iS6 



THE AMERICAN ENTOMOLOGIST. 



subsequently reared from the flower-stem of 

 Yucca. The variation in size is considerable, 

 exceptional ? 9 's expanding to 24""™. The spots 

 on the wings are sometimes so small as to be 

 confined to a single scale, while the primaries 

 are sometimes perceptibly more acvmiinate with 

 the white of wings usually more silvery, less 

 creamy than in Pronuba, with the dark shades, 

 as of the eyes, and the dark hairs on the palpi, 

 front legs, tarsi, and at base of costa on primaries 

 more pronounced and blackish. 



• Larva. — Length from 5 to 7""". Perfectly apo- 

 dous, plump, broadest on joints 2 and 3, tapering 

 thence posteriorly, with the dorsum strongly 

 arched and the head and prothoracic joint more 

 or less fully bent down on the breast. The body 

 is glabrous and not conspicuously wrinkled. 

 Head small, retractile. Stigmata placed as in 

 Pronuba, i. c, the first pair on the hind portion 

 of the prothorax and rather lower down than the 

 succeeding 8 pairs which are on the anterior por- 

 tion of joints 4 to II, the prothoracic spiracles 

 somewhat larger than the rest. Color of body 

 either pale yellowish-white, or emerald-green, 

 this last being the more usual color of the mature 

 and especially of the hibernating specimens. The 

 head is honey-yellow with a dusky spot on each 

 side, a dash on each suture of the epistoma, the 

 mouth dark brown, the mandibles black, labium 

 and maxillae white ; the mandibles have four 

 teeth, much blunter than in Pronuba, as com- 

 pared with which they (the mandibles) are more 

 prominent. All the other troplii and the ocelli 

 are as in Promiba, though the labial palpi are 

 smaller and more plump and the labium and 

 maxillae do not surpass the mandibles. The 

 cervical shield is not defined as in Pronuba, but 

 consists of 4 chitinous patches of the same color 

 as the head. 



Chrysalis. — Average length about 6""™. Of the 

 same color as in Pronuba but much more 

 slender, with the dorsum less arched and lack- 

 ing the characteristic dorsal, arcuated plates with 

 their peculiar recurved, flattened spines, there 

 being in place of them the barest indication of a 

 transverse row of minute points or teeth near 

 the anterior border of joints 6-11, joint 5 which 

 is so strongly armed in Pronuba, being here per- 

 fectly smooth. Joint 12 in both sexes is unarmed 

 as in i but not in the S Pronuba,* while the 

 terminal subjoint is much swollen and curved 

 upward, with two minute spines taking the place 

 of the broader, compressed processes in Pronuba. 

 The sexes are only distinguishable by the some- 

 what less swollen subjoint in the 9 and her 

 longer leg-sheaths, which reach a little beyond 

 the tip of body, whereas in the i they fall short 

 of the tip. 



^ — ^ 



A NOTE ON MELISSODES NIGRIPES. 



BV \V. H. PATTON, WATERBURV, CT. 



There has been a strange confusion in regard 



* I have already pointed out (Trans. St. Louis Ac. Sc. iii, 

 p. 178) that the sexes may be infallibly distinguished in Pro- 

 nuba in the chrysalis state. The two broad terminal processes 

 in $ are from joint 12, whereas in the ^5 they really belong to 

 the anal subjoint, so that there is in the ^ a greater distance 

 between them and the preceding row of spines than in the $ 



to the sexes of Melissodes desponsa Sm. and Syn- 

 halonia atrivcnlris {M. atrivcntris Sm.). The 

 latter species is of interest as being the only 

 northern member of the genus occurring in Con- 

 necticut and other northern States. Smith de- 

 scribed a S under the name M. desfonsa, a f, 

 under the name M. atriventris, and both i and 

 S under the name M. nigripes. But unfortunately 

 his fj ai nigripes is in reality that sex of desponsa 

 and his 2 of ?;?]i,'"^7]^£\r belongs to atrivcntris; this 

 can be at once seen by anyone having specimens 

 and the descriptions before him, the two sexes 

 described as nigripes belonging to distinct genera. 

 I have often taken the two sexes of desponsa to- 

 gether in August upon the thistle-heads ; the 

 habits of atriventris must be different, as that 

 species, like others of its genus, flies in spring. 

 The confusion has been made com])lete by Mr. 

 Cresson in his recent Catalogue of North Amer- 

 ican Apidtc, where atriventris is quoted as a syn- 

 onym of desponsa, again a union of species gen- 

 etically distinct. This being the case and the 

 date of publication of the three names being the 

 same, it seems best to drop " M. nigripes" en- 

 tirely. The form withfuscous wings which Smith 

 describes as a variety of J/, desponsa does cer- 

 tainly not belong to that species, but appears to 

 be A/, bimaculata (Lepel.) Cress., a species which 

 Smith did not identify. 



A PARASITE ON PRODOXUS DECIPIENS. 



BY C. V. RILEV. 



ExoTHECUS PRODO.xi n. sp. — Average length, 

 exclusive of ovipositor, 3.3"""; expanse, s.b""". 

 Color, dark honey-yellow; abdomen toward the 

 tip a little paler ; antennae with the terminal half, 

 black or blackish ; mesosternum, yellowish- 

 white, sometimes a little darker at middle ; legs, 

 pale yellow. Head, with the gena; and face shin- 

 ing, impunctate ; occiput very finely and trans- 

 versely aciculate, opaque ; antennae but little 

 shorter than the body. Pro- and mesothorax and 

 scutellum opaque, sculptured like the occiput ; 

 mctathorax distinctly rugose. Pro- and meso- 

 sternum shining, impunctate. Wings sub-hyaline; 

 stigma dusky, paler at base. Abdomen with the 

 two basal joints opaque, densely and moderately 

 strigose longitudinally, the basal joint with two 

 short, oblique basal carina:. Joints, three to five, 

 very finely and longitudinally strigose anteriorly, 

 sinooth and shining posteriorly ; the succeeding 

 joints smooth and shining. 



Described from 8 ,; and 2 9 , bred from Pro- 

 doxus decipiens, part issuing in autumn, part in 

 spring. 



The larva is, when full-grown, about 4""" in 

 length, elongate, not curved, attenuate at each 

 end. Head white and smooth ; mouth-parts 

 difficult to distinguish, being unicolorous with 

 the head ; the rest of the body is yellowish-white, 

 less shining ; thoracic joints not difl^ering in 

 shape and length from the abdominal joints. 

 It is an interesting fact that the larva does not 

 seem to spin a separate cocoon of its own, and 

 the fly gnaws its way out of a small circular hole 

 of the size of an ordinary pin hole. 



