none. Dioryctria ponderosae Dyar, D. tumicolella Mutuura, Munroe and Ross, and D. zimmermani (Grote) are the three most damaging borer pests of pines in Nebraska. D. tumicolella and D. zimmermani have similar 1-year life cycles with adults present from late July to early September. Larvae overwinter as first instars under bark scales on the surface of the trunk and branches, begin boring into trees in April, pupate in July, and emerge as adults in late July and August. The life cycle of D. ponderosae varies in length from 14 to 24 months. Larvae spend either one or two winters in tunnels beneath the bark. Most adults are present from the end of May through mid-July. Some emerge in August. Three species of hymenopteran parasitoids were reared from larvae of D. ponderosae: Bracon rhyacioniae (Muesebeck), Exeristes comstockii (Cresson), Hyssopus novus Girault. Three species were reared also from larvae of D. tumicolella: Hyssopus novus Girault, Orgilus dioryctriae Gahan, and Chelonus sp.