136 
Psyche 
[Vol. 90 
Materials and Methods 
Claeocleres hivittata adults were studied on a dying tree of Qua- 
rarihea asterolepis (Bombacaceae) on Barro Colorado Island (9° 09' 
N, 79°51' W) in the wet season of 1980. 
On June 9 all weevils from ground level to 2 m on the standing 
tree were collected, placed in a bag, sexed, measured in length to the 
nearest mm, and replaced. On June 13 all weevils up to a height of 2 
m were collected and brought to the laboratory, where they were 
sexed, measured, cleaned of most mites with masking tape, and 
weighed to the nearest tenth mg on a Mettler H35AR balance. On 
June 14 these weevils were replaced on the trunk. On six dates 
between June 28 and July 14 the behavior of individually marked 
weevils of different sizes was described into a portable tape recorder, 
for a total of 13 hours. Rectangular and trapezoidal arenas about 
1 / 3 m" were drawn on the sides of the trunk between buttresses. On 
a given date the trunk was circled clockwise. The reproductive and 
competitive behavior that was centered around all male-female pairs 
in an arena was recorded, until none of the pairs originally in the 
arena remained. Durations of acts were timed with a stopwatch. 
Weevil density on the trunk slowly dwindled from 27-36/ m- on 
June 28 to 15 or fewer/ m- on July 14. A few weevils were collected 
in alcohol for identification and dissection. 
Description of Weevil Activities 
Oviposition 
Before drilling, a female walks slowly over the smooth trunk, 
touching the substrate with her antennae. When a favorable site is 
found the female chews for 30-60 min until her rostrum is buried to 
the depth of the antennal insertion. Periodically she withdraws her 
snout, lifts her head, and expels sawdust from her jaws. 
To oviposit, a female turns around and locates the drilled hole by 
tapping with rear end and hind legs. She then everts her telescoped 
sclerites, bringing the ovipositor to the hole, and remains still for 70 
sec to 3 min. The hole drilled is the right size for one egg. 
After oviposition the female rocks by bending and straightening 
her forelegs 12 times per min for 3.5-12 min, repeatedly moving the 
tip of her abdomen between the hole and positions further back. As 
the female rocks out, a bristled tergite is everted, to which bits of 
