DRAGONFLIES AND DAMSELFLIES IN PONDFISH CULTURE. 221 
had repeatedly seen A’schnine feeding upon gnats and mosquitoes in the late afternoon. 
A specimen of Telephiebia godejfroyi was once observed flying round and round a small 
bush at about 7 o’clock in the evening, when the mosquitoes were particularly trouble- 
some. After 10 minutes it was captured and its mouth was found so full of mosquitoes 
that it was unable to shut it. 
There must have been over a hundred all tightly packed into a black mass. I have frequently 
seen 4ischna brevistyla take gnats and mosquitoes in dozens while on the wing. ‘There can be no doubt 
that those dragonflies which fly late in the day are of great value in checking the spread of the various 
objectionable Culicide that are on the wing from just before sundown. 
Needham and Hart (1901, p. 29) make a similar statement: ‘‘The usefulness of the 
Aischnide imagos, especially Anax junius, on account of the enormous quantities of 
pestiferous gnats and mosquitoes which they destroy, puts them among the particular 
friends of mankind.” The Anax imago hunts after sunset, continues flying as long 
as there is light enough to render its prey visible, and is probably the last dragonfly to go 
to roost. In its search for food it frequently mounts high up in the air, sometimes dis- 
appearing from sightin this manner. The male of L. Juctuosa has similar habits, but does 
not carry them quite as far. 
Dr. Lamborn (1890) made an investigation to determine the practicability of the 
artificial use of dragonflies for destroying mosquitoes and flies. While nothing very 
practical in the way of artificial breeding was suggested, the investigation emphasized the 
immense service rendered by dragonflies under natural conditions in keeping down these 
pests. 
The members of the family Simuliide are even greater pests than the mosquitoes. 
One species, Simulium pecuarum, is known as the southern buffalo gnat and causes the 
death of many mules and other domestic animals throughout the Mississippi Valley. 
Another species, Simuliwm meridionale, is known as the turkey gnat, and it also infests 
all kinds of domestic animals, especially the turkey. ‘‘Many cases of the death of human 
beings from the bites of buffalo gnats have been reported, and some of them seem well 
authenticated” (Needham, 1903, pt. 2, p. 343). However this may be, all the species 
are bloodsuckers and intolerable pests, and anything which eats them is thereby dis- 
tinctly beneficial. 
Consequently, even if it could be proved that nymphs had a fondness for young 
fish, and that they were not themselves of any value as fish food, it would still seem 
to the present author that the incessant warfare which they wage against gnats and mos- 
quitoes ought to earn them a cordial welcome to every fishpond. It would certainly be 
better for some of the fish to die than for the pond to become a breeding place for blood- 
suckers and disease carriers. And if, in addition to this service, it can be shown, as has 
been attempted, not only that the nymphs are harmless to the fish as long as they can 
obtain other food (p. 206), but also that they themselves furnish one of the best of foods 
for the growing fish (p. 225), they become practically a necessity if fish breeding is to be 
carried on successfully. 
Another positive benefit to mankind is the wholesale destruction of house flies by so 
many of the odonates. It will be noted that this disease carrier appears as an article of 
diet in nearly every one of the lists. Aischna is frequently captured while devouring flies 
on the screens and screen doors of dwelling houses and factories, and Anax has often been 
reported from similar localities. A list has already been given of those species which 
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