A new pest that destroys leeks, onions, garlic, chives, shallots
and green onions has spotted in Lancaster, Pa., says the state department of
agriculture.
A tiny allium leafminer fly was discovered for the first
time on a farm in Lancaster County in December and has since been identified in
four other counties, including Chester, Dauphin, Delaware and Lehigh, reports
Olena Goncharova of the Pittsburgh Post-Gazette.
It’s the first time in has been identified in the Western
hemisphere.
“For our farmers an infection of this pest could mean a loss
in production of allium crops. And for our consumers, this could result in a
lack of availability of these crops for consumption,” Agriculture Secretary
Russell Redding said.
The allium leafminer, or Phytomyza gymnostoma, was first
detected in 1850 and in 2003 was spotted in the United Kingdom.
It has affected farms in Poland and Germany, and has been
reported in Asia, Turkey, parts of Russia and Turkmenistan.
Adult leafminers are about three millimeters long and look
like gray or black flies with a distinctive yellow or orange patch on the top
and front.
They show up at the end of winter and lay eggs at he base of
plant stems from March to May.
The eggs are white, about 0.5 millimeters in length and
slightly curved. Infected plants usually have wavy, curled and distorted leaves
with a row of white dots.
Leafminers are most likely transported with commercial cargo
or in passenger baggage. They frequently escape detection at ports of entry.
There is a lot of Mennonite traffic between farms in Lancaster
County and Ontario.
Scientists are still working to understand the nature of
this species. Shelby Fleischer, a Penn State professor of entomology, says it’s
too early to predict the damage it may cause and how fast this pest might
spread across the country, but it could be a “significant problem.”
More studies need to be done, Mr. Fleischer said.
Previous research show that the pest can be more damaging in
organic, non-commercial farms or homeowner gardens. Then are no threat to human
health.
A delay in planting, which normally begins in March for fall
for allium crops such as leeks, can be used to minimize crop exposure.
Covering onion, chive and garlic plants before the emergence
of adults, and keeping plants covered could keep leafminers out. European
growers also used pesticides.
Farmers and gardeners can submit photos of damaged crops to
Badbug@pa.gov to help with identification and obtain advice.
