184 AMERICAN MIDLAND NATURALIST. 
horse or praying mantis, Stagomantis carolina, were also com- 
on at one time. They are both of such extraordinary ap- 
been killed wantonly because people “do not like bugs.” The 
former is known as the devil’s darning needle and doubtless 
the word “devil” in association with it has created something 
of a superstitious fear for it. There has also been a reduc- 
tion of mosquitoes and other aquatic insects, due to draining 
of marshy land. 
o summarize the changes of insect fauna: The increase 
has been more marked than the decrease. A number of species 
have been introduced by man and some have migrated into 
the State. It is diffieult to destroy the species that are pests 
because they are not easy to find, and many have a very rapid 
rate of reproduction. The introduced species have a good 
chance in the struggle for existence because they have few 
enemies and an abundant food supply. : 
e species native to the United States but new to Indi- 
ana have apparently migrated in from the south and west. 
The eastern migration is easily explained, as the prairie spe- 
cies from regions immediately west have only been able to 
find congenial homes and food after the forests were cleared. 
e northward migration is not so easily explained. May i 
be a part of the general northward movement of the temper- 
ate biota that followed the retreat of the ice sheet? 
insects that have diminished are aquatic or wood 
loving species whose homes or food have been destroyed, or 
they are species harmful to man, or they are of such unusual 
size or appearance as to attract notice. 
GENERAL SUMMARY. 
There is a tendency for certain ecological groups to dis- 
appear and for others to increase. Those that tend to dis- 
appear are: 
1. Large species; not only have the larger species of the 
fauna, as bison and wapiti, disappeared, but the largest spe- 
cies of any natural group tend to disappear before the smaller 
species of the same group. ; 
2. Aquatic species suffer from changes in the various 
bodies of water. 
3. Forest-dwelling species are exterminated through loss 
of homes and food. 
4. Species dangerous or supposedly dangerous to man 
oe ra es d 
. Species economically injurious are actively destroye 
whenever. possible. "n $ 
