1 color is black, with yellow mouth-parts and legs. The 
are transparent and beautifully iridescent under the magni- 
glass. The male closely resembles the female, but has two 
irticles in each of its antennae and has the tip of its abdomen 
instead of sharp pointed. The following more detailed des- 
n will serve to distinguish the species from those which in- 
her plant lice. 
ilytus maidaphidis, nov. sp. Head and thorax black, shining, 
h. Abdomen reddish brown, darkest on the middle of the 
nts, with a few short whitish hairs. Front with whitish hairs, 
age dull black. Mouth-parts pale honey yellow. Coxae of an- 
and middle legs, trochanters of all the legs, anterior and 
1 femora, anterior tibiae and tips of middle and hind tibiae 
•yellow. Posterior femora mostly black. Limbs clothed with 
ised silky white pubescence, thickest on the tibiae and tarsi, 
coxae black. Tarsi dusky. Wings transparent, iridescent, with 
yellow at base and a basal half of costa. Stigma smoky 
, with a touch of yellow at its inner angle. Nerves black. 
subsplierical. Eyes large and -prominent. Three ocelli 
cuous. Antennae of 13 articles in the female; with 15 
e male. Two proximal articles equal in length, shorter 
he others, about as long as wide. The succeeding articles 
equal in length, about twice as long as wide. Distal article 
tale longer than the others; in the male it is about equal to 
The articles are longitudinally, finely carinate. Thorax ob- 
elevated anteriorly, impunctured. Abdomen spindle shaped, 
sed, pointed in the female, blunt in the male. Legs long and 
r; femora spindle-shaped, about three-fourths the length of 
triae. Tibiae slender at base, gradually enlarging to their ex¬ 
iles. First article of tarsi long and uniform in diameter; about 
g as the three succeeding together. Second article a little 
than the following ones and slightly swollen. Three distal 
s subequal. Length, 2 mm. 
ing the summer and autumn these little flies may be seen 
ig rapidly about on the corn which is infested with lice, and 
ched will be seen now and then to approach a plant louse, 
gently with the antennae, and if the louse seems to be satis- 
y, the abdomen of the parasite is suddenly bent downwards 
len forwards between the legs, the victim is stabbed by the 
sharp pointed ovipositor and an egg is inserted at the same 
n its body. The parasitized louse continues to feed after the 
is been deposited as if nothing had occurred to discommode 
1 if young may continue to grow until the natural size is 
id. All this time the great grub hatched from the egg is 
y upon its tissues and growing rapidly so that by the time it 
|s growth the body of its host is swollen out greatly beyond 
ual proportions. The grub seems to avoid the vital organs 
host until the last so that the louse does not entirely succumb 
he grub is ready to become a pupa, at which time it seems 
i our all the remaining tissues or crowd them aside to make 
i [or itself. The body of the louse has by this time become 
and dry, and though outwardly looking like a very plump 
louse is really only a skin enclosing a parasite. By some 
, not ascertained, the swollen body becomes glued to the leaves 
