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Egg retention in the presence of a host in Trichogramma females
Author(s) -
Reznik S. Ya.,
Voinovich N. D.,
Umarova T. Ya.
Publication year - 1998
Publication title -
journal of applied entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 60
eISSN - 1439-0418
pISSN - 0931-2048
DOI - 10.1111/j.1439-0418.1998.tb01544.x
Subject(s) - biology , trichogramma , oogenesis , host (biology) , diapause , zoology , botany , parasitoid , ecology , larva , oocyte , microbiology and biotechnology , embryo
Laboratory experiments with Trichogramma principium suggest that Trichogramma females may be in one of two alternative states: the parasitization state or the egg retention state. Dissections show that T. principium females at emergence have ≅ 20 mature ovarian eggs. Females in egg retention state have practically the same mean number of mature ovarian eggs, while the distribution is different, suggesting that both oosorption and oogenesis may occur during egg retention. In parasitizing females, additional maturation starts simultaneously with the oviposition. However, ovipositing females tend to lay eggs with maturation, which is why they mostly carry few (< 5) mature ovarian eggs. The mean number of eggs laid during the first 48 h of the oviposition does not depend on whether the parasitization is delayed or not, suggesting that egg retention is connected just with oviposition behaviour rather than with the intensity of oogenesis. We conclude that ‘voluntary’ egg retention in the presence of a host does not differ with the state of ovaria from ‘forced’ egg retention under host deprivation. Supposedly, egg retention with the availability of a suitable host may be considered as a sort of short‐term adult diapause‐like state when not oogenesis, but oviposition is subject to hormonal regulation.