Bactrocera (Bactrocera) invadens Drew, Tsuruta & White

Drew, R. A. I. & Hancock, D. L., 2022, Biogeography, Speciation and Taxonomy within the genus Bactrocera Macquart with application to the Bactrocera dorsalis (Hendel) complex of fruit flies (Diptera Tephritidae: Dacinae), Zootaxa 5190 (3), pp. 333-360 : 348-349

Bactrocera (Bactrocera) invadens Drew, Tsuruta & White

Musca ferruginea Fabricius, 1794: 342 . Preoccupied by Musca ferruginea Scopoli, 1763 .

Bactrocera (Bactrocera) invadens Drew, Tsuruta & White, 2005: 149 ; Drew et al., 2007: 4; Drew & Romig, 2013: 99; 2016: 7. Holotype in NMKE.

Common Name: Invasive Fruit Fly.

Definition: Face fulvous with a pair of medium-sized to large oval black spots; postpronotal lobes and notopleura yellow; scutum with basic colour dark orange-brown to red-brown with a lanceolate fuscous to black pattern that varies in size (occasionally entirely black or entirely pale); narrow to medium-width lateral postsutural yellow vittae ending at or just behind ia. seta; medial postsutural yellow vitta absent; anepisternal stripe reaching midway between anterior margin of notopleuron and anterior npl. seta dorsally; scutellum yellow; legs with femora entirely fulvous, tibiae mostly fuscous; wing with cells bc and c colourless, microtrichia in outer corner of cell c only, a narrow fuscous costal band confluent with R 2+3 and remaining narrow around apex of wing, a narrow pale fuscous anal streak, supernumerary lobe of medium development (see figure 46 in Hancock et al., 2021 for a photograph); abdominal terga III-V dark orange-brown with a dark fuscous to black ‘T’ pattern (the transverse band across anterior margin of tergum III generally broad and can cover the entire tergum), narrow lateral dark fuscous margins on terga IV and V, ceromata on tergum V dark orange-brown, abdominal sterna dark fuscous to black.

Distribution: Sri Lanka, India, Pakistan, Bhutan, Nepal and Bangladesh; introduced and widespread in Africa, Mascarenes and Grand Comore Island (see Drew & Romig, 2013; Leblanc et al., 2019; Hancock et al., 2021). Recently detected in Italy ( Nugnes et al., 2018).

Hosts: Recorded from a wide range of edible/commercial host fruits in Africa (see Drew & Romig, 2013; Hassani et al., 2022, as dorsalis ; Rasolofoarivao et al., 2022, as dorsalis ).

Attractant: Methyl eugenol.

Comments: This species, which we now call B. invadens , was originally described in 1794 by Fabricius as Musca ferruginea , named after its red-brown appearance. We have studied the type of M. ferrugenea held in the Zoological Museum, Department of Entomology, Universitetsparken, Copenhagen, and we attest that this clearly is morphologically what we are now calling B. invadens . Due to homonomy (and thus unavailability), we could not use the name ‘ ferruginea’ and thus were obliged to describe the species under a new name. The closest Bactrocera species in appearance is the Australian B. cacuminata (Hering) , which has a similar scutum pattern of basic red-brown coloration with a dark overlaying lanceolate marking. In B. invadens , over 60% of specimens possess a pale scutum whereas in B. dorsalis fewer than 20% do so. Further, the pale scutum pattern in B. dorsalis is entirely different from that in B. invadens , never possessing the lanceolate pattern of B. invadens . In analyses of the mitochondrial genes COI and ND5, B. invadens is considerably distant from B. dorsalis , B. carambolae , B. ochroma , B. occipitalis and B. papayae ( Drew & Romig, 2013) . Further, in our new studies on the male aedeagus, B. invadens and B. dorsalis are distinct in the structure of the phallus and preglans appendix. In B. invadens the glans is elongate and tubular and the mean length of the phallus is 3.73 times longer than the preglans appendix, whereas in B. dorsalis the glans is subovate and the preglans appendix is 2.55 times longer. See Drew & Romig (2013, 2016) for a detailed discussion of this species. Maneesh et al. (2022) illustrated the glans and preglans appendix of a specimen from northern India and Leblanc et al. (2013) illustrated scutal variation in specimens from Burkina Faso and (as B. dorsalis ) from Bangladesh; they also (Leblanc et al., 2019) noted that the scutal pattern of specimens from Nepal showed variation typical of those from Bangladesh.