DEFENSIVE ADAPTATIONS OF SOME NEOTROPICAL 
LONG-HORNED BEETLES (COLEOPTERA, 
CERAM BYCIDAE): ANTENNAL SPINES, 
TERGIVERSATION, AND DOUBLE MIMICRY 
By Robert E. Silberglied and Annette Aiello 
*Smithsonian Tropical Research Institute, 
P.O. Box 2072, Balboa, Panama Canal Zone 
The large and diverse beetle family Cerambycidae is well-repre- 
sented in the neotropical region, and contains numerous examples 
of species with interesting and often bizarre defensive adaptations. 
These include examples of cryptic coloration, defensive use of 
mandibles, body spines, death feigning, unpalatability coupled 
with aposematism, and Mullerian and Batesian mimicry. Linsley 
(1959a, 1959b, 1961) has reviewed the subject of structural and 
behavioral defense adaptations, protective coloration and mimicry 
in this family (see also Chemsak and Linsley, 1970, Funke, 1957). 
Wc here report field observations on three new and unusual cases 
of defensive adaptations of these beetles, made during 1976 on 
Barro Colorado Island, Panama Canal Zone. 
Antennal spines. 
Both sexes of Hammaticherus batus (Linnaeus) have elongate 
recurved spines on segments 3-6 of their antennae (Figure 1A). 
These downward-projecting lateral extensions, located at the 
distal end of the segments, are sharply-pointed, with the inner 
edge of each point continuing basally as a concave, knife-like 
ridge (Figure IB). Other members of the genus have similar spines, 
and, since their distribution among the basal segments differs 
from species to species, they have been employed as taxonomic 
characters within the genus. Such spines as occur on the body 
and appendages of cerambycids and other insects have often been 
assumed, in general, to be defensive in function (Edmunds, 1974, 
Linsley, 1959a, 1961), but there are few accounts of the ways in 
which spines are actually employed. 
Upon being grasped transversely with the fingers, Hammati- 
cherus batus extends its head slightly, flailing the antennae back- 
* Present address: Department of Biology, Harvard University, Cambridge, 
Massachusetts, U.S.A. 02138 
256 
