no. 3644 TIPHIIDAE — KROMBEIN 13 



Myzine tricolor Smith. — Bingham, 1897, in part, p. 66 [the specimen from Assam]. 

 Elis (Mesa) tricolor (Smith). — Turner, 1912, in part, p. 720 [the specimens from 



Assam and W. India]. 

 Elis (Mesa) tricolor longiceps Turner, 1918, p. 87. — Rohwer, 1921, p. 90. 

 Mesa tricolor longiceps (Turner). — Guiglia, 1965, p. 315. — Baltazar, 1966, p. 207. 



For many years specimens of longiceps were confused with tricolor 

 even by Turner. The latter author eventually recognized longiceps 

 as a discrete taxon at the subspecific level; however, it must certainly 

 rank as a good species, and it is, in fact, one of the most easily recog- 

 nized species of Hylomesa. The more elongate head of the female 

 separates that sex immediately from females of other species except 

 bakeri. The shagreened pygidium, the obtusely angulate posterior 

 margin of the hind femur, and the much greater ocelloccipital :ocell- 

 ocular ratio separate longiceps from bakeri females. The male genitalia 

 are also quite distinctive; this sex also may be identified readily by 

 having somewhat more elongate intermediate flagellar segments and 

 in having the hypostomal length subequal to the distance between 

 the hypostomal and occipital carinae. 



Hylomesa longiceps is also noteworthy in that it is the most widely 

 distributed species of the genus with definite records of capture in 

 Ceylon, India, Assam, Burma, Malaysia, and the Philippines. 



It is also the only Hylomesa for which we have any information 

 on host preferences. Turner (1912) stated that T. R. Bell "informed 

 me that he bred this species from the larva of a longicorn beetle." 

 This statement is at variance with the label data on the only female 

 longiceps bearing a Bell label: "in dead wood with longicorn larvae 

 14-1-07." 



Female. — Length 15-23, forewing 10-16 mm. Black, the head 

 except apex of mandible and hypostomal area and occasionally the 

 ocellar triangle, varying from light to dark red; scape, pedicel, and 

 from one to four of basal flagellar segments also red; abdomen occa- 

 sionally with metallic blue reflections; forewing entirely infumated 

 or with basal area lighter in some specimens, the darkened area with 

 violaceous reflections. 



Head more elongate than in other species, from above with length 

 (apex of antennal insertions to occiput) subequal (0.94-1.0) to width 

 across eyes; in larger specimens the sides of head are somewhat rounded 

 out behind eyes so that eyes are not so protuberant as in smaller 

 specimens; clypeal keel weak, present only on basal half or two- 

 thirds; clypeal margin with the median teeth weak, slightly more 

 separated than in shuckardi; median frontal sulcus extending halfway 

 to anterior ocellus; front with punctures moderate in size and con- 

 tiguous or almost so; vertex with more scattered punctures on anterior 

 third and almost impunctate on posterior two-thirds; ocellocular 

 distance 2.17-2.43 times the postocellar distance, and 0.42-0.44 times 



