punctures made near the midrib. The larvae mine the tissues 
between the leaf surfaces. The mine is hairlike at first but gradu- 
ally widens as the larva continues to grow. Eventually it becomes 
blotchlike (fig. 171). Heavily infested leaves become unsightly 
and usually drop prematurely. Leaves damaged by feeding punc- 
tures become roughened, twisted, and stunted. The winter is spent 
in the larval stage in the mine. Pupation occurs from early March 
to early April and the adults emerge from mid-May to late June. 
There is one generation per year. 
COURTESY CONN. AGR. EXPT. STA. 
FIGURE 171.—Injury by the holly leaf miner, Phytomyza ilicicola: 
Left, undamaged leaves; right, mined leaves. 
Several other members of the family also mine the leaves or 
produce galls on their hosts. Japanagromyza viridula (Coq.)— 
produces blotch mines in the leaves of red oak; Melanagromyza 
schineri (Gir.)—causes the formation of slight swellings on the 
smaller twigs of poplar; M. tiliae (Couden)—produces swellings 
about half an inch long on the twigs of basswood; Phytobia posti- 
cata (Meigen) —produces blotch mines in the leaves of sweetgum; 
and Phytomyza clara (Melander)—produces blotch mines on Ca- 
talpa bungit. 
FAMILY ANTHOMYIIDAE 
Members of this family are quite similar in appearance to those 
of the family Muscidae. The maggots vary in habits, some feeding 
on the roots of plants, some as scavengers, and others as parasites 
of other insects. The seed corn maggot, Hylema platura (Meigen), 
damaged red cedar seedlings in a forest nursery in Tennessee 
(766). In this case, the larvae chewed through the bark of the 
main stem just below the ground line and fed on the roots. Large 
numbers of seedlings were killed. 
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