THE LIFE HISTORY OF THE JAPANESE CARRION 
BEETLE PTOMASCOPUS MORIO AND THE ORIGINS OF 
PARENTAL CARE IN NICROPHORUS (COLEOPTERA, 
SILPHIDAE, NICROPHORINI).* 
By Stewart B. Peck 
Department of Biology, Carleton University, 
Ottawa, Ontario, K1S 5B6, Canada 
Introduction 
The subject of the origin and evolution of sociality in insects has a 
rapidly growing literature. Most of this pertains to the Hymen- 
optera. Within the Coleoptera, presocial or subsocial parental care 
and division of labor are known in at least nine families (Wilson, 
1971). The most advanced form of parental care known in beetles is 
that of the Nicrophorus carrion or burying beetles (tribe Nicro- 
phorini). This generalization is based on the study of six European 
species by Pukowski (1933, 1934) which has since been abstracted 
and popularized by many (e.g., Balduf, 1935; Milne and Milne, 
1944, 1976; Wilson, 1971, 1975). Briefly, a male and female form a 
conspecific pair at a carcass of a mouse or other small vertebrate. 
They work cooperatively to exclude competitors, to bury the 
carcass, and to shape it into a ball in a crypt. The male leaves after 
oviposition but the female tends the developing larvae, calling them 
to the carrion by stridulation, and repeatedly feeds them by 
regurgitation. Such behaviors do not exist in the other tribe of 
silphid carrion beetles, the Silphini. 
The only work on the life cycle of a North American Nicrophorus 
is a short note by Leech (1934) on N. defodiens (under the name N. 
conversator). Thus, it is not really known how general or wide- 
spread is the phenomenon of parental care in the genus, nor if all 
species are equally advanced behaviorally. There are about 20 
species in the New World, and at least 65 species in all the world, in 
several lineages within the genus. 
As part of a series of studies on the comparative biology and 
evolution of silphid beetles, I undertook a study of the life history of 
Ptomascopus morio Kraatz of Japan, to learn something of the 
* Manuscript received by the editor October 29, 1981. 
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