Efficacy of indigenous entomopathogenic nematodes (Rhabditida: Heterorhabditidae, Steinernematidae), from Rio Grande do Sul Brazil, against Anastrepha fraterculus (Wied.) (Diptera: Tephritidae) in peach orchards

Abstract

Laboratory, greenhouse, and field experiments were performed with the objective of selecting efficient indigenous strains of entomopathogenic nematodes (EPNs) from Rio Grande do Sul (RS) state, Brazil, for controlling the South American fruit fly, Anastrepha fraterculus (Wied.). Laboratory experiments were conducted in 24 well-plates filled with sterile sand and one insect per well. In greenhouse experiments, plastic trays filled with soil collected from the field were used, while in field experiments, holes were made in soil under the edge of peach tree canopies. Among 19 EPN strains tested, Heterorhabditis bacteriophora Poinar RS88 and Steinernema riobrave Cabanillas, Poinar, & Raulston RS59 resulted in higher A. fraterculus larval (pre-pupal) and pupal mortality, with LD(90) of 1630, 457 and 2851, 423 infective juveniles (IJs)/cm(2), respectively. Greenhouse experiments showed no differences in pupal mortality at 250 and 500IJs/cm(2) of either nematode. In the field, H. bacteriophora RS88 and S. riobravae RS59 sprayed individually over natural and artificially infested fruit (250IJs/cm(2)) resulted in A. fraterculus larval mortality of 51.3%, 28.1% and 20%, 24.3%, respectively. There was no significant difference in A. fraterculus pupal mortality sprayed with an aqueous suspension of either nematode; however, when using infected insect cadavers, H. bacteriophora RS88 was more efficient than S. riobrave RS59. Our results showed that H. bacteriophora RS88 was more virulent to insect larvae, with an efficient host search inside the infested fruit and control of pupae in the soil after being applied by aqueous suspension or infected cadavers.

Assessment of the entomopathogenic nematodes against maggots and pupae of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), under laboratory conditions

“…Minas et al (2016) observed that mouth, spiracles, and anus, were quite open for penetration into pupae. However, the pupae of Anastrepha fraterculus were found to be vulnerable to infection by some EPN species, as it was highly susceptible to infection by S. riobrave and H. bacteriophora (Barbosa-Negrisoli et al 2009). Similarly, Patterson Stark and Lacey (1999) gained high mortality rates (62.5 and 40%) of Rhagoletis indifferens pupae after application of H. bacteriophora and S. riobrave, respectively, but S. feltiae, S. carpocapsae, H. bacteriophora, and H. megidis effectively controlled all the life stages of L. decemlineata.…”

Susceptibility of olive fruit fly, Bactrocera oleae (Diptera: Tephritidae) pupae to entomopathogenic nematodes

“…Third instar larvae (Yee and Lacey 2003;Toledo et al 2005;Barbosa-Negrisoli et al 2009;Malan and Manrakhan 2009;Rohde et al 2012;Langford et al 2014;Shaurub et al 2015) and pupae (Barbosa-Negrisoli et al 2009) of several tephritid flies were reported to be susceptible to EPNs. To date, only one laboratory study has been carried out by Sirjani et al (2009) on the olive fruit fly.…”

Isolation of entomopathogenic nematodes in an apple orchard in Southern Brazil and its virulence to Anastrepha fraterculus (Diptera: Tephritidae) larvae, under laboratory conditions

“…In this work, for convenience, all isolated are called EPN, including Oscheius. EPNs have been studied as biocontrolers candidate of several fruit flies species (Lezama-Gutiérrez et al, 2006;Barbosa-Negrisoli et al, 2009;Rohde et al, 2012;Toledo et al, 2014). However, few studies at orchard condition were found in the literature and even less works reporting EPNs natural occurrence.…”