Bulletin of Entomological Research (1970) 59, 707-718

P. Hunter-Jones (1970)
The effect of constant temperature on egg development in the Desert Locust Schistocerca gregaria (Forsk.)
Bulletin of Entomological Research 59 (4), 707-718
Abstract: The relationship between incubation temperature and duration of the incubation period in Schistocerca gregaria was investigated in the laboratory. When egg-pods were incubated at constant temperature, the duration of the incubation period ranged from 50 days at 19.7°C to 11-12 days at 35-41°C. The colour of the resulting hatchlings showed dependence on temperature, ranging from grey-white at 41°C to overall black at 20°C. The minimum temperature at which embryonic development took place was 15.1°C, while the minimum temperature for the hatching sequence was about 20-24°C. The upper lethal limit for embryonic development depended both on temperature and on the duration of exposure of the eggs to that temperature. Embryonic development was complete when the eggs had experienced 224 degree-days above 15.1°C, except at temperatures in excess of 35°C. Egg viability was not adversely affected by a period of two days at 10°C, although mortality was increased after seven days at this temperature and most eggs were killed after 14 days. However, eight hours spent each day at 10°C did not adversely affect viability when the rest of each day was spent at 28°C. When egg-pods were incubated for part of each day at one temperature, and the remainder of the day at a different temperature, 15.1°C was again the minimum temperature for embryonic development, while the thermal constant averaged 222 degree-days. It is suggested that these threshold temperatures for egg development may be related to the speed of action of the enzymatic processes. At the minimum threshold of development the enzymes may cease to function, while the upper threshold may be associated with enzyme breakdown. The hatching threshold, however, is largely synonymous with the activity threshold of newly hatched nymphs.
(The abstract is excluded from the Creative Commons licence and has been copied from Acridological Abstracts with permission by NRI, Univ. of Greenwich at Medway.)
Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Schistocerca gregaria