NO. 1530. THE DECTICIN.E OF NORTH AMERICA— CA UDELL. 357 



much discolored, are now in the National Museum. They are nearly 

 yellow with the posterior portion of the upper part of the lateral 

 lobes of the pronotum, just below the lateral carinjv?, black, as are 

 also the margins of the abdominal segments. Some specimens, prob- 

 ably ones killed soon after transformation, are wholly yellow, while 

 others are nearly black. 



Measurements. — Length, pronotum , male, 7-11.5 nun. , female, 0-11. 5 ; 

 posterior femora, male, 12.5-19, female, 14-21; ovipositor, 16-21:. 



Type.—QdX. No. 1107, U. S. National Museum. 



Specimens examined. — The types, two discolored alcoholic speci- 

 mens, male and female, from '' eastern Colorado," and specimens from 

 Colorado — Pikes Peak, Manitou, Longs Peak, Palmer Lake, Colorado 

 Springs, Lakespur, South Park, Ward, Livermore, and summit of 

 Vega Pass; from Cumbres, New Mexico, southern Idaho, northern 

 Utah, and Fort McLcod, British America. Also specimens referable 

 to this form from Wallace County, Kansas, and Lincoln, Nebraska. 

 These specimens represent the merging of this ordinarily higher alti- 

 tude form with the ordinary prairie form. Specimens of coloradus 

 from high altitudes are invariably smaller than those from places of 

 less elevation. Thus the specimens from Livermore and Colorado 

 Springs are decidedly larger than ones taken high up in the mountains. 

 These larger specimens inhabiting the lower altitudes merge cpiite 

 imperceptibl}^ into typical simplex. Coloradus seldom occurs below 

 6,000 ft. altitude. 



Anabrus simplex., with its several races, is, economically, our most 

 important member of the subfamily Decticint^j. Great bodies at times 

 march from their breeding places in neighboring hills into the sur- 

 rounding cultivated fields, causing great damage. Such swarms are 

 often several miles in extent, and usually, I believe, consist of the 

 typical form with some of the variety nigra. Such an invasion 

 occurred in Route County, Colorado, in 1904, and is thoroughl}^ dis- 

 cussed by Gillette and Johnson in Bulletin No. 101 of the Colorado 

 Experiment Station, where the habits and life history are ably de- 

 scribed. Doten,'* discusses the question of remedies, while a short 

 summary of the subject is given by Aldrich in Bulletin No. 41 of the 

 University of Idaho. The breeding habits are treated of by Gillette.^ 

 For a thorough study of this interesting species the above-mentioned 

 articles, as well as other older ones, should be consulted. 



This insect generally breeds in hilly places where vegetation is 

 scarce, preferring clay soils containing surface cracks which facilitates 

 the insertion of the ovipositor. In ovipositing, the female l)rings 

 the tip of her ovipositor forward beneath the abdomen and forces it 

 nearly perpendicularly into the ground. The eggs are chocolate 



« Bulletin No. 56, Nevada Exj)eriment Station. 

 6 Entomological News, xv, pp. 321-324. 



