is an important part of medfly courtship.
Pheromone puffs suppress mating by Plodia interpunctella and Sitotroga cerealella in an infested corn store
Authors: Fadamiro Henry Y. , Baker Thomas C. 
Published: October 2003

AbstractThe efficacy of pheromone mating disruption was investigated in a 7 × 6 × 3 m corn storage room harboring a high population density of Indian meal moth, Plodia interpunctella (Hübner) and Angoumois grain moth, Sitotroga cerealella (Olivier). Pheromones were released from a controlled release dispenser, the metered semiochemical timed release system (MSTRS™) at emission rates of ∼ 0.6 μg min−1 (Z9,E12:14:Ac for Indian meal moth) and ∼ 0.2 μg min−1 (Z7,E11‐16:Ac for Angouimois grain moth). Mating disruption efficacy was evaluated using three parameters: male capture in pheromone traps, visual examination of mating behavior, and the incidence and frequency of mating as measured by spermatophores. In three trials, comparisons were made between data collected before pheromone treatment and during treatment. Disruption of pheromone source location by males averaged 70% and 40% for P. interpunctella and S. cerealella, respectively, in the three trials. In addition, reduced levels of copulation by both species were recorded during pheromone treatment. More importantly, significant reductions were recorded in the incidence and frequency of mating by females of both species collected during the treatment period. While ∼ 85% of P. interpunctella females collected before pheromone treatment in three trials had mated at least once, only 50% of the females collected during treatment had mated. The mean number of matings, as measured by spermatophores, ranged between 0.8–1.1 and 0.5–0.7 before and during pheromone treatment, respectively. Similarly, a ∼ 20–30% reduction in the proportion of mated S. cerealella females was recorded during pheromone treatment. In the three trials, mean number of spermatophores per S. cerealella female averaged 1.0 and 0.7 during the pretreatment and treatment periods, respectively. Additional tests conducted in small boxes also recorded significant mating disruption of both species.
Developing a branch‐mimicking trap for adult plum curculios
Authors: Leskey Tracy C. , Prokopy Ronald J. 
Published: October 2003

AbstractWe conducted field and semi‐field experiments to determine the most visually stimulating and acceptable version of a branch‐mimicking trap (PVC cylinder topped with an inverted screen funnel) to capture adult plum curculios, Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae) foraging within canopies of host trees. Cylinder traps (25 cm tall × 6 cm diam) coated with different colors of gloss or flat latex paint captured similar numbers of feral adults in field tests. Tall cylinder traps (50 cm tall × 6 cm diam) captured significantly more feral adults in field tests in 1999 than cylinder traps of lesser height and/or different diameter, and significantly more released adults arrived at traps with these dimensions compared to cylinder traps of lesser height in semi‐field tests. In field and semi‐field tests, respectively, significantly more adults were captured by and numerically more adults arrived at tall cylinder traps (50 cm tall × 6 cm diam) attached in an upright, standard position to a horizontal limb than attached at angles of 45°, 90°, 135°, or 180° to horizontal limbs.
Oviposition behaviour of the aphid parasitoid, Aphidius ervi: Are wet aphids recognized as host?
Authors: Weinbrenner Manuela , Völkl Wolfgang 
Published: October 2003

AbstractFemales of the central European population of the aphid parasitoid, Aphidius ervi, did not attack wet pea aphids (Acyrthosiphon pisum) that were washed previously with water. After 1 hour, this phenomenon disappeared and A. ervi attacked washed hosts to the same degree as dry ones. Similarly, A. ervi attacked dead aphids killed in liquid nitrogen readily if they were dry but not if they were wet. This effect was also reversible and disappeared after 1 h. When A. ervi females were foraging on broad beans (Vicia faba), they laid significantly more eggs into dry aphids than into wet aphids. Resource utilization of wet aphids, however, was significantly lower in this design than in Petri dishes, due to a changed drop‐off behaviour of the aphid. We conclude that females did not use visual cues for host recognition but instead relied on chemical cues. These cues may be covered by a thin water layer directly after aphids became wet. Our results also demonstrate the importance of abiotic factors for the estimation of the reproductive success of parasitoids in the field.
Host location and selection cues in a generalist tachinid parasitoid
Authors: Stireman John O. 
Published: October 2003

