﻿THE CATTLE GRUBS OR OX WARBLES 



31 



The fifth-stage larva of H. bovis is slightly larger, but otherwise very similar 

 in shape to that of H. lineatum. The armature arrangement is similar to that 

 of H. lineatum, except ventrally, where only segments 2 to 9, inclusive, are 

 armed ; very rarely a specimen is found with armature on the tenth segment 



and with a single or a few spines on the anterior 

 border only. In H. lineatum there is always a 

 fairly broad band of spines on the posterior 

 border. The posterior 

 stigmal plates of H. a 



bovis are deeply exca- ^ 



vated or funnel shaped 

 toward the pseudostig- 

 mal orifice. This char- 

 acter is very reliable 

 for distinguishing the 

 species in this stage 

 (fig. 18). 



THE PUPARIUM 



The puparium retains 

 all the larval charac- 

 ters, except that it as- 

 sumes a different shape 

 and darkens in color 

 to almost black. Its 

 dorsal side is nearly 

 straight and flat, with 

 the anterior end plain- 

 ly showing the opercu- 

 lum (fig. 16, d-r'). The 

 flat stigmal plates of 

 H. lineatum and the p^Q^ IS.—Hyjioderma hoi 



Fig. 12. — Hy^pod^nyia Uneatiim.' 

 Cephalopharyngeal skeleton 

 and mcuth hooks of third- 

 stage larva. A, spine; B, an- 

 terior end, and D, posterior 

 end of mouth hooks ; C, tooth. 

 Greatly enlarged (Laake) 



funnel-shaped plates 

 of II. bovis remain the 

 .same as in the ma- 

 ture larva and serve 

 to distinguish the two 

 species. 



THE ADULT 



Cephalopharyngeal skele- 

 ton and mouth hooks of 

 third-stage larva. A, 

 spine ; B, anterior end, 

 and C, posterior end, of 

 mouth hooks. X 125 

 (Laake) 



The adult of H. lineatum (fig. 19) measures from 12 to 13 millimeters in 

 length and has a wing expanse of from 23 to 25 millimeters. The female 

 with ovipositor fully extended measures 17 millimeters in length. The gen- 

 eral color of the adult is black, banded with .vellowish and orange hair. The 

 .shade of the colors varies somewhat with different specimens and also 

 changes according to the position and light in which the insect is viewed. 

 The front, sides, aJid back of the bead are covered with yellowish-white hairs. 

 The thorax is 

 clothed with 

 yellowisli hairs 

 ekcept dorsal- 

 ly, where tbe 

 posterior pari 

 of the protbo- 

 O rax and tlu? 



mesothorax an; 

 Fio. 14. — Hypfiderma line- more thinly 

 atuni.- I'osterlor stigmal f.,.^,,y(,,\ with i- 

 plates of fourth-stage ^V, ^iin j, 



larva. Greatly en- black and some 

 larged (Laake) yellow luiirs. 



On this urea 

 there are four distinct longitudimil lines wbic-h arc nearly naked and sbining. 

 The basal segments of tbe abdonn-n arc covenul with graylsb-ycllow liairs, tbe 

 middle segments are brownish black, and (be Icrtninal segments are clolbed in 

 orange-yellow liairs. The femora an; black and tbe tlblte and tarsi brown. The 

 entire legs arc well covered wllb black iind orange-colored liairs. Tbe wings 

 are slightly fu.scous and tbe veins are dark brown to black. 



'i. ir». — Hy/iofleniia Iiovih: Posterior 

 stigmal plates of fourth-stage larva. 

 (;reHtly enlarged (Laake) 



