990 



FAMILY XXXII. — VELIID^E. 



Fig. 198. Microvelia borealis Hueno. <i, Adult wingless male; 6, adult wingless 

 female; C, winged female, X 15. (After Hungerford). 



surface fuscous-brown, thickly clothed with very fine silvery-gray pu- 

 bescence. Joints 1 and 3 of antennae subequal in length, the former much 

 the stouter, 2 shortest, half the length of 3, 4 fusiform, .slightly longer 

 than 3. Pronotum as long as broad, its humeral angles swollen. Male 

 with elytra as wide as abdomen and hind tibiae distinctly curved. Female 

 with connexivum slightly exposed. Wingless form — Darker, the under 

 surface wholly blackish; female with dorsals of abdomen 1 — 3 black at 

 middle, 4 and 5 wholly black; remainder with a leaden bloom, connexivals 

 each with a small yellow spot; male with these markings vague or ab- 

 sent. Mesonotum in great part visible, its middle one-half as long as 

 pronotum, the latter with transverse impressed line very distinct. Length, 

 1.6—2 mm. (Fig. 198 5 " 5 *). 



Marion and Putnam counties, Ind., Sept. 23 — 28. In Marion 

 County all stages were taken in numbers from a pond contain- 

 ing much calcareous sediment and many water weeds. M. ameri- 

 cana was not found in this pond but was abundant in the cold 

 water of spring-fed branches not one hundred yards distant. 

 Clark Junction, Ind., April 4; Chicago, 111., July 22 (Gerhard). 

 White Plains, N. Y., Sept. 29 (Barber). Ranges from Maine and 

 Massachusetts west to Illinois and Kansas. Not recorded south 

 of New Jersey. Of its habits Bueno (loc. cit.) says : 



"This is perhaps the most abundant of our native Microvelias, and 

 may always be found in large colonies on the matted Lemna or duck- 

 weed on still ponds. It is just as predaceous as its larger congeners and 

 is most frequently found in the wingless form, although the fully winged 

 one is not rare. It begins to breed on emergence from its winter quar- 

 ters, and lays its eggs on the under side of the duckweed leaves with the 

 head end toward the edge of the leaf, in the usual gelatine. The nymphs 

 emerge in 8 to 13 days, and after four molts reach the adult stage in 

 about 16 days minimum or 24 days from the egg to the adult, which would 

 allow for eight generations in a summer. As one female may lay sev- 

 eral batches of eggs, her progeny may be found in various instars at 

 the same time. Attention is directed to the unusual number of molts, as 

 the general rule in Heteroptera is five." 



""a In the figure the hind tibiae of male are erroneously shown as straight. 



