1981] 
Steiner — Anti-predator Strategies 
15 
egg is invariably glued right behind the fore legs, where the crust was 
also located, this would indicate that the regurgitated fluid could 
also be a serious obstacle to egg-laying or egg development. Prionyx 
wasps lay their egg at the base of one hind leg . . . where the risk of 
such “flooding” is clearly much reduced or even nil! Furthermore, 
paralyzed grasshoppers cannot remove the spilled fluid by groom- 
ing, as they normally do. Consequently “cleaning” of the soiled prey 
can be done only by the wasps, if at all. 
This chemical defense is apparently even more effective in mole 
crickets against another larrine wasp: Larra (Williams 1928). Thus 
Larra sanguinea wasps were found with their mouthparts com- 
pletely glued together by the very viscous fluid. Remarkably, some 
of these wasps managed to catch their mole cricket in spite of such 
crippling handicap! Ants are repelled by fecal material or chryso- 
melid beetle larvae (in Matthews and Matthews 1978, p. 343), and 
refuse to carry away pieces of grasshopper treated with their own 
repelling fluid (Eisner 1970). 
In conclusion, the importance of mouth-based regurgitative 
defenses can be assessed by (1) the care with which these wasps try 
to eliminate the fluid from the prey and from their own body, (2) 
evolution of a specialized sting in the throat that abolishes mouth- 
based defenses, (3) the priority given by Prionyx wasps to mouth- 
based defenses (first sting in the throat), (4) dramatic effects, 
including death, observed on some wasps like small Tachysphex, (5) 
toxic effects reported in the literature, for mammals, such as topical 
irritation of eyes, vomiting when swallowed and severe symptoms 
caused by injection (Matthews and Matthews 1978, p. 335). 
Such defenses are therefore particularly efficient against smaller 
predators like arthropods, wasps included. More experimentation is 
clearly needed, however. 
Postural defenses, displays, replacing escape 
(Figs. 3, 4 and 5d) 
Such complex postures and displays will be analyzed in terms of 
their various components or aspects. 
a) Color flash, startle response 
Sudden display of colored wings, of hidden and bright structures 
(deimatic behavior) is common in insects, particularly in otherwise 
cryptically colored moths such as Catocala scripta, Triphaena 
