. Eastern forest insects. Forest insects. F-519912 Figure 177.—Larvae of Neo- diprion pratti pratti, the Virginia pine Eggs are deposited individually within slits made by the female ovipositor along the flat sides of needles, usually before the end of November. There is one generation per year (63J+, 536). Prior to the development of an outbreak in Maryland, Virginia, and North Carolina during the late fifties, this species was not considered an important pest in the Middle Atlantic States. Sur- prisingly, the outbreak occurring at that time swept over more than 14 million acres of p
. Eastern forest insects. Forest insects. F-519912 Figure 177.—Larvae of Neo- diprion pratti pratti, the Virginia pine Eggs are deposited individually within slits made by the female ovipositor along the flat sides of needles, usually before the end of November. There is one generation per year (63J+, 536). Prior to the development of an outbreak in Maryland, Virginia, and North Carolina during the late fifties, this species was not considered an important pest in the Middle Atlantic States. Sur- prisingly, the outbreak occurring at that time swept over more than 14 million acres of pine and pine-hardwood type before it subsided. Tree mortality was not serious although some scattered killing was reported, but growth loss was severe. White-footed mice and ants destroy large numbers of cocoons and prepupae in heavy infestations. The hymenopteron, Exen- teras canadensis Provancher, is also an effective parasite of un- cocooned prepupae on the ground (86). Dahlbominus fuscipennis (Zett.), an introduced parasite of sawfly cocoons, has been liber- ated and established in infested stands in Virginia. A native polyhedrosis virus has destroyed up to 70 percent of sawfly larvae when applied from an airplane (U85). The jack-pine sawfly, Neodiprion pratti banksianae Rohwer, occurs in southeastern Canada from New Brunswick to Manitoba, and in the Lake States. Jack pine is the favored host, but red and Scotch pines are occasionally attacked by larvae if they are grow- ing with heavily infested jack pine. Full-grown larvae are yellow- ish-green and about 22 mm. long. The head is black and there are two longitudinal pale greenish-gray stripes running down the back. There is also a single row of 11 black spots on each side. Winter is spent in the egg stage and hatching occurs in May or June. The larvae feed gregariously on previous year's needles only. Feeding is completed by early July. The larvae then drop to 442. Please note that these images are extracted from scanned
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Keywords: ., bookcentury1900, bookcollectionbiodive, booksubjectforestinsects