Bengalia favillacea (Walker, 1859), 2018

Rognes, Knut, 2018, Revision of the Bengalia torosa Wiedemann, 1819 species-group (Diptera: Calliphoridae), with notes on the systematic position of B. robertsi Kurahashi, 1987 and B. subnitida James, 1964, Zootaxa 4391 (1), pp. 1-71 : 63-64

Bengalia favillacea (Walker, 1859) , stat. rev.

( Figs 251–256 )

Musca favillacea Walker, 1859: 135 . Described from an unstated number of females, but at least two [as “Foem.” including a “Var. β” (text in Latin) / “ Female ” including a “Var.β” (text in English )], from “ Makessar ” [ Indonesia, Sulawesi, Makassar , at 5°7′49.4″S 119°24′27.99″E]; only one synType now in NHMUK . LecToType ♀ (NHMUK; see below for deTails), here designated.

Anisomyia favillacea: Senior-White (1924 : 104; 1926: 138); Senior-White et al. (1940: 91) [as synonym under their “ Bengalia lateralis ” (= Bengalia jejuna )].

Musca favillacea: Townsend (1931b: 371) . Townsend (1) examined the “Female Ht in London, from Macassar [Sulawesi]” and (2) claimed that it belonged to the same taxon as “ Bengalia lateralis, Macq , female Ht in Paris, from Pondicherry ” [= Musca torosa Wiedemann, 1819 ]. I do not consider the first statement as a valid indirect lectotype designation for Musca favillacea Walker in the sense of Article 74.5 of the Code (ICZN 1999) (see also Rognes et al. 2015). It is not clear whether Townsend was aware of the fact that there once existed at least two syntypes. Further, when using the term holotype [as “Ht”], Townsend did not explicitly indicate that he was selecting from the type series a particular specimen to serve as name-bearing type. The second statement, i.e., that the specimen belongs to the same taxon as Bengalia lateralis Macquart , cannot be accepted either (see discussion below). I accept the phrase “ Bengalia lateralis, Macq , female Ht in Paris, from Pondicherry ” as an indirect lectotype designation for Bengalia lateralis Macquart (cf. Rognes et al. 2015) [see above under Bengalia torosa (Wiedemann) ].

Musca favillacea: James (1977 : 529; catalogue entry under Bengalia jejuna , erroneously citing the publication date as “1860” and the type material as “♂♀”).

Musca favillacea: Thompson & Pont (1994: 74) . These authors assigned the name as a synonym of Musca ieiuna Fabricius , even though they referred to Townsend (1931b: 371), who misidentified the lectotype of Musca favillacea as Bengalia lateralis Macquart [= Musca torosa Wiedemann ]. They cited the specimen in NHMUK as “HT ♀ ”, following Townsend (1931b).

Discussion. Even though Musca favillacea was described from at least two females, there is now only a single specimen in NHMUK. It is staged on a narrow strip of cardboard and labelled (1) LECTO / TYPE [circular label with a purple frame]; (2) favillacea [handwritten by Walker]; (3) Macassar, / Celebes. / A.R.Wallace. [handwritten]; (4) SYNTYPE ♀ / Musca / ( Anisomyia ) / favillacea / Walker, 1859, J. Proc. / Linn. Soc., 4: 135 [handwritten by Pont on white square label with a red frame]; (5) LECTOTYPE ♀ / Musca / favillacea / Walker / Designated by / Dear and Pont. [handwritten by Pont on white square label with red frame except first word and last two lines, which are printed] ( Fig. 254 ).

There is no date indicating when the syntype and lectotype labels were affixed to the specimen, but an unpublished manuscript in my possession since 1982, authored by J. P. Dear and A. C. Pont and entitled “ A list of types and other material of Calliphoridae (Diptera) in the British Museum (Natural History), London”, gives a clue. It is dated December 1977 and in it the name favillacea Walker , placed as a synonym under B. jejuna Fabricius , is annotated with a “LT ♀ ”. According to the list “[m]ost of the lectotypes are based on our as yet unpublished designations”.

Since the lectotype “designation” by Dear and Pont was never published, I hereby designate the single female in NHMUK as lectotype of Musca favillacea Walker in accordance with the labels on the specimen.

The lectotype does not belong to the taxon Bengalia torosa (Wiedemann) as surmised by Townsend. The vibrissa is not high above the mouth edge ( Fig. 251 ) and there is no concavity present in the hind margin of the eye in profile ( Fig. 252 ). The anepimeron agrees with B. torosa in having only pale setulae on the left side ( Fig. 255 ), whereas there is one black setula among the pale ones in the upper part on the right side ( Fig. 256 ). The abdomen is very dark, with broad dark bands on T3 and T4, and T5 black ( Fig. 253 ). These features suggest that the Musca favillacea lectotype possibly belongs to B. kanoi . This species is known to occasionally have very few black setulae on the anepimeron, e.g., in the B. kanoi specimen from Bantimurung, Sulawesi (ZMHB), not very far from Makassar. Such an assignment is also compatible with the geographical distribution of B. kanoi . Bengalia recurva Malloch also has all pale setulae on the anepimeron and has been collected in Sulawesi (ZMHB), but it has much narrower dark bands on the abdomen and at most only the posterior half of T5 dark.

Should Musca favillacea Walker be accepted as being synonymous with B. kanoi , this taxon would have to be renamed Bengalia favillacea based on seniority, with Bengalia kanoi as a junior synonym. Since females of the Bengalia torosa species-group are not very well known, I choose not to make this name change.

The current position of Musca favillacea as a junior synonym of Bengalia jejuna ( James 1977) is, however, untenable in view of the fact that Bengalia jejuna is not known from outside the Indian subcontinent (India and Sri Lanka). Since the lectotype is not reliably identifiable at present, I remove the name from synonymy under B. jejuna but keep it as an unplaced species in the Bengalia torosa species-group.

Figures

FIGURES 251–256. Bengalia favillacea (Walker) (lectotype of Musca favillacea Walker, NHMUK). 251. Head, frontal view. 252. Head and most of thorax, left lateral view. 253. Abdomen, dorsal view. 254. Labels. 255. Left anepimeron. 256. Right anepimeron.