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Aphidius (Proan) ayenaphis. Fitch. Grain-louse Aphidius. 
Black; legs base of the abdomen and also a sub-basal band, yellow; 
abdomen as long as the thorax, but narrower, oval, first segment form¬ 
ing a pedicel; antennae as long as the body, slender, 20-jointed, black, 
thorax egg-skaped, black and shining. Length, 0.10 inch. Parasitic 
on the oat or grain Aphis (Aphis avence). 
Toxares tritioaphis. Fitch. Wheat-louse Aphidius. 
Black, shining; antennae, thread-like, longer than the body, and 25- 
jointed; thorax egg-shaped and rather broader than the head; abdo¬ 
men flattened, long oval, a little longer than the thorax, but scarcely 
as broad. Wings transparent,slightly smoky, strongly iridescent; stig¬ 
ma pale brown; veins brownish black. Length 0.08 inch. 
Parasitic on Aphis avence. 
Trioxys salicaphis. Fitch. Willow-louse Aphidius. 
Black and shining, with a long elliptical abdomen of honey-yellow 
color at the base, but gradually passing to black posteriorly; legs, yel¬ 
low; feet, dusky; antennae two-thirds as long as the body, 13-jointed. 
Length, 0.06 to 0.07 inch. 
Trioxys populaphis. Fitch. Poplar-louse Aphidius. 
Black and shining, the abdomen long, elliptical and much narrower 
than the thorax, the basal suteres yellow; legs yellow except the pos¬ 
terior thighs, which are black; antennae nearly as long as the body, 15- 
jointed; outer margin of the fore wings, blackish; stigma dusky. 
Length, 0.07 inch. Parasitic on an Aphis found on the leaves of the 
Balm of Gilead. 
Trioxys oerasaphis. Fitch. The Cherry-louse Aphidius. 
Black with the palpi and legs pale yellowish brown, antennae almost 
as long as the body, 18-jointed; abdomen elliptical, rather narrower 
and shorter than the thorax, with scarcely any pedicel at its base, 
