The Dacini fruit fly fauna of Sulawesi fits Lydekker’s line but also supports Wallacea as a biogeographic region (Diptera, Tephritidae)

Abstract

Although there is scientific consensus on most of the major biogeographic regions in the world, the demarcation of the area connecting Southeast Asia with Australia and Oceania remains debated. Two candidate boundaries potentially explain faunistic diversity patterns in the regions: Lydekker’s and Wallace’s lines. The islands in between both ‘lines’ are jointly termed Wallacea, with Sulawesi as the largest landmass. We surveyed Dacini fruit flies (Tephritidae: Dacinae) in Sulawesi between 2016 and 2019 using traps baited with male lures, resulting in 4,517 collected flies. We identified all specimens to species level, which adds 15 new species records to the island, bringing the total number of Dacini species in Sulawesi to 83. The biogeographic affinity of species in the updated checklist reveals a strong connection with former ‘Sunda’ (41% of species); validating Lydekker’s line, but also a high level of endemism (47% of species), confirming the uniqueness of Wallacea as a biogeographic region. We further describe a new species, Bactrocera (Bactrocera) niogreta Doorenweerd, sp. nov. and discuss the taxonomy of several interesting species.

Review of species, host plants, and distribution of fruit flies (Diptera: Tephritidae) in Indonesia

“…The distribution of fruit flies in Western and Eastern Indonesia is influenced by the zoogeographic boundaries. Zoogeographic boundaries were initially created to show the striking faunal differences between the area and neighboring areas, known as the Wallace line and Lydekker line, between these lines is the Wallacea area [5][6][7]. According to zoogeography experts, the Wallacea region is referred to as a transition zone.…”

Diversity and species composition of fruit flies (Diptera: Tephritidae) in Lombok Island, Indonesia

“…As a tropical Island in the Wallacea region, Lombok has a wide variety of endemic flora and fauna with several types of habitats in tropical rainforests and orchards. According to Doorenweerd et al (2020), in any case, the geographic history of the islands has undoubtedly played a significant role in the evolution of the fauna.…”

“…However, these also have the potential to reduce the quality and quantity of fruit production. Doorenweerd et al (2020) suggested that the Dacini fruit flies (Tephritidae: Dacinae) are a tribe of 938 described exclusively Old World species.…”