Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 11

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Sex ratio, weight, fecundity, fertility and longevity of codling moth, Cydia pomonella (L.) wild adults from wild populations of Southern part of Syria were examined. In addition, percentage of larvae entering diapause from each generation was investigated and the relationship between female weight and fecundity was examined. The results showed that sex ratio was about 1: 1 (males to females), adult weight ranged, on average, from 14.4 to 25.7 mg for spring generation males and females respectively and from 19.5 to 32.6 mg for summer generation males and females in the same order. Fecundity of the spring generation moths was close to 85 eggs/female; this number increased by about 30% for summer generation females and a strong relationship was found between female weight and fecundity. Adult fertility, for both generations (spring and summer), exceeded 90%, longevity ranged from about 10 days for spring generation adults to about 9 days for summer generation moths and males lived little longer than females. These results may serve as a reference in quality control measures for codling moth mass rearing in Syria.
The sex ratio in the natural population of most Hymenopteran parasitoids is 1 : 1. Females of these parasitoids, however, can regulate the sex of their offspring in response to environmental and biological factors. Under certain circumstances, this may lead to an overproduction of males, which can result in a very negative impact on any control program using these parasitoids. For these reasons, understanding the effect of these factors is very important. In this study, five biological and environmental factors known to affect sex ratio in parasitic Hymenoptera were investigated for Ascogaster quadridentata Wesmael, a parasitoid of Cydia pomonella L. Results showed that food, ambient temperature, and parasitoid age had significant effects on the sex ratio of the offspring of Hymenopteran parasitoids. The percentage of females decreased with lack of food, parasitoid age (when it became 10-days-old or older), and at low (15°C) and high (35°C) temperatures. The effect of host age and density, however, was not significant.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.