SUBFAMILY I. — PENTATOMIN^E. 135 



rails whose sides are partly buried in dead leaves or vegetable 

 mould. About April 1 the survivors begin to emerge and for 

 a fortnight or more can often be taken on the wing. From 

 then on until the hoar frosts of autumn it occurs on the flowers 

 and foliage of weeds along roadsides and in open woodlands, 

 frequenting especially those of thistle, mullein and goldenrod. 

 As a species it ranges from Nova Scotia, Quebec and New Eng- 

 land west to Colorado and Washington, and south to Florida, 

 Louisiana, Oklahoma, Texas and Mexico. The race or variety 

 tristigmns, as above described, occurs for the most part in the 

 Upper Austral Life Zone, between the parallels 38 and 41 

 degrees of the territory mentioned. Barber records it from 

 Sanford and Jacksonville, Fla., though his records doubtless 

 refer to the form pyrrhocerus. Olsen (1912, 52) states that it 

 has been bred from egg to imago on the fruit of elder and also 

 on moth mullein. Other food plants mentioned are potato and 

 cotton. Of its habits in Iowa, Stoner (1920, 83) writes: 



"Ordinarily this bug is found in or along more or less wooded and 

 shady places and moist situations grown up in rank weeds and bushes. 

 At Lake Okoboji it is one of the commonest woodland forms and occurs 

 most frequently on wild black raspberry on which plant numerous ex- 

 amples have also been taken in other parts of the State. Sometimes it 

 occurs on wild red raspberry, and not infrequently are specimens found 

 on the cultivated plants in our gardens. In late summer the species 

 also occurs on hazelnut bushes. Adults are often found hibernating 

 under leaves in the vicinity of clumps of such bushes." 



Three forms of E. tristigmus occur in Indiana and the eastern 

 states, each belonging to a different life zone and fauna, 1 ' but 

 merging gradually one into another and probably best desig- 

 nated as geographic races. In order that the student, if so 

 inclined, may label his specimens with trinomials, they may 

 be separated by the following key : 



KEY TO RACES OR VARIETIES OF EUSCHISTUS TRISTIGMUS (SAY). 



a. Humeri broadly rounded; scutellum with apical fifth mostly pale 

 marked with scattered fuscous punctures ; fifth joint of antennae 

 and apical half of fourth distinctly fuscous. (Alleghanian fauna.) 



88a. LURIDUS. 

 era. Humeri not broadly rounded; scutellum with extreme tip only pale; 

 last two joints of antenna? wholly pale, or at most brownish. 



33 See the author's "Coleoptera of Indiana," p. 4, for a map showing the life 

 zones of the State: also his paper entitled "The Life Zones of Indiana as Illustrated 

 by the Distribution of Orthoptera and Coleoptera within the State." (Proc. Ind. Acad. 

 Sci. for 1908 (1909), pp. 185-191. 



