. Eastern forest insects. Forest insects. The adult is reddish-brown to black and about to mm. long. The declivity is shallowly excavated and deeply punctured. Each side is armed with four small teeth and the apical margin is slightly produced. One to several long, winding egg galleries originate from a central nuptial chamber (fig. 97). Larval gal- leries are short, transverse, and each ends in a pupal cell in the phloem. In the south, the life cycle may be completed in 18 to 25 days, and there may be 10 or more generations per COURTESY OF DUKE UNIV. SCH. OF FOREST. Figure 97.—
. Eastern forest insects. Forest insects. The adult is reddish-brown to black and about to mm. long. The declivity is shallowly excavated and deeply punctured. Each side is armed with four small teeth and the apical margin is slightly produced. One to several long, winding egg galleries originate from a central nuptial chamber (fig. 97). Larval gal- leries are short, transverse, and each ends in a pupal cell in the phloem. In the south, the life cycle may be completed in 18 to 25 days, and there may be 10 or more generations per COURTESY OF DUKE UNIV. SCH. OF FOREST. Figure 97.—Galleries of Ips avulsus in bark of short- leaf pine. Note radiate tunnels of adults, short larval mines, and pupal chambers. The pine engraver, Ips pini (Say), occurs throughout the boreal forests of North America and south to Tennessee in the Eastern States. It breeds in several species of spruce and probably all species of pine within its range. Infestations usually develop in slash and windfalls or in trees dying of other causes. When heavy populations build up in this type of material, nearby healthy trees may be attacked and killed. Heavy infestations have oc- curred in cut-over and burned-over areas in Canada. The adult is brown to black, is from to mm. long, and has four teeth on each side of the declivity. Egg galleries, from three to six, radiate away from a central nuptial chamber in the phloem, deeply scarring the sapwood. Larval tunnels extend a short distance in the inner bark and end in pupal cells. Adults remain under the bark for a short period before emerging. While there, they eat irregular, meandering food tunnels, deeply en- graving the wood. Winter is spent in the adult stage on the ground. There appears to be three generations per year as far north as Wisconsin {6J+1). Other less common eastern species of Ips include: (1) /. per- turbatus (Eichh.)—breeds in white spruce in the Lake States and Canada. (2) /. perroti Swaine.—breeds in red and
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Keywords: ., bookcentury1900, bookcollectionbiodive, booksubjectforestinsects
