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Knulliana cincta
Classification
Diagnostic Features of Larvae
- Larva. Body elongate, slender, subcylindrical; integument firm and tough, somewhat shining, densely covered with long, fine, castaneous hairs; body in life a lemon-yellow to orange color. Head subquadrate, widest behind and constricted above middle; mouth-frame firmly corneous, dark reddish brown; epistoma suddenly emarginate in middle; anterior edges of hypostoma sub-tuberculate; labrum elongately orbicular, entirely covered with long, dense, castaneous hairs; mandible piceous, shining, basal piece reddish, about one-third length of distal, a fine carina on outer face; antennae long, first and third joints subequal, second slightly longer; one large distinct ocellus contiguous to base of antennae and enclosed by shouldered gena, latter not setose; joints of palpi all subequal; process of palpifer long, that on first maxillary joint, distinct. Prothorax transversely rectangular, about twice as wide as long: anterior margin Hearing eight transverse ochraceous plates, four tergal, two presternal, and two lateral, the two presternal ones transverse, slightly separated; pronotum anteriorly regularly punctured, bearing dense, fine hairs, posteriorly shining, striate, median suture entirely impressed, deepest behind; sternum hairy; eusternal spots separated, triangular, smooth, shining. Mesonotum having the scutellum distinct; metanotum with a transverse impression. Legs four-jointed, very long and slender. Abdomen elongate, very slightly compressed; ampullae prominent, oval, widely separated, granulate, granules flattened, faintly shining, dorsal ampullae marked by two lateral and two transverse impressions, ventral with one transverse. Pleural disc rugose, not distinct. Spiracles very broadly oval, large, peritreme thin. Pupa: Pronotum beset with dense short hairs except on posterior half of discs; mesonotum and metanotum bearing a few finer ones; abdominal terga beset with short acute asperities projecting posteriorly, those on fourth, fifth, and sixth segments arranged more or less in an oval manner, with two groups of three each in center; seventh with six or eight larger recurved spines on posterior margin; a few small points on eighth; lateral region of abdominal terga hairy. Adapted from Craighead (1923).
Biology and Economic Importance
- The larva attacks the rather dry, dead branches or larger limbs of Carya, Quercus, Juglans, and Castanea, excavating the mines beneath the bark but principally in the wood proper. The latter part of the mine is sometimes 2 feet long. Much frass is extruded and the greater part of the burrow in the wood is open. Before pupation a large protruding wad of frass is placed in the exudation hole. Normally two years are required to complete the life cycle, but this is sometimes extended to three. The adult transforms in the fall and hibernates in the cell, or pupation takes place in the spring. The eggs have been found laid on dry, barkless branches in checks of the wood. Adapted from Craighead (1923).
Selected References to Larvae Specimens
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