. Class book of economic entomology, with special reference to the economic insects of the northern United States and Canada. Beneficial insects; Insect pests; Insects; Insects. 138 ECONOMIC ENTOMOLOGY ^ Fig. aphids: daphis. HH. Frontal tubercles without the promi- nent tooth-like projection; cauda more or less sickle shaped.—Myzus. GG. First antennal segment not conspicuously gibbous on inner side. H. Head with distinct and more or less prominent frontal tubercles. I. Cornicles clavate; antennae sel- dom longer than body; cauda tapering and knobbed.—Rhopalo- siphum. II. Cornicles cylindrical
. Class book of economic entomology, with special reference to the economic insects of the northern United States and Canada. Beneficial insects; Insect pests; Insects; Insects. 138 ECONOMIC ENTOMOLOGY ^ Fig. aphids: daphis. HH. Frontal tubercles without the promi- nent tooth-like projection; cauda more or less sickle shaped.—Myzus. GG. First antennal segment not conspicuously gibbous on inner side. H. Head with distinct and more or less prominent frontal tubercles. I. Cornicles clavate; antennae sel- dom longer than body; cauda tapering and knobbed.—Rhopalo- siphum. II. Cornicles cylindrical or incon- spicuously swollen; antennae usu- ally longer than body; cauda ensiform.—Macrosiphum. HH. Head with frontal tubercles absent or slight. I. Cornicles distinctly clavate.— Siphocoryne (Hyadaphis). II. Cornicles usually cylindrical and of moderate length; if clavate they are only slightly swollen and quite small. J. Cornicles very short, much shorter than cauda, slightly swollen; beak short; antennae shorter than body.—Hyalop- ierus. J J. Not as above, , cornicles moderately long, usually longer than cauda, cylindri- cal; antennae usually as long as or only slightly shorter than body.—Aphis. BB. Media of fore wings once forked or simple. C. Media simple. D. Hind wings with two oblique veins.—Pemphigus. DD. Hind wings with but one oblique vein. E. Antennae 6-segmented.—Tetrancura. EE. Antennae 5-segmented.—Hamamelistes. EEE. Antennae 3-segmented.—Hormaphis. CC. Media once forked. D. Cornicles present, an Aphis-like species.—Toxoptrra. DD. Cornicles vestigial or wanting. E. Hind wings with two oblique veins.—Eriosoma. EE. Hind wings with one oblique vein.— 90.—Front of head of a, Chaitophorus; h, Hya-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Lochhead, Will
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectinsects, bookyear1919
