Controlling
spread of Parthenium in vacant lands has for long been a challenging
task not only for officials, but even for residents in their vicinity
with many of them susceptible to severe allergies.
In
an novel attempt the Horticulture Department officials have left
leaf-feeding beetle Zygogramma on the parthenium which has grown in
large hectares of land of Linganbudhi Lake.
The
Zygogramma insect was released in the vicinity of the lake around three
months ago and the insects have multiplied into thousands. These
insects have been successful in eradicating pathenium in around 40 per
cent of the surroundings of the Linganbudhi Lake, by eating leaves and
flowers of the parthenium.
“The use of insects
to control spread of parthenium is a naturally phenomenon. Spraying of
pesticides destroys leaves and not seed. Meantime, pesticides makes soil
toxic,” say officials.
Horticulture Department
Assistant Director Balu BP Gowda informed that they collected around 40
insects found feeding on Parthenium plants growing on vacant places and
left on the land of lake. The insects in a short time of 30 days have
reproduce in thousands, he adds.
“Zygogramma is
an accepted biological weapon to control growth of parthenium weeds. As
these beetles feed on Parthenium plant it begins preventing pollination
and new growth. The insects are found in the open only at certain
places and will not harm other cultivated crops. Anybody can collect the
insect on their own and release the same in places infested with
Parthenium. So that it can be completely eradicated," he added.
"Parthenium
weeds grow and spread very quickly within no time. The insect prevents
production of seeds produced by parthenium weeds by eating flowers. This
helps in prevention of allergic reactions and other health hazards
caused by parthenium weeds," says another official.
Interesting facts
* Parthenium Hysterophorus weed was brought to India along with PL480 Mexican wheat seeds when they were imported in 1950s.
*
The Indian Institute of Horticulture Research introduced the
leaf-feeding beetle Zygogramma Bicolorata (Coleoptera:Chrysomelidae)
also brought from Mexico in 1983.
* Necessary permission for conducting field trials were obtained from the Plant Protection Advisors in 1984.