INSECT ENEMIES OF EASTERN FORESTS 539 
The larva of Scaptomyza adusta (Loew) is 11-segmented, uniformly 
clothed with short spines, and with the posterior segment produced 
into a large tubercle bearing the spiracles. 
Drosophila melanogaster Meig., the pomace fly, is typical of the 
family. This and allied species are frequently seen in large numbers 
about decayed fruit or vegetables. The flies are attracted by ferment- 
ing matter, and they often enter houses and cause considerable annoy- 
ance at preserving time. The species breeds prolifically in confine- 
ment and has been the subject of many experiments by geneticists. 
Other species are fungivorous and a few are strictly phytophagous, 
mining the leaves of small plants. Malloch (287) found Scaptomyza 
adusta in flowing sap, and the same species was recorded as a leaf 
miner by Chittenden (85) and by Frost (172). Drosophila dimidiata 
Loew has been bred from fungus in a decayed tree. Scaptomyza 
graminum (Fall.) and Chymomyza amoena Loew were reported by 
MacAloney (278) to have been reared from weeviled white pine 
leaders. 
Famity STRATIOMYIIDAE 
Soldier Flies 
The Stratiomyiidae are characterized by a peculiar wing venation, 
the veins being crowded forward toward the costal margin. The em- 
podium is pulvilliform, the third antennal segment annulated, giving 
the appearance of more than three segments, and the costal vein 
ends at or close to the wing tip. The larvae of this family have a 
nonretractile head with well-developed maxillae and antennae. The 
body is flattened, its surface finely reticulate. | 
The family contains both aquatic and terrestrial species. The ter- 
restrial species are mostly scavengers, although a few of them are be- 
lieved to be predators. The larval habits are variable. Some species 
live in carrion and manure, whereas others are found in the nests of 
Hymenoptera or rodents. Geosargus spp. have been found in the 
flowing sap of elm trees, Zabrachia polita Say has been bred from 
beetle-infested elm logs and from decaying pine logs, Pachygaster spp. 
has been taken from decayed wood, and numerous specimens of an 
undetermined stratiomyiid have been found under elm bark. 
Famity SYRPHIDAE 
Hover or Flower Flies 
The spurious vein between the third and fourth longitudinal veins 
in the Syrphidae is unique and serves to distinguish this family from 
all others. The adults, known as hover flies, love flowers and are 
often taken as they hover over them. 
The larvae, while differing from one another in many respects, are 
represented in this family by at least seven forms, each having a 
reduced head furnished with one pair of short sensory organs. The 
body segmentation is obscure, usually amphipneustic, with the poste- 
rior spiracles situated on two tubes of variable length, which are ap- 
parently fused except at the extreme tip. 
The species of this large family, which are either terrestrial or 
aquatic, are primarily beneficial. Many species are scavengers living 
in decaying vegetable matter, filthy water, or in the nests of various 
