Some Aspects of the Role of Water in Insect Hibernation

Diapause in Relation to the Ecology of Insects

“…During the final phases of the diapause stage and particularly during post-diapause development the egg rapidly increases its capacity to hold water, and by the time it is nearly ready to hatch the weight of the egg exceeds 7 mg. and the ratio of water to dry matter is about 4.5 (Birch & Andrewartha, 1942). Further examples are given by Hodson (1937) and Wigglesworth (1939); and others could be added, for this phenomenon is indeed commonplace.…”

Diapause/Dormancy

“…Moist places are preferred by Col. maculata (Hodson 1937, Solbreck 1974, Benton & Crump 1979, Jean et al 1990, Roach & Thomas 1991. The vertical distribution of active adults on the plants and their susceptibility to desiccation also indicate a preference for higher humidity (eg.…”

“…Thus the aggregations are formed in similar places year after year, but also new clearings are occupied. The beetles exhibit a marked preference for litter with 20% moisture (Hodson 1937 ). Hagen (1962) assumed that Hip.…”

Overwintering of the sycamore aphid, Drepanosiphum platanoidis

“…Field observations of egg abundance indicated that oviparae move from their feeding sites, on leaves in late senescence, down the twigs to the lower branches and trunk region. This downward migration is probably under the control of negative phototaxis and, perhaps, is a geotactic response (Hodson, 1937). A combination of negative phototaxis and positive thigmotaxis will tend to direct insects into overwintering sites (e.g., in small hollows, bark crevices, under stones and debris) where they are less conspicious to large predators as well as protected from the vagaries of the winter environment.…”