294 BULLETIN 45, UNITED STATES NATIONAL MUSEUM. 



Museum contains a fresli s])ecinien, roared March 20, 1.S82, by Hi". Riley 

 from AJeuroileH sp. occurrinj;- on Aver ilanifcarpina at Arlington, Va., 

 while my collection contains a sinyle specimen cai)tnretl with the 

 sweeping net. 



Prof. Haldeman gives the following interesting facts respecting it: 

 "Parasitic <m the larva of Alcurodis corni llakl., of which it destroys a 

 great many. 1 found it with that insect beneath the leaves of CoruKs 

 sericcd on the margin of a water coui'se. It leaps, walks, and Hies with 

 facility, and when toui'Jied sinndates death. The antenna; are kept in 

 a constant state of vibration. I have kept them a week or more, liv 

 ing in c(mlinement. The ova (crushed from the ovaries) are fusiform, 

 rounded at one extremity and prodnce<l at the othei- like the neck of a 

 flask." 



The insect described by Prof. Forbes as Ehcptus aleuroilin, reared 

 from Aleurodes acerifi Forbes, is evi«lently i<leiitical. 



Geottroy has described an Aleurodes accria in Europe, and I woidd 

 here suggest the name .1. Forbcsii^ for Prof. Forlx s species. 



TRICHACIS F<ir8t.'r. 



Hyiii. Stud., 11, p. 108 (185(5). 



(Type, T.pcsh Walli.) 



Head transverse; the frons subconvex, the occiput not<»r only deli- 

 cately margined ; ocelli 3, in a triangle, the lateral ocelli their width away 

 from the margin of the eye. 



Antennas 10-jointed in both sexes, in 9 ending in a o-joiuted club, 

 thelirstand third funiclar joints minute, the second lengthened, as long 

 as the pedicel and lirst funiclar joi nt t« >gether ; first clu b Join t the shortest, 

 the last the largest, ovate; in S with the club thinner, the,j<»ints more 

 elongate, cylindrical, the first and second fnuidar joints h)ng, notsnuiU, 

 or the first very minute, the second swollen. 



Thorax ovate, the pronotum produced into a slight neck anteriorly; 

 mesonotura convex, about twice as long as wide, with 2 deep furrows; 

 scutellum somewhat elevated, Avith a tuft of hair Tit tip, but without a 

 thorn or tubercle; metathorax very short, with two me<lian keels, the 

 pleura pubescent. 



Wings ciliated, veinless, the submarginal vein traceable basally. 



Abdomeu in 9 conic-ovate, 4 Jointed, the first segment petioliform, stri- 

 ated, the second ..s hmg as the two fidlowing together, with 2 foveohe at 

 base, the third less than one-third the length of the fourth, with trans- 

 verse rows of small punctures, the fourth or last conical, compressed 

 from above and bel(»w, margined, the apical half very fiat or subcon- 

 cave, with stria; at base followed by a slight smooth prominence ; in S 

 oblong-oval, 8 jointed, the last two segments very miimte, segments 3, 

 4, and 5 nearly equal, usually with transverse rows of i)unci,are8. 



Legs clavate, the basal joint of hind tarsi more than twice as long 

 as the second. 



