792 FAMILY XXIX. — MIRID^E. 



nigra Marsh., in the dune region of southern Michigan. Knight 

 (1923, 566) says that the food plant is "Fraxinus americana but 

 found developing only on young plants in much shaded situa- 

 tions." This species seems to form a sort of connecting link 

 between the genera Neoborus and Xenoborus, as only the front 

 half of pronotum has the sides carinate. 



XXIII. Xenoborus Reuter in Van Duzee, 1908, 112. 



This genus is very close to, if not a synonym of, Neoborus. 

 It differs mainly in the characters given in the generic key, 

 p. 752, and, as stated above, the carinae of side margins of prono- 

 tum in Neoborus pubescens are abbreviated, that species there- 

 fore connecting up the two genera. Four species are known, 

 all occurring in our territory. 



KEY TO EASTERN SPECIES OF XENOBORUS. 



a. Larger, length 6.4 or more mm. ; upper surface in great part green- 

 ish-yellow, darker only along the sides of the claval commissure. 



831. COMMISSURALIS. 



on. Smaller, length not over 5.7 mm.; elytra usually in great part dark 

 brown or blackish. 

 b. Membrane fuscous with an oval paler spot at middle; calli and a 

 spot or stripe each side of median line of pronotum, inner half of 

 clavus and a spot on apical third of corium, dark brown or fus- 

 cous-black; length, 5 mm. 832. plagifer. 

 bb. Membrane uniformly dark fuscous or black. 



c. Hind tibia? wholly pale; hind femora pale or rarely dusky near 

 apex; embolium, basal half of corium and entire cuneus pale in 

 both sexes; length, 5.4 mm. 833. neglectus. 



cc. Hind tibia? fuscous, blackish near base; hind femora blackish 

 apically or annulate with dark and pale; embolium and basal 

 half of corium dark, rarely pale in female. 834. pettiti. 



831 (1046). Xenoborus commissuralis Reuter in Van Duzee, 1908, 112. 



Pale greenish-yellow, more or less tinged with reddish-brown; front 

 of head and calli pale brownish-yellow tinged with reddish, strongly shin- 

 ing, tylus black; scutellum wholly greenish-yellow; apical half of clavus 

 dark brown to fuscous, cuneus pale yellowish translucent; membrane 

 dusky, paler along the margins ; legs pale yellow, tip of beak and tarsal 

 claws darker; antenna? dark brown to fuscous-black, the incisures paler. 

 Beak reaching middle coxae. Joint 1 of antenna? about as long as head; 



2 twice as long as 1, female, two and a half times longer than 1, male; 



3 and 4 much more slender, 4 one-half the length of 3. Pronotum about 

 one-fifth shorter than its basal width, calli prominent, disk behind them 

 thickly and rather coarsely rugose-punctate. Scutellum sparsely, similar- 

 ly punctate. Elytra finely and sparsely punctate, each puncture bearing 

 a very fine suberect yellowish hair. Length, 6.4 — 7 mm. 



