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Insects and Diseases
pests
and beneficials
...which
we see in our nursery
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Beneficial
Insects
Since
we never use synthetic pesticides, our nursery is alive with little
creatures ! |
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Here are an Assassin Bug
and a Preying Mantis.
These beneficials patrol our Pawpaw trees, in search of insects
to devour.
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Insect
Pests
In
its native habitat the Pawpaw has few pests of any importance. The
pests that do attack the Pawpaw plant are uniquely adapted to do
so, since all parts of the plant except the wood contain potent
pesticides. These are the insect pests which we see here in the
Ozarks: |
This
is Omphalocera munroei, the Asimina
webworm moth.
The caterpillar feeds on Pawpaw leaves, buds and twigs in
the late Summer and Fall, and can devastate young trees. It
can be controlled by dusting with Bacillus thuringensis, (
BT ), while the larvae are feeding. |
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Here
are the Adult Moth
and Pupa.
These two photos:
Copyright © 2007 Jeff Hollenbeck |
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These
are the leaf roller larvae. |
This
is what they do! Nasty! |
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Another
"pest" is Eurytides marcellus,
the Zebra Swallowtail Butterfly, whose larvae feed exclusively
on young Pawpaw foliage, but never in great numbers.
The adult butterfly is of such great beauty that Pawpaw
trees are sometimes planted to attract them.
Sometimes we have Zebra chrysalises for sale.
Please email
if interested.
(See
also our Butterfly
Garden page.) |
Zebra
Swallowtail Butterfly adult,
on a Pawpaw leaf in our nursery.
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The
Larva. |
The
Chrysalis. |
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These are "Stinging Rose Caterpillars",
Parasa indetermina (Family Limacodidae).
We've only seen it once on Pawpaw leaves. They are also found
on apple, cottonwood, dogwood, hickory, oak, redbud, sycamore
and rose bushes, usually in August.
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Does
Climate Change Cause New Insect Problems?
In the late summer of 2010, when it was was unusually hot and dry
here, we first observed Japanese Beetles and Striped and Spotted
Cucumber Beetles nibbling on the leaves of the Pawpaw trees in our
nursery. We did not observe them on the wild or orchard Pawpaw trees
nearby. This may have been because our nursery trees were well watered
and fertilized, in contrast with most other plants in the area,
thus making them relatively attractive to these insects which do
not ordinarily feed on Pawpaw leaves. We will see if this happens
again in 2011, and post our observations and pictures here. |
Diseases
Small brown spots sometimes appear on Pawpaw leaves
in humid
conditions, such as might occur with young trees in poorly ventilated
greenhouses, in tubular tree shelters, or if
they are surrounded by dense weeds. This is caused by fungi, is
usually not serious, and can be alleviated by improved air circulation.
There
is an disease of Pawpaw trees that has been reported in the Pacific
Northwest, in which the trees have bark lesions, which show blue
streaking in the cambium when cut open. The trees often die. The
cause is not known. We have not seen this disease here. |
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All
images (other than Jeff' Hollenbeck's) are © 2011 Blossom Nursery |
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