Selection of entomopathogenic nematodes and evaluation of their compatibility with cyantraniliprole for the control of Hypothenemus hampei

Abstract

Attack by the coffee berry borer Hypothenemus hampei causes significant damage to coffee crops because it affects the quality of the coffee fruit during different developmental stages, which results in production losses. Control of the borer is difficult owing to its cryptic behavior and the fact that it spends its entire life cycle inside the coffee berries. This makes it difficult for natural enemies to reach it, as well as for it to come into contact with chemical insecticides. The objective of the present study was to select and evaluate the virulence of entomopathogenic nematodes (EPNs) on the coffee berry borer H. hampei and their compatibility with the insecticide cyantraniliprole under laboratory conditions. Initially, the pathogenicity and virulence of 16 isolates of Steinernema and Heterorhabditis towards coffee berry borer larvae and adults were evaluated. The most virulent isolates to both larvae and adults were determined by topical inoculation tests in coffee fruits (berries) infested by the insect, using a concentration of 100 infective juveniles (IJs)/fruit. The same isolates were also evaluated for viability and infectivity when combined with cyantraniliprole. The isolates S. feltiae (IBCB-n 47) and Heterorhabditis amazonensis (GL) displayed the highest virulence towards adults (54% ResumoA broca-do-café Hypothenemus hampei causa significativos prejuízos a esta cultura, pois seu ataque afeta a qualidade dos frutos de café em seus diferentes estádios de desenvolvimento e consequentemente leva a perdas na produção. O controle é dificultado devido ao seu comportamento críptico, uma vez que passa todo o ciclo dentro dos frutos de café, dificultando a ação de inimigos naturais, bem como o contato com inseticidas químicos. O objetivo deste estudo foi avaliar a virulência de nematoides entomopatogênicos (NEPs) sobre a broca-do-café H. hampei e a sua compatibilidade com o inseticida ciantraniliprole em condições de laboratório. Inicialmente, foram avaliadas a patogenicidade e virulência de 16 isolados de Steinernema e Heterorhabditis para larvas e adultos de H. hampei. Os isolados mais virulentos para larvas e adultos foram utilizados no teste de inoculação tópica em frutos de café infestados pelo inseto, utilizando uma concentração de 100 juvenis infectantes (JIs)

Association of Heterorhabditis amazonensis and Beauveria bassiana aiming the control of Hypothenemus hampei

“…Acevedo and Núñez (2009) found that H. bacteriophora is capable of causing an average mortality of 46% H. hampei, confirming the ability of IJ to penetrate coffee fruits and cause insect mortality of larvae, pupae and adults. However, this result differs from that found by Guide et al (2018) who, despite having observed 100% mortality of H. hampei larvae when Heterorhabditis spp. and S. feltiae were applied directly to the insects, found that when they were applied to bored fruits, infective juveniles were not able to penetrate the fruit.…”

“…The nematode H. amazonensis MC01 was used since it is a population found in the region where the experiments were carried out, thus being better adapted to local conditions. In addition, according to Guide et al (2018), high larval mortality rates were obtained with H. amazonensis isolates RSC5 and GL, 100% and 97%, respectively, and H. amazonensis GL was one of the nematodes that caused the highest adult mortality, 54%.…”

Resistance of insecticide-treated coffee berries of different varieties to the penetration of Hypothenemus hampei (Coleoptera: Curculionidae: Scolytinae)

“…In addition to exposure to entomopathogenic fungi, entomopathogenic nematodes can infect H. hampei females that stay on the berry's surface longer. This can be achieved because some nematode isolates can show approximately 50% virulence for adults of H. hampei (GUIDE et al, 2018), which could be even higher if these nematodes were to be applied to coffee varieties crops that hinder H. hampei drilling abilities. These isolates were shown to resist up to 48 hours after exposure to cyantraniliprole (GUIDE et al, 2018).…”

“…This can be achieved because some nematode isolates can show approximately 50% virulence for adults of H. hampei (GUIDE et al, 2018), which could be even higher if these nematodes were to be applied to coffee varieties crops that hinder H. hampei drilling abilities. These isolates were shown to resist up to 48 hours after exposure to cyantraniliprole (GUIDE et al, 2018). This compatibility is useful because as H. hampei takes longer to penetrate the berry, the nematodes can infect the female in this period when the insect is exposed, drilling the berry.…”

“…The coffee borer beetle, Hypothenemus hampei (Coleoptera: Curculionidae: Scolytinae), is considered one of the most aggressive pests that attack coffee berries. H. hampei pierces the crown region, penetrates the seed, and feeds on its endosperm (ALBA-ALEJANDRE, ALBA-TERCEDOR;VEGA, 2018;GUIDE et al, 2018;INFANTE, PÉREZ;VEGA, 2014;VEGA et al, 2015). H. hampei continues its biological cycle within the seed: females lay from 1 to 3 eggs a day, the larvae hatch and pupate, and then adults emerge (ROMERO;CORTINA, 2007).…”