ACTIVITY PATTERN AND THERMAL BIOLOGY OF A DAY-FLYING HAWKMOTH (MACROGLOSSUM-STELLATARUM) UNDER MEDITERRANEAN SUMMER CONDITIONS

1. The daily activity pattern and aspects of the thermal biology are d escribed for the day-flying hawkmoth, Macroglossum stellatarum L. (Lep idoptera: Sphingidae), while foraging at a flowering population of Lav andula latifolia (Labiatae) under the dry-hot summer conditions of a s outheastern Spanish locality. 2. The average abundance of M. stellatar um remained fairly constant from sunrise to about 17.00 hours (GMT), a nd a distinct peak occurred in the evening (18.00-20.00 hours). 3. For aging took place over a broad range of microclimatic conditions, as de scribed by air temperature (T(a); range 19-36-degrees-C) and solar rad iation (IR; range 1-1025 Wm-2). 4. The thoracic temperature (T(th)) of insects remained within relatively narrow limits (39-46-degrees-C), w ith the highest values occurring around noon. Variation in T(th) mainl y reflected differences in T(a) between foraging sites and times. T(th ) was nonlinearly related to T(a), the rate of increase of T(th) with T(a) decreasing with increasing T(a). 5. The unusual tolerance of high T(th) exhibited by M. stellatarum, and its enhanced thermoregulatory capacity at high T(a), enable this species to withstand the severe env ironmental conditions faced during diurnal foraging in the Mediterrane an summer.