Crocidolomia pavonana Fabr. (Lepidoptera: Crambidae) is a major pest on various cabbage crops in Indonesia. Various insecticides have been used to control this insect pest including several entomopathogenic fungi, and this cabbage caterpillar has become resistant to various insecticides. In order to develop insecticides from entomopathogenic fungi, species or varieties from natural area such as forest are needed. A bioassays of Cordyceps sp. and Beauveria bassiana has been carried out in the laboratory. Inoculum of Cordyceps sp. obtained from the Dipterocarpaceae forest in South Kalimantan, Indonesia recovered from dead ants by the mycelium of Cordyceps sp. Four concentration of Cordyceps sp. and Beauveria bassiana inoculum and tween80 as a control were tested against 3rd instar larvae of C. pavonana with five replications. Field efficacy trial was carried out in a screen house (8 x 12 M2) using Chinese cabbage plants (Brassica juncea) aged 28 days after sowing, with a spacing of 0.4 M between rows. Three formulation of Cordyceps sp. and tween80 as a control were used with 6 replications. The result of the bioassays in the laboratory showed that Cordyceps sp. with concentration of 1 x 107 conidia mL-1 was able to give 100% mortality od C. pavonana larvae, while B. bassiana with the same concentration caused morality of C. pavonana larvae of 98.33%, although statistically not significantly different. The results of probit analysis also showed that LC90 Cordyceps sp. against cabbage caterpillar larvae was 1.57 x 106 conidia mL-1, while B. bassiana required a concentration of 2.6 x 106 conidia mL-1 to reach the LC90 value. The results of filed trial showed that the formulation of Cordyceps sp. 1 x 107 conidia mL-1 using palm oil cooking oil was able to give an average mortality of 86.7%, and significantly higher (P<0.05) than the other treatment. The results of this study indicate that the inoculum of Cordyceps sp. from Dipterocarpaceae forest is very promising to be developed as an insecticide to control C. pavonana in cabbage
Black and white pepper have been considered as the most important perennial crops in some regions of Indonesia yet it took about 3-5 years before the plant start producing. One of the possible approaches to maintain the income of the farmer in the perennial plantation is multi-cropping with high-value annual crops, such as vegetables. However, many pests of vegetables already showed resistance to the common synthetic pesticide applied on the black pepper plant. Thus, it is necessary to apply another strategy for pest control, by applying entomopathogenic fungi. In this study, bioassays and field efficacy of two local isolates of entomopathogenic fungi (Beauveria bassiana and Cordyceps sp.) against one of the most insecticide-resistant pests, larvae of Crocidolomia pavonana (Fabr.) was conducted. In this study, exposure to 1 x 104 conidia mL−1 to 1 x 107 conidia mL−1 resulted in mean larval mortalities from 23.33 to 100% in two days. The probit analysis showed that the LC50 of B. bassiana was estimated at 4.26 x 104 conidia mL−1 which significantly more toxic than Cordyceps sp. (1.57 x 105 conidia mL−1) although the lethal time was similar. From the field tests, cabbage was sprayed with suspension contained 107 conidia mL−1. Means percent of mortality for all treatments was more than 75% and significantly higher (P < 0.05) than the control (tween 80). Conidia of Cordyceps sp. in palm oil cooking oil offered the most promising result against the C. pavonana.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.