Identification of new attractants and behavior-modifying odors for the Mediterranean fruit fly

Authors: Cloonan, Kevin; Gill, Micah; Yang, Xiangbing; Tabanca, Nurhayat; Rohde, Barukh; Kendra, Paul

Submitted to: Fruit Flies of Economic Importance International Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 6/23/2022
Publication Date: 11/29/2022
Citation: Cloonan, K.R., Gill, M.A., Yang, X., Tabanca, N., Rohde, B.B., Kendra, P.E. 2022. Identification of New attractants and behavior-modifying odors for the Mediterranean fruit fly. Fruit Flies of Economic Importance International Symposium. Sydney, Australia. 13 – 18 Nov 2022.

Interpretive Summary:

Technical Abstract: The Mediterranean fruit fly, or medfly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) is one of the most economically important pests of fruit crops worldwide. The Caribbean fruit fly, or caribfly, Anastrepha suspensa (Loew) (Diptera: Tephritidae) is a quarantine pest of citrus in Florida, and a pest of guava and other specialty fruits in the Americas. Currently, trimedlure is used to monitor male medfly populations, and protein-based baits and lures are used to monitor male and female populations of both species. Developing alternative attractants based on host volatiles will improve monitoring for both species, and female-targeted attractants will have the added benefit of being compatible with sterile male release programs. To identify alternatives to the current protein-based and male-targeted attractants, a series of electroantennogram (EAG) and small-cage assays were used to screen host fruits and essential oils to identify novel attractants for sterile male medfly and fertile caribflies. In small-cage bioassays, essential oils from the leaves and fruits of foetid juniper, Juniperus foetidissima Willd., were attractive to male medflies. Hydrodistalltion revealed that a-thujone and ß-thujone composed almost 40% of the distillates from both the leaves and fruits. In subsequent behavioural assays, both a-thujone and ß-thujone were less attractive than a known strong attractant, tea tree oil (TTO), though both a-thujone and ß-thujone were more attractive than TTO after 90 minutes. Similar bioassays also showed that essential oils from crimson beebalm, Monarda didyma L., and oregano, Origanum vulgare L., were equally attractive to male medflies compared to the TTO control. GC-EAD (gas chromatography coupled with electroantennography) work is underway to identify the attractive compounds from M. didyma and O. vulgare that may have potential use as synthetic lures for male medflies. Additional GC-EAD and behavioural work is being conducted to screen for odors that are antennally sensitive and attractive to caribfly females from the headspace of ripe and unripe common guava, Psidium guajava L, and other caribfly host fruits. This is the first report on attraction of male medflies to the essential oils from J. foetidissima, M. didyma, O. vulgare, and a- and ß-thujone. Further, to our knowledge, this is the first report to analyse the volatiles from ripe and unripe guava fruit for attraction of female caribflies. Developing alternative attractants for medfly and caribfly will benefit regulatory agencies in designing improved pest detection programs, especially programs that support sterile male release.