166 INSECTS INJURIOUS TO VEGETATION. 



are very prevalent on our salt marshes, it will be advisable to 

 mow the grass early, so as to secure a crop before it has suf- 

 fered much loss. The time for doing this will be determined 

 by data furnished in the foregoing pages, where it will be seen 

 that the most destructive species come to maturity during the 

 latter part of July. If then, the marshes are mowed about 

 the first of July, the locusts, being at that time small and not 

 provided with wings, will be unable to migrate, and will con- 

 sequently perish on the ground for the want of food, while a 

 tolerable crop of hay will be secured, and the marshes will 

 suft'er less from the insects during the following summer. This, 

 like all other preventive measures, must be generally adopted, 

 in order to prove effectual ; for it will avail a farmer but little 

 to take preventive measures on his own land, if his neighbors, 

 who are equally exposed and interested, neglect to do the 

 same. Among the natural means which seem to be appointed 

 to keep these insects in check, violent winds and storms may be 

 mentioned, which sometimes sweep them off in great swarms, 

 and cast them into the sea. Vast numbers are drowned by 

 the high tides that frequently inundate our marshes. They 

 are subject to be attacked by certain thread-like brown or 

 blackish worms {Filaria), resembling in appearance those called 

 horse-hair eels [Gordius). I have taken three or four of these 

 animals out of the body of a single locust. They are also 

 much infested by little red mites, belonging apparently to the 

 genus Ocypete; these so much weaken the insects by sucking 

 the juices from their bodies, as to hasten their death. Ten or 

 a dozen of these mites will frequently be found pertinaciously 

 adhering to the body of a locust, beneath its wing-covers and 

 wings. A kind of sand-wasp preys upon grasshoppers, and 

 provisions her nest with them. Many birds devour them, 

 particularly our domestic fowls, which eat great numbers of 

 grasshoppers, locusts, and even crickets. Young turkeys, if 

 allowed to go at large during the summer, derive nearly the 

 whole of their subsistence from these insects. 



