There is nothing in a
caterpillar
that tells you it's going to be a butterfly.
- Buckminster Fuller
|
Have you seen this critter? A new pest of some concern:
Synanthedon myopaeformis commonly called the red-belted clearwing
moth, or if you’re in Europe, the apple clearwing moth.
Last summer (2005) yielded and exciting new find in the unique fruit growing
region of British Columbia’s Similkameen Valley. In two apple (Malus
sp.) orchards in Cawston, a mere 14 miles to the Washington border
of Okanogan County, several adult clearwing moths (Sesiidae) were found.
After careful examination by taxonomic specialists, the specimens were
determined to be the red-belted clearwing moth, Synanthedon myopaeformis
(Borkhausen). Which, up until now has not been known to occur in
North America. The moth is native to Europe from southern Scandinavia
through central Europe to North Africa and Asia Minor.
What host trees to watch out for:
The host range includes important horticultural and landscape trees in
the Rosaceae family, including members of the stone fruits as well as
such popular favorites as apple, pear, hawthorn, quince and mountain ash.
Some notable comments on the family Sesiidae:
This family occurs worldwide with over 1,000 different species. Closer
to home, North America boasts 20 genera and 123 species. The family is
noted for containing some of the best wasp mimics among all of the insects.
The common name ‘clearwing’ comes from the lack of scales
covering both pairs of wings hence one of the reasons they can be mistaken
for a wasp. Not only at first glance do they look like wasps but they
also behave like wasps, some produce a buzzing sound in flight, others
perform abdominal movements that imitate stinging and still others have
the ability to hover in one place as do bees and wasps. Remarkable! They
are mostly diurnal species and frequently visit flowers which compound
their mimicry. Sesiidae moths are known as clearwing borers because their
larval stage (caterpillars) bore in the stems, trunks, and/or roots of
various plants. Damage from the tunneling larvae can be severe and lead
to the decline and death of the host trees, especially in younger plants.
Economically important species include the ash borer and the peachtree
borer, just to name a couple.
Many of the more pestiferous species have synthesized sex pheromones which
aid greatly in Integrated Pest Management programmes worldwide. These
pheromones can be used for monitoring techniques as well as control measures
such as mass trapping, mating disruption and attract and kill. (This in
itself is a lesson for a different time.)
Specific description of Synanthedon myopaeformis:
The adult moth has a 20-28 mm (0.79-1.1 in) wingspan. It has a long and
slender body, with dark blue-black thorax and abdomen with a red horizontal
band. Wings of course are clear (do not have scales). Forewings are narrow
and slightly smoked on the side, the hind wings are much shorter and triangular
with veins.
The larvae, which will be found in tree trunks where they bore deep sub-cortical
galleries of 20-25 mm (0.79-0.98 in) long and cut into the phloem, are
25 mm (0.98 in), grayish white with a brown head. Pupae can be found pushed
out from exit holes in the bark of the host plant.
Damage specific to Synanthedon myopaeformis:
In Europe, until the 1960’s, the apple clearwing has been regarded
as one of the secondary pests of apple trees that were previously stressed
by other factors. It was thought that the damage was rarely serious as
the larvae can only develop in declining trees in which the sap circulates
poorly.
But now, in Europe, with the changes in apple production technology it
has become a significant pest. High production, intensive orchard plantations
were established and rootstocks with low growing capacity were introduced.
With these unfavourable environmental conditions may result in the early
death of young trees that find themselves under attack by this previously
non-threatening pest. The larvae of the apple clearwing moth have been
reported to cause some damage to fruit trees in parts of Europe (Belgium,
the Netherlands).
Where are we now:
The Canadian Food Inspection Agency (CFIA) has not yet determined a course
of action related to this insect. But, will carry out surveys in the Cawston
area during the adult flight period this summer (2006) to determine the
distribution of this pest. A Pest Risk Assessment (PRA) by the CFIA has
been initiated and the quarantine status of the pest is under review.
So keep an eye on your backyard plants from the Rosaceae family and take
a second look at those ‘wasps’ you see, do they have a big
orangey-red band across their body? If so you might have the notorious
unforeseen opportunity to be the first in Whatcom County to collect a
new pest species to North America!
Watch for sucker growth at the base of trees and flagging
in the tree canopy
Photographer: K.K. Schlamp
"Just living is not enough," said the butterfly.
"One must have sunshine, freedom, and a little flower."
- Hans Christian Andersen