244 MOXOGEAPn or the laboulbeniace^. 
f th 
Hosts of Laboulbexiace^. According to our present knowledge all membe 
are entomogenous, and occur only upon members of the orders Col 
optera, Diptera, and Neuroptera, with a single instance found among the Arachnida. 
Peyritsch in his third paper refers to an observation recorded by Hngen, where 
he does not state^ of the occurrence of a member of the family on one of the 
Orthoptera; and although this must be considered of doubtful authenticity, it seems 
more than probable that others of the insect orders, especially the Hymenoptera, may 
prove to be similarly parasitized. It will be noticed in the appended host index that 
coleopterous hosts outnumber very greatly all others; yet it should be borne in mind 
that this predominance of beetles in the list may be due in part to the fact that no 
other group has been examined with any care in this connection. The known occur- 
rence of species on such diverse insects as the delicate fly Drosophila, the larva of a 
white ant, and the acarid Antennophorus, certainly suggests many possibilities as to the 
types of hosts likely to be affected. There seems no good reason, then, why a much 
greater variety of insects than are at present known should not be added to the list, 
especially from the tropics, provided that they fulfil the apparent requirement of over- 
lapping generations and moderate longevity, coupled with a cleanly and not too 
solitary habit. 
The relative numbers infesting the various orders and families of insects may be 
seen at a glance from the following table, which includes all forms known to the 
writer, whether described or otherwise, and is approximately correct, though not abso- 
lutely so, m so far as regards the number of the undetermined species of hosts. 
A. 
4 
Table of Host Insects of LAB0ULBE^^IACE^. 
Total number of species of insects known to become the hosts of members of the Laboul- 
Dcniaccae ••.... 
Total number of genera represented by these hosts 86 
Total number of hosts belonging to the order Coleoptera ' . * 241 
Total numbers of hosts in the different families of this order- 
250 
Carabidje . 
u V ^^^ genera 47 
-fclaliplidas ■ „ « 
Dytiscidae 
Gjrinidae ... 
" 
it 
Hjdrophilidffi 
Staphylinid^e 
Coccinellidae . 
ii 
a 
u 
li 
3 
3 
4 
18 
1 
li 
a 
species, 156 
2 
8 
15 
9 
50 
1 
a 
a 
u 
u 
Total number of hosts belonging to the order Diptera 6 
> 
