Biocontrol potential of entomopathogenic nematodes against camel tick, Hyalomma dromedarii (Acari: Ixodidae)

Abstract

Entomopathogenic nematodes (EPNs) are a well-established biocontrol agent for insect pests. Using such a bio-agent to eliminate ticks has only been reported in a few cases. The current study intended to determine how the camel tick, Hyalomma dromedarii Koch, 1844 (Acari: Ixodidae), engorged female, was affected by various concentrations and timing of exposure to infected juveniles of five EPN isolates from two species. The six groups of engorged females, each with 25 ticks, were subjected to five concentrations of 50, 100, 150, 300, and 600 infective juveniles (IJs)/female in order to perform the work. Female mortality was observed every day for up to 72 h. The groups' average weights were statistically equivalent. The following biological parameters: initial weight of the female (mg); pre- and oviposition periods (days); survival period (days); initial weight of the egg mass (mg); hatching percentage (%H); nutritional efficacy index (NEI); and the control efficacy (%) of the engorged females as influenced by Heterorhabditis indica NEM-23 and H. bacteriophora NEM-26 infections were also measured. The results showed a linear increment in female mortality with the increase in EPN concentrations. Three days after being exposed to H. bacteriophora at 300 or 600 IJs/Female, all H. dromedarii individuals died, while the group containing 50 IJs/Female of the same EPN reached 75 %. All biological parameters were altered by EPNs, and there were extremely noticeable variations between the concentrations and the untreated group. These findings indicate that both Heterorhabditis isolates acted negatively on the parameters that were being observed, encouraging one to believe that this EPN was effective in controlling engorged females of H. dromedarii in the laboratory.

Keywords

• Entomopathogenic nematodes
• Hyalomma dromedarii
• Biological control
• Biological parameters