Photo by: Bob Richard, USDA-APHIS-PPQ.
Origin: This insect is native to the
countries of Southeastern Austria and Czechoslovakia, Hungary. Also Yugoslavia
and some report possibly in Romania, and south of USSR. The Original sources
are Hungary and the former Yugoslavia. (1)
Common name: Hungarian clear wing moth.
The Life cycle:
Generations per year: one.(1)
Over wintering stage: Larval (in the root).(1)
Egg stage: Eggs are laid shortly after mating. Each female produces
an average of 205 eggs which are usually laid singly. During the spurge
flowering period, most eggs are laid on the bracts (modified leaves around
the flower). After the plants have flowered, eggs are laid on the leaves
and stems. The eggs are light brown, measure 0.75 mm by 0.50mm (0.03 by
0.02 in ), are oval and flattened with the shell divided into distinct
polygonal structures and covered with minute papillae. (1)
Larval stage: The larvae hatch about 17 days after the eggs
are deposited and penetrate into the shoot a few centimeters (nearly an
inch) above the ground. Larvae from eggs deposited earlier around the flower
apparently have a better survival rate than larvae from eggs laid later
on the leaves and stems. The young larvae mine the stem just below the
epidermis for a few centimeters (about an inch) before they move into the
pith and down into the root where most feeding occurs. There are seven
larval instals; the sixth and seventh occur before winter. In the spring
the larvae mine up to the stem base and prepare an emergence hole a few
centimeters (about an inch) above the ground. (1)
Pupil stage: Pupation occurs in the spring within the stem of
the host plant a few centimeters (nearly an inch) above the ground. The
empty pupil case is left protruding from the exit hole after emergence.
Adult stage: The adults emerge between mid-May and the end of
June in the former Yugoslavia and Hungary; at higher elevations they may
emerge until the end of July. Adult females use a scent to attract the
males. The abdomen is black and contains whitish bands on segments two,
four, and six, with numerous greenish scales on the back. The male also
has whitish bands on segment seven. Their bodies are 10 to 14 mm (0.4 to
0.56 in ) long. The top of the antennae is black while the ventral side
is brown. The outermost area of the 7 to 10 mm ( 0.28 to 0.4 in ) long
wings are black with yellow scales between some of the veins. A black spot
is located at the tip of the wing. Three transparent areas of the fore
wing are clearly visible.(1)
Destructive stage: Larval. (1)
Plant species attacked: Euphorbia lucida, E. palustris,
leafy spurge (E. esula-virgata complex), and possibly E.
lathyris as a marginal host.(1)
Site of attack: Roots. (1)
Impact on the host: By feeding within the roots of the host,
larvae deplete root reserves and hamper the plant's ability to replace
those root reserves, causing loss of plant vigor and often death. (1)
First introduced into the United States: 1993, Montana. (1)
Now established in: Montana. (1)
Habitat: In its native lands, it is generally found in plants
growing in moist, loamy soils and in partly shaded habitats such as river
banks, swampy areas, and ditches. It apparently does not like dry, sunny
Stage of transfer: larval. (1)
Redistribution: Dig plants of E. esula-virgata after
this agent has become established. Infested roots can be stored at cool
temperatures of 4 to 12 C (39 to 51 F) for three or four months if the
plants are dug in the fall. Rear the larvae and release adults. Adults
can be collected with a sweep net, but only a few sweeps should be made
per series so that netted moths are not damaged. (1)
No chamaesphecia species have been recorded on an annual spurge.
In nature, this moth has only been reported on E.Lucida and E.esula-virgata,
the latter has not not been confirmed. In feeding tests. it restricted
itself to spurges in the E. esual-virgata
a marginal host. Since E. lucida is absent in North American and
because this agent does attack leafy spurge (E. esual-virgata),
is very likely that this moth may be valuable as a strong biocontrol agent
of certain leafy spurge biotypes in moist areas without endangering any
other spurges in the United States.
In the host testing, it was also determined that
the the Euphorbia subgenera Chamaesyche, Agaloma, and Poinsettia
did not support any larval feeding. No rare and endangered native North
American spurges are at risk, nor is the economically important. E.
pulcherrima. Other plants of concern, such as E.robusta which
belongs to the subgenus Esula, live in dry climates and are out
of the range of this species.
(1) Biological Control of Weeds in the West. Society of weed Science.
USDA Agricultural research service. Montana Department of Agriculture.
Montana State University Bozemen Montana 1966.
By Beau Welch
to Biological Control Agents, By Weed