Article from
VSCNews, Vegetable and Specialty Crop News
by Breanna
Kendrick
Pointers for Peachtree Borer Management
Pupal casings from a peach tree borer. The adult moth has already emerged. This is a sign of a recent infestation.
Cory
Penca, entomology Ph.D. candidate and a student in the Doctor of Plant
Medicine Program at the University of Florida, recently spoke to
growers about peach pests at the Stone Fruit Field Day in Citra,
Florida. One of the many pests he discussed was peachtree borers.
Peachtree
borers are moth species. There’s two different species, lesser
peachtree borer and the peachtree borer. Their larvae feed on the wood
of the tree, which could lead to loss of limbs and tree death. The
lesser peachtree borer lays its eggs and develops on the scaffold limbs
and above the trunk of the tree, while the peachtree borer lays its
eggs and develops at the base of the tree and below.
There aren’t many curative options, so growers are limited to pest
prevention.
One
way to monitor for both borers is to use pheromone traps. This type of
trap is essentially two parts: a sticky bottom with a plastic or paper
roof. When the moth gets to the lure inside the trap, it flutters
around and makes contact with the sticky bottom and gets trapped. Penca
said these traps are very effective and that in a week or so of placing
them, several moths will be captured. “If they are present in the area,
you’re very likely to catch them,” he said.
Penca said one way to help identify peachtree borers is by looking for
gummosis damage on trees.
“Gummosis
itself isn’t going to tell you if you have peachtree borers because
there are several fungal diseases that can lead to gummosis, and just
damage from physical or mechanical injury,” stated Penca. “If you look
closer at this gummosis in these areas you might see frass, which will
look like a gummy, grainy-like texture that looks like a bunch of tiny
pellets that were stuck together in syrup. This is the feces of
caterpillars, and they are pushing it out of the wound of the tree.
Within these wound sites, you may also find casings of the pupa of the
moth. Those casings show you that you have an active infestation. You
can remove those casings and come back over time and see if there are
new casings. That can help you determine how active the infestation is
in your area. If you spray and then you don’t see any new casings next
year, you may have succeeded at controlling the infestation.”
During
the growing season when there’s peaches on the tree, applications for
other pests may help provide some control. However, during the summer
when growers are making cover sprays for the dormant season, they still
need to control these pests. One method is using trunk sprays of
Lorsban to control the peachtree borer.
Penca advised protecting
the trees after pruning because there will be new wound sites that may
be used for oviposition (the act of laying eggs). “There are some
non-chemical methods that are being worked out. One of them is the use
of the pheromone to disrupt mating,” said Penca. “The idea is that if
the males can’t find the females, the females won’t mate or be able to
lay eggs. There’s also been work with nematodes to control these
peachtree borers when they are lower down in the tree.”
Cory Penca
is an entomology Ph.D. candidate and a student in the Doctor of Plant
Medicine program at the University of Florida.
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