Hi cary,
Well, based on what you've told me, I can give you several options on
what your Redbud Tree is suffering from. I've provided a selection of
sites below that give good descriptions of the insect and disease
damage, as well as some good illustrations for you to use as
comparisons.
DISEASES
There are three main diseases of redbud: leaf anthracnose,
Mycosphaerella cercidicola, Botryosphaeria canker, and Verticillium
wilt (6). The most serious is the canker Botryosphaeria ribis or its
variety chromogena.
BOTRYOSPiHAERIA CANKER
[note the photo on the right]
http://www.ipm.uiuc.edu/publications/rpds/rpd813/rpd813.htm
WOODBORERS
Numerous wood borers have been found in redbud. Agrilus otiosus, three
species of Hypothenemus, three species of Micracis, two species of
Microcisella, Pityophthorus lautus, Ptosima gibbicollis, and Thysanoes
fimbricornis all inhabit portions of the wood of redbud.
http://wildwnc.org/trees/Cercis_canadensis.html
Good photos of flatheaded borer damage --
The beetle involved is a flatheaded borer. The adult beetle of this
family lays eggs on the bark where stress has caused it to thin and
scale.
http://www.termite-proof.com/Redbud%20damage%20by%20wood%20boring%20beetles%201.htm
Wood boring beetles
http://ohioline.osu.edu/hyg-fact/2000/2127.html
Xylosandrus compactus, bores in the twig of many species of trees in
Florida; but dogwood, redbud and magnolia seem especially susceptible.
http://edis.ifas.ufl.edu/BODY_MG007
TWIG GIRDLERS & TWIG PRUNERS
These guys make the "bracelet" grooves I was mentioning earlier.
Probably not exactly your parasite, but check them out just in case.
"The twig girdler, Oncideres cingulata, and twig pruner,
Elaphidionoides villosus, can be problems in nurseries and landscapes.
The main difference between these two pests is that girdlers cause
damage when adults sever a twig from the outside, whereas pruner
damage occurs when the larvae sever the twig from the inside. Both the
twig girdler and pruner attack a variety of trees including elm, oak,
linden, honeylocust, hackberry, redbud, poplar, sweetgum, and
sassafras. Branches up to 3 feet long may drop from the tree because
of attack by these insects.
"http://www.ag.uiuc.edu/cespubs/hyg/html/200013e.html
[scroll down this page for damage photos]
http://insects.tamu.edu/extension/bulletins/b-5086.html
Twig girdler (Oncideres cingulata) -
"Biology: The adult beetle is about three-fourths of an inch long,
stout, grayish-brown with a lighter colored band across its elytra
(wing covers) and has antennae as long as its body.
http://muextension.missouri.edu/xplor/agguides/pests/g07276.htm
WOODPECKERS
"Borer damage should not be confused with woodpecker damage.
Woodpeckers make small V-shaped impact holes. There is no tunnel and
the holes do not bend, turn, or "go anywhere." The yellowbellied
sapsucker, a type of woodpecker, makes a series of such horizontal
marks and, upon superficial examination, may give the "shot hole"
appearance of some borer damage."
http://www2.ncsu.edu/unity/lockers/project/pestmngt4/srurban/CHAP4/OPM/chap5.htm
Yellow bellied sapsuckers drill holes that ring a tree, and if close
enough together can give the impression of a trench or tunnel. They
are generally confined to the trunk and large branches however.
http://animaldiversity.ummz.umich.edu/media/phil/sapsucker_holes.jpg
WHO TO CONTACT FOR MORE INFO
For information regarding your specific problem, you should contact
your County Cooperative Extension Service. These folks will have all
of the information you need for diagnosis and treatment and it will be
specific to your area. They may even be able to send someone out to
look at your tree.
http://www.ifplantscouldtalk.rutgers.edu/information/coop.htm
I hope this has narrowed down your tree's problem. I would highly
recommend you contact the Cooperative Extension. I've used them as a
resource for several tree-related problems in the past (in NY, CO, and
MD) and have always found them to be knowledgeable and helpful.
Oh, and by the way, thank you for introducing me to a tree I had never
heard of before! How beautiful!
--K~ |
