380 NEW YORK STATE MUSEUM 



tennae black, covered with short whitish pile; palpi blacky 

 thorax velvety black, with an oblique bluish white metallic 

 humeral spot, the posterior margin also metallic; scutellum 

 velvety black; and pectus black, grayish pruinose. Abdomen 

 deep velvety black; on each side on the margin of the first 

 abdominal segment is a tuft of fuscous hairs, underneath which 

 the segments appear metallic. The posterior part of the venter 

 appears metallic. Legs, black and yellow. The extensor sur- 

 face of front tibiae, and a basal ring on the middle and hind 

 tibiae, silvery white; the fore coxae, basal half of <ill femora, 

 tibiae and metatarsi, and sometimes also bases of some tarsal 

 joints more or less yellowish; the rest black. The anterior tibia 

 with a rudimentary spur, middle and hind pair each with two 

 spurs; tarsal claws trifid. Halteres orange-yellow; wings whit- 

 ish hyaline. Leng-th 2 to 2.5mm. 



Female. Black. Antennae black covered with short whitish 

 pile; two basal joints usually yellowish; palpi black with i)ale 

 hairs; face and front gray pollinosa. Dorsum of thorax black, 

 bluish gray pollinose, particularly on the sides and front cor- 

 ners, sparsely covered with verj' short yellow hairs. Scutellum 

 black, with erect black bristles; pleura black, gray pollinose. 

 Abdomen black, the anterior segments velvety, the posterior ones 

 subshining brown. Legs yellowish, middle and hind coxae brown, 

 tips of femora and tibiae, the whole of fore tarsi, tips of the 

 middle and hind, first and second tarsal joints and usually the 

 whole of the remaining joints, black. Sometimes the femora 

 are wholly black. The extensor surface of all tibiae is silvery 

 white. The first and third joints of the fore tarsi are each pro- 

 vided with a pair of long black hairs near the tip, besides the 

 usual shorter ones. The anterior tibia with rudimentary spur, 

 middle and hind ones each with a pair. Tarsal claws simple. 

 ^A'ings whitish hyaline, the heavy veins yellowish brown, quite 

 yellowish at the base at point of attachment. Halteres ]>ale 

 yellow. Length 2 to Hmm. 



This species is very common in the AdirondaclvS, where it 

 proves to be a great annoyance to travelers. It seems to have 

 a wide distribution, having been reported by Mr Coquilletti as 

 occurring in Canada, New Hampshire, New York, ]\richigan, 

 Minnesota, Wyoming, British Columbia, California, Texas, Lou- 

 isiana, Mississippi and Florida. I have found it in Ithaca N. Y., 

 and I have seen specimens from Moscow, ^larsh and Albion Id., 

 and Battle Creek ]\rich. 



lU. S. Dep't Agric. Bui. 10, n. s. 2. 1898. 



