INSECT ENEMIES OF EASTERN FORESTS 515 
Felt makes a globose swelling at the base of needles on scrub pine (fig. 
134). Ttonida pinirigidae (Pack.), the pine needle gall fly, is 
rather common on pitch pine, and is believed to be the species that 
produces the conspicuous subglobular swelling at the base of the 
needles, causing their abortion. The larva of Retinodiplosis resinicola 
(O.S.), the pitch pine midge, is yellowish orange. It has been reared 
from extruded resin masses on pitch pine. It lives in the small patches 
of semifluid resin exud- 
ing from wounds in the 
branches. 
PRUNUS SEROTINA (WILD 
BLACK CHERRY) 
The larva of /tonida 
serotinae (O. S.), the 
wild cherry bud gall, is 
bright yellow or red, and 
is beheved to be the cause 
of the irregular terminal 
shoot and bud gall. The 
gall measures about 1.5 
cm. in diameter. 
PRUNUS VIRGINIANA 
(CHOKECHERRY ) 
Contarinia virginian- 
tea (Felt), the choke- 
cherry midge, is one of 
the causes of swollen and 
deformed fruit of the 
chokecherry. 
PYRUS (PEAR) 
The pear midge (Con- 
tarinia pyrivora (Riley) 
emerges late in April and 
in May and deposits its 
eggs in the blossom buds. 
When full grown, the 
maggots drop to the 
ground or remain in the 
infested fruit until they 
are shed from the tree. 
There is only one genera- 
tion, the species passing 
the winter as a puparium. 
Mundinger and Hart- 
zell (312) reported sat- 
isfactory control with 
from 84 to 1 pint of nico- 
tine sulfate in 100 gallons 
of spray mixture, used 
with 1 or 2 gallons of  pygure 134.—Galls on pine caused by Janetiella 
summer-oil emulsion. coloradensis. 
