Today, I would like to talk about an insect that attacks stone fruit trees. It is the Peachtree borer also referred to as the Greater Peachtree borer. This borer is a major pest of mainly peaches, but sometimes causes serious damage to cherry, plum, apricot, and nectarines.

The adult Peachtree borer is a clear-winged moth that has started flying in Southwest Michigan. They emerge from late June until September. Usually, they mate and lay eggs within 30 minutes of emergence. The female lays most of her eggs on the trunk of the tree near the soil line. About 10-15 days later, the eggs hatch and the larvae start to feed on the bark of the tree. Now is the time to start applying controls for this pest. Ideally, borer sprays should be applied in a spray directed to the trunk and lower scaffold limbs being careful not to spray the foliage and or fruit. One trunk spray per year with Lorsban 3 EC is the most reliable and recommended method of control. We do now have a new formulation, a wettable powder formulation that does not have as much of an odor as the emulsifiable concentrate. Growers should consider trying this option. Another chemical alternative and the only one available on prunes and plums is two trunk sprays of Thiodan 3 EC about 30 days apart. Do not forget that young, nonbearing-trees are just as susceptible to this pest as older trees. If an infestation occurs on young trees, the feeding can lead to death. Homeowners can protect their trunks with Sevin insecticide, but several repeat treatments will be needed because of the emergence that extends until September.

So, keep those trunks protected against borers and keep your peach trees alive. That is all for today. This is Al Gaus for Berrien County Michigan State University Extension.