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Psyche 
[Vol. 94 
to have some opportunities for mating with females still searching 
for quality oviposition sites. The vigorous competition which I 
observed between large males was apparently for the last mating 
before oviposition. This suggests the existence of sperm precedence 
and an advantage to the last mating male (Smith 1984). Locking an 
opponent above the back may be one of several ways individuals of 
this species insure that theirs was the last mating before oviposition. 
Summary 
Females of the neotropical tortoise beetle, Acromis sparsa, 
invested 40 or more days per generation in post ovipositional care of 
offspring. Broad elytra were used to shield eggs, larvae and pupae 
from invertebrate enemies. No egg masses or larval groups from 
which mothers were removed escaped opportunistic predators for 
longer than a few days. Defended groups suffered a slow attrition of 
offspring to parasitoids. Thirty-two to 75 percent of eggs, 3 to 1 1 
percent of larvae and 68 percent of pupae survived to the next 
developmental stage in defended groups. The considerable variation 
in survival was generated by large differences in the importance of 
egg parasitoids among sites. 
Courtship, mating, oviposition and early larval feeding occurred 
on apical foliage of the second-growth vine, Merremia umbellata 
(Convolvulaceae). Males attempted to chase, immobilize or dis- 
lodge competing males at these sites — often before females had 
arrived to oviposit. Of several characters measured, only those 
involved in combat, pronotum width and the extension of the 
humeral angle of the elytra, increased more rapidly in males than 
females with increasing body size. The elytra of most large males 
had small oblong holes, opened while young and subsequently 
enlarged by the entry by the pronota of opponents during combat. 
Holes appeared to help lock an opponent above the back where it 
was helpless to interfere or supercede in mating. 
Acknowledgments 
I thank the Smithsonian Tropical Research Institute for provid- 
ing financial and logistical support. The paper benefited from the 
critical reviews of A. Aiello, W. Eberhard, W. Nentwig, N. Smith 
and H. Wolda. H. Stockwell and D. Englemann provided identifi- 
cations of the important species and encouragement throughout. E. 
