Thermoreception in Insects
- 3. H.Tichy,E.Gingel.(2001) “problems in hygro and thermoreceptors” springer Heidelberg,newyork :271-287 • THERMORECEPTION • Process by which different level of heat energy in the environment and or in body is detected by organisms. • Insects evolved mechanisms to survive. • So, rapid detection of environment and body temperature is important for their survival • Control of insect body temperature by physiological or behavioral means indicates presence of thermoreceptors
- 4. • In insects humidity and temperature receptors usually present together in a single sensillum • These receptors are found in antennae of insects • A typical thermo hygro receptive sensillum contains about 2-5 sensory cells. • Surrounding cells of sensillum deals with thermoreception. R.F.Chapman(1998) “The insects; structure and function”Cambridge university press,UK:524
- 5. General thermohygro receptive sensillum
- 6. • THERMORECEPTION IN FRUIT FLIES • Fruit flies need a quick and efficient system for sensing dangerous temperatures and escaping • Fruit flies have “hot” and “cold” thermoreceptor neurons in their antenna, similar to the ones we have in our skin. • The “hot cells” are activated by heat while the “cold cells” are activated by cold. • Each cell type is also inhibited by the other temperature B.CHRISTMAN(2015) “breaking research: how brain recognizes hot and cold”.
- 8. IN COCKROACHES • Possess only one type of thermoreceptor neurons on antennae ,excited by cooling and inhibited by warming. • There are about 20 cold receptors per antenna. • Each cold receptor consists of a delicate hair like structure sensillum emerging from a ring-shaped wall. • At constant temperatures the cold receptor is continuously active. K.Rogers(2016)“thermoreception”encyclopeadia britanica
- 9. THERMORECEPTION IN MOSQUOTOES A pair of antagonistic thermoreceptive cells is associated with each of two sensilla located on the antennal tip of Aedes aegypti
- 10. • EXPERIMENT: • Electrode was inserted into the wall between the two sensilla. • For example, a rapid temperature change of an air stream caused the warm cell to respond with a sharp rise in frequency. • The cell also responded to a sudden temperature drop. • The same step-like cooling sharply increased the frequency of the cold cell. E. Gingl, A. Hinterwirth, H. Tichy(1 July 2005 ) “Sensory Representation of Temperature in Mosquito Warm and Cold Cells”Journal of Neurophysiology :176-185
- 11. • THERMOSENSITIVE BEHAVIOR OF LOCUSTS • First movement :it is awakening with the sunrise. Able to exhibit responses at this time. • Morning descent: when thermoreceptor sense rise in temperature they move down from their host plants and bask • Evening ascent : when temperature drops during evening they again ascend on surrounding vegetation. M.Abdullah(1961) “Behavioral Effects of Temperature on Insects” the Ohio Journal of Science:216-217
- 12. • IN HONEY BEES • They learn to associate thermal stimuli with a nectar reward. • Honeybee foragers returning from a good food source can warm bodies to higher temperatures, than when returning from less concentrated. • Elevated temperatures perceived by workers receiving food samples from these successful foragers, because their antennae contain thermosensitive sensillae . Honeybees possess paired thermoreceptive antennae. • when temperatures rise above the thermal optimum of the hive (34°C), workers stand at the hive entrance and fan their wings to decrease in-hive temperature. R Menzel, G. Manz, R Menzel,. &U Greggers.(2001). Massed and spaced learning in honeybees: 198-208