Webbing coneworm, Dioryctria disclusa Heinrich (27, 33, 35, 42, 43, 52, 53)

BIOLOGY. - The webbing coneworm has a single generation per year. Moths emerge in late spring and early summer in the Georgia Piedmont, and lay eggs. These hatch but the young larvae diapause until the following spring. Presumably, young larvae infest male flowers. Cones are infested early in the growing season, when older larvae are found to be present. Mature larvae pupate in the host cone behind a network of silken threads across the larval hole.

INSECT IDENTIFICATION. - Larvae of the webbing coneworm are grayish-buff above, paling beneath. Seta-bearing elevations are pale, while the dark beadlike patterns of pits are moderately noticeable (as in the blister coneworm).

Moths have striking yellow to orange-colored forewings, with sharp white crossbands and markings.

Adult. (2 1/2X)

Larva. (3X)

DAMAGE IDENTIFICATION. - Infested cones have a characteristic mass of heavily webbed frass, similar to that produced by the pine webworm (Tetralopha robustella Zeller) over the larval entry hole. Internally, the infested cones are nearly-to-completely hollowed out and often contain much silken material.

Damage to loblolly pine cone. (1X)

IMPORTANCE. - The webbing coneworm is occasionally abundant, causing moderate losses of Virginia and loblolly pine cones in the South.