Synanthedon pictipes
Written by:
Jaime Pinero
Overview.
The adult LPTB is a clear-winged, metallic-blue moth that has two or more yellow bands across the abdomen, giving it a wasp-like appearance. In the Northeast, LPTB causes comparatively less damage than PTB. Peach, nectarine, and cherry are the preferred hosts of LPTB, but all stone fruits may be attacked. Injury by LPTB is almost always associated with previous tree injuries such as incidence of Cytospora canker and, to a lesser extent, pruning wounds, winter injury, and mechanical damage.
Biology.
LPTB overwinters as a larva in various stages of development ranging from young to nearly full-grown. In the spring, larvae resume feeding, complete their development, and pupate. Adult emergence usually takes place around shuck-split or shuck-fall and continues for several weeks.
LPTB attack higher on the trunk and scaffold branches, especially where there are injuries and callus tissue. The flight period for LPTB is about June 1st through late August, depending on the region. Moths are active during the day, with mating and oviposition occurring soon after emergence. Female moths are attracted to damaged and previously infested trees and deposit eggs in cracks or under bark scales of wounded sites.
Monitoring.
LPTB adults can be monitored using pheromone traps. Use at least 2 traps per block to determine adult flight. Install LPTB traps by petal fall. Populations seldom need treatment when trap catches peak at less than 10 moths/trap/week. Use of monitoring traps is recommended in combination with mating disruption.
Inspect wounded areas on the upper trunk, scaffold limbs and branches for larvae and empty pupal cases protruding from the bark. An early sign of LPTB injury is the presence of wood chips, sawdust, and frass
produced by feeding borers in the gum in cankered areas. Control is recommended if 1-2 larvae or empty pupal cases are found per tree.
Management.
Mating distruption and insecticides are two control options for growers.
For mating disruption, use Isomate PTB-Dual at a rate of 150 pheromone ties per acre. Dispensers should be deployed at shuck split before LPTB moth flight begins. Use a higher rate (200-250/A) for outside edges of border rows, areas that haven’t been disrupted before and have high populations, and in blocks smaller than 5 acres. Larger blocks are better sites to use this control method compared to small (especially long, narrow) ones.
When applying insecticides for LPTB, cover the trunk and scaffold limbs using a hand-gun with low pressure and high volume. Ideally, protect the trees for the entire period when the females could be laying eggs. If peachtree borer is also a problem, then the insecticide spray should be made within the first 2 weeks of September. If only LPTB is present, sprays may be applied to late maturing varieties in early August.


