Like many crucifer-specialist herbivores, Pieris rapae uses the presence of glucosinolates as a signal for oviposition and larval feeding. Arabidopsis thaliana glucosinolate-related mutants provide a unique resource for studying the in vivo role of these compounds in affecting P. rapae oviposition. Low indole glucosinolate cyp79B2 cyp79B3 mutants received fewer eggs than wild type, confirming p...

Oviposition attractants could be used for monitoring as well as controlling mosquitoes by attracting them to lay eggs at chosen sites. In the present study, culture filtrates of seven bacterial species were tested for their attractancy against gravid females of Culex quinquefasciatus. When their oviposition active indices (OAI) were studied, the culture filtrates of Bacillus cereus and Pseudomo...

A three-step, quasi-double-bind approach was used as a proof-of-concept study to screen twenty compounds for their ability to reduce oviposition of gravid female navel orangeworm(NOW), Ameylois transitella (Lepidoptera: Pyralidae). First, the panel of compounds, whose identity was unknown to the experimenters, was tested by electroantennogram (EAG) using antennae of two-day old gravid females a...

Investigations on biology of shoot and fruit borer (Earias vitella) okra revealed that the freshly laid eggs were spherical, bluish green finally become brownish. These measured 0.52± 0.02 x 0.51± mm.The incubation period was 3.35± 0.76 days, larval stage passed through four instars. The first,second, third fourth instar 2.16± 0.71, 1.43± 0.50, 2.26± 0.73 3.30±1.02 respectivelywith total 9.13± ...

This research intended to evaluate the development of Zabrotes subfasciatus (Boh.), a stored-grain pest, on bean genotypes (Phaseolus vulgaris L.) commonly cultivated in the State of Parana and containing arcelin, and the possible resistance of these genotypes to the bruchine. Tests were performed under laboratory conditions (27 masculineC, fotophase 12h, 50 +/- 10 % RH) with the genotypes TPS-...

The process of egg production has to be regarded as severe metabolic stress to the hen. Elevated corticosterone concentrations have been described to precede oviposition for one to two hours, but may be masked by the diurnal changes in levels of glucocorticosteroids (corticosterone, cortisol). Increased corticoid levels were discussed either to be involved in the local induction of the process ...

Experiments were conducted to determine the settling behavior, survival, and reproduction of the beet leafhopper, Circulifer tenellus (Baker), when maintained on selected host plants. This leafhopper was recently identified in the Columbia Basin of Washington and Oregon as the probable vector of the beet leafhopper-transmitted virescence agent phytoplasma, causal agent of several vegetable crop...

Oviposition site selection is an important aspect of the behavioural ecology of insects. A comparison of the habitats used by a species enhances our understanding of their adaptation to altered environments. We collected data on the oviposition behaviours of Gasterophilus pecorum (Diptera: Gasterophilidae) in its habitat in Kalamaili Nature Reserve (KNR), Xinjiang, China between March and Octob...

An experiment with laying hens and broiler breeders of two ages (young 22 vs. 36 weeks, old 83 vs. 64 weeks) and at temperatures of 20 and 28°C was carried out to evaluate the interactions between oviposition time (7:30; 11:30, and 15:30 h), age, and temperature on the one hand and egg quality on the other. A significant interaction (P ≤ 0.011) was determined in oviposition time. The highest nu...

Dioecy, a breeding system where individual plants are exclusively male or female, has evolved repeatedly. Extensive theory describes when dioecy should arise from hermaphroditism, frequently through gynodioecy, where females and hermaphrodites coexist, and when gynodioecy should be stable. Both pollinators and herbivores often prefer the pollen-bearing sex, with sex-specific fitness effects tha...