Developing Botanical Formulation For The Management Of Pink Mealybug Maconellicoccus Hirsutus Green

Abstract

Laboratory experiments were conducted to evaluate botanicals for their newlineinsecticidal activity on pink mealybug, Maconellicoccus hirsutus (Green) (Hemiptera: newlinePseudococcidae). The insecticidal and repellency efficiency of aqueous, solvent extracts newlineand emulsifiable concentrate of Calotropis gigantea (L.) W. T. Aiton on M. hirsutus and newlineits effects on predators, Chrysoperla zastrowi sillemi (Esben-Peterson) (Neuroptera: newlineChrysopidae) and Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) were newlineevaluated along with phytochemical analysis of C. gigantea. newlineOut of the 50 botanicals tested, 7 plants viz. C. gigantea, Ricinus communis L., newlineHelicteres isora L., Centella asiatica (L.), Colocasia esculenta (L.), Ocimum tenuiflorum newline(L.) and Curcuma longa L. showed more than 80 per cent mortality while 50 to 80 per newlinecent mortality was observed in 13 plant extracts at 72 Hours After Exposure (HAE). The newlinehighest mortality was caused by C. gigantea (98·30% at 72HAE) which was statistically newlinesuperior over all other treatments. newlineAmong the plant parts of C. gigantea, maximum mortality of M. hirsutus was newlineobserved in leaf (93·33%) followed by fruit pericarp (90·00%) and flower (88·33%) at newline72HAE. Shoot tip, stem bark and immature seed showed moderate toxicity while the newlineleast effective part was mature seeds. The maximum LC50 values of aqueous extracts newlinewere observed in flower (5·989, 4·151 and 3·560 per cent at 24, 48 and 72HAE, newlinerespectively) followed by leaf (4·681, 3·633 and 3·055 per cent at 24, 48 and 72HAE, newlinerespectively) while the fruit pericarp showed the lowest LC50 values (4·639, 3·408 and newline2·895 per cent at 24, 48 and 72HAE, respectively). Therefore the toxicity was in the newlineorder fruit pericarp gt leaf gt flower. newlineThe per cent yield of solvent extracts was higher in leaves than flower. Ethanol newlineyielded highest per cent (41·23 for leaf, 22·60 for flower) followed by ethyl acetate and newlinehexane. newlineAmong the total six extracts (hexane extract, ethyl acetate extract and ethanol newlineextract of leaf; and hexane extract, ethyl acetate extract and eth