Melithaea delicata (Hickson, 1940)

Acabaria delicata Hickson, 1940: 16, fig. 6; pl. 1, fig. 3 (Ghardaqa, Red Sea).

Acabaria gracillima Ofwegen 1987: 41, fig. 26 (specimen of Stiasny 1940: 147 (Red Sea)).

Not Acabaria aff. delicata Ofwegen 1987: 38–42, fig. 24–25.

Not Acabaria delicata Grasshoff 2000: 17–19, figs. 25–27.

Opinion: There is no evidence that this species occurs in the region.

Justification:

Literature analysis: This species was originally named Acabaria delicata. In his original description, Hickson stated that the sclerites were mostly very narrow, with simple well-spaced tubercles and unlike those of any other species of the genus and he figured four, very simplistic, sclerite drawings, but Ofwegen (1987) figured the sclerites from a specimen identified by Stiasny as Acabaria gracillima Ridley which he stated were identical to those on one of Hickson’s microscope slides of the type of M. delicata. The sclerites figured by Kumar et al. (2019) include many large, robust, heavily warted spindles—some unilaterally developed; and they bear very little resemblance to those figured by Ofwegen. It seems likely the authors based their identification on Grasshoff’s (2000) description of the species as the list of synonyms is the same and the figured sclerites are similar, but they do not cite Grasshoff’s paper.

The paper of Kumar et al. (2019) appears not to have been peer reviewed as it contains many errors, both typographic and contextual. For example: 1) the list of valid synonymic references for A. delicata is the same as that given by Grasshoff, but it includes three that Grasshoff specifically stated were not conspecific; 2) they include as a synonym A. biserialis Grasshoff 1976, but that is also given as a synonym in their description of Melthaea biserialis; 3) part of the text states, “The coenenchyme has spindle simple irregular tuberculation sclerites and club shape sclerites presented in the calyx