نتایج جستجو برای: egg masses density
تعداد نتایج: 498739 فیلتر نتایج به سال:
Interspecific competition between G. ashmeadi, G. triguttatus and G. fasciatus for GWSS egg masses was investigated in the laboratory using three experimental designs. Overall parasitism by G. ashmeadi was consistently higher (up to 76.0%) compared with G. triguttatus and G. fasciatus, for all three experimental designs. Exposing females to individual egg ages (1, 3 or 5 days) showed that G. as...
Variation in sperm precedence was examined in the Colorado potato beetle, Leptinotarsa decemlineata Say, using neutral allozyme markers. Two temporal components were studied: (1) pairing duration and (2) time since initial pairing. We used two pairing protocols that differed in the timemales and femaleswere allowed tomate for Þrst and secondpairings.Whenpairingswere limited to 8 h each for the ...
Chironomids (Diptera: Chironomidae), also known as non-biting midges, are one of the most abundant groups of insects in aquatic habitats. They undergo a complete metamorphosis of four life stages of which three are aquatic (egg, larva, and pupa), and the adult emerges into the air. Chironomids serve as a natural reservoir of Aeromonas and Vibrio cholerae species. Here, we review existing knowle...
Host-foraging responses to different intra- and interpatch densities were used to assess three Trichogramma spp. (Hymenoptera: Trichogrammatidae) Trichogramma deion Pinto and Oatman, T. ostriniae Pang and Chen, and T. pretiosum Riley - as potential biological control agents for the Indian meal moth, Plodia interpunctella Hübner (Lepidoptera: Pyralidae). Single naïve females were allowed 6 h to ...
A number of species of forest caterpillars fluctuate in density with a periodicity of 8–11 yr. One explanation for these ‘‘cycles’’ is that changes in food quality or quantity and crowding influence the growth rate and final size of moths at high density. Carryover of these influences to the next generation through maternal effects could modify the dynamics of the population. To determine wheth...
Five treatments were used to exclude naturally occurring predators and parasitoids, based on body size and flight ability, to assess their effect on Ostrinia nubilalis (Hübner) populations on corn plaits. Two initial O. nubilalis egg densities (one egg mass and three egg masses per plant) were assigned to each treatment. Egg predation was higher in uncaged treatments than in caged treatments. F...
Two regression estimators were developed for determining densities of late-instar gypsy moth, Lymantria dispar (Lepidoptera: Lymantriidae), larvae from burlap band and pyrethrin spray counts on oak trees in Vermont, Massachusetts, Connecticut, and New York. Studies were conducted by marking larvae on individual burlapbanded trees within 15-m diameter plots and recapturing them with pyrethrin sp...
Parental care is a defining feature of animal breeding systems. We now know that both basic life-history characteristics and ecological factors influence the evolution of care. However, relatively little is known about how these factors interact to influence the origin and maintenance of care. Here, we expand upon previous work and explore the relationship between basic life-history characteris...
Oviposition preference by European corn borers, Ostrinia nubilalis (Hübner), for or against transgenic corn would influence amounts of refuge required for resistance management. The objective of this research was to determine if various Bacillus thuringiensis (Bt) corn transgenic events influence O. nubilalis oviposition. All commercially available events (currently 5) were evaluated, plus 1 ex...
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