108 S. S. Haldeman on new Insects. 
It is well known that where mere contact (without metallic 
nt 
the current be frequently broken, the heat at these points is still 
more augmented. It is for this reason we are able to use various 
kinds of metals for the experiment, without reference to their 
conducting powers and expansibilities. 
Washington, D. ©., Dee. 3d, 1849. 
Art. XVI.—On four new species of Hemiptera of the genera 
Ploiaria, Chermes, and Aleurodes, and two new Hymenoptera, 
parasitic in the last named genus ; by S. S. Haupeman. 
Prosarta macu.ata, Hald. 1847. Proceed. Acad. Nat. Sc. 3, 151. 
Brown, darker beneath, above whitish sericeous ; head subglobu- 
lar posteriorly, eyes black and prominent, a transverse impression 
between them: antenne and feet annulate with brown and white: 
mesonotum fulvo-sericeous, with an oblong marginal dark brown 
pale ea elongated spine directed backwards between the 
closed wings: superior wings pale gray covered with whitish 
Me i am and pale brown macule ; apex and a larger marginal 
triangle towards the base, dark brown, divided by pale reticula- 
tions, which leave a series of large spots around the apex.— 
lines long. Pennsylvania in June and July: rare. This species 
is the analogue of the Kuropean P. vagabunda, to which it bears 
a close resemblance. ‘The first description was taken from a mu- 
tilated specimen. 
Cuermes Castanex. F'lavous, thorax, pectus, and eyes black ; 
wings translucent, inner half of the stigma scarcely discolored ; 
Ist and 3d transverse nervure normal ; 2d arising from the middle 
wingless individuals are entirely flavous, with the eyes ‘rufous. 
Inhabits both riage of the leaf of the chestnut, forming lines 
along the midrib, and Sibel the leaf to curl. Pennsylvania 
in August and Septast mber 
ALEURODES ABUTILONEA. White, body pale flavous, with a tinge 
of greenish: wings each with a single nervure, the superior ones 
with two irregular obscure bands across them, and a circular 
apical spot: eyes black, double upon each side, inferior ones large 
and prominent : thorax above, with large irregular fuscous spots ; 
as long as the head, 2-articulate, apex black: antenne with the 
ean articulation robust : feet with short hairs, slender, dimerous. 
long. 
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