104 
Psyche 
[March 
Brood Guarding Behavior 
Generally the female deposits more than one egg mass in a small 
area and this appears to be the number of egg masses a male will 
guard. I observed individual males guarding as few as one to as 
many as seven egg masses. The male (body length 9-10 mm) usu- 
ally assumes a guarding position directly over the egg masses or 
will stand not more than 3-4 cm from the nearest egg mass. 
Two simple tests were conducted to compare the behavior of 
guarding and non-guarding (not positioned near any egg mass) 
males. In the first test, which may have simulated the approach 
of a large predator, I passed my hand within about 10 cm of each 
male. Thirteen guarding males were tested; one took flight and 
the others simply dodged to one side to avoid my hand. With re- 
peated passes of my hand no escape behavior other than dodging 
was triggered. Seventeen non-guarding males were similarly tested: 
nine flew away; another five dodged to avoid my hand at first but 
with one or two repeated passes they too flew away; the remaining 
three only dodged to avoid my hand. In the process of grasping 
44 guarding males for marking or removal during another part of 
this study, I found that none took flight; the only reaction was to 
dodge my hand. Application of the chi-square test to these data 
shows that guarding males are significantly (p<0.01) less likely to 
flee from a potential predator than are non-guarding males. 
The second test involved a model parasite made of a bit of black 
tape attached to the end of stiff nylon line on the end of a long 
hollow glass tube. I carefully presented the model parasite so that 
the male would only perceive the model. Of the ten guarding males 
tested, one avoided the model completely, one exhibited no reac- 
tion, and seven others readily attacked the model by grasping it 
with the forelegs. The attacks appeared especially aggressive when 
the model came close to the egg masses. The tenth male, which was 
about 7 cm from his egg masses, avoided the model when it was 
brought near him. However, when the model approached the egg 
masses the male was guarding, he rapidly moved to attack it. 
The non-guarding males were less ready to attack the model 
wasp. Of eight non-guarding males tested, only one readily attacked 
the model. Four males avoided the model parasite but when touched 
by it they did attack. The other three non-guarding males avoided 
the model completely. The chi-square test results show that there 
