Virulence and biochemical activities of Heterorhabditis indica (Nematoda: Heterorhabditidae) against Bactrocera zonata and Ceratitis capitata (Diptera: Tephritidae)

Abstract

This study examines the impact of Heterorhabditis indica entomopathogenic nematodes on mature larvae of the peach fruit fly, Bactrocera zonata (Saunders), and the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), both of which are highly detrimental species in the Tephritidae family. The investigation is conducted in a laboratory setting using two types of soil: sandy loam and sand. The research focuses on the virulence and biochemical effects of the nematodes. The results indicate that H. indica is more effective in sandy loam soil than sandy soil. This is supported by the LC50 values (the lethal concentration that kills 50% of the tested organisms) of 566.656 Infective Juveniles/ml for B. zonata and 250.53 Infective Juveniles/ml for C. capitata in sandy loam soil, whereas the corresponding values in sandy soil were 1149.051 and 701.839 Infective Juveniles/ml, respectively. Consequently, C. capitata larvae are more susceptible to entomopathogenic nematodes than B. zonata larvae. The infection by the nematodes also leads to changes in specific enzymatic activities of the larvae. This includes significant reductions in amylase, trehalase, and acetylcholine esterase, alongside an increase in invertase activity. Moreover, varying decreases are observed in chitinase, acid phosphatase, and alkaline phosphatase activities. In conclusion, the nematodes effectively reduce the emergence of adult flies by targeting the final stages of insect development. Furthermore, they offer an eco-friendly alternative to chemical pesticides.

Highlights

• Entomopathogenic nematodes is an alternative biological control for fruit flies.

• H. indica is a soil control agent and adapted well to field situations.

• H. indica suppressed fruit fly larvae and could restrict their population expansion.

• Individuals of C. capitata were more comparatively susceptible than B. zonata ones.

• H. indica caused disturbance in specific enzymatic systems of both species larvae.

Graphical Abstract

Keywords:

• Virulence activity
• biological control
• biochemical effect
• Heterorhabditis indica
• Bactrocera zonata
• Ceratitis capitata

Disclosure statement

No potential conflict of interest was reported by the author(s).

Ethical Approval

The Ethics Commission on Animal Use of the International Animal Care and Use Committee at the Agricultural Research Center reviewed and approved the study procedures for Laboratory Animal Research (ARC- IACUC, Protocol Number, ARC -ARU-23-23). The study rigorously followed institutional and national guidelines designed to protect the welfare of animals.