Natural parasitisation by the exotic parasitoid, Leptomastix dactylopii Howard, on Planococcus citri (Risso) infesting custard apple.
7
Citation
0
Reference
20
Related Paper
Citation Trend
Abstract:
The citrus mealybug, Planococcus citri (Risso) was found in large numbers infesting custard apple at Indian Institute of Horticultural Research Farm, Bangalore during August-October 2004. Sampling of infested custard apple fruits during this period revealed the presence of Leptomastix dactylopii Howard. Adult parasitoids were recovered after five years of its release in 1983 and again in 2004 in the present study indicating the permanent establishment. In general, the activity of parasitoids particularly on mealybugs on custard apple was very low. The natural parasitisation by L. dactylopii ranged from 0.41 to 2.72 percent but the presence of L. dactylopii indicated that there is some scope of exploiting L. dactylopii in the suppression of P. citri infesting custard apple.Keywords:
Custard-apple
Mealybug
Encyrtidae
Mealybugs, known to be 'hard to kill pests', live in protected areas and most stages in their life cycle are covered in a waxy coating. Several insecticides are found ineffective against mealybugs. Fortunately, mealybugs - being sessile insects - are more amenable to biological control. The exotic parasitoid, Leptomastix dactylopii How., was found to be highly effective in suppressing citrus mealybug, Planococcus citri (Risso.) permanantly on citrus, sapota, guava, pomegranate and coffee. This is one of the recent successes in classical biological control attempts in India. However, the Australian ladybird beetle, Cryptolaemus montrouzieri Muls., often provides spectacular control of heavy infestation of P. citri on acid lime, lemon, sweet orange, pummelo, Crossandra and custard apple. Though Anagyrus dactylopii (How.), is a potential parasitoid of pink hibiscus mealybug, Maconellicoccus hirsutus (Green), on grapes, releases of C. montrouzieri only help in suppression of the pink hibiscus mealybug on grapes, ber, guava, sapota, custard apple, citrus and hibiscus. The encyrtid parasitoid, Tetracnemoidea indica (Ayyar), was able to check the oriental mealybug, Planococcus lilacinus (Ckll.) on acid lime and pomegranate. The predators, C. montrouzieri and Spalgis epeus Westwood, also play a major role in suppression of P. lilacinus on guava, ber, sapota and chow-chow. The local parasitoid, A. dactylopii was seen to play a major role in suppression of spherical mealybug, Nipaecoccus viridis (Maskell) on citrus and jackfruit. Nevertheless, releases of C. montrouzieri are found highly effective in controlling N. viridis on acid lime and pummelo. Similarly release of C. montrouzieri is found to be highly effective in controlling striped mealybug, Ferrisia virgata (Ckll.), on guava, tuberose and Acalypha in 30-40 days of release. A local parasitoid, Aenasius advena Comp., also plays a major role in suppression of F. virgata on guava, mango, guava, hibiscus, fig, citrus, etc. Release of the coccinellid predator, C. montrouzieri, was found very effective in controlling the mango coccid, Rastrococcus iceryoides (Green) on mango and also on the medicinal plant Decalepis hamiltonii. The encyrtid, Praleurocerus viridis (Agarwal), was found very effective in reducing populations of R. iceryoides on guava. Spalgis epeus was found to be the predominant predator of the papaya mealybug, Paracoccus marginatus Williams and de Granara Willink, but releases of the exotic parasitoid, Acerophagus papayae(Noyes&Schauff), only provide excellent control of P. marginatus within 3-4 months of release. The second successful classical biological control attempt on mealybugs in India. The brinjal mealybug, Coccidohystrix insolita (Green), is known to attack brinjal, Coleus, Hibiscus, etc. Cryptolaemus montrouzieri effectively controlled mealybugs on these three crops in 30-40 days of release. Verticillium lecanii Zimm. (Phule bugicide @ 2g/L) is found to be effective in killing the mealybug. Other fungal pathogens, viz., Beauveria bassiana (Bals.) Vuill and Metarhizium anisopliae (Metch.), are also seen to infect mealybugs in rainy season under humid conditions.
Mealybug
Hibiscus
Cite
Citations (18)
Ber ( Zizyphus mauritiana (L.)) has been found attacked by four mealybug species viz. , Nipaecoccus viridis (Newstead), Planococcus citri (Risso), P. lilacinus (Ckll.) and Maconellicoccus hirsutus (Green) around Bangalore. A total of 11 natural enemies on N. viridis , three on P. citri and two on P. lilacinus were recorded. Attempts were also made to use the exotic natural enemies like Cryptolaemus montrouzieri Muls. and Leptomastix dactylopii How to suppress the mealybug population in ber orchards. The local parasitoids and predators appeared in large number and were mainly responsible for the suppresion of N. viridis and P. citri on ber.
