1981] 
Steiner — Anti-predator Strategies 
19 
Similar explanations would seem to apply to the odd cricket 
postures (Steiner 1968) but in the form of “frozen jumping and/ or 
kicking” rather than “frozen flight” and reduced access to the 
vulnerable ventral stinging sites is also indicated. Startle displays 
have also been interpreted in terms of conflict between flying and 
freezing for some mantids (Crane 1952). 
Efficiency of such defenses has been clearly demonstrated in only 
a few cases. Parker et al. (1974), for instance, showed that defense 
postures exhibited by Locusta migratoria had a significant negative 
effect on bout continuance between conspecifics. With wasp studies 
the problem is further complicated by wide moment-to-moment 
fluctuations in responsiveness of the hunting wasps (Steiner 1962, 
1976, 1979). Such variables must be controlled, manipulated or 
eliminated to get clear answers and this was not done in the present 
study. 
Quantitative Data 
Quantifications were too limited and inappropriate to make a 
statistical analysis of the effectiveness of such defenses very mean- 
ingful. Only 128 cases were known in sufficient detail to be included 
in the analysis. In 41 .27% (n = 26) of the cases the defenses (lumped 
together) had no apparent effect and complete stinging followed and 
in 58.73% (n = 37) at least some possible effects were recorded, such 
as temporary, permanent, interruption or even deletion of stinging. 
When no defenses were observed (or unknown status) the percent- 
ages of complete vs incomplete stinging were approximately re- 
versed as predicted: 55.38% (n = 36) and 44.62% (n = 29). These 
differences in proportions (Fig. 6) were not significant, however, 
since the calculated x 2 was only 3.689 for a critical value of 5.991 
(p ^ 0.05; df = 2; G-test of independence of rows and columns: 
Sokal and Rohlf 1969, p. 599). A slight advantage can have a 
decisive selective value in the long run, however. 
Conclusion 
Prey as harmless as herbivorous crickets and grasshoppers pos- 
sess a rather complex, well integrated, system of anti-predator 
devices they can use against their wasp enemies. Even if some of 
these responses are merely obstructive, they do in fact increase the 
