PSYCHE. 
more abundant than the %, is yet compar- 
atively rare. It is of a buff or salmon 
color, with eleven segments, pink on their 
posterior margins, and overlapping. Head 
narrow, with projecting muzzle, but im- 
perfect organs of manducation. Eyes small, 
round, black, on sides of the head. Anten- 
nae shorter than thorax, approximate, sit- 
uated in front of the eye, pale yellow, fee- 
bly pectinate. Thorax with margin re- 
flexed, subrugose. Adjoining the shield 
are the rudimentary elytra, semicircular 
and very small. Feet feeble, compressed ; 
the body is disproportionately large, and 
) 
as) 
the insect consequently moves with sudden 
nervous action, and pauses every few steps. 
Though there are no special phosphores- 
cent vesicles visible through the membrane, 
yet it emits light from the entire ventral 
surface of the three posterior segments. 
This is very brilliant, and when less intense 
posteriorly, appears diffused over the body. 
This brilliancy continues until oviposition. 
This @ insect is similar to Packard’s illus- 
tration 428, of an apterous ¢ from Mada- 
gascar, plus the aborted elytra and pectin- 
ate antennae. 
NOTE ON NORTH AMERICAN TRYPETIDAE. 
BY CHARLES ROBERT OSTEN SACKEN, HEIDELBERG, GERMANY. 
- Among a number of diptera, collected by 
Mr. J. Boll in Dallas, Texas, and purchased 
by me in Geneva a short time ago, there 
were 25 % and 2 specimens of a Trypeta, 
bearing on a label ‘‘ bred from galls on 
Ambrosia.” The insect could be easily 
identified with 7’. gibba Loew, and as the 
habits of this species were hitherto un- 
known, I deem it worth the while to put 
Mr. Boll’s observation on record. 
The gall, which is likewise in the collec- 
tion, is an oblong swelling of the stem, 
probably terminal. 
The habits of the following North Amer- 
ican Trypeta have been hitherto investi- 
gated and published (the name of the dis- 
coverer is in parentheses) : — 
Rhagoletis pomonella.— Fruit of the apple-tree 
(Walsh). 
Oedaspis polita. —Gall on Solidago (O. S.). 
«  gibba. — Gall on Ambrosia (Boll). 
Eurosta solidaginis. — Gall on Solidago (Harris). 
ELutreta diana.—Gall on Artemisia tridentata 
(Riley). 
Aspilota alba. — Seeds of Vernonia (Riley). 
This is a very small number, in compari- 
son to that of the described N. A. Trypeta ; 
but the most striking circumstance in con- 
nection with it is that among six Trypeta, 
whose habits are known, not less than four 
should occur in galls, and only one in the 
heads of a composite flower. In Europe 
the Trypeta bred from galls form an imper- 
ceptible minority, and most of the species 
are obtained from the heads of composites. 
Compare, for instance, the list of 60 species 
bred by Frauenfeld (Verh. k.-k. zool.-bot. 
Gesell. Wien, 1863, p. 221-224), among 
which only three formed galls on the stem 
of the plant. 
It would be worth while for American 
entomologists to collect dry heads of com- 
posite plants in autumn, for the purpose of 
breeding Trypeta ; a large number of new 
species of these pretty flies would probably 
be obtained. 
September, 1879. 
