28. 
29. 
30. 
ol. 
32. 
33. 
36 
Larvae with a distinct structure like a breastbone near 
Anterior End eee Diptera, Cecidomyiidae 
Larvae without breastbone; mouth parts well de- 
veloped? 11.2. 2 See eee cs mees Diptera, Berouiyzide 
Larvae legless or with only minute legs 0.0... 
Legs well developed, also prolegs present 0... 
Woody galls containing plain evidences of mining ac- 
tivity of the larvae; larvae with a well-developed head 
capsule and mandibles 
Coleoptera, Buprestidae, Cerambycidae, Curculionidae 
Larval mines not obvious; white larvae, curved or grub- 
like in form, legless, and with distinct head capsule, 
each contained in a specialized cell 
Hymenoptera, Cynipidae, Chalcididae 
On, willow. 26-2 Hymenoptera, Tenthredinidae 
On locust, poplar, maple... Lepidoptera, Olethreutidae 
F. Sucking Insects 
Injury or insects present on leaves ..... 
Injury primarily confined to twigs ... i 
Injury primarily confined to branches and main stem __ 
Leaves off-color, yellowish or spotted from feeding punc- 
tures of active, jumping insects: 
Homoptera, Cicadellidae 
Hemiptera, Tingidae 
Leaves bearing galls or abnormal spots: 
On Nackberty- 2) Sane Homoptera, Phyllidae 
On elm, poplar, willow, witch-hazel, hickory, oak, 
chestnut, etc. 
Homoptera, Aphididae, Phylloxeridae 
On: conifers2542 54 eae Homoptera, Phylloxeridae 
Exposed insects on the leaves: 
Sealelike, gall-like, or soft grublike insects covered 
with wax in the form of powder or tufts 
Homoptera, Coccidae 
Fringed, scalelike immature forms associated on the 
leaves with white 4-winged flies 
Homoptera, Aleyrodidae 
Soft-bodied insects with long conspicuous antennae 
Homoptera, Aphididae 
Insects surrounded by a conspicuous frothy mass of 
spittle; ends of branches and trees slowly dying in 
severe infestations; pines ......... Homoptera, Cercopidae 
Injury consisting of ragged slits in the twigs, often 
breaking at incision; the tips of the branches hanging 
with withered leaves; hardwoods 
Homoptera, Cicadidae 
Homoptera, Membracidae 
Injury consisting of gall-like or gouty swellings on limbs 
ANG CWilLeiSrOl tlie ee. ee Homoptera, Chermidae 
Tips of hard pines flagged (needles yellowing’) ; scales 
embedded in pits in bark Homoptera, Coccidae 
29 
30 
32 
33 
34 
