Temperature dependent virulence of the entomopathogenic nematodes against immatures of the oriental fruit fly, Bactrocera dorsalis Hendel (Diptera: Tephritidae)

Hafiz Muhammad Aatif,Muhammad Raheel,Azhar Abbas Khan,Muhammad Ferhan,Muhammad Shahid Hanif,Qaiser Shakeel,Muhammad Zeeshan Mansha,Sajjad Ali,Muhammad Irfan Ullah

doi:10.1186/s41938-020-00248-7

Abstract

Fruit flies have a great influence on fruit and vegetable industry of Pakistan. Bactrocera dorsalis Hendel (Tephritidae) is a polyphagous pest in large number of fruit and vegetable crops worldwide. Virulence of 4 entomopathogenic nematodes (EPNs) species, Heterorhabditis bacteriophora, H. indica, Steinernema carpocapsae, and S. asiaticum, was evaluated at different temperature degrees (15, 20, 25, 30 and 35 °C) against the immature stages of fruit fly species, B. dorsalis. The tested EPNs species showed a temperature dependent virulence against the fruit fly immatures. All EPNs showed a poor infectivity at the lowest temperature (15 °C) and a high infectivity at the highest temperature (35 °C). In overall, H. bacteriophora performed the best against the fruit fly larvae and pupae at all temperature degrees. At 35 °C, all the EPNs caused more than 95% mortality in fruit fly maggots, but H. bacteriophora and S. carpocapsae performed better than the others. The EPNs infectivity increased with increasing the temperature and exposure time. Similar results were recorded in case of pupae. H. bacteriophora and S. carpocapsae caused more than 70% pupal mortality rates at 35 °C.

Highlights

Fruit flies are economically important insect pests responsible for attacking a wide range of fruits and fleshy vegetables in the tropical and subtropical zones of the world (Roger et al 2015)
Numerous studies have reported the association of entomopathogenic nematodes (EPNs) and environment as they are well adapted to the prevailing environmental conditions and regarded as one of the best biological control agents of insect pests (Zadji et al 2014)
The highest mortality rate was recorded by H. bacteriophora at all temperature degrees

Summary

Background

Fruit flies are economically important insect pests responsible for attacking a wide range of fruits and fleshy vegetables in the tropical and subtropical zones of the world (Roger et al 2015). The oriental fruit fly, Bactrocera dorsalis Hendel (Diptera: Tephritidae), is a highly polyphagous species with wide dispersals. It is the most damaging pest of more than 170 commercial fruits and vegetable varieties in tropical and sub-tropical zones of the world (Ye and Liu 2005). Numerous studies have reported the association of EPNs and environment as they are well adapted to the prevailing environmental conditions and regarded as one of the best biological control agents of insect pests (Zadji et al 2014). The present study aimed to evaluate different EPN strains at different temperature degrees to find out the favorable one for their application as a control measure against fruit flies under laboratory conditions

Materials and methods

Results and discussion

Conclusion