Early infestation volatile biomarkers of fruit fly Bactrocera dorsalis (Hendel) ovipositional activity in mango (Mangifera indica L.)

Authors: CHESETO, XAVIER - African Insect Science For Food And Health (ICIPE); Rering, Caitlin; Broadhead, Geoffrey; TORTO, BALDWIN - African Insect Science For Food And Health (ICIPE); Beck, John

Submitted to: Phytochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/19/2022
Publication Date: 12/1/2022
Citation: Cheseto, X., Rering, C.C., Broadhead, G.T., Torto, B., Beck, J.J. 2022. Early infestation volatile biomarkers of fruit fly Bactrocera dorsalis (Hendel) ovipositional activity in mango (Mangifera indica L.). Phytochemistry. 206:113519. https://doi.org/10.1016/j.phytochem.2022.113519.
DOI: https://doi.org/10.1016/j.phytochem.2022.113519

Interpretive Summary: When agricultural products become infested by insect pests the negative impacts can be significant. The impacts include fruit or vegetable spoilage resulting in consumer rejection, loss of product and revenue to the grower and producers, import and export restrictions, food safety issues due to potential pathogens introduced by the insect, and the introduction and spread of invasive pest issues. The oriental fruit fly (Bactrocera dorsalis) is considered a highly invasive insect pest with populations reported in 75 countries, with prevalent distributions in Asia and Africa. B. dorsalis is has a very broad preference for many crops, with a range encompassing more than 250 fruits and vegetables. Damage to the fruits or vegetables is incurred through the laying of eggs (oviposition) and subsequent larval feeding resulting in spoilage. Early detection of insect pest infestations is a critical component for ensuring food safety as well as controlling introduction and spread of invasive insects. However, ovipositional activity and early larval development is visually difficult, thus rapid and non-destructive detection often relies on odors associated with infestation. USDA-ARS scientists at the Center for Medical, Agricultural, and Veterinary Entomology in Gainesville, FL in collaboration with scientists at the International Centre of Insect Physiology and Ecology (icipe) in Nairobi, Kenya investigated the odors (volatile chemical compounds) of mangos (Mangifera indica L.) infested with B. dorsalis and compared these odors to those of non-infested and mechanically damaged mangos 24 h post-infestation. Analyses provided the identification of ten odors unique or more abundant in the infested mangos than the mechanically damaged or non-infested fruit. Statistical analysis showed modest separation of the three treatments. Results indicated sufficient compositional and quantity differentiation of volatile profiles among treatments for detection of infested fruit at points of commerce. Successful detection and removal of infested fruit or vegetables will help protect consumers, agricultural commodities, and the spread of invasive insect species.

Technical Abstract: Infestation of agricultural commodities by insect pests results in significant economic, import and export, food safety, and invasive insect introduction issues for growers, consumers, and inspectors. The Oriental fruit fly (Bactrocera dorsalis) is considered a highly invasive insect pest with populations reported in more than 60 countries, with prevalent distributions in Asia and Africa. B. dorsalis is phytophagous with a host range encompassing hundreds of fruits and vegetables. Damage to the fruit or vegetable is inflicted through oviposition and subsequent larval feeding resulting in spoilage. Early detection of insect pest infestations is a critical component for ensuring food safety as well as controlling introduction and spread of invasive insects. However, detection of ovipositional activity and early larval development is visually difficult, thus rapid and non-destructive detection often relies on odors associated with infestation. We investigated the odors of mangoes (Mangifera indica L.) infested with B. dorsalis and compared the volatile profiles of infested mangoes to non-infested and mechanically damaged mangoes 24 h post-infestation. GC-MS and multivariate analyses provided the identification of eleven compounds unique to infested mangoes compared to mechanically damaged or non-infested fruit. Results indicated compositional and quantitative differentiation of volatile profiles among treatments for detection of infested fruit at quality checks or points of commerce.