Decerpber, '14] FELT: ARTHROCNODAX CONSTRICTA 481 



Ames, Iowa. Described from one female (type) labelled "Experi- 

 ment 113 (1911), April 7, 1912," and one male (allotype) labelled in 

 the same fashion. The paratypes bear various "Experiment" num- 

 bers and most of them are reared. Certain specimens of this species 

 were also collected around Storm Lake, Iowa, on May 2, 1912 by Il„ L. 

 Webster. 



Type, allotypes and paratypes in the U. S. National Museum under 

 Catalog Number 18357. Other paratypes in the collection of Dr. 

 A. D. MacGillivray and in the collection of the Experiment Station at 

 Ames, Iowa. 



ARTHROCNODAX CONSTRICTA n. sp. 



By E. P. Felt, Albany, N. Y. 



The midges described below were reared from garden beans infested 

 with the common red spider, Tetranychus bimaculatus, and probably 

 predaceous thereupon. The specimens were collected by Thomas 

 H. Jones, June 21, 1913, at Rio Piedras, P. R. The species runs in 

 om- key to A. rhoina Felt, from Avhich it may be easily separated by 

 the greater length of the distal part of the stem of the fifth antenna] 

 segment and the marked differences in genitalia. 



Male: Length 1 mm. Antennse fully as long as the body, sparsely haired, yel- 

 lowish-browTi, yellowish basally; 14 segments, the fifth having the basal portion of 

 the stem with a length one-fourth greater than its diameter, the distal part with a 

 length two and one-half times its diameter. Palpi; the first segment subquadrate, 

 the second narrowly oval, the third and fourth nearly equal, each with a length 

 nearly four times the diameter. Mesonotum yellowish brown, the submedian lines 

 yellowish. Scutellum yellowish bro'mi, lighter apically, postscutellum j-ellowish. 

 Abdomen yellowish brown. Halteres pale yellowish. Coxa; and legs mostly 

 yellowish straw, the pulvilli nearly as long as the claws. Genitalia; basal clasp 

 segment long, slender; terminal clasp segment rather long; dorsal plate short, broadly 

 and roundly emarginate; ventral plate long, broad, roundly truncate; st^'le long, 

 rather slender and strongly constricted near the distal third. 



Female: Length 1.25 mm. Antenna; nearly as long as the body, sparse!}- haired, 

 yellowish, the fifth segment with a stem one-fomth the length of the cylindric basal 

 enlargement, which latter has a length about two and one-half times its diameter, 

 the fourth palpal segment distinctly longer than the thii'd. Ovipositor pale yellowish, 

 the terminal lobes narrowly oval, tapering distally and thickly haired. Other char- 

 acters nearly as in the male. Type C. a2.572. 



