68 
Psyche 
[September 
Eventually, within less than a minute, the earwig was again under 
assault. The attacks were at first countered by the pincers alone, but 
soon the swarm was dispersed as before by another discharge. 
Several earwigs were tested in this way, the results being similar 
in all cases. 
One earwig was left with the ants until well after all its secretion 
had become depleted. It was soon overrun by a swarm, and was by 
now entirely dependent on its pincers for defense. Under these con- 
ditions it became particularly clear how effective the pincers really 
are. During a period of 20 seconds that was timed, the earwig seized 
and successfully removed from its body a total of 19 attacking work- 
ers. This was, of course, a mere fraction of the total swarm, and the 
earwig was eventually bitten and stung repeatedly, and finally killed. 
During none of these encounters did any of the ants receive lasting 
noticeable injury. Neither did the earwigs — not, at least, for as 
long as their secretion lasted. 
praying mantids [Hierodula patellifera (Serville)] 
The fifteen earwigs that were given to the three adult female man- 
tids that were tested, were all caught and eaten in rapid succession, 
the mantids showing no signs of being affected by either the secretion 
or the pincers. 
The same species of mantid also accepts the quinone-secreting cock- 
roach Diploptera punctata Eschscholtz (Roth and Stay, 1958; Eisner 
!958b), hut it rejects the bombardier beetle Brachynus ballistarms 
Leconte (Eisner 1958a), the secretion of which is likely to be quin- 
onoid like that of its congeners ( Schildknecht, 1957). The reason for 
these inconsistencies in acceptability may be due to the fact that the 
various secretions do not contain precisely identical quinones, but 
also may have something to do with the special properties of the 
Brachynus spray, which differs from that of the others in that it is 
hot, and is discharged with a clearly audible detonation. [At the 
time I wrote on Brachynus (Eisner, 1958a), I was unaware of the 
thermal properties of its spray]. 
VERTEBRATES 
The animals tested were two small toads ( Hyla versicolor Le 
Conte), one bird [ Cyanocitta cristata (Linn.)], and one mouse ( Mus 
musculus Linn.). 
Both bird and mouse ate readily every one of the several earwigs 
that was offered to them (within a period of a few hours), betraying 
no abnormalities during the meal, or ill effects thereafter. It would 
be well to bear in mind, however, that before ruling out the repug- 
