May, 1918] Parasites of Leaf-IIoppers 275 



Genus Aphelopus Dalman. 



Gonatopus (part) Dalman. vSwenska A. k. Handl., p. 82, 1818. 

 Dryinus (Aphelopus) Dalman, Anatccta ent., p. 14, 1823. 

 Aphelopus Haliday, Ent. Mag., v. 1, p. 273, 1833. 

 Ceraphron (part), Ratzchurg. Ichneum, v. 2, p. 141, nr. 2, 1848. 



Head transverse, anteriorly slightly narrowed, posteriorly deeply 

 arcuate. Eyes almost reaching the hind margin, oval, with a short, 

 scattered, indistinct pubescence. Ocelli forming a triangle, the lateral 

 ones nearer the hind edge than to the eye, farther apart than from the 

 eye. Mandible twice as long as broad, distally truncate and three- 

 dentate, the teeth three-angled, of equal length, the middle often with 

 a little tooth at its base. Maxillary palpus with fine long joints, labial 

 palpus two or three jointed. Antennae originating close or the clypeus 

 and farther apart than from the eyes, pubescent. Pronotum barely 

 visible from above; mesonotum convex, transverse, anteriorly rounded, 

 with two posteriorly converging parpasidal furrows extending only 

 part way down the mesonotum, seldom without such. Scutellum 

 posteriorly rounded, anteriorly with a transverse impression; propo- 

 deum large, at first horizontal, then gradually sloping; propleura 

 concave; mesopleura strongly convex, with an oblique longitudinal 

 furrow, separated from the metapleura by a ridge reaching from the 

 wHng bases to the hind edge of the middle coxae. Venation as above 

 given. Hind wings without distinct veins, with four frentila. Spur of 

 fore tibia hairy, narrowed on the whole ventral side to a base, hyaline 

 lamella, which is discontinued suddenly before the distal end of the 

 spur, this thus appearing two-lobed, all claws simple. Abdomen 

 strongly laterally compressed, as long or shorter than the thorax. 



Key to Species of Aphelopus. 



1. Thorax without white color 2 



Thorax in part white, at least first two pairs of legs white or pale yellow. . 10 



2. Radius very short one-third as long as the pterostigma, abdomen reddish 



brown 1 . riifiventris 



Radius at least as long as the pterostigma, abdomen black 3 



3. Propodeum w'ith a smooth median field, head without red coloring 5 



Propodeum without a medium field 4 



4. Face, clypeus, mandible and gena; ferruginous 2. affinis 



Face white to just above bases of antennas 9. comesi 



Face black 3. dikraneuri 



5. Mesonotum smooth and shining 5. americanus 



Mesonotum dull and coriaceous 6 



6. Head with mandibles above white 7. arizioncus ( 9 ) 



Head with white facial markings 7 



7. Clypeus alone white 4. microleucus 



More than clypeus white 8 



8. White facial markings extending a little above the antennae. . . .8. viduus 

 White facial markings extending at least as far as the anterior ocellus, 



along the eye margins 9 



9. Mesonotum densely minutely shagreened 7. arironicus (cf) 



Mesonotum coriaceous 6. varicornis ( 9 ) 



10. Only pronotum and prostemum white, the rest of the thorax black 



10. albopictus 



Mesonotum, except middle section, pleura, and sternum white 



11. pulcherrimus 



