Zeugodacus scutellaris species complex

Taxonomy

In the identification keys of Drew & Romig 2016, the Z. scutellaris species 'complex' includes 20 species. This not a monophyletic group (San Jose et al. 2018San Jose et al. 2018:
San Jose M, Doorenweerd C, Leblanc L, Barr N, Geib S, Rubinoff D, 2018. Incongruence between molecules and morphology: A seven-gene phylogeny of Dacini fruit flies paves the way for reclassification (Diptera: Tephritidae). Molecular Phylogenetics and Evolution 121: 139–149. https://doi.org/10.1016/j.ympev.2017.12.001 ) but maintained  here for lack of a better alternative.

Note the easy clerical confusion between the similarly named species Zeugodacus scutellatus and Z. scutellaris, which are the two category C pests in this species complex, and Z. scutellarius, which is not part of the complex.

Valid name: Zeugodacus (Zeugodacus) scutellatus (Hendel, 1912)
Preferred common name: striped fruit fly

Valid name: Zeugodacus (Zeugodacus) scutellaris (Bezzi, 1913)
Valid name: Zeugodacus (Zeugodacus) freidbergi (White, 1999)
Valid name: Zeugodacus (Zeugodacus) tappanus (Shiraki, 1933)
Valid name: Zeugodacus (Zeugodacus) biguttatus (Bezzi, 1916)
Valid name: Zeugodacus (Zeugodacus) kaghanae (Mahmood, 2005)
Valid name: Zeugodacus (Zeugodacus) assamensis (White, 1999)
Valid name: Zeugodacus (Zeugodacus) diaphorus (Hendel, 1915)
Valid name: Zeugodacus (Zeugodacus) hekouanus (Yu, He & Yang, 2011)
Valid name: Zeugodacus (Zeugodacus) yoshimotoi (White & Hancock, 1997)
Valid name: Zeugodacus (Zeugodacus) baoshanensis (Zhang, Ji, Yang & Chen, 2011)
Valid name: Zeugodacus (Zeugodacus) hoabinhiae (Drew & Romig, 2013)
Valid name: Zeugodacus (Zeugodacus) dorsirufus (Drew & Romig, 2013)
Valid name: Zeugodacus (Zeugodacus) proprescutellatus (Zhang, Chen & Gao, 2011)
Valid name: Zeugodacus (Zeugodacus) liquidus (Drew & Romig, 2013)
Valid name: Zeugodacus (Zeugodacus) namlingiae (Drew & Romig, 2013)
Valid name: Zeugodacus (Zeugodacus) atrifacies Perkins, 1938
Valid name: Zeugodacus (Zeugodacus) sonlaiae (Drew & Romig, 2013)
Valid name: Zeugodacus (Zeugodacus) menglanus (Yu, Liu & Yang, 2011)
Valid name: Zeugodacus (Zeugodacus) nakhonnayokiae (Drew & Romig, 2013)

Morphology-based identification

Species in the Z. scutallaris complex are grouped together based on having a round spot distal on the wing that makes the costal band either 'interrupted' or, more commonly, with a 'distal expansion that does not cross vein M'. In most cases, a confident identification of both Z. scutellaris and Z. scutellatus is possible based on morphology alone.

Molecular identification

Of the species that are morphologically similar, the Doorenweerd et al. 2024Doorenweerd et al. 2024:
Doorenweerd C, San Jose M, Leblanc L, Barr N, Geib SM, Chung AYC, Dupuis JR, Ekayanti A, Fiegalan E, Hemachandra KS, Hossain MA, Huang C, Hsu Y, Morris KY, Maryani A. Mustapeng A, Niogret J, Pham TH, Thi Nguyen N, Sirisena UGAI, Todd T, Rubinoff D, 2024. Towards a better future for DNA barcoding: Evaluating monophyly‐ and distance‐based species identification using COI gene fragments of Dacini fruit flies. Molecular Ecology Resources 24: e13987. https://doi.org/10.1111/1755-0998.13987 COI dataset has reference sequences for Z. scutellaris, Z. tappanus, Z. diaphorus, Z. yoshimotoi, Z. scutellatus, Z. proprescutellatus, Z. liquidus, Z. atrifacies, and Z. nakhonnayokiae. Based on the available reference data, Z. scutellatus and Z. scutellaris can be identified using COI sequence data.

Distribution

All species in the Z. scutellaris complex are found in Southeast Asia. Zeugodacus scutellaris is found from India to Vietnam, and south to peninsular Malaysia. Zeugodacus scutellatus is found from Bhutan to Vietnam, and reaches north to Taiwan and the Ryukyu islands of Japan. Native ranges are unclear.

Further information

Zeugodacus scutellaris and Z. scutellatus are reported as a "category C" pests of Cucurbitaceae flowers in Vargas et al. 2015Vargas et al. 2015:
Vargas RI, Pinero JC, Leblanc L, 2015. An overview of pest species of Bactrocera fruit flies (Diptera: Tephritidae) and the integration of biopesticides with other biological approaches for their management with a focus on the pacific region. Insects 6: 297–318. https://doi.org/10.3390/insects6020297. A category C pest is there defined as "relatively minor oligophagous or specialist fruit or cucurbit pests".