Evaluation in vitro of the infection times of engorged females of Rhipicephalus (Boophilus) microplus by the entomopathogenic nematode Steinernema glaseri CCA strain

Abstract

Studies have shown that ticks are susceptible to infection by entomopathogenic nematodes. These studies indicate different susceptibilities of ticks to infection by these fungi, depending on the tick species, development phase, entomopathogenic nematodes species and strains and the time the ticks are exposed to them. Usually this period ranges from 24 to 72 hours. The aim of this study was to evaluate the infection times in vitro of engorged Rhipicephalus (Boophilus) microplus females by the entomopathogenic nematodes Steinernema glaseri CCA strain, by analysis of the ticks' biological parameters. The results show that a 2-hour exposure time was sufficient for the engorged R. microplus females to be infected by S. glaseri CCA, but that a minimum exposure time of 24 hours was necessary to generate treatment efficacy above 90%.

First report of pathogenicity of entomopathogenic nematodes of the genus Heterorhabditis on partially engorged females of Dermacentor nitens (Acari: Ixodidae)

“…Entomopathogenic nematodes are used successfully in various locations around the world to control different insect pests (Grewal et al, 2001;Dolinski et al, 2006), and in the past two decades, research has sought to enable the use of EPNs to control ticks (Samish et al, 2008). Most studies have been directed toward the control of R. microplus (Vasconcelos et al, 2004;Reis-Menine et al, 2008;Molina-Ochoa et al, 2009;Monteiro et al, 2010b;Carvalho et al, 2010;Monteiro et al, 2012) and Rhipicephalus annulatus (Say, 1921) (Samish and Glazer, 1991;Samish and Glazer, 1992;Samish et al, 2000;Glazer et al, 2001;Alekseev et al, 2006). To the best of our knowledge, this is the second study on the pathogenicity of EPNs on D. nitens and the first to investigate the efficacy of nematodes of the genus Heterorhabditis, which have been identified as the most virulent types on ticks (Samish et al, 2008).…”

Infection and reinfection of Stomoxys calcitrans larvae (Diptera: Muscidae) by entomopathogenic nematodes in different times of exposure

“…However, this comparison should be made carefully, since the EPN (S. glaseri CCA) used in the aforementioned study belongs to another genus, different from the genus used in this study work, in which the two EPNs were of the genus Heterorhabditis. Another important fact is that Carvalho et al (2010) used a concentration of 1000 IJs per ingurgitated female, while the concentration used in the present study was five times lower (200 IJs/fly larva). In fact, the superior results reported the aforementioned authors can be attributed to this higher concentration.…”

“…However, comparing the mortality rates caused to the two dipteran species by H. baujardi LPP7 and H. indica, this factor did not have a significant impact, since their mortality rates were similar. Carvalho et al (2010), who evaluated different periods of exposure of ingurgitated females of Rhipicephalus microplus (Acari: Ixodidae) to the EPN Steinernema glaseri CCA strain (Nematoda: Steinernematidae), reported that treatments of 2, 6, 12, 24 and 48 h resulted mortality rates of 66%, 78% and 83.7%, 99.9%, and 99%, respectively. These rates are higher than those of this study with the stable fly, where the highest mortality rate was 91.7% (H. bacteriophora HP88-48h).…”

In vitro Analysis of the Efficacy of Selected Commercial Acaricides on The Cattle Tick Rhipicephalus (Boophilus) annulatus (Acari: Ixodidae)

“…Tick-borne diseases such as babesiosis, anaplasmosis, theileriosis and cowdriosisgenerally affects the blood and lymphatic systems. In such situations of disease outbreaks, chemical acaricides with different modes of action are generally used [25]. However, the widespread and indiscriminate use of these acaricides, especially at doses lower than the recommended dose, has led to the development of acaricidal resistance.…”