A brief assessment of Drosophila suzukii (Diptera: Drosophilidae) abundance in forest and non-forested habitats across an altitude gradient on Mauna Loa, Hawai‘i

Authors: CURBELO, KEENA - University Of Hawaii; PRICE, DONALD - University Of Nevada Las Vegas, Las Vegas, Nv; Koch, Jonathan

Submitted to: Pacific Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/22/2021
Publication Date: 11/23/2021
Citation: Curbelo, K., Price, D., Koch, J. 2021. A brief assessment of Drosophila suzukii (Diptera: Drosophilidae) abundance in forest and non-forested habitats across an altitude gradient on Mauna Loa, Hawai‘i. Pacific Science. 75(4):513-524. https://doi.org/10.2984/75.4.4.
DOI: https://doi.org/10.2984/75.4.4

Interpretive Summary: Drosophila suzukii (Diptera: Drosophilidae) is a significant pest of wild and cultivated soft summer fruits. The insect pest was first detected outside of its native range in 1983 on Mauna Ka‘ala in Wai‘anae, Hawai‘i, USA. While extensive research has been conducted in continental landscapes, little is known about the persistence of D. suzukii in habitats dominated by native and endemic species in Hawai‘i. In this study, we characterize ‘ohelo (Vaccinium reticulatum) host use, distribution, and abundance of D. suzukii across an altitude gradient on the eastern slope of Mauna Loa, Hawai‘i. In total we collected 2,503 D. suzukii across 14 field sites over a four-month period in 2016. Endemic ‘ohelo is an important host for D. suzukii, as we detected an emergence rate of up to 1.88% per 1 mL of berries across non-forested field sites. D. suzukii abundance decreases with increasing altitude and are more abundant in forested habitats than in non-forested habitats on Mauna Loa. Our study has determined that D. suzukii is an established invasive species in Hawai‘i and is readily using habitats composed primarily of native and endemic species.

Technical Abstract: Drosophila suzukii (Diptera: Drosophilidae) is a significant pest of wild and cultivated soft summer fruits. D. suzukii was first detected outside of its native range in 1983 on Mauna Ka‘ala in Wai‘anae, Hawai‘i, and has since spread throughout North America, South America, and Europe. While D. suzukii is not considered a crop pest in Hawai‘i, little data is available on the distribution of the species on a landscape scale on the archipelago. In this study, we characterize ‘ohelo (Vaccinium reticulatum) host use, distribution, and abundance of D. suzukii across an altitude gradient on the eastern slope of Mauna Loa, Hawai‘i. In total we collected 2,503 D. suzukii across 14 field sites over a four-month period in 2016. Endemic ‘ohelo is a host for D. suzukii as we detected up to 1.88% adult emergence across field sites per 1 mL of berries. Our preliminary population data shows that D. suzukii abundance is greater at higher altitudes and in forested habitats on Mauna Loa. Given the population abundance of D. suzukii and their ability to use at least one of the three endemic Vaccinium in Hawai‘i as a host, further research on host-use interactions between D. suzukii and native/non-native insects is warranted.