PRESS RELEASE ON
COTTON MEALY BUG
Breakthrough in biological control of the cotton mealy bug in
Pakistan
(Riaz Mahmood, CABI SA, Rawalpindi)
Mealy bug is a new pest on cotton in Pakistan. This exotic insect originally
described from California was recorded first time in Pakistan in 2005. CABI
SA a centre for south Asia of CAB International who had conducted 15 year
survey of scale insects and mealy bugs in Pakistan did not find this complex
of species of Phenacoccus on cotton before 2005. The mealy bug has gained
prime importance as serious pest of cotton overtime in Pakistan. This insect is
highly polyphagous and has attacked about 160 species of plants as surveyed
by CCRI, Multan. During last three years it has caused huge economic loss to
cotton crop and is a potential threat to agriculture in Pakistan. The study by
FAST National University in 2007 revealed that this insect was responsible for
ruining an estimated 3.1 million bales of cotton. Further more farmers had to
bear additional costs of Rs 1500 per acre for its control with insecticides. In
most of the cases the insecticides were ineffective in controlling this pest
(DAWN News, 22 October, 2007).
To address the issue of mealy bug one year project titled “Control of cotton
mealy bug in Pakistan” was initiated by Ministry of Food, Agriculture and
Livestock (MINFAL) Government of Pakistan in 2007. Under this project
country wide field interventions were started according to a planned approach
to look for possibilities of biological control of this pest. On collecting basic
information on biology and fulfilling other prerequisites for biological control of
this pest a three year extension of the project has also been approved by
CDWP of Government of Pakistan for biological control of cotton pests
including mealy bug.
For biological control of the mealy bug two pronged approach is being used.
On one hand techniques are being developed for conservation and
augmentation of the existing endemic natural enemy fauna of this pest and on
the other hand exotic natural enemies of the pest from its origin are being
imported for release on farmers’ fields by CABI SA who has a lead role in this
project.
Establishment of natural enemies field reservoirs (NEFR): Three field
reservoirs one each of 5 acres at Multan, Tando Jam and Lasbela has been
established to develop mass rearing techniques of mealy bug predators and
their conservation. At these farms cotton and other host plants of the mealy
bug are grown where mealy bug can fairly develop its colonies. Insecticides
sprays are strictly prohibited on these farms to give fare chance to natural
enemies of the pest to work against it. This technique for inviting endemic
biocontrol agents to get associated with this exotic pest has produced results
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as was expected. Initial successes have been achieved in production of
predators in thousands over a fortnight interval leading to the possibility of
building capacity of producing predators’ overtime in millions. Studies for
conservation of predators are also going on at these field reservoirs. Some of
the promising predators have been identified who are density dependent and
their populations fluctuate along with the population of mealy bug and play
effective role in suppressing mealy bug population on cotton and other plants.
Discovery of a parasitoid killing high numbers of mealy bug: A chalcidid
parasitoid (Picture 1) has been recorded first time in August 08 in the history
of the project at natural enemy field reservoir Tando Jam (Hyderabad). This is
a large sized insect and preferably attacks the mealy bug females before they
reach maturity. This parasitoid is building up its high population, causing more
than 50% mortality of the pest on cotton and other plants (Pictures 2 &3). It is
also spreading fast in the adjoining areas there. Surveys in Punjab are also
being carried out to detect the parasitoids on the mealy bug.
This discovery will go long way in controlling the pest on cotton and other
plants. The cultures of the parasitoid have been established at the Tando Jam
laboratory. This parasitoid will be distributed to all components of the project
in Punjab, NWFP, Balochistan and Sindh for mass production and release in
farmers fields and then to follow up its performance in controlling the mealy
bug on cotton and other plants round the year. The parasitoid has been sent
to Natural History Museum, London, UK for proper identification.
A predator Cryptolaemus montrouzieri (Picture 4) known as mealy bug
destroyer, was introduced by CABI SA from California in December 2007.
This is being mass produced at Multan and Tando Jam and has been
supplied to ARI, Tando Jam; AARI, Faisalabad; NIAB, Faisalabad; CCRI
Multan and ARI Dera Ismail Khan who are mass producing this at their
centres for release in farmers’ fields. Initial recovery surveys indicate a
positive trend towards its establishment in Pakistan. This will be a valuable
addition to endemic natural enemy fauna of the mealy bug. At Multan and
Tando Jam since the time it is released by CABI SA and other components
such as CCRI Multan and ARI Tando Jam in fields the recoveries have been
made from the release sites more or less regularly from March onwards this
year. Initially the numbers recorded were small. Overtime on acclimatization
with Pakistan environment it will build up high population and contribute
substantially in controlling the pest.
Under the present three year project of MINFAL three big insectaries one
each in Sindh, Balochistan and Punjab will be established primarily for the
purpose of mass production of endemic and exotic parasitoids and predators
of mealy bug and other cotton pests for releases in farmers fields. With the
onset of these activities the natural resources will strengthen with the
consequent decrease in pests’ populations in agricultural crops, decrease in
pesticides use and assist in increasing crops yield. With decrease in
populations levels of insect pests the crops losses due to their damage will
reduce.
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Picture 1. Newly recorded adult mealy
bug parasitoid at Tando jam
Picture 2. Parasitized mealy bug
(brown dead mealy bug individuals)
on Abutilon indicum at NEFR Tando
Jam
Picture 3. Parasitized mealy bug (brown
dead mealy bug individuals) on cotton
at NEFR Tando Jam
Picture 4. Cryptolaemus montrouzieri
introduced from California feeding on
mealy bug in field at Multan
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What needed onwards is to immediately take up programs of mass
production of natural enemies of the mealy bug and their release at farmers’
fields, start farmers participatory training and implementation programs of
biological control of cotton pests involving Provincial Agriculture Extension
and farmers’ communities.
Mr. Muhammad Zia ur Rehman, Secretary, MINFAL; Mr. Shahid Hussain
Raja, Additional Secretary, MINFAL; Doctor Qadir Bux Baloch, ADC, MINFAL;
Dr Masood Amjad Rana, Project Director CMP, MINFAL; and Dr. M. Ashraf
Poswal, Regional Director, CABI SA, are gratefully acknowledged for support
and encouraging the efforts being made under the project for biological
control of cotton pests.
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