Dacus longicornis

Taxonomy

Valid name: Dacus (Callantra) longicornis Wiedemann, 1830
Preferred common name: None
Synonyms:
   Mellesis longicornis (subsequent combination in Bezzi, 1919)
   Callantra longicornis (subsequent combination in Perkins, 1937)
Bactrocera vespoides Doleschall, 1858 (junior synonym)
   Callantra vespoides (subsequent combination in Enderlein, 1920 )
   Dacus vespoides (subsequent combination in Bezzi, 1909)
Callantra smieroides Walker, 1860 (junior synonym)
   Dacus smieroides (subsequent combination in Malloch, 1939 )
   Callantra smicroides (unjustified emendation in Bezzi, 1913)
Callantra unifasciatus Hardy, 1982 (junior synonym)
Callantra variegata Wang, 1990 (junior synonym)
   Dacus variegatus (subsequent combination in Liang et al., 1993)
Mellesis bioculata Bezzi, 1919 (junior synonym)
   Callantra bioculata (subsequent combination in Perkins, 1937)
Mellesis destillatoria Bezzi, 1916 (junior synonym)
   Dacus destillatoria (subsequent combination in Liang et al., 1993)
   Callantra destillatoria (subsequent combination in Perkins, 1937)
Mellesis eumenoides Bezzi, 1916 (junior synonym)
   Dacus eumenoides (subsequent combination in Kapoor, 1993)
   Callantra eumenoides (subsequent combination in Perkins, 1937)

Not to be confused with Bactrocera (Bactrocera) longicornis.

Morphology-based identification

Dacus longicornis can be identified reliably using morphological characters, but there are two distinct forms (Doorenweerd et al. 2020Doorenweerd et al. 2020:
Doorenweerd C, Ekayanti A, Rubinoff D, 2020. The Dacini fruit fly fauna of Sulawesi fits Lydekker’s line but also supports Wallacea as a biogeographic region (Diptera, Tephritidae). ZooKeys 973: 103–122. https://doi.org/10.3897/zookeys.973.55327). Dacus longicornis form icariiformis lacks a medial yellow vitta on the scutum and has an overall red-black appearance, and Dacus longicornis form longicornis has a medial yellow vitta and an overall red-orange appearance. Spot characters are the elongated (wasp-like) abdomen and markings on the abdomen with an anterior dark to posterior light color gradient on each segment.

Molecular identification

COI sequence data can be used to identify D. longicornis (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).

Distribution

Dacus longicornis is widespread across Southeast Asia from Bhutan to the Philippines and south to Indonesia.

Further information

Dacus longicornis is a minor pest that has been reared from the fruits of several Cucurbitaceae, including luffa (Luffa acutangula, L. aegyptiaca) and cucumber (Cucumis sativus).