Humidity Reactions ofMelanoplus bivittatus(Say) andCamnula pellucida(Scudd.) (Orthoptera: Acrididae): Reactions of Starved and of Moulting Grasshoppers

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Abstract
Previous work (11) showed that two species of grasshoppers,Melanoplus bivittatus(Say) andCamnula pellucida(Scudd.), normally prefer a dry atmosphere. The present paper deals with the effects of starvation and of moulting on the humidity reactions of these species.Materials and MethodsTo test the effect of starvation on humidity reactions, adults of the two species from laboratory-reared cultures were used. Each adult was placed in a separate, cylindrical, plastic-screen cage, which mas eight inches long, two inches in diameter, and corked at both ends, The caged insects, without food or water, were placed for four or five days, or until death, in racks in a rearing room maintained at 30 ± 0.5°C. and 46 ± 1 per cent relative humidity. At intervals triplicated samples of ten adults, of one species and sex, were removed from the cages to test their reactions to alternative humidities of 0 and 90 per cent in an olfactometer (11).