514 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
are pale green when first formed, changing to a reddish brown later. 
The species has not been reared. The ash midrib gall of Contarinia 
canadensis Felt is a large, tumid, midrib gall found on white ash. It 
is from 5 to 15 mm. long. 
JUNIPERUS (JUNIPER) 
The larva of Contarinia juniperina Felt, the juniper midge, is a 
small yellowish maggot that produces a blister at the base of the 
needles, often causing them to drop to the ground. Numerous dead 
tips are the result of an infestation of this species. The adults emerge 
in April and lay their eggs beneath the needles. When fully developed 
the larvae drop to the ground, where they pass the winter in the soil. 
There is only one generation (Felt, 752). Pruning and soil treatment 
are recommended as control measures. 
LIRIODENDRON (TULIP) 
Thecodiplosis liriodendri (O.S.), the tulip gall fly, is yellowish and 
about 14 inch long, and it produces a purplish blister gall with a 
diameter of about 3 mm. on the leaf. The species also attacks poplar, 
and was once reported as so abundant that the foliage was seriously 
disfigured. 
PINUS (PINE) 
The larva of Retinodiplosis inopis O.S., the gouty pitch pine midge, 
is yellowish orange. It is the cause of the subcortical twig swellings 
with pitch exudations on pitch pme. When full grown it forms its 
whitish oval cocoon on the needles or tip of the twig. Contarinia col- 
oradensis Felt, the pine bud gall (fig. 133), produces swollen needles 
or needle bundles on pinon and stone pine. J/anetiella coloradensis 
FIGURE 155.—Galls on pinion caused by Contarinia coloradensis. 
