278 Psyche [September 
average number of parasites 
per female host. 
host male female 
Masaridinse 
2. 
1 . 
4. 
Zethinse 
1.2 
1 . 
1.25 
Eumenes 
1.25 
1 . 
1.5 
Odynerus 
Pachody- 
1.34 
1.15 
1.52 
nerus 
Ancistro- 
2.38 
2.5 
2.29 
cerus 
1.14 
1 . 
1.3 
per host, per male host, and 
host male female 
Monobia 
2.25 
2.33 
2. 
Montezumia 
1.33 
1.33 
Belonogas- 
ter 
1.15 
1 . 
1.20 
Polistes 
1.75 
2. 
1.68 
Vespa 
1 
1 . 
1 . 
In most groups, female hosts support a slightly higher 
average number of parasites than males. 
In Pierce’s table of maximum parasitism per individual 
(1909, p. 26; 1918, p. 397) and in our own notes (1927, p. 
189), it is very noticeable that heavily infested Polistes 
contain largely or exclusively male parasites. Eleven Polistes 
bearing four or more parasites are mentioned in those 
tables and four others in the present list; the entire fifteen 
containing parasites as follows : 1-2 32 9 , 1-3 3 1 9 , 1-4 $ , 
2-5 $ , 1-3 $ 3 $ , 1-63,1-63 1 9 , 2-7 3 , 1-8 3 , 1-9 3 , 1-10 3 , 
1-11 $ , 1-15 $ . There are here included 100 3 and 7 9 . One 
is led to recall the interesting discovery of Cobb, Steiner, 
and Christie (1927) who have shown the striking pre- 
ponderance of male nematodes in heavily infested hosts. In 
stylopized Eumeninse as well as in infested bees the opposite 
seems to hold, and in cases of heavy stylopization, female 
parasites are in the majority. 
The Geographical Distribution of Stylopized Vesphx® 
Our list includes vespid hosts from all the continental 
areas and many islands, and where records are lacking we 
must, at the present state of our knowledge, attribute their 
absence to insufficient collecting or study. 
Some interesting problems in distribution are furnished 
by the Strepsiptera. The chance of their establishment in 
