l.) % 2 FAMILY V. TETUIGIILK. THE GROUSE LOCUSTS. 



it sometimes difficult to locate them. This protective resemblance is car- 

 ried out to perfection, the little insects living on the soil scattered with 

 debris faded out by the hot sun, and the lights and shadows, in whatever 

 way they play, are copied exactly. No shade, color or arrangement of 

 markings seems impossible of simulation, and every individual is a study 

 in color harmony. 



' 



Fig. 59. Showing variations in the color of the short form of a common grouse locust, 

 Acrydium ornatum Say. (After Hancock.) 



"The grouse locusts feed upon the vegetable mold or decomposing soil 

 sometimes mixed with algse, or on the lichens, mosses, tender sprouting 

 grasses, sedges, germinating seeds of plants and debris found in such sit- 

 uations. Particularly sought-after morsels are the various colored surface 

 clays and the black muck, consisting of rich vegetable mold. They are ra- 

 venous eaters, as one might infer from the dietary list just mentioned, and 

 the fecal excrement, on reaching the end of the abdominal appendages, is 

 thrust away from the body by a rapid kick of the hind tibia. 



"In the middle of May (Illinois) the first eggs are laid in the ground, 

 the female accomplishing this act by making a shallow burrow with her 

 ovipositor. The young larvae, hatched from this brood, mature by fall, 

 passing the following winter in the adult state. The broods hatched in 

 late June and early July are often immature by the time winter arrives, 

 and we find them hibernating in the pupal state. Thus it is that the Te- 

 trigidae are about the earliest insects to be found in the spring, appearing 

 as early as March. The time of incubation varies with the temperature, 

 the early broods of Acrydium (Tettix) hatching in twenty-three days, but 

 as tl:e days become warmer this period is shortened to sixteen days. The 

 uum] er of eggs of At-rydium and Paratettix vary considerably, but there 

 are more often ten, thirteen or sixteen in each burrow; in Tettigidea vary- 

 ing from twelve to twenty-six. 



' During the life of these little Tetrigians they are more or less con- 

 stantly in danger of enemies among the arachnida, insecta, and some of 

 the vertebrata- The larva of a red mite (Troiubidian) is one of the most 

 frequent sources of annoyance. Acting as a parasite the Trombidian larva 

 clings on the body and attaches itself out of the reach of the victim. 

 There it remains to sap the juices of the host's body. It is found on many 

 species. Among insect pests, ants and bugs are sometimes deadly to them. 

 In a wet ditch in June the writer found a number of small, dark-brown 

 ants dragging along the ground a female Acrydium ornatum which had 

 just been killed by them. When endeavoring to capture some grouse lo- 

 custs at the same place my attention was drawn to a colony of these ants 



