Evaluation of Sex Pheromones and Plant Essential Oils Combination as Rubber Foam Dispenser For Controlling Fruit Fly (Diptera : Tephritidae)

Abstract

Tephritid fruit flies are one of the most devastating pests and concerning issues across the world. Among tephritid fruit flies, Bactrocera dorsalis and Zeugodacus cucurbitae are critical in terms of damage. Male lures like methyl eugenol (ME) and cue lure (CL) along with an insecticide are commercially used to attract and kill these fruit flies, which may contribute to excessive use of pesticides and is not environmentally safe. This study aimed at male annihilation of tephritid fruit flies through trapping without insecticides. It focused on using mixed lures on rubber foam, selecting the best plant essential oil, killing tephritid fruit flies using an eco-friendly method, and testing it in laboratory conditions, as well as combining it with single and mixed lures in field conditions. Finally, investigating the best proportion of these two lures to attain a satisfying result in controlling these fly species in a mixed cropping system. Five experiments were conducted to fulfill the aims of the study. Experiment results: i) single ME traps were more effective in attracting Bactrocera dorsalis than mixed lure traps. ME+CL combination worked very well compared to CL alone for Zeugodacus cucurbitae. Moreover, mixed lures caught more species than single lures in the field. ii) Among plant essential oils of basil, clove, citronella, eucalyptus, and basil oil performed best in terms of weathering of the essential oil in rubber foam. iii) For B. dorsalis, ME alone and ME mixed with basil oil gave 15.7-20.3% attractancy. For Z. cucurbitae, attractancy of CL mixed with basil oil (9.3% attractancy) was lower than CL alone (20.3% attractancy) and ME + CL (21.5% attractancy). iv) It was found that in both cases, mixing and separate placing of ME and CL (ME: CL), for B. dorsalis only, ME (100: 0) without CL, showed the highest number trapped. However, for Z. cucurbitae, the highest number of trapped flies in 25: 75 traps in both cases while separate combination was significantly different from only CL traps. v) Surprisingly, in-field test for B. dorsalis ME traps (5.5 ±1.0 FTD) was more effective than that mixed with basil oil (3.8 ± 0.8) and mixed lures (2.0 ± 0.0 FTD). In the case of Z. cucurbitae, that of both CL (0.4±0.0 FTD) and ME + CL (0.4 ±0.1 FTD) were equally effective as basil oil (ME + CL/BO) (0.2 ± 0.0 FTD). Overall, mixed lures (ME + CL) could be a good choice in trapping Z. cucurbitae in mixed cropping. However, ME alone represents the most appropriate trap to catch B. dorsalis.