INSECT FLIGHT BEHAVIOR IN A NATURAL-ENVIRONMENT .6. LOCOMOTORY BEHAVIOR IN A POPULATION OF THE TIGER BEETLE SPECIES CICINDELA-HYBRIDA ON A SMALL, HOT, SANDY AREA (COLEOPTERA, CICINDELIDAE)

The locomotory behaviour of tiger beetles on a very hot, sandy area is described. Running speed and propensity to run was higher at higher s urface temperature T-s. Maximum running speed was at least 50 cm s(-1) at maximum surface temperature of T-s = 53.5 degrees C, measured betw een 1.00 and 3.00 h pm. Periods of rest on the hot sand did not last l onger than 01-10 s. Sudden transitions were observed when the beetles were disturbed. In the evening, to flights of up to 3 m s(-1) were obs erved when the beetles were disturbed. In the evening, at T-s approxim ate to 20 degrees C, the beetles run slowly (v approximate to 20 cm s( -1)) for short distances and usually refrained from flying, even when disturbed. Any prey found during the day at T-s approximate to 30 degr ees C was attacked immediately and repeatedly grasped, released and re grasped, even smooth insects such as Coccinellidae. At T-s approximate to 30 degrees C, body position was oblique, and the head held 5-6 mm above ground. At higher temperatures body position was steeper. With t he legs fully stretched (at T-s approximate to 40 degrees C on), the h ead was approximately 10 mm above ground, thus obviously escaping heat radiation from the surface. The beetles only remained in the shadows of grasses or branches during extremely high temperatures (T-s approxi mate to 45 degrees C). Surface and near surface temperatures as well a s temperature profils near the ground of the biotope were recorded und er various ambient conditions (sun, clouds, wind, time of day) and cor related to the beetles' locomotory behaviour.