174 
female of which was taken by Mr. Webster, at Lafayette, Ind., on 
wheat. 
This species. may be recognized by its being entirely black in both 
sexes, which easily separates it from both D. arvensis and D. collaris. 
NEMATUS (MESSA?) MARYLANDICUS NORTON. 
(Syn. Nematus aureopectus Norton.) 
Of all the Saw-flies found to breed on wheat, etc., perhaps the most 
interesting species, both on account of its numbers and of the interesting 
question of generic relationship which it presents, is the one named 
above. This Saw-fly has been carried through two successive genera- 
tions in confinement, which experience, together with notes and ob- 
servations made in the field, affords a pretty full knowledge of its life- 
round and habits. 
Larve evidently of this species collected on wheat were received 
June 6, 1884, from Mr. Webster, from Normal, Ill. Additional larvee 
found feeding on timothy were sent by him from Oxford, June 23, of 
the same year, and still another lot found on grass was received from 
the same place May 28, 1885. No adults were obtained from these 
specimens, and larve of the first lot only were saved. 
July 25, 1884, Mr. Lawrence Bruner forwarded us two larve collected 
July 7 in Holt County, Nebr. These are closely allied, if not identical, 
with the Webster material. 
Mr. Webster had had better success in rearing the adults from the 
larvee collected in 1884, and forwarded us eggs May 4, 1885, deposited 
in a blade of wheat by reared specimens. Additional eggs, in a living 
wheat plant, were received from Mr. Webster a little later, and from 
these two perfect insects were eventually obtained. Mr. Webster also 
successfully reared adults from eggs deposited in confinement by reared 
Specimens. 
The habits of this insect may be summarized as follows: 
The adult insects (Fig. 14, e, male; /, female) appear during the lat- 
ter part of April and first of May, the males antedating the females sev- 
eral days, as is the rule generally with Tenthredinide. In nature the 
flies do not emerge much before the last week of April, as shown by the 
fact that repeated sweepings of wheat fields in the middle and latter 
half of April failed to secure any adults. In the breeding cage speci- 
mens appeared somewhat earlier, or from April 15 to May 1. 
The eggs, when first laid, are four-fifths by one-fifth millimeter, and 
of a light green color. They are inserted to the number of two to five 
or more together along the edge of the wheat blades and just beneath 
the epidermis (Fig. 14, a a). Some fifteen or sixteen days elapse before 
hatching, during which period the eggs increase very considerably in 
size 
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