Acta Ecologica Sinica (2005) 25, 2940-2946

Chun-Sen Ma, Gang Ma, Yao Du and He-Ping Yang (2005)
Current status and future perspectives for behavioural response of insects to temperature gradient
Acta Ecologica Sinica 25 (12), 2940-2946
Abstract: Insects, as free moving living organisms, can avoid detrimental temperatures and search for favourite temperatures by active crawling or flying under natural conditions. How ever, the tested insects were forced to live under uniform temperature conditions in most experiments for studying effects of constant or alternative temperatures on insects. Results from those experiments cannot demonstrate what are the favourite temperatures for those insects in nature. Temperature gradient is a temperature field in which temperature continuously decreases or increases from one side to the other. Investigations on thermotactic behaviours of insects in temperature gradients can show preference of insects to the optimal temperature, and it is useful for understanding spacial dynamics, improving prediction techniques and innovating new control methods of those insects. We reviewed the research progress on behaviors of insects in temperature gradients and the devices used in those experiments. We described the methods to produce a temperature gradient across a plant organ, a circular plate, a rectangular board, a cylinder of grain or soil. Those devices cooled or heated the experimental arena with water bath or electronic thermostat, measured temperatures with a group of thermometers, thermocouples or temperature sensors and recorded the behaviors of insects with naked eyes, video cameras or a group of microphones. We listed preferred temperatures of 16 species of insects for development, inhabitation, deposition or feeding. The changes of preferred temperature of insects were attributed to both internal physiological and external environmental conditions. The preferred temperatures of insects were different not only between various species but also between different development stages or life activities of the same species. Males preferred higher temperature than females for most species of insects. Different type of a polymorph insect species might prefer different temperatures. Light and relative humidity were important factors that affect the response of insect to temperature gradient. Preferred temperatures of insects might alter after a period of temperature acclimation. Some species of insects performed particular diurnal or seasonal responses rhythms to temperature gradient. Usually, unfed insects had lower preferred temperatures than the fed ones. The existence, directions and extent of the temperature gradient influenced activities of insects. We analysed the weak aspects of previous studies and pointed out the works needed to do in the future. Entomologists have not yet explored thermotactic behaviours of most species of the important insect pests and their natural enemies in China. We should investigate the behaviours and the physiological mechanisms of tho seinsects in temperature gradient. Moreover, we should clarify the effects of environmental conditions on thermotactism of the important insect species in the future. Key words: temperature gradient; preferred temperature; thermotactism; insect
(The abstract has been supplied by the author or ISPI and is excluded from the Creative Commons licence.)
(original language: Chinese)
Database assignments for author(s): Chun-Sen Ma

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.