13 
nicles short and brown, as also is the tip of the rostrum. ‘This last organ reaches to 
the second cox. Wings rather short, with stout coarse veins and stigma. 
Its Injuries.—The injuries this species does are more apparent in early 
spring and late fall than at any other time, for it is then that they are 
most plentiful, and less subject to the attacks of their numérous natural 
enemies. 
They are found in colonies, on the upper and lower surface of the 
leaf; often hidden in the wrinkles and folds of the leaf, deep down at 
its base and on the leaf-stalk. 
3ucktonsays: ‘Both theupper and under sides of the foliage of which 
last plant (Brassica oleracea) it often crowds in such numbers that the 
leaves become hidden by the living mass. Indeed sometimes, weight 
for weight, there is more animal than vegetable substance present. The 
leaves then become putrid, offensive in odor, and quite disgusting to the 
eye.” 
It is seldom that plants are so badly infested in Florida as described 
by this author, although some years ago I did see old cabbage-stalks 
that had been left go to seed in an old cabbage patch so affected. 
Every stalk was literally covered, promiscuously piled one upon 
another, with living, pumping, slimy aphids, rendered such by the exud- 
ing sap of the plants. I was unable to touch a portion of the stalk with- 
out my fingers being covered with the slimy, viscid mass. 
Natural Enemies and Parasites.—Fortunately, in Florida, the species 
has very many natural enemies and parasites which keep it from increas- 
ing very rapidly. 
In Europe, too, it has several parasites. Buckton mentions a Coruna, 
a Ceraphron, and a Trionyx (T. rape Curtis) as having been bred from 1t 
in Europe; also “several species of Syrphidee and Ichneumonide act 
effectually as checks upon the increase of A. brassice. The larve of 
the former dipterous flies, living in the midst of such plenty, soon gorge 
themselves and become of great size.” 
Trionyx rape Curtis has also been bred from it inthis country. It was 
received at the Department February 27, 1880, from Norfolk, Va., and 
redescribed by Mr. Cresson in the Annual Report, U.S. Department Ag- 
riculture for 1879, page 260, as a new species, Trionyx piceus. Professor 
Riley bred it at Saint Louis, Mo., as early as 1871, and I have bred it here 
in great quantities in May, June, and July. 
It is one of the principal checks in keeping this pest within bounds, 
and but few of the Aphids escape its sting. 
But there are other parasites; and below I give descriptions of sev- 
eral others bred here which are apparently new and as yet undescribed. 
The rearing of a parasitic Cynips from this species is quite interest- 
ing, inasmuch as the habits of but few of our species are known. Up 
tothe present time Allotria avena, A. tritici Fitch, and A. lachni Ashm. 
are the only Cynipids bred from Aphids in North America. 
