January 2013. A question on the natural controls (enemies) of Paracoccus marginatus by FSM stimulted a number of responses.
There are some successful biological control agents of the papaya mealybug reported from India: http://ecoport.org/ep?Arthropod=127373&entityType=AR****&entityDisplayCategory=AR****2500
Both the papaya mealybug and its parasitoids (used as classical biological control agents) originate from the Neotropical Region.
A quote from:
Muniappan, R., Watson, G.W., Vaughan, L., Gilbetson, R. & Noussourou, M. (2012) New records of mealybugs, scale insects, and whiteflies (Hemiptera: Sternorrhyncha) from Mali and Senegal. Journal of Urban and Agricultural Entomology28: 1-7.
“Several countries in the Caribbean, South America, and the Pacific region have successfully implemented classical biological control to suppress populations of P. marginatusby introducing the endoparasitoids Acerophagus papayaeNoyes & Schauff, Anagyrus loeckiNoyes, and Pseudleptomastix mexicanaNoyes & Schauff (Hymenoptera: Encyrtidae) from the USDA APHIS parasitoid-rearing laboratory in Puerto Rico (Meyerdirk et al. 2004, Muniappan et al. 2006). In Asia, Sri Lanka was the first country to import these parasitoids and to release them in May 2009; this brought about complete control of papaya mealybug by August 2009 (Anon. 2009). India imported the parasitoids and field-released them in October 2010 [J. Rabindra (National Bureau of Agriculturally Important Insects, Bangalore, Karnataka, India), personal communication]. On a visit to Java, Indonesia in July 2010, the IPM CRSP team found heavy parasitization of papaya mealybug by a fortuitously introduced parasitoid, A. papayae. Some of the papaya mealybug samples from the Philippines were also heavily parasitized but the identity of the parasitoid was unknown. While the samples of P. marginatuscollected from Cambodia and Thailand showed no evidence of parasitism, it is possible that A. papayaeor some other parasitoid may also become established; otherwise these countries should consider a classical biological control approach similar to that used in Sri Lanka, India, islands in the Pacific, and the Caribbean.”
Acerophagus papayaeseems to be the parasitoid that has been most effective against papaya mealybug. The mealybug is now under good control in India.
A note from Thailand (PestNet moderator, Banpot Naponpeth
“The papaya mealybug, Paracoccus marginatus, was detected on papaya and plumeria in Thailand in 2008. When first detected, it caused moderate infestation on papaya and plumeria. The mealybug has been recorded on 10 plant species including cassava. Now it is no longer of economic importance or threatening in Thailand.
We attempted to introduce the parasitoids from Puerto Rico in 2009, but our request met with some technical difficulty and the introduction was to be aborted.
The survey of resident natural enemies conducted by Dr Samaporn Saengyot of Maejo University from 2009-2011 revealed 12 species of natural enemies consisting of 3 parasitoids (Aenasiussp., Anagyrussp. and an unidentified encyrtid); 5 predaceous coccinellids (Cryptogonus orbiculus (Gyllenhal), Sasajiscymnus quinquepunctatus(Weise), Scymnus quadrillumMotschulsky, Scymnus(Pullus) coccivora Ayyar and Stethorussp. (Coleoptera: Coccinellidae); the apefly, Spalgis epius(Westwood) (Lepidoptera: Lycaenidae: Miletinae); two lacewings (Chrysoperlasp. (carnea-group) and Mallada basalis(Walker) (Neuroptera: Chrysopidae); and an unidentified syrphid fly. Among them, the coccinellid S. quinquepunctatusand the apefly, S. epius, showed the highest potential for augmentative biological control.
However, beginning from 2012 the populations of P. marginatus in all previously infestation locations have declined significantly to such an extent that no further augmentative measure is necessary and that P. marginatusis no longer a problem. This is most probably due to the naturally-occurring biological control exerted by these and probably other resident natural enemies whether they may be considered generalists and not so prey specific”.
A member noted: It seems that quite often that when P. marginatusis introduced accidentally, it brings one of the Neotropical biological control agents with it, which is fortuitous when it happens.