Evaluation in vitro of the virulence of two entomopathogenic heterorhabditid nematodes in the control of Stomoxys calcitrans (Diptera: Muscidae) larvae in byproducts of the sugar and alcohol industry

Abstract

Stomoxys calcitrans causes losses to livestock, mainly to cattle. This study aimed to determine the pathogenic potential of Heterorhabditis bacteriophora HP88 and H. baujardi LPP7 against S. calcitrans larvae after being exposed to byproducts of the sugar and alcohol industry. The efficacy of EPNs on stable fly larvae was evaluated in bioassays with vinasse at three temperatures (16, 25 and 35 °C) and concentrations (0, 50 and 100%), as well as in relation to larva age (4, 6 and 8 days) in filter cake and EPNs concentration (100, 300 and 500 IJs/larva) in sugarcane bagasse. H. bacteriophora showed higher efficacy than H. baujardi at all temperatures. Vinasse did not have a negative effect on the virulence of H. bacteriophora. The age of fly larvae did not affect the mortality rates caused by the EPNs. In bagasse, H. bacteriophora presented higher mortality rates than the control group. It is concluded that EPNs can be a potential component in integrated strategies of stable fly control and outbreak prevention in areas of sugar and alcohol production.

Assessment of infection of Stomoxys calcitranslarvae by entomopathogenic nematodes Heterorhabditis amazonensis NEPT11

“…Monteiro Sobrinho et al (2023) reported larvae mortality rates of 73.3% in sugarcane bagasse ash. Studies involving H. bacteriophora HP88 and H. baujardi LPP7 to control S. calcitrans larvae in vinasse, filter cake and sugarcane bagasse (Monteiro Sobrinho et al, 2023) also showed higher mortality rates than those found in the present study, even this not using sugarcane substrate that could interfere in the action of H. amazonensis NEPT11.…”

“…Entomopathogenic nematodes (EPNs) have emerged as alternatives for use in biological pest control (Kaya & Gaugler, 1993), and these microorganisms have already proved their ability to kill stable fly larvae (Leal et al, 2017;Monteiro Sobrinho et al, 2021), even when the latter are in substrates originating from the sugar and alcohol industry (Monteiro Sobrinho et al, 2016, 2023. Therefore, new species of EPNs must be tested and evaluated in order to increase the alternatives for controlling S. calcitrans.…”

Virulence of Entomopathogenic Nematodes and their Symbiotic Bacteria against Insect Pests, with Special Reference to Agrotis ipsilon (Lepidoptera: Noctuidae): A Comprehensive Review.

“…20-30 °C (Kim and Alston, 2008;Power et al, 2009). In the specific case of HeterorhabditisbaujardiLPP7, an optimal temperature of 28°C for replication and infection had been reported by Sobrinho et al (2023), with emphasis on the origin of this EPN strain, the Amazon rainforest strain; hence, it is probably already adapted to tropical environments (Dolinski et al, 2007). The cold-active EPN species, like S. kraussei, provide an interesting potential for further developments into EPN-based pest control strategies in orchard environments (Willmott et al, 2002).…”

“…On the other hand, reported the viability of H. baujardi LPP7 at temperatures of 35°C for two hours, with no loss in efficacy against G. mellonella larvae. Whereas, a studyby Sobrinho et al (2023) revealed that H. baujardi LPP7 lost efficacy against larvae of the stable fly Stomoxyscalcitrans (Diptera:Muscidae), after 72 h at 35°C. Moreover, several studies reported the adaptation of different EPN species to temperatures around 35°C (Kusakabe et al, 2019).…”

Evaluation of the effect of Heterorhabditis bacteriophora (HP88) on Stomoxys calcitrans(Linnaeus, 1758) larvae (Diptera: Muscidae) in sugarcane bagasse ash

“…Evaluation of the effect of Heterorhabditis bacteriophora (HP88) on Stomoxys calcitrans (Linnaeus, 1758) larvae (Diptera: Muscidae) in sugarcane bagasse ash Monteiro Sobrinho et al (2023) reported that EPNs are effective on S. calcitrans larvae in a variety of sugarcane substrates, and sugarcane bagasse ash is a substantial substrate produced by sugar mills, and although it is produced in smaller quantities than vinasse, bagasse and sugarcane straw, it is also used for the fertilization of sugarcane fields, favoring the development of immature stages of the stable fly, which causes significant losses in livestock and in the sugar and alcohol industry (Corrêa at al., 2013).…”