Diapause in Microplitis mediator Haliday (Hymenoptera: Braconidae) is manifested during the pupal stage and normally occurs during the winter season because of a photoperiodic response that is highly dependent on temperature. No diapause was observed at temperatures above 20 Cregardless of the photoperiod.Only a small part of the population entered diapause at 20 Cunder short daylengths of ligh...

Understanding gene interaction and pleiotropy are long-standing goals of developmental and evolutionary biology. We examine the genetic control of diapause in insects and show how the failure to recognize the difference between modular and gene pleiotropy has confounded our understanding of the genetic basis of this important phenotype. This has led to complications in understanding the role of...

Predicting insect responses to global climate change involves understanding cross-generation effects of temperature. The majority of temperate insects overwinter in a state of diapause, a pre-emptive response to winter conditions associated with increased cold hardiness. Diapause is often induced following maternal adult detection of an environmental cue signifying the onset of winter, whilst d...

The boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), has been the most important pest of cotton (Gossypium spp.) wherever it occurs. Although eradication programs in the United States have reduced the range of this pest, the weevil remains an intractable problem in subtropical Texas, Mexico, and much of South America. A key to managing the weevil in the subtropics an...

Larvae of the bamboo borer, Omphisa fuscidentalis are in diapause for more than nine months (Singtripop, T., Wanichaneewa, S., Tsuzuki, S., Sakurai, S. 1999. Larval growth and diapause in a tropical moth, Omphisa fuscidentalis Hampson. Zool. Sci. 16, 725-733). To examine the endocrine mechanisms underlying this larval diapause, we assayed the responsiveness of the diapausing larvae to 20-hydrox...

Annual killifish adapted to life in seasonally ephemeral water-bodies exhibit desiccation resistant eggs that can undergo diapause, a period of developmental arrest, enabling them to traverse the otherwise inhospitable dry season. Environmental cues that potentially indicate the season can govern whether eggs enter a stage of diapause mid-way through development or skip this diapause and instea...

Recent studies on adult diapause in the western tarnished plant bug, Lygus hesperus Knight (Heteroptera: Miridae), have highlighted the need to identify a reliable external marker for the internal changes that differentiate a normal animal from one that is overwintering. To test the efficacy of a color based discrimination system, L. hesperus of both genders were reared from eggs through day 10...

Many species produce eggs or seeds that refrain from hatching despite developmental preparedness and favorable environmental conditions. Instead, these propagules hatch in intervals over long periods. Such variable hatch or germination tactics may represent bet-hedging against future catastrophes. Empiricists have independently recognized these approaches in diverse species. Terms such as seed ...