Potential of Entomopathogenic Fungi as Biological Control Agents of Diamondback Moth (Lepidoptera: Plutellidae) and Compatibility With Chemical Insecticides

Abstract

The objectives were to evaluate the efficiency of entomopathogenic fungi against Plutella xylostella (L.) and the compatibility of the most virulent isolates with some of the insecticides registered for use on cabbage crops. Pathogenicity tests used isolates of Beauveria bassiana, Metarhizium rileyi, Isaria fumosorosea, Isaria sinclairii, and Lecanicillium muscarium standardized at a concentration of 10(7) conidia/ml. Cabbage leaf discs were immersed in these suspensions, and after evaporation of the excess water, were placed 10 second-instar larvae of P. xylostella, totaling 10 leaf discs per treatment. Mortality was assessed 7 d after treatment, and the isolates that caused mortality>80% were used to estimate LC50 and LT50. The compatibilities of the most virulent isolates and the insecticides were tested from the mixture of these into the culture medium, and after solidifying, the medium was inoculated with an aliquot of the isolated suspension. The following parameters were evaluated: growth of the colony, number and viability of conidia after 7 d. The isolated IBCB01, IBCB18, IBCB66, and IBCB87 of B. bassiana, LCMAP101 of M. rileyi, and ARSEF7973 of I. sinclairii caused mortality between 80 and 100%, with LC50 and LT50 between 2.504 to 6.775×10(4) conidia/ml and 52.22 to 112.13 h, respectively. The active ingredients thiamethoxam and azadirachtin were compatible with the entomopathogenic fungi. The results suggest that the use of these isolates is an important alternative in the pesticidal management of P. xylostella, with the possible exception of the associated use of chemical controls using the active ingredients thiamethoxam or azadirachtin.

The Time–Concentration–Mortality Responses of Western Flower Thrips, Frankliniella occidentalis, to the Synergistic Interaction of Entomopathogenic Fungus Metarhizium flavoviride, Insecticides, and Diatomaceous Earth

“…In our previous studies, it was found from many different fungal candidates that M. flavoviride WSWL51721 has good potential in controlling WFT adults, in which the mortality reached 82.65% at a concentration of 1.0 × 10 7 conidia/mL [26]. The compatibility levels between different chemical insecticides and EPF have been shown to be different [19]. We chose three chemical insecticides-imidacloprid, buprofezin, and abamectin-that have been commonly used to control WFT in the field.…”

“…The fungal strain culture was performed as described in Section 2.2. After autoclaving, when the SDA medium temperature dropped to 45°C, but was not yet solidified and would not affect the pesticide activity [19], each different concentration of pesticide prepared with sterile distilled water was added to the culture medium for homogenization, and then poured into the Petri dishes for solidification. Next, 4 mm diameter fungal strain cores were taken from the M. flavoviride cultures and placed upside down in the middle of Petri dishes containing SDA medium with 0 (control), 10, 50, and 100 ppm of imidacloprid, buprofezin, and avermectin solution, respectively.…”

“…Entomopathogenic fungi (EPF) are biological control agents with insecticidal activities against a variety of agricultural insect pests worldwide [16][17][18][19]. Most importantly, they do not pollute the environment, are harmless to humans and animals, have an ecologically wide distribution, and target a variety of host species, demonstrating a broad spectrum of insecticidal effectiveness and strong pathogenicity against many insect pests in the agricultural field.…”

A New Frontier for Biological Control against Plant Pathogenic Nematodes and Insect Pests I: By Microbes

“…The broken line inset box indicates the common microbial determinants of both insecticidal and nematicide capacity. Duarte et al, 2016;Gonzalez et al, 2016;Khan et al, 2016;Malekan et al, 2015;Mascarin and Jaronski, 2016;QuesadaMoraga et al, 2006;Ramanujam et al, 2014;Safavi, 2013;Xu et al, 2009 Metarhizium anisopliae Haase et al, 2015;Monteiro et al, 2012;Ramanujam et al, 2014;Yang et al, 2012HezeSNPV Helicoverpa zea Gemstar, HzNPV CCAB Haase et al, 2015Lacey et al, 2015;Rowley et al, 2011 MabrNPV Mamestra brassicae;H. armigera;S.…”

White grub (Coleoptera: Melolonthidae) mortality induced by Ophiocordyceps melolonthae

“…However, the selection pressure induced by excessive applications may lead to the development of resistance in these populations. To minimize this problem, different biological control agents can be used, especially specific entomopatogenic microorganisms (DUARTE et al, 2016).…”