. 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. Fig. 91.—Venation of Macro- siphum. {After Patch.) Fig. 92.—Venation of Toxoptera. {After Patch.) Plant-lice or Aphids are gregarious sucking insects, often abundant on many varieties of plants, and doing much injury. Three forms occur: i, sedentary wingless viviparous agamic females, 2. migra- tory winged viviparous agamic females, 3. sexual males and females —the females oviparous and wingless and the males winged or

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. 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. Fig. 91.—Venation of Macro- siphum. {After Patch.) Fig. 92.—Venation of Toxoptera. {After Patch.) Plant-lice or Aphids are gregarious sucking insects, often abundant on many varieties of plants, and doing much injury. Three forms occur: i, sedentary wingless viviparous agamic females, 2. migra- tory winged viviparous agamic females, 3. sexual males and females —the females oviparous and wingless and the males winged or wingless. Sc+P-^M+Cut/sM sc Sc*ff*M*Cu*lstA. 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, William, 1864-1927. Philadelphia : Blakiston

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Keywords: ., bookcentury1900, bookdecade1910, booksubjectinsects, bookyear1919