Tue Insect FAUNA orf THE GENUS CRATAEGUS 1085 
a long, narrow slit on the oppo- 
site side of the leaf. These galls 
occur very commonly in groups 
on the same leaf or on adjoining 
leaves. A single yellow larva, 
1 millimeter long, and slender, 
is found in each gall in July or 
August. 
Pineapple gall (maker unknown) 
Red or green spiny galls, 
~ shaped and armored like a pine- 
apple (figs. 122, 123, and 124), 
3 millimeters in diameter and 
5 millimeters high, are found 
on the upper side of Crataegus 
punctata leaves in July and 
August. The pineapple gall is 
thick and is covered with fleshy 
spines at the base, but becomes 
slender, with long, slender 
spines, toward the apex, which 
is composed of two flat, leaflike, 
vertical plates. The gall opens 
Fie. 122. PINEAPPLE GALLS between these two plates. Gen- 
| erally but one gall is found on 
a leaf and it is commonly on the midvein. 
Trypetidae 
pomonella Walsh, Rhagoletis (Apple maggot) 
The maggots of Rhagoletis pomonella have been reared and flies obtained 
from the fruits of Crataegus punctata, C. albicans, C. pruinosa, C. brainerdi, 
and C. macrosperma. The species probably lives also in the fruits of 
other large-fruited hawthorns. 
No larvae have been found in 
the small fruits of C. neofluvialis 
and C. oxyacantha, although 
these have been carefully 
watched. The maggots leave 
the fruit to enter the ground 
in autumn, and the flies emerge 
from the brown puparia in June » 
and July. 
