1987] 
Windsor — Tortoise beetle, Acromis sparsa 
145 
other. Eventually, one of the males ran off and the female retreated 
to a nearby leaf. 
Male-male encounters were easily staged by bringing two vine tips 
with resident males into contact or by transferring a male with a 
blade of grass. On several occasions the transferred male antennated 
the resident for 10 to 20 minutes and then walked off the leaf. Other 
encounters ended with one male rapidly chasing or flipping the 
other from the leaf. Using staged encounters of this sort it should be 
possible to directly investigate the importance of size in determining 
the outcome of male-male competition. Indirect evidence suggests 
that larger males are often the winners. Of twenty-one unmanipu- 
lated plants each with more than one male present, the largest male 
was nearer the vine tip in sixteen cases (2-sided, binomial probabil- 
ity = 0.03). 
Males were occasionally observed locked firmly together for con- 
siderable periods of time, always on the host-plant and usually on or 
just below the youngest leaves of the plant. One male would be 
normally standing on the substrate supporting a second male held 
rigidly in the air, feet free, body perpendicular to the substrate (Fig. 
7). The lower male was often simultaneously courting or copulating 
with a female. The lifted male was held by the elytra tip caught 
between the posterior edge of the pronotum and the leading edge of 
the elytra of the lower male. The pronotum of the lifted male was 
inserted into the elytral hole of the lower male. Thus, it appears that 
elytra holes may be made by opponents as they are flipped up and 
their pointed elytra pulled down onto the elytra of the lower male. 
Elytral holes may thus facilitate holding an opponent in a locked 
position for a period of time during which it is helpless to interfere 
with mating or attempting to mate with a female. 
Discussion 
Female A. sparsa guard their offspring on apical foliage against 
predators and parasitoids from oviposition through pupation. 
Unlike the larvae of many Cassidinae without parental care, A. 
sparsa larvae are seemingly defenseless without their mother. Preda- 
tion comes swiftly and inevitably as ants and wasps quickly discover 
and harvest undefended larvae. Mortality in defended groups takes 
the form of a slow attrition of offspring over the entire development 
