DESCRIPTION OF THE DEVELOPMENTAL STAGES 
OF THE MITE PREDATOR, OLIGOTA OVIFORMIS 
CASEY, WITH NOTES ON THE OSMETERIUM 
AND ITS GLANDS (COLEOPTERA: STAPH YLINIDAE) 
By Ian Moore, E. F. Legner and M. E. Badgley 1 
Department of Entomology 
Division of Biological Control 
University of California, Riverside 92502 
Oligota oviformis was described by Casey in 1893. Quayle (1912, 
1913) called attention to the fact that both larvae and adults were 
predaceous on spider mites and consequently beneficial in orchards 
where mites were a pest. Quayle partially outlined the life history 
of O. oviformis but was unable to induce pupation. Ewing (1914) 
and Essig (1926) reviewed Quayle’s work. Badgley and Fleschner 
(1956) were able to induce pupation by providing a floor of sand 
in which pupation took place. However, little detailed description 
of the early stages was provided. A brief account of the osmeterium 
of the larva and its protective opercula. was given by Badgley and 
Fleschner. The osmeterium is of particular interest as its occurrence 
appears to be widespread among the Aleocharinae, although it has 
been misinterpreted (Badgley and Fleschner, 1956). 
Larva of Oligota oviformis Casey 
Length 2.1 mm (mature larva). Body elongate, subcylindrical, 
tapered at each end ; integuments soft, not chitinized, without dis- 
tinct sclerites; pale testaceous with the opercula of the osmeterium 
piceous, darkest along the posterior margin of eighth tergite, os- 
meterium bright orange. Head oval, about as wide as long, with a 
single ocellus on each side behind the antennal fossae. Epicranial 
suture absent. Antennal fossae located at sides of head outside the 
bases of the mandibles. Antennae three-segmented ; first segment 
about as long as wide; second segment narrower than first, a little 
more than twice as long as wide, with two long setae near the 
middle and a modified “acorn seta” without obvious articulation at 
base; third segment about half as wide as second and a little more 
than twice as wide, with two long setae at apical third and a shorter 
1 Staff Research Associate, Professor of Biological Control, and Staff 
Research Associate, respectively. 
Manuscript received by the editor June 16, 1975 
l8l 
