INSECT ENEMIES OF EASTERN FORESTS 537 
tain species are of economic importance. Others are occasionally of 
more than casual interest because of their association with injurious 
species or because of inquiry regarding them. The identification of 
such species is difficult and should usually be left to the specialist. A 
few familes that include species of such habits are described on the 
following pages. 
Famity MUSCIDAE 
The Muscidae are medium-sized flies with well-developed squamae, 
and either hypopleural or pteropleural bristles are present. The an- 
tennal arista is plumose to tip. The abdominal bristles are reduced 
except at the posterior end. The larvae (fig. 128, 7) of most species 
taper anteriorly from a usually truncated or broadly rounded pos- 
terior end. The body is with or without lateral or dorsal processes, 
it is amphipneustic, and the mouth hooks usually are paired (in the 
Muscinae there is only one). 
The habits of the family are varied, but it is believed that most of 
the species are scavengers. The housefly (M/usca domestica L.) is 
perhaps the best-known member of this large family. This species 
breeds in manure and decaying vegetable matter, and is believed to be 
the carrier of many disease organisms. A few species, such as the 
stablefly (Stomoxys calcitrans (.)) and the horn fly (Siphona irri- 
tans (L.), are blood suckers, and they are also suspected of disease 
transmission. 
Famity ANTHOMYIIDAE 
The Anthomyiidae differ from the Muscidae and allied families in 
that both hypopleural and pteropleural bristles are absent. The first 
posterior cell is shghtly, if at all, narrowed in the margin. 
A number of the species are plant feeders causing serious injury to 
several crops of economic importance. The seed-corn maggot (Hy- 
lemya cilicrura (Rond.)) was reported by Wilford (433) as at- 
tacking cedar seedlings and causing considerable damage to nursery 
stock at Lebanon, Tenn. This species has also been bred from the 
exposed roots of living larch, in which case the larvae were believed 
to be feeding on the fungi growing on the decaying bark. The larva 
of H. cilicrura (fig. 128, D) is yellowish white and about 14 of an 
inch long. The anal segment has four simple tubercles in a trans- 
verse row below the spiracular plates. The posterior spiracles have 
three spiracular openings, and the anterior spiracles have about six 
lobes. The basal pieces of the mouth hooks are longitudinally striated 
on the ventral surfaces. 
Control measures, based on preliminary tests, indicate that a 50-per- 
cent miscible carbon disulfide solution diluted with water (1 quart of 
stock chemical to 50 gallons) and sprinkled evenly on the soil at the 
rate of 1 pint per square foot of surface would give satisfactory results. 
Famiry SARCOPHAGIDAE 
The Sarcophagidae differ from the Muscidae in that both hypo- 
pleural and pteropleural bristles are present. ‘They are usually gray- 
ish or silvery in color, and have a tessellated abdomen. ‘The aristae 
are plumose for about half their length. The larvae are of the usual 
muscid-form type with the posterior spiracles located in a pit. The 
