44 Transactions. — Zoology. 



Gasterophilus equi. 



Gastrus equi, Meigen, Dipt, iv., 175, i., pi. 38, figs. 21, 22. 



Body tawny, with testaceous hairs. Wings with a trans- 

 verse grey band beyond the middle. Male lighter in colour 

 than the female. Length, 11-17 mm. ; wing, 10 mm. 



Hab. Throughout New Zealand. Introduced. 



I first saw this species in 1892. Both it and the following 

 species were exceedingly troublesome for the next two years, 

 but since then their numbers have declined. In America it 

 is thought that they are kept in check by sparrows feeding 

 on the pupae. 



Gasterophilus hsemorrhoidalis. 



(Estrus hcemorrlioidalis , Linnseus, Syst. Nat., ii., 970, 4 (1761). 



Body black, with testaceous hairs. Abdomen with a black 

 band in the middle, and pale-yellow hairs at both ends. 

 Wings clear. Length, 10-11 mm. ; wing, 9 mm. 



Hab. Throughout New Zealand. Introduced. 



Mr. M. Murphy, secretary to the Canterbury Agricultural 

 and Pastoral Association, informs me that this fly was first 

 noticed in the North Island in 1889, and in Canterbury in 

 1891. It is thought to have been introduced by some Mexican 

 circus-horses from San Francisco. 



Genus (Estrus, Linn. (1748). 



Body pubescent, the front broad. Antennae very short, 

 seated in a cavity of the face, the third joint round ; arista 

 bare. Squamae large. Fourth longitudinal vein bent forwards 

 and joining the third longitudinal at a short distance from the- 

 tip of the latter. 



CEstrus ovis. 



(Estrus ovis, Linnaeus, Syst. Nat., ii., 970. (Estrus perplexus, 

 Hudson, Man. N.Z. Ent., p. 63, pi. vii., fig. 12. ' 

 Head and thorax pale-brown above, with numerous mi- 

 nute black tubercles. Abdomen dark-brown, tessellated with 

 silvery. Legs pale-tawny. Wings clear. Length, 11mm.; 

 wing, 9i mm. 



Hab. Throughout New Zealand. Introduced. 

 1 first noticed this species at Homebush Station, in Can- 

 terbury, in 1873, but it is not common. 



Family TACHINIDiE. 



" Arista of antennae bare, or with very short pubescence. 

 Thorax short. First posterior cell closed or only slightly 

 opened. Legs short " (Loew). 



Parasitic insects which lay their eggs on the larvae of 

 other insects. 