AbstractTachinid flies are diverse and ecologically important insect parasitoids. However, the means by which tachinid species locate and select hosts are poorly known. Many tachinids exhibit unusually wide host ranges and they also possess well‐developed visual systems. These characteristics suggest that tachinids differ from parasitic wasps in their reliance on various sensory modes and types of cues. A series of behavioral assays using the generalist tachinid Exorista mella Walker (Diptera: Tachinidae) were conducted to examine what types of cues this parasitoid uses to locate and accept hosts, and how the cues used may reflect its ecological relationships with hosts. Female E. mella responded strongly to host motion in assays using both live hosts and host corpses, and this cue is shown to be an important elicitor of attack behavior. Females also responded to volatile chemicals associated with damaged food plants of their host in an olfactometer. Flies responded only weakly to direct visual contact with stationary hosts and odors directly associated with hosts. The behavior of female E. mella changed with experience such that more experienced flies recognized and attacked hosts more readily than did inexperienced flies. The use of general olfactory and visual cues by E. mella may be an effective strategy by this polyphagous parasitoid to locate a broad range of potential hosts.
Host selection by the heteronomous hyperparasitoid Encarsia pergandiella: multiple‐choice tests using Bemisia argentifolii as primary host
Authors: Bográn Carlos E. , Heinz Kevin M. 
Published: October 2003

AbstractThe ovipositional patterns of the heteronomous hyperparasitoid Encarsia pergandiella Howard (Hymenoptera: Aphelinidae) in the presence of its primary host Bemisia argentifolii Bellows & Perring (Hemiptera: Aleyrodidae), and in the presence or absence of conspecific and heterospecific secondary hosts (Encarsia formosa Gahan and Eretmocerus mundus Mercet; Hymenoptera: Aphelinidae) were examined to assess host species preferences. Host preferences by heteronomous hyperparasitoids may affect the relative abundance of co‐occurring parasitoid species and may influence host population suppression by the parasitoid community. Four combinations of hosts were tested: (1) B. argentifolii, E. mundus, and E. formosa, (2) B. argentifolii, E. formosa, and E. pergandiella, (3) B. argentifolii, E. mundus, and E. pergandiella, and, (4) B. argentifolii, E. mundus, E. formosa, and E. pergandiella. Arrays of hosts (24) were constructed in Petri dishes using leaf disks, each bearing one host. Thirty arrays of each host combination were exposed to single females for 6 h. All hosts were dissected to determine number of eggs per host. Encarsia pergandiella parasitized E. formosa hosts as frequently as E. mundus hosts. However, E. pergandiella parasitized either of these heterospecific hosts more frequently than conspecific hosts in treatments including two secondary host species. When a third parasitoid species was included in host arrays, E. pergandiella parasitized conspecific hosts as frequently as heterospecific hosts. Developmental stage of the hosts did not significantly influence host species selection by E. pergandiella. Our results indicate that host selection and oviposition by heteronomous hyperparasitoids like E. pergandiella, vary with the composition of hosts available for parasitization, and suggest a preference for heterospecific over conspecific secondary hosts.
Adaptation of a generalist moth, Operophtera brumata, to variable budburst phenology of host plants
Authors: Tikkanen Olli‐Pekka , Lyytikäinen‐Saarenmaa Päivi 
Published: October 2003

AbstractThe adaptation of three allopatric populations of a generalist moth, Operophtera brumata (L.), on two tree species, Prunus padus (L.) and Quercus robur (L.) which represent the extremes of the timing of budburst in spring, was studied in Finland and Sweden. The synchrony of the hatching and budbursting was monitored, and its importance to dispersal and growth of larvae was assessed by rearing cohorts of larvae, whose hatching dates were manipulated, on both hosts. In addition, the realised heritability of the hatching time was estimated.Experimental populations hatched in approximate synchrony with the budburst of their original host species. As a result of the manipulation of the hatching dates of larvae, the growth rates of larvae decreased and the dispersal rates increased on both hosts in relation to the ageing of foliage. The realised heritability of hatching times was rather high (0.63). There were fewer differences in the host use efficiency and behaviour of the experimental populations than in the hatching phenology. The synchrony of hatching with the budburst of the local dominant host plant is probably a result of stabilising selection.
Female sex pheromone of the Chinese tortrix Cydia trasias
Authors: Fu Xiaoyan , Pan Xiangqing , Meng Xianzuo 
Published: October 2003

