IDENTIFICATION OF INSECTS INJURIOUS TO CROPS 73 



Ears: 



(a) Developing kernels eaten; presence of much excrement. — Corn Ear Worm 



(Heliothis ohsoleta), p. 195. 

 (i) Stalks of ears covered with plant-lice. — Corn Plant-louse {Aphis maidis), 



p. 142. 

 (c) Developing kernels eaten; cob and tassel stalk tunneled. — European Corn 

 Borer {Pyrausta niihilalis), p. 212. 



III. INSECTS INJURIOUS TO CLOVER AND ALFALFA 



(Consult Bull. 134 Illinois Agric. Exper. Station, 1909) 

 Roots: 



(a) Second year plants wilted and dead, breaking off easily at the crown. 



Main root tunnelled and occupied by white footless grubs or little dark 



brown cylindrical beetles. — Clover Root Borer (Hylastinus ohscurus), p. 341. 



{b) Plants wilted and leaves dead, mealy bugs near crown of root. — Clover 



Root Mealy Bugs (Pseudococcus trifolii), p. 133. 



Stems: 



(a) A long burrow with brown discolored walls in the pith of the stem which 

 falls to the ground prematurely. — Clover Stem Borer (Languria mozardi). 



(b) Stems cut off or eaten. — Cutworms, Army-worms {Cirphis tinipuncta) and 

 Grasshoppers, p. 109. 



(c) Stems and leaves withered and dead; plants covered with large green 

 long-legged plant -lice. — Pea or Clover Plant-louse (Macrosiphum pisi), 



p. 149. 

 Leaves: 



(a) Leaves fuU of round holes, and edges gnawed. — Clover Leaf Weevil (Phy- 

 tonomus punctatus), p. 331. 



(b) Leaves eaten and with a ragged appearance. — Grasshoppers, p. 109. 



(c) Leaves folded along midrib, yellowish or brownish, with white or orange 

 maggots or silken cocoons within the folds. — Clover Leaf Midge (Dasyneura 

 trifolii), p. 248. 



Heads and Seed: 



(a) Florets at blossoming-time green and undeveloped; the ovaries empty or 

 with an orange pink or whitish maggot. — Clover Seed Midge (Dasyneura 

 leguminicola), p. 246. 

 {b) Florets withered and seeds undeveloped; the presence of frothy masses on 



stems. — Meadow Fro ghop per {Philanus spumarius), p. 153. 

 (c) Seeds eaten, becoming brown, brittle, and hollow; affected seeds dull brown 

 and often misshapen and of small size; maggot minute, white and footless. — 

 Clover Seed Chalcid (Bruchophagus funebris), p. 355. 

 {d) Unopened blossoms destroyed, a cavity eaten in the head. — Clover Seed 

 Caterpillar (Laspeyresia inter stitictana), p. 228. 

 Stacked or Stored Clover Hay: 



(a) Hay containing white silky webs and particles of excrement. — Clover Hay- 

 worm (Hypsopygia costalis), p. 208. 



