414 NATURE SKETCHES IN TEMPERATE AMERICA 



rays thaw the ground. The time of incubation varies with 

 the temperature, the early broods of the ornate grouse locust 

 hatching in twenty-three days; but as the' days become warmer 

 this period is shortened to about sixteen days. The number of 

 the eggs of the grouse locust varies considerably; in the genera 

 Tetrix and Paratettix they often consist of ten, thirteen, or 

 sixteen in each burrow. In the genus Tettigidea they more 

 often range from twelve to twenty-six in number. The eggs 

 are laid at the bottom of the rather shallow burrow. They 

 are deposited one by one, side by side, on the same level, and 

 when all are laid they form a pear-shaped mass. In Tetrix 

 the eggs are covered up with minute fragments which the mother 

 scrapes off the ground with her hind feet. During the life of 

 these little Tettigians they are more or less constantly in danger 

 of enemies among the spiders, insects, birds, toads, and other 

 animals. The larva of a red mite is one of the most frequent 

 sources of annoyance. Acting as a parasite, this Trombidian 

 larva clings to the body and attaches itself out of reach of 

 its victims. It is found on many species. Among insect 

 pests, ants and bugs are sometimes deadly to them. In June 

 in a wet ditch I found a number of small dark brown ants 

 dragging along the ground a female Tetrix ornatus which had 

 just been killed by them. When endeavoring to capture some 

 Tetrix at the same place, my attention was drawn to a colony 

 of these ants acting excitedly. Further investigation showed 

 that the ants had darted upon the insect I was pursuing, 

 tumbling it over and biting it savagely about the neck. The 

 little locust finally escaped by a vigorous jump. 



The bug known as Galgulua oculatus captures many Tetrix. 

 It suddenly leaps on the grouse locust, and embracing it between 

 its front femora and tibise, sucks out the locust's vital juices. 

 I have frequently seen these curious bugs with prominent eyes 

 in numbers in the same habitat with these little locusts. Toads, 

 fishes, and birds devour these insects and help to swell the 

 mortality among them. The hermit thrush, as I have noted 

 in another chapter, during its spring migration consumes Tetrix 

 and Tettigidea to the extent of seven per cent of its entire food. 

 Nabours informs me that he found several species of spiders 

 preying on these insects in the South, especially in Louisiana. 



