The
information below is provided courtesy of
http://walterreeves.com/insects_animals/article.phtml?cat=21&id=336
Asian Ambrosia Beetle - Control
I wrote in 2001 about my travails with a flowering cherry tree in my back yard.
It was a large one and my wife had noticed that half of it was completely dead.
I vowed to wait a bit longer to see if anything further happened to the tree.
I’m glad I did! Jerry Allen, of Organic Landscape and Design, was visiting me
last week when I asked him to examine my cherry. “It just up-and-died!” I
exclaimed, walking toward it. “I can’t find a single cause.” Arriving at the
tree, I slapped the trunk for emphasis. Sawdust poofed from beneath my palm.
Surprised, I looked more closely at the bark.
Oh no! Protruding from it in a dozen places were tiny “toothpicks” of sawdust:
the tell-tale sign of an Asian ambrosia beetle attack.
I’d mentioned the pests before but had not yet seen them on my property. The
tiny female beetle bores into the trunk of susceptible trees (crape myrtle,
redbud, dogwood, cherry, etc.) and deposits her eggs. Lovingly she leaves a
deposit of ambrosia fungus in the hole, to provide a first meal for the larvae
when they hatch. Unfortunately, the beetle fungus is usually contaminated with
other, more virulent, fungi - which often lead to a tree’s demise.
There is no treatment for an Asian ambrosia beetle attack. The fungus inside the
tree can not be eliminated. The attacked side of my cherry tree died and the
other half died in 2003.
Asian ambrosia beetle is serious pest. Once it attacks a tree the only treatment
is to cut the tree down. Crepe myrtles might resprout and grow another trunk to
replace what you remove but most other trees do not respond so nicely.
If you notice the "toothpicks", your best bet is to spray susceptible trees each
spring with cypermethrin, permethrin or deltamethrin in order to protect them.
To know when to spray, you can build a trap to monitor their emergence in early
spring.
The following information provided courtesy of Stephen D. Pettis, CEA
Agricultural and Natural Resources Agent
Gwinnett County Cooperative Extension Service
The female Asian ambrosia beetle (AAB) emerges in spring and travels to a
nearby shrub or tree. She prefers a small plant or limb 1 to 2 inches thick, and
she bores into it at up to 1 inch per day. As the female bores, she pushes her
sawdust out of the limb. The sawdust particles and insect excrement or frass,
stick straight out of the bark for than 1 inch or more, like a toothpick.
The female lines her tunnel with a fungus, which grows in the moist environment
of the inner tree. When her eggs hatch, they feed on the fungus. The fungus
clogs the vascular system of the plant cutting off water and causing it to wilt
and eventually die. So, the beetle doesn't hurt the tree, the fungus does.
Almost the entire life cycle of the insect is spent inside the plant, making the
beetles hard to control with insecticides. The only time out of the tree is when
it emerges in early spring to either reinfect the same tree or a new one. Traps
can be used to monitor the insect's emergence in February.
The beetle can invade many species of otherwise healthy trees and shrubs. So
far, they have been have seen attacking ornamental cherry, crape myrtle,
goldenrain tree, redbud, hickory and Japanese maple but elm, oak, Bradford pear,
poplar, apple and others can be affected, too. AAB will attack almost any
broadleaf tree or shrub with smooth bark and that is a suitable size.
Asian ambrosia beetles must be controlled but how? There are no systemic
insecticides that will kill the beetles in the trees. Once in the tree, the
beetle itself is harmless. It is the fungus that actually kills the tree.
Infested trees will most likely die eventually. The best way to control AAB
damage is by prevention. Trunk sprays using properly labeled pyrethroid
insecticides such byfenthrin applied in late February or when the first beetle
is trapped offers protection. Reapply as stated on the label. ALWAYS READ
CHEMICAL LABELS CAREFULLY. ONLY APPLY PESTICIDES TO SITES AND PESTS AS DIRECTED
ON THE LABEL. Affected plants or plant parts should be removed and burned and
trunks of remaining plants should be treated with an insecticide labeled for
this pest or site and kept under observation.
Tempo
TEMPO® Insecticide is an advanced-generation pyrethroid
insecticide proven to be highly effective against a broad range of
surface-feeding and foliar insects on turf and landscape ornamentals. Tempo
provides fast knockdown and residual control of up to 30 days.
Tips for Use
- For maximum perimeter control of pests, including treating the soil, turf and substrate adjacent to buildings.
- Also treat the building foundation, walls, around doors, windows, and soffit areas.
- Because mulch and pine straw make control of perimeter pests more difficult, you should rake back before application, wherever possible.
