1976] 
Silberglied & Aiello — Defensive Adaptations 
259 
Figure 2. Oreodera glauca: tergiversation. The insect appears headed toward 
the right, but in fact it is oriented in the opposite direction, [scale = 1 cm.] 
pair of legs is directed in such a way as to appear to be a first pair, 
an effect enhanced by the first and second pairs of legs which are 
grouped together at the true pronotum. The total effect is of a 
rather nondescript insect headed in a direction that is the reverse 
of its true orientation. 
Predators are well-known to attack insects at the head end, 
often using the eyes of the prey for orientation. False eyespots 
and other patterns employed by prey to redirect the attack to less 
vital regions afford them the opportunity to escape, and are com- 
mon in many insects, especially Lepidoptera. Their adaptive sig- 
nificance has been experimentally confirmed on several occasions, 
most notably by Blest (1957). Such eyespots, and other features 
so employed, have been aptly termed “deflection marks.” We 
here employ the term “tergiversation” (literally, “to turn the back”) 
to refer to the complete illusion of reversed orientation. Tergiver- 
sation is variously defined as “the desertion of a direction or of 
a cause, ... an equivocation, ... a subterfuge, ... an evasion, . . . 
a turning of the back, as in flight.” We feel that tergiversation is 
a more general term, which includes the behavioral components 
as well as pattern elements, and emphasizes the complete effect, 
rather than the parts (such as deflection marks) that produce it. 
Incidentally, Oreodera glauca has no distinctive eyespots or de- 
flection marks at all! 
