Thermoregulation. Peter B. McEvoy Insect Ecology Ent 420/520. Classifying Thermal Relationships. Homeotherm. Body Temperature Tb. Poikilotherm. Ambient Temperature Ta. Homeothermy in Ectotherms Hyles lineata (Lepidoptera: Sphingidae). Occurs in Mojave desert of SW USA
Peter B. McEvoy
Body Temperature Tb
Ambient Temperature Ta
Tb = Ta
Tb – Ta is greater for low T than for high
windHow Do Caterpillars Maintain Steady Tb Above Ta?
% on ground decreases, % vertical increases, with increasing T
The head-standing beetle (Onymacris unguicularis) creeps to the crest of a dune when fog is present, faces into the wind and stretches its back legs so that its body tilts forward, head down. As fog precipitates onto its body and runs down into its mouth the beetle drinks (Armstrong 1990).
Short day, low reflectance, high melanin
Long day, high reflectance, low melanin
Thermoperiod and photoperiod out of phase
Slope (signal strength) and scatter (precision in prediction)
By incubating brood with abdomen, queen can produce a batch of workers in ~2 weeks