Entomopathogenic Potential of Native Strain in Suppressing Invasive Whitefly, Martin (Hemiptera: Aleyrodidae), Infesting Coconut.

In 2016, infestation of an exotic polyphagous pest, the rugose spiraling whitefly (RSW), Martin (Hemiptera: Aleyrodidae), was documented on coconut for the first time in India. Instantaneously, RSW has garnered wide attention owing to its damage severity and rapid spread across the coconut-growing regions of the country. Hence, an attempt was made to devise a sustainable integrated pest management (IPM) module using biological control agents as a mainstay component. The present study documented the identification and characterization of a potential entomopathogenic fungal isolate for the management of RSW. An entomopathogenic fungus isolated from nymphal cadavers of RSW was identified as based on morphological and phylogenetic analyses. A gradient of five conidial concentrations (1 × 10, 1 × 10, 1 × 10, 1 × 10 and 1 × 10 conidia/mL) of the were tested against eggs, first instars, second to third instars and pupae of RSW. Results revealed that is highly virulent to all developmental stages of RSW by causing mortality rates of 95.20%, 87.33%, 85.38% and 72.85%, in eggs, initial, middle and later instar nymphs of RSW, respectively, at the highest tested concentration (1 × 10 conidia/mL) at seven days after exposure. The LC and LT values of were 4.72 × 10, 4.94 × 10, 5.11 × 10, 5.92 × 10 conidia/mL and 4.27, 4.86, 4.56, 5.89 days against eggs, initial, middle and later instar nymphs of RSW, respectively. Further, preliminary field trials with strain at 1 × 10 conidia/mL exhibited a significant reduction in the egg and nymphal population by 57.8% and 56.3%, respectively. This report thus demonstrated that the newly isolated is an effective pathogen at suppressing all the developmental stages of RSW. This is the first record of infecting RSW, and it has a great potential to be developed as a mycoinsecticide.