294 
Psyche 
[September-December 
MATERIALS AND METHODS 
The larvae used in this study were from the garden of the Ian 
Moore residence in Riverside. Repeated attmpts for over a year to 
obtain larvae of Ocypus olens at that site had failed until 4 April 
1975 when 5 large larvae ranging in size from 21 to 25 mm were 
found beneath oleander plants. Under these plants was a dense ac- 
cumulation of decomposing leaves from the oleanders as well as from 
neighboring trees. The habitat was very moist as a result of recent 
rains. The 5 O. olens larvae were underneath or within this ma- 
terial. One of the larvae was injured with a trowel and consequently 
died. The remaining four were brought to the laboratory for bio- 
logical studies. 
In the laboratory each beetle larva was housed in a circular 16 oz. 
plastic food container with a wire screen lid. Room temperature 
was maintained at 23°C ± i°. The substrate within the containers 
consisted of 1%. to D/2 inches of moist soil from the collecting site. 
A loose mulch of dead leaves approximately ^ inch in depth was 
added on top of the soil. Two Helix aspersa whose shells measured 
about 10 to 12 mm were placed in each unit. Small amounts of 
lettuce were added :as food for the snails and also to induce them 
to come down from the top or side of the container where they 
would be more vulnerable to staphylinid attack. As snails were 
killed fresh hosts were added so there were never more than two 
living snails per observation unit. 
BIOLOGY 
The larvae of O. olens were fed an exclusive diet of Helix aspersa 
for a period of 2 to 3 weeks. During this period larvae consumed 
from 2 to 8 snails each. Attack and feeding usually occurred at 
night. Generally, the shells were left intact. However, some of the 
smaller shells showed various degrees of destruction from the body 
whorl to the apex. Attack by an adult beetle resulted in more severe 
mutilation of the shell. 
Once feeding was completed the mature larvae then burrowed 
through the substrate to the bottom of the unit and formed individual 
cells which were elliptical in shape, approximately 2.5 cm long, and 
1.6 cm high and flat on the bottom as a result of the container shape. 
Had the substrate been deeper the larvae probably would have bur- 
rowed to a greater depth as all cells were tight against the bottom 
of the unit. 
