Several cDNAs isolated from brains of diapausing pupae of the flesh fly, Sarcophaga crassipalpis, show expression patterns unique to diapause. To isolate such cDNAs a diapause pupal brain cDNA library was screened by using an elimination hybridization technique, and cDNAs that did not hybridize with cDNA probes constructed from the RNA of nondiapausing pupae were selected for further screening....

BACKGROUND Many insects enter a developmental arrest (diapause) that allows them to survive harsh seasonal conditions. Despite the well-established ecological significance of diapause, the molecular basis of this crucial adaptation remains largely unresolved. Sitodiplosis mosellana (Gehin), the orange wheat blossom midge (OWBM), causes serious damage to wheat throughout the northern hemisphere,...

The Asian tiger mosquito, Aedes albopictus, is a highly invasive mosquito species that transmits chikungunya and dengue. This species overwinters as diapausing eggs in temperate climates. Early diapause termination may be a beneficial strategy for winter mosquito control; however, a mechanism to terminate the diapause process using chemicals is not known. We tested the hypothesis that a hormona...

Theoretically, asymmetric gene flow along an environmental gradient can limit species range expansion by keeping peripheral populations from locally adapting. However, few empirical studies have examined this potentially fundamental evolutionary mechanism. We address this possibility in the cricket Allonemobius socius, which exist along a season-length gradient where the probability of producin...

A novel hypothesis for the origin of castes in Polistes has recently been proposed: the worker and gyne castes among offspring of a Polistes colony are based on the underlying ground plan of reproductive physiology that would have characterized the non-diapause and diapause generations of a bivoltine solitary vespid wasp. Here the hypothesis is reviewed in light of the dynamic nature of diapaus...

The western tarnished plant bug (Lygus hesperus Knight) (Hemiptera: Miridae) is a polyphagous pest of numerous western crops. This pest overwinters in a relatively short duration adult diapause, but many details regarding diapause induction and maintenance remain unstudied. Instar-specific responses to a switch from short (10-h) to long (14-h) days, long to short days, and a temporary (4-d) swi...

The fall webworm, Hyphantria cunea (Drury), enters facultative diapause as a pupa in response to short-day conditions during autumn. Photoperiodic response curves showed that the critical day length for diapause induction was 14 h 30 min, 14 h 25 min and 13 h 30 min at 22, 25 and 28°C, respectively. The photoperiodic responses under non-24 h light-dark cycles demonstrated that night length play...

A key characteristic of overwintering dormancy (diapause) in the mosquito Culex pipiens is the switch in females from blood feeding to sugar gluttony. We present evidence demonstrating that genes encoding enzymes needed to digest a blood meal (trypsin and a chymotrypsin-like protease) are down-regulated in diapause-destined females, and that concurrently, a gene associated with the accumulation...

The effect of temperature on the voltinism of the silkworm, Bombyx rnori, was discovered by Watanabe (1918) over 45 years ago. This followed the rinding of the important role of photoperiod during the incubation period of silkworm eggs (Kogure, 1933). In brief, whether diapause or non-diapause eggs are laid depends on temperature and light experienced by the mother during her embryonic life. In...

The cabbage butterfly, Pieris melete hibernates and aestivates as a diapausing pupa. We present evidence that the optimum of low temperature and optimal chilling periods for both summer and winter diapause development are based on a similar mechanism. Summer or winter diapausing pupae were exposed to different low temperatures of 1, 5, 10 or 15°C for different chilling periods (ranging from 30 ...