IO Moth
Caterpillars are Putting
a "Sting" into Spring in Bexar County
Asp
EXPRESS-NEWS
GARDENING, ETC
Sunday, May 5, 2002
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IO Moth |
Caterpillars are Putting
a "Sting" into Spring in Bexar County
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Asp |
Nathan Riggs, Extension Agent, Integrated Pest
Management, Bexar County
Most people know that bees, wasps, hornets and
some ants can sting to defend themselves or their nests. Only a few people realize,
usually from first hand experience, that handling some caterpillars can produce
some painful results. Recognizing the few stinging caterpillar species may prevent
irritating encounters. This week's article from the Bexar County Extension office
is in response to several calls regarding stings inflicted by stinging caterpillars
over the past two weeks.
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Caterpillar stages of moths often have spines and barbed hooks. Generally,these are for show and are quite harmless. The Black Woolybear caterpillar is a very common example. The spiky black hairs could possibly be irritating to extra sensitive persons, but generally they are harmless. Here we show the Great Leopard Moth--the metamorphosis of the Black Woolybear. |
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But there are a few Stinging caterpillars of various shapes, sizes and colors. Stinging caterpillars possess hollow quill-like hairs, connected to poison sacs, that are used as defensive weapons. When these hairs are touched they break through the skin releasing the poison. Reactions can range from a mild itching to the more severe pain, dermatitis, and even intestinal disturbances.
Giant Silkworm Caterpillars
Two members of this group possess poisonous spines.
These are large leaf feeding caterpillars with numerous tufts of spines over
the body. The two-inch long Buck Moth caterpillar is brown to purplish-black
with numerous yellow spots and a maroon-colored head. The body is protected
with tufts of branched reddish or spines that may have red or black tips. These
can be quite common on oak or willow from spring to mid-summer. The adult stage
is a large moth with black and white wings and red legs. At present, this caterpillar
is very numerous in Bexar County.
The Io Moth caterpillar is overall light lime green, but along
each side there is a narrow reddish line bordered below by a white line. Grown
caterpillars are two inches long and covered with tufts of branched, black-pointed,
lime green spines. They feed on a variety of plants including corn, roses, willow,
linden, elm, oak, locust, apple, beech, ash, currant, and clover. The adult female
is a large moth with brown forewings and a second pair of wings with one large
eyespot on each wing. Males are large yellow moths with eyespots on all four wings.
Slug-Like Caterpillars
There are several species of slug-like caterpillars
that have poisonous spines. Slug caterpillars are short and stocky and creep about
on leaves in a slug-like manner. The head and legs are not visible. Typically,
there is one generation per year with the grown larvae found in the late summer.
The one-inch Puss Moth caterpillar, locally known as the
"asp," is covered with a dense wooly coat of soft brown hair that lies flat against
the body, with tail-like hairs at the rear end. Beneath the hairs are numerous
short poisonous spines that can cause severe irritation. They are often found
feeding on various trees and shrubs, including elm, maple, hack berry, oak, sycamore,
ligustrum and others. Young caterpillars often feed in groups. Sting severity
increases with size of caterpillar. Puss caterpillar stings are often more severe
than those of other caterpillars. Adults of this caterpillar are an unobtrusive,
fuzzy brown moth with a 1 to 1 and one-half inch wingspan.
The Saddleback caterpillar is brown in the front and rear and
green in the middle with a purple spot in the center of the green "saddle."
There are prominent horns on the front and rear. Stings by this insect can cause
severe irritation. Saddlebacks are typically found on deciduous trees such as
basswood, chestnut, cherry, oak, and plum, but occasionally they can be found
on corn. Again, the stinging spines on this caterpillar are borne in tufts on
each end and around the edges of the body.
The pale yellow-green Euclea caterpillar has four dark
patches of spines toward the rear and numerous spiny, yellow or red fleshy lobes.
Grown caterpillars have a brown area on the back. It feeds on oak, beech, flowering
crabapple, willow, pear, bayberry, sour wood, wild cherry and other trees. It
is less venomous than the saddleback caterpillar. At full size, it is one inch
long.
How to Avoid Stings
Most encounters with stinging caterpillars result
from accidently brushing against leaves on which they are feeding. The chances
of running into these insects are relatively low, but occasionally one species
may be very abundant. Also the more time spent in wooded areas, the greater
the opportunity for contact. With the exception of puss caterpillars, most of
these caterpillars are distinctly marked or brightly colored. This can allow
you to see and avoid them. If you find one on yourself, don't brush it off or
slap it with a bare hand. Use a stick or other object to remove it carefully.
Hollow spines may break off in clothing or gloves.
First Aid for Stings
No really effective home first aid treatments
for caterpillar stings are available. Adhesive tape or transparent tape may
be used to pull out some of the broken spines in the sting area. Washing the
area thoroughly with soap and water may help remove some of the irritating venom.
Prompt application of an ice pack or baking soda may help to reduce pain and
prevent swelling. Antihistamine drugs, often administered for bee and wasp stings,
are reportedly ineffective. See a physician if sever reactions occur. Very young,
aged or persons in poor health are more likely to suffer severe reaction symptoms.
Control
Where stinging caterpillars are numerous or present hazards
to people, such as around residences, recreation areas or schools, infested
shrubs and trees may be sprayed to eliminate or reduce the caterpillars. Use
products containing Bacillus thuringiensis or carbaryl for control.
Always read and follow label instructions. For more information on these caterpillars
or to get an identification of a suspicious caterpillar, call the Bexar County
Extension office at (210) 467-6575.
EVENTS: Thursday, May 9, Schultze House Brown Bag Program, "Cryptanthus" by Ed Edmiston, Alamo Bromeliad Society. Schultze House, 514 Hemisfair Park, 12:00 - 12:30 p.m. 229-9161.