AbstractThe Chinese tortrix, Cydia trasias (Meyrick) (Lepidoptera: Tortricidae), is a major pest of the Chinese scholar‐tree (Japanese pagoda tree), Sophora japonica L.. Cydia trasias has two or three generations in Beijing, China and overwinters as larvae in seed pods, bark crevices, and twigs of the Chinese scholar‐tree (Chen, 1992; Chen & Qi, 1992). The larvae attack both petioles and seed pods. During outbreaks, the larvae can cause extensive leaf drop, bare twigs, and seed pod damage, reducing the ornamental and economic value of the tree (Enda & Yamazaki, 1987; Chen, 1992). Since the Chinese scholar‐tree is one of the most popular ornamental trees in urban and suburban areas, trees are sprayed with insecticide to control C. trasias outbreaks. Earlier field trials showed that C. trasias can be controlled by mating disruption (Zhang et al., 2001). In our early paper and patent (Fu & Meng, 1997; Meng et al., 1998), we reported E8,E10‐dodecadienyl acetate (E8,E10‐12:Ac) as a pheromone component of C. trasias, but the identification of C. trasias sex pheromone was not complete. We report here the identification and field testing of the female‐produced sex pheromone in C. trasias.
Trapping noctuid moths with synthetic floral volatile lures
Authors: Meagher Robert L. 
Published: October 2003

AbstractMale and female noctuid moths were collected from plastic bucket traps that were baited with different synthetic floral chemicals and placed in peanut fields. Traps baited with phenylacetaldehyde, benzyl acetate, and a blend of phenylacetaldehyde, benzyl acetate, and benzaldehyde collected more soybean looper moths, Pseudoplusia includens (Walker), than benzaldehyde‐baited or unbaited traps. Females comprised over 67% of the moths captured and most were mated. At peak capture, over 90 male and female moths per night were collected. In another experiment, phenylacetaldehyde delivered in plastic stoppers attracted more P. includens moths than traps baited using other substrates, but this chemical delivered in wax attracted more velvetbean caterpillar moths (Anticarsia gemmatalis Hübner). Other noctuid male and female moths collected included Agrotis subterranea (F.), Argyrogramma verruca (F.), Helicoverpa zea (Boddie), and several Spodoptera species. Aculeate Hymenoptera were collected in large numbers, especially in traps baited with phenylacetaldehyde delivered from stoppers.
Food mixing strategies in the desert locust: effects of phase, distance between foods, and food nutrient content
Authors: van der Zee Brenda , Behmer Spencer T. , Simpson Stephen J. 
Published: October 2003

AbstractFood mixing strategies were compared in the cryptically coloured, relatively sedentary ‘solitarious’ and the highly mobile, conspicuously coloured ‘gregarious’ phases of the desert locust, Schistocerca gregaria. Based on phase related differences in behaviour and nutritional regulatory responses, we predicted that solitarious nymphs, compared to gregarious nymphs, would move less between nutritionally complementary foods, particularly as the distance between the foods increased. We manipulated the nutritional composition [protein (p) and digestible carbohydrate (c) content] of two foods in an experimental arena and varied the distance between the foods using a factorial experimental design. Results indicated that in general, solitarious nymphs showed greater fidelity to individual food dishes than did gregarious insects (i.e., they concentrated their feeding mainly on one dish). However, results also demonstrated that for both phases fidelity to a particular food dish increased as the distance between the dishes increased, and that the number of switches between dishes decreased with increasing distance. In the smallest arenas, though, gregarious nymphs switched more frequently between the two food dishes than solitarious nymphs, even when the two dishes contained the same, near‐optimal food (p18:c24). When challenged by having the two dishes either placed furthest apart (2 m) or more divergent in nutritional composition (p29:c13 vs. p7:c35), insects of both phases regulated protein intake more strongly than carbohydrate intake, by eating more from the dish containing higher‐protein food.