Papaya mealy bug has created havoc in Tamil Nadu in the past two years. It infests nearly 60 host plants including Papaya, Tapioca, Mulberry, Bhendi, Brinjal, Tomato, Turmeric, Cotton, Jatropha, Kapak, Teak, Sugarcane etc.,

Because of its damage, papaya production came down by 60 – 80 per cent. Chemical pesticides have been able to provide only temporary relief and farmers went for repeated sprayings and pesticide cocktails which resulted in ecocidal effects.

Natural enemies were considered the only last resort for management of this pest. Available natural enemies like Cryptolaemus montrouzieri and Scymnus coccivora were also not able to keep the pest population under check.

Imported varieties

The National Bureau of Agriculturally Important Insects (NBAII), Bangalore took efforts in importing three exotic papaya mealy bug parasitoids such as Acerophagus papayae, Pseudleptomastix mexicana and Anagyrus loecki from Puerto Rico during July, 2010.

NBAII, Bangalore and TNAU, Coimbatore have standardized the mass production techniques of these parasitoids. Various Research Stations, Krishi Vigyan Kendras and Colleges under TNAU started mass multiplication of these parasitoids and distributed them to farmers for field release, free of cost.

All the three tiny parasitoids are solitary, species specific, have good host searching capability and attack only papaya mealy bug.

Good result

All these three parasitoids proved highly successful in Tamil Nadu. These parasitoids especially Acerophagus papayae, established very well and brought significant control of papaya mealy bug not only on papaya, but also on other crops.

The released parasitoids should be conserved by avoiding use of chemical pesticides and maintaining alternate hosts like weed crops such as parthenium, acalypha, plumeria etc. and tree crops like kapak, teak etc. This classical biological control programme has become popular among large sections of farmers in Tamil Nadu.

(A. Suganthi, Asst Prof and S. Nanthakumar, programme co-ordinator, Krishi Vigyan Kendra, TNAU, Virinjipuram, Vellore, Tamil Nadu, Phone:0416-2272221.)