Interactions between the entomopathogenic fungus Beauveria bassiana and the Neotropical predator Eriopis connexa (Coleoptera: Coccinellidae): Implications in biological control of pest

Abstract

Aphids (Hemiptera: Aphididae) are serious pests of crops causing direct damage by feeding and indirect by the transmission of plant viruses. The use of conventional insecticides for controlling aphids has caused different problems and insecticide resistance. Accordingly, there is more interest in alternative control methods such as biological control by natural enemies for sustainable agricultural management. Among biological control agents, entomopathogenic fungi are one of the most significant microbial pathogens of insects. Also, Coccinellidae, as a major group, is a serious natural enemy. Both larval and adult stages of Coccinellidae feed on different soft-body pests, such as aphids. Eriopis connexa (Germar) (Coleoptera: Coccinellidae) is a common species in agroecosystems of the Neotropical region where it is considered to be a potential control agent. Pathogens and arthropod natural enemies may contribute to the control of phytophagous pests; however, it is important to assess potential interactions within biological control agents that share hosts (intraguild interaction) to evaluate their combined use for pest control. Therefore, the aim of this study was to evaluate the compatibility and interaction (lethal and sublethal effects) between E. connexa and the entomopathogenic fungus Beauveria bassiana (Bals.-Criv.) Vuill. (Ascomycota: Hypocreales). Both are important biological control agents of aphids. The pathogenicity of B. bassiana against larvae, pupae and adults of the predator E. connexa was evaluated, and results showed, that B. bassiana infected the coleopteran. On the other hand, interaction between B. bassiana and the predator was evaluated through infected-prey. The effects of fungus on larvae survival were significantly different when we analyzed the accumulated survival (from first larval instar to adulthood). The daily fecundity was significantly reduced at five days compared to control group. By contrast, no significant differences were observed between the five oviposition days in the rate of hatched eggs. This study shows that despite having received a single dose of the fungus in its life cycle, the population parameters of the predator E. connexa are affected. More studies would be necessary to help identify interactions between microbes and natural enemies to increase and enhance opportunities and further develop biological pest control programs.

Effects of Entomopathogenic Fungi on the Biology ofSpodoptera litura(Lepidoptera: Noctuidae) and its Reduviid Predator,Rhynocoris marginatus(Heteroptera: Reduviidae)

“…Zhang et al 48 have confirmed that Isaria cateniannulata fungus has no deleterious effects on the vitality and fertility of the predator Euseius nicholsi (Ehara & Lee) (Acari: Phytoselidae). Similarly, Scorsetti et al 49 also reported that B. bassiana -infected Rhopalosiphum padi L. (Hemiptera: Aphididae) did not affect the development of the predator Eriopis connexa (Germar) (Coleoptera: Coccinellidae). The efficacy of these entomopathogens may vary under the field condition where the predator interacts with the pest and environment.…”

Sub‐lethal effects of Metarhizium anisopliae on the life table parameters of the predatory coccinellid Menochilus sexmaculatus Fabricius

“…at the same time, it must have a minimal negative effect on non-target organisms (Riddick et al, 2009;Scorsetti et al, 2017). Likewise, the pathogenicity of M. anisopliae IRN.1 show that this isolate is more ef- sexmaculatus adult, serving as a suitable agent in the aphid management programme.…”

“…anisopliae (LC 20 ). The successful biological agent must be virulent to the target pests; at the same time, it must have a minimal negative effect on non‐target organisms (Riddick et al, 2009; Scorsetti et al, 2017). Likewise, the pathogenicity of M. anisopliae IRN.1 show that this isolate is more effective on A. gossypii and has low effects on Men.…”

“…The success of mycoinsecticide depends on both low virulence against non‐target insects and high efficacies against insect pests. Entomopathogenic fungi (EPF) have a wide host range of biological agents to control sap‐feeding pests and may have effects on beneficial insects (Khan et al, 2012; Scorsetti et al, 2017). However, it is crucial to consider the use of EPF as biological control agents with broad compatibility with others such as coccinellid predators (Trizelia et al, 2017).…”

Compatibility and Efficacy of the Parasitoid Eretmocerus hayati and the Entomopathogenic Fungus Cordyceps javanica for Biological Control of Whitefly Bemisia tabaci

“…Using a single biological product to suppress the population of whitefly may be difficult in practice. To this end, some previous studies have investigated the compatibility of entomopathogenic fungi and parasitoids and have evaluated the interactions between these two types of natural enemies as a potential biological control strategy for managing different types of insects, including coccids, aphids and whiteflies [39][40][41][42][43]. In order to improve the effectiveness of biological control of whitefly pests, it is imperative to know if a combination of two different biocontrol agents, such as an entomopathogenic fungus and an insect parasitoid, is more effective than their individual applications.…”