Many other species of gall midges have been recorded attacking various species 
of eastern trees. A few of the more common ones are: Parallelodiplosis florida 
(Felt)—produces elongate, pocketlike swellings on the veins and midribs of scrub 
and pin oak leaves; Obolodiplosis robiniae (Haldeman)—causes the margins of 
black locust leaves to fold; Caryomyia holotricha (Osten Sacken), C. sanguinolenta 
(Osten Sacken), and C. tubicola (Osten Sacken)—produce galls on hickory; Poly- 
stepha pilulae (Beutenmuller)—produces subglobose or globose, irregular, 
wrinkled, reddish galls on red oak leaves; Janetiella coloradensis Felt—causes 
swellings at the bases of Virginia pine needles; Prodiplosis morrisi Gagné—feeds 
on the young leaves of cottonwood in the South, causing them to turn black, unfold 
improperly, and frequently drop off; terminal growth is sometimes severely stunted. 
The dogwood clubgall midge, Resseliella clavula (Beutenmiller), produces club- 
like swellings on small twigs of dogwood, which sometimes kills up to 8 cm of the 
damaged twigs. Semudobia spp. feed on and destroy the seeds of birch. 
Aphidoletes thompsoni Mohn, a European predator of the balsam woolly adelgid, 
has been released in aphid-infested stands of balsam and Fraser firs in the Northeast 
and the Southern Appalachians, but establishment is doubtful in the Southern 
Appalachians. 
Family Xylophagidae 
Ichneumonlike Flies 
These flies, as their common names suggests, often resemble members of the 
hymenopterous family, Ichneumonidae. The adults are usually observed feeding on 
sap, the nectar of flowers, or other liquid matter in forested or wooded areas. The 
larvae appear to be either predators or scavengers in rich soil, in decaying vegetable 
matter, under the bark of trees, or in decaying logs. Xylophagus lugens Loew larvae 
may occur in large numbers under the bark of elm in association with the elm borer. 
The larvae of X. abdominalis Loew feed on beetle larvae under the bark of pine. 
Family Stratiomyidae 
Soldier Flies 
Soldier flies are brightly colored, moderately large, nearly bare, and thinly 
pilose. Many species are wasplike in appearance but the majority are broad and 
greatly flattened, and their wings lie parallel upon each other while at rest. These 
flies occur chiefly in wooded or forested areas or in meadows near water. Many are 
attracted to flowers. The larvae are usually terrestrial but sometimes aquatic and act 
mostly as scavengers. Zabrachia polita Coquillett has been reared from decaying 
pine logs and from beetle-infested elm logs. 
Family Tabanidae 
Deer and Horse Flies 
Many members of this family are important bloodsucking pests of livestock and 
wild animals. Some species also attack people and can be extremely annoying. 
Their bites are sharp and painful, and many are capable of removing considerable 
quantities of blood from their hosts, especially when they attack in force. They may 
also transmit such animal diseases as anthrax, anaplasmosis, surra, swamp fever, 
and tularemia. 
Most of the large horse flies usually seen belong to the genus TZabanus. These 
flies breed mostly in marshes, swamps, bogs, and ponds. The largest and best 
known species is the black horse fly, 7. atratus F. The adult is up to 25 mm long 
and its bite can result in the loss of a considerable quantity of blood. Other 
important species are: the striped horse fly, 7. Jineola (F.), T. abactor Phillip, T. 
quinquevittatus Wiedemann, T. sulcifrons Macquart, and 7. nigrovittatus Mac- 
quart. 
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