To elucidate the relationship between diapause and cold hardiness in the oriental corn borer, Ostrinia furnacalis, the levels of various substances, cold hardiness and respiration were measured in diapausing and post-diapausing overwintering larvae. Under field conditions, diapause terminated between November and January, although O(2) consumption, measured at 20 degrees C in the laboratory, re...

The brown marmorated stink bug, Halyomorpha halys, is an agricultural and urban pest that has become widely established as an invasive species of major concern in the USA and across Europe. This species forms large aggregations when entering diapause, and it is often these aggregations that are found by officials conducting inspections of internationally shipped freight. Identifying the presenc...

Living in seasonally changing environments requires adaptation to seasonal cycles. Many insects use the change in day length as a reliable cue for upcoming winter and respond to shortened photoperiod through diapause. In this study, we report the clinal variation in photoperiodic diapause induction in populations of the parasitoid wasp Nasonia vitripennis collected along a latitudinal gradient ...

One of the major challenges of overwintering in the mosquito, Culex pipiens, is prevention of dehydration. In this study, we compare the water balance requirements of nondiapausing and diapausing adult females of C. pipiens. Although their percentage water content is lower, diapausing females contain both higher initial and dry masses than nondiapausing individuals. Both nondiapausing and diapa...

We examined the relationship between body size and the phenology of the tick complex Rhipicephalus appendiculatus/Rhipicephalus zambeziensis. These ticks transmit Theileria parva in cattle. In Africa, the body size of R. appendiculatus increases with latitude while the body size of the morphologically similar Rhipicephalus zambeziensis is constant at two different latitudes. A larger body size ...

Summer diapause in Helicoverpa assulta (Hübner), which prolongs the pupal stage, particularly in males, is induced by high temperatures. In the laboratory, 3(rd)-, 4(th)-, 6(th)-instar and prepupal larvae were exposed to high temperatures - 33 and 35 °C with a photoperiod of LD16:8 - until pupation to induce summer diapause. The results showed that the incidence of summer diapause was influence...

To test the hypothesis that long-term survival of sugarbeet root maggot in storage is facilitated by larvae undergoing prolonged diapause, respiration and gene expression patterns of field-collected diapausing larvae were compared with those of 1-, 2-, and 5-year laboratory-stored larvae. Additional assessments were made on post-storage survival, emergence, and reproductive fitness of stored la...

In late September 1996, during a routine survey for Aedes albopictus in Italy, a population of Aedes atropalpus s.s. was discovered in the Veneto Region (northern Italy). Larvae were collected in 2 tire storage areas belonging to tire recapping companies that imported loads of car and large equipment used tires from eastern Europe and North America. Aedes atropalpus is found only in North Ameri...

Invertebrates and their dormant stages are an essential component of most freshwater and marine ecosystems (Cáceres 1997). As the active invertebrate community has a very variable distribution, both in time and space (Arnott et al. 1999, Folt & Burns 1999), reliable assessment of community diversity consequently requires repeated sampling across multiple locations for a prolonged period of time...