374 ERNEST A. BACK. 



Type. — Dioctria octopunctata Say. 



Mr. Coquillett agrees with me that Dioctrodes flavipes, the 

 type species of his genus Dioctrodes, is a rather small specimen 

 of Taracticus octopunctatus. The tibial spurs in this genus 

 are very small, slender, and not always easily detected. I 

 agree with Dr. Williston, who states in Trans. Am. Soc, XI, 

 page 22, the improbability of Ceraturgus niger Macquart be- 

 longing to Taracticus. 



Taracticus octopunctatus (PI. Ill, fig. 6; PI. XI, fig. 7). 



Dioctria %- punctata Say, Jour. Acad. Sci. Phil., Ill, 49, 1823; 

 Compl. Works, II, 63. 



Dioctria octopunctata Wiedemann, Auss. Zw., I, 365. 



Dioctria octopuncta Schiner, Verh. Zool.-Bot. Ges., 1866, 675; 

 1867, 369. 



Taracticus octopunctatus Loew, Cent., X, 24, 1872. 



Taracticus octopunctatus Williston, Trans. Am. Ent. Soc, XI, 

 22, PI. II, fig. 2.2a. 



Dioctrodes flavipes Coquil., Proc. Ent. Soc. Wash., VI, 181, 1904. 



Dioctria rufipes Jones, Tr.. Am. Ent. Soc, XXXIII, 276, 1907. 

 % 9 . — Length 6-8.5 mm. — Black; halteres, femora, tibias except 

 apices of hind pair, and the bases of all the tarsal segments yellow ; 

 abdomen punctate with eight white pruinose spots; all the posterior 

 cells of the hyaline wings open. Head whitish, sometimes golden 

 pruinose, the ocellar tubercle and sometimes the center of the face 

 polished. Antennas distinctly longer than the height of the head; 

 segment 1 about one and one-half times the length of segment 2; 

 segment 3 more than twice the length of segments 1 and 2 taken 

 together, slender, microscopically pubescent, beyond the center on 

 the upper side with an emargination at the proximal end of which is 

 a short forward-directed spine; style hardly distinguishable. Thor- 

 acic dorsum with three golden pruinose stripes, the outer ones being 

 dilated before and inclosing a dusky spot upon the humeri; pleura? 

 bare, together with the coxae, grayish-white pruinose, somewhat 

 browner immediately below the dorso-pleural suture. Abdomen black, 

 polished, punctate, with a silvery-white spot on the posterior lateral 

 angles of segments 2-5: tip of male abdomen, including the genitalia, 

 red. Legs slender, the hind femora with two long slender bristles 

 beneath near the base, the tibias with more numerous but similar 

 bristles. Hind femora are sometimes in part black. All the bristles 

 and pile of the entire body and legs pale. Wings hyaline, violaceous, 

 all the posterior and anal cells open. 



Type. — Lost. The type of Dioctrodes flavipes Coquillett is 

 at the U. S. N. M., Cat. No. 7953. 



