Entomological Review (2003) 83, 779-782

N.D. Voinovich, T.Ya. Umarova, T.S. Kats and S.Ya. Reznik (2003)
Variation of the photoperiodic reaction in Trichogramma embryophagum Htg. (Hymenoptera, Trichogrammatidae)
Entomological Review 83 (7), 779-782
Abstract: A laboratory study of photoperiodic control of diapause in the egg parasitoid Trichogramma embryophagum Htg was carried out. Experiments conducted at 20° C and eight photoperiods (day-lengths of 3, 6, 9, 12, 15, 18, 21 and 24 h) revealed the long-day type response based on the maternal influence on prepupal diapause in progeny at 15° C. The maximum rate of diapause in progeny was recorded at day-lengths of 12-15 h, the estimated threshold photophases were between 6-9 h (left threshold) and 16-17 h (right threshold). A comparative analysis of photoperiodic responses in seven laboratory generations reared under constant conditions revealed endogenous variability of the tendency toward diapause. The left threshold day-length was highly variable, whereas the right threshold day-length remained relatively constant. The possible reason is that the right threshold is subject to stabilizing selection in the natural conditions, whereas the left threshold zone is a selectively neutral character revealed only in laboratory experiments.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Sergey Ya. Reznik

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Trichogramma embryophagum (parasitoid)