Mealybug
Cite
Citations (4)
Mealybug
Encyrtidae
Cite
Citations (1)
'Leptomastix dactylopii' Howard and 'Aphytis lingnanensis' Compere are mass reared for augmentative release in Queensland citrus in the spring - early summer against citrus mealybug 'Planococcus citri' Risso and red scale 'Aonidiella aurantii' (Maskell) respectively. This paper reports the results of studies on the effects of host density and inoculum size on parasitoid production in a system using 'P. citri' as host for 'L. dactylopii' and oleander scale 'Aspidiotus nerii' Bouche for 'A. lingnanensis', both grown on butternut pumpkins, 'Cucurbita moschata' (Duchesne ex Lam.) Duchesne ex Poiret (Cucurbitaceae). For 'L. dactylopii', highest production was achieved when mealybugs (21 days old at 25 degreesC) were exposed to a parasitoid inoculum of 3 per cm2. A host density of 20 per cm2 (6 000 per pumpkin) was most efficient because it resulted in higher levels of parasitism, produced numbers of parasitoids only slightly less than the higher density and suffered lower losses due to rotting of the pumpkins. 'A. lingnanensis' production was highest when the density of oleander scale was 60 per cm2 and the parasitoid inoculum 33 per cm2.
Aphelinidae
Encyrtidae
Mealybug
Cite
Citations (1)
Abstract Introduction of parasitoids gave improved biological control of Planococcus citri (Risso) in a large glasshouse stocked with a variety of ornamental plants, supplementing that achieved by the predator Cryptolaemus montrouzieri Mulsant. Following parasitoid release, there was evidence of pest population regulation on guava and coffee bushes with reduced and stabilized mealybug numbers and stable percentage parasitism. The mean temperature during one sampling period was significantly correlated with the percentage parasitism two months later, indicating that temperature has a major impact on parasitoid efficiency. Leptomastidea abnormis (Girault) was responsible for about 90% of the parasitism observed; the remainder was by Leptomastix dactylopii Howard. The effects of supplementary inoculative releases of Leptomastidea abnormis were variable, but resulted in increased percentage parasitism only when the number released contributed significantly to those already established. No evidence of pest population regulation was found on Aristolochia or Passiflora vines nor on potted Gesneriaceae plants of the genera Streptocarpus and Saintpaulia. Peak mealybug populations on these last plants coincided with periods of new growth, fruiting or flowering. Host-plant quality thus seems to be a major factor inducing mealybug outbreaks.
Mealybug
Encyrtidae
Cite
Citations (20)
Mealybug, Planococcus citri (Risso) is not only a serious pest of citrus but also at times serious on pomegranate, guava, grapes, etc. Insecticidal sprays have failed to give adequate control of this mealybug in recent years. Releases of an exotic parasitoid. Leptomastix dactylopii (How.)(Hym., Encyrtidae) in citrus orchards against P. citri in and around Bangalore have resulted in establishment of the parasitoid and complete control of mealybugs within four months in 1984-85 (Krishnamoorthy and Singh, 1987). Subsequently a survey was conducted by making field recoveries to evaluate the dispersal and establishment of the parasitoid in other areas on different crops, where releases were not effected.
Mealybug
Encyrtidae
Gracillariidae
Cite
Citations (1)
Mealybug
Cite
Citations (3)
Cite
Citations (5)
Cite
Citations (7)
The parasitoid Leptomastix dactylopii Howard (Hymenoptera: Encyrtidae) has been used as test organism in a study on the side-effects ofNAF-85 (Spinosad), a mixture of spinosyn A and D, a new product belonging to the spinosyn class. Contact and ingestion toxicity of spmosad was evaluated by laboratory tests carried out on glass test units. Harmful effect (100% mortality after 24 h exposure) and persistence (lOO % mortality after 25 days) were recorded. These data were confirmed in an extended laboratory-persistence test performed by treating potted citrus plants and collecting leaves after 5, 10, 15, 20 and 25 days from the treatment. These leaves were placed in Petri dish units. In each of these units IQ individuals (5 females and 5 males) of L. dactylopii were released. 5 untreated units were formed by using leaves of plants treated only with water. Mortality was recorded in 24 h intervals. Mortality of the tested wasps after 24 h exposure was lower than in the laboratory test (OILB category 3), however total mortality was observed in all cases at the latest after 96 h exposure. Finally, in a semi-field persistence test, 5 branches of 2 plants, treated at the rate of 10 mllhl, werc isolated in a funnel with organdie net top. At the bottom of the funnel neck a plastic vial was inserted. Other 2 plants were treated only with water and 5 branches of them were used to make up the untreated units. Every 5 days newly emerged adults were introduced into the funnel and mortality was recorded after 24 h. In this test, both mortality and lethal persistence strongly decreased in comparison with those registered for the extended laboratory-persistence test. According to these data spinosad should be classified as slightly persistent (OILB category: B) and moderately harmful (OILB category: 3), but for a definitive evaluation other semi-field persistence tests, in different periods of the year and locations, are needed.
Encyrtidae
Mealybug
Persistence (discontinuity)
Cite
Citations (12)