Hi Lacey,

I'm not sure that is shoot borer because what I read is they pupate in their tunnels, not exposed like your photo shows.  I forwarded your photos to our forest entomologist for her opinion.  She's out until the 20th.  Hit me up again in 10 days or so if you haven't heard from me.

Howard

Hi Lacey,

Sorry about not getting back to you sooner.  I don't think your pest is eastern shoot borer because they are reported to pupate in soil liter, not as partially exposed pupae on the shoots like your photo shows. So that leaves the European pine shoot moth as the prime suspect.

The European pine shoot moth, Rhyacionia buoliana (Lepidoptera: Torticidae), can be a serious pest in nurseries, Christmas-tree plantations and landscape plantings. EPSM will attack red, mugo, Scots, and Austrian pines, however, Austrian and mugo pines are the preferred hosts.

In early spring, European pine shoot moth larvae crawl onto new shoots and tunnel into the base of buds or shoots where feed before transforming into the pupal stage within the shoot. In late May to early June, the female moths lay small, flattened eggs on new pine shoots near the base of needles or bud scales. These eggs hatch in mid June and the young larvae tunnel into the needle sheaths and then mine needles at or near the base. Early injury symptoms are yellow needles near the tips of twigs and pitch near new bud clusters. Mined needles will eventually turn brown and die. The larvae can kill terminal and lateral growth due to their tunneling into the base of needles, shoots, or buds. Trees may appear reddish due to the presence of many dead tips. In nurseries and landscapes, small trees may be killed. In Christmas-tree plantations, repeated infestations may leave trees appearing distorted, unsightly, and possibly unmarketable. Resin-coated webbing may be present near wounds or entry sites. In late summer to early fall, the larvae stop feeding for the growing season. They overwinter in needles near shoot tips that were mined during the summer. The larvae, which are 2 to 3 millimeters long, turn deep black in color and are covered with resin-coated webbing. The European pine shoot moth has only one generation per year.

Management of European pine shoot moth primarily involves pruning out infested terminals. Control with insecticides is difficult. Insecticide applications must be timed to when overwintering larvae are moving to new shoots, this is usually in early to late April. Recommended insecticides include bifenthrin (sold as Ortho Bug-B-Gon and cyfluthrin (sold as BioAdvanced Garden Insect Control). The trees can be sprayed again in late June or early July after larvae have hatched from the eggs. Once they enter the growing tips, they are protected from insecticide applications and are very difficult to kill. Concentrate sprays on the ends of branches where the larvae are most likely to be located. Be sure to irrigate trees during periods of extended drought as dry weather and poor soil conditions may lead to increased susceptibility to attack from both pests.

Be sure to read and follow all instructions and safety precautions found on the label before using any pesticide.

Best regards,

Howard

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