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The biology, temperature response, and prey requirements for Scolothrips sexmactllatus were studied in the laboratory with Tetranychus pacificus as the main prey. At 26.7 C and 50% relative humidity, the mean life cycle was 8.9 (range: 7.6-10.3) days; egg, 7.2 days; Ist-stage larva, 2.8 days; 2nd-stage larva, 2.5 days; prepupa, 1.2 days; and pupa, 2.5 days. Male and female immatures developed in the same length of time, but as larvae, killed significantly different mean numbers of prey eggs, 43.0 and 56.0, respectively. Eggs of S. sexmaculatus are inserted into leaf tissue. Larval eclosion lasted a mean 7.6 min, and larvae commenced feeding a mean 40.3 min after vacating the chorion. No larval preference or nonpreference was noted for any given prey stage. Imaginal molts lasted a mean 9.1 min, and the new,adult commenced feeding after a mean 92.7 min. For adult females, no preference or nonpreference was noted for any prey developmental stage. Mating was unnecessary to induce oviposition, which usually commenced on the Ist imaginal day. Unmated females produced only male progeny. Thus, S. sexmaculatus is a facultatively arrhenotokous species. Larval and adult thrips were behaviorally well adapted to preying on tetranychids which produce copious webbing. Thigmotaxes were evident in all instars, and cannibalism did not occur until prey became scarce.

As the level of prey availability was increased predators expressed corresponding increases in fecundity per reproductive period, in daily ovipositional rate, in total number of prey killed per reproductive period, in daily number of prey killed per reproductive period and in female:male sex ratio. The number of prey kills per predator egg produced initially increased with increasing prey availability but levelled off at higher levels of prey availability. The total number of reproductive days also increased initially but then declined at the higher levels of prey availability.

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(Bridwell), and an undescribed species of Opius. Parasitization of tephritids in coffee ranged from l 0-56 %, with an average 35 % parasitism in a research plantation and 17 % in acommercial plantation. Parasitism in fruits other than coffee was less than 5 %. The most commonly reared tephritids from coffee were Trirhithrum coffeae Bezzi and C.