198 



HTMENOPTEEA. 



pale honej'-yellow species, with a long club-shaped abdomen. 

 It lives in Cuba, 



Bogas is a genus differing from Braeou in having the three 

 first abdominal rings long, forming a slender petiole. 



In Microgaster, a genus containing numerous species, the 

 antennae are eighteen-jointed, and the abdomen is shorter than 

 usual, and clavate. There are two or three 

 subcostal, cells, the second very small. Mi- 

 crogaster neplioiMricis (Plate 3, figs. 3, 3 «) is 

 parasiti(3 on Nephopter3'x Edmandsii, found in 

 the cells of the Humble-bee. 



Apliidms, the parasite of the Plant-lice, is 

 a most valuable ally of man. It is known by 

 its small size, and by having the second and 

 third segments of the abdomen moving free on 

 each other. There are thi-ee cubital cells, though 

 the wings are sometimes wanting. Aphidius (Praon) avena- 

 pMs of Fitch, the Oat-louse Aphidius, is black with honey- 

 yellow legs, and is one-tenth of an inch long. Ap)lddius 

 (Toxares) triticaphis Fitch, the Wheat-louse Aphidius, is black, 

 shining, Avith thread-like antennae composed of twentj'-five 

 joints. Its length is .08 inch. Frequently the large size of 

 the parasite causes the body of the dead Aphis to swell out 

 into a globular form. 



Proctotrypid.^ (Proctotriipii) Latreille. Egg-parasites. 

 In this famil}^ are placed very minute species of parasitic Ich- 

 neumon-like Plymenopters which have rather long and slender 

 bodies, with straight or elbowed antenniB of various lengths, 

 often haired on the joints, usuall}'' ten to fifteen, sometimes onl}' 

 eight in number, while the wings are covered with minute hairs 

 and most of the uervures are absent. The maxillary palpi are 

 three to six, the labial palpi usually three-jointed. The abdo- 

 men has from five to seven joints, and the tarsi are mostl}' five- 

 jointed, rarety four -jointed. These insects are often so minute 

 that they can scarcely be distinguished by the naked eye unless 

 it is specially trained ; they are black or bro^ii, and A'ery 

 active in their habits. They may be swept oft' grass and 

 herbage, from aquatic plants, or from hot sand-banks. They 



