Environmental Entomology (1990) 19, 1457-1462

Winfield Sterling, Allen Dean, Albert Hartstack and John Witz (1990)
Partitioning boll weevil (Coleoptera: Curculionidae) mortality associated with high temperature: Desiccation or thermal death?
Environmental Entomology 19 (5), 1457-1462
Abstract: Mortality of boll weevil, Anthonomus grandis Boheman, larvae and pupae resulting from exposure to high temperatures can be partitioned into two categories, "desiccation" and thermal death. Larvae and pupae that die from thermal death turn a greybrown color after death, do not move when probed or squeezed, and lose the resiliency of their integument. Those dying from "desiccation" will show the same characteristics but do not turn the grey-brown color; they generally retain the same color as live insects but have a very dried-out appearance. Thermal death is a function of exposure time and high temperatures. Low levels of thermal mortality appear in <3 h at 54.4°C. An estimated 99% mortality should result from a 2-h 18-min exposure at 60°C. Because soil surface temperatures sometimes reach 60°C, high temperatures may be an important cause of mortality in some locations. A model for forecasting time and temperature thresholds for thermal mortality is presented.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)

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

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Anthonomus grandis