CHEMICAL DEFENSE AND SOUND PRODUCTION 
IN AUSTRALIAN TENEBRIONID BEETLES 
( ADELIUM SPP.)* 
By Thomas Eisner, Daniel Aneshansley, Maria Eisner, 
Ronald Rutowski, Berni Chong, and Jerrold Meinwald 
Section of Neurobiology and Behavior, and Department of Chemistry, 
Cornell University, Ithaca,, N. Y. 14850 
Introduction 
Girdled eucalyptus trees, felled to make room for grazing pasture, 
are a common sight in rural Australia. In the dead and decaying 
stumps that are strewn through the countryside, many insects flourish. 
Two of these, the congeneric tenebrionid beetles Adelium percatum 
and A. pustulosum (subfamily Adeliinae) possess interesting defense 
mechanisms that we here describe. Both have eversible abdominal 
glands such as are commonly found in Tenebrionidae (Roth, 1945), 
but some features of the chemistry and biology of the glands are 
anomalous. Moreover, A. pustulosum has a stridulatory apparatus 
that may function for acoustical reinforcement of the chemical de- 
fense. 
Materials and Methods 
Both species of Adelium are black and, lacking hindwings, are 
flightless. Several dozen specimens were taken singly and in small 
groups in and under pieces of decaying eucalyptus wood in sheep 
pasture near Gudgenby, Australian Capital Territory, in mid-April, 
1973 (Fig. 2). They were maintained in plastic containers, and given 
water, sucrose, and a variety of cereal-based foods. Initial behavioral 
and electronmicroscopic studies were done at the laboratories of the 
Division of Entomology, C. S. I. R. O., Canberra, where T. E. and 
M. E. were guests. Secretion was shipped to B. C. and J. M. for 
chemical analysis at the University of California, San Diego. Some 
beetles survived travel to Cornell, where acoustical studies were made 
by D. A., R. R. and T. E. 
Scanning electronmicrographs were made with a JEOL (JSMU- 
UE) instrument. Preservation of beetles with everted glands was 
*Paper no. XXXIX in the series Defense Mechanisms of Arthropods. 
Manuscript received by editor March 5 , 1974. 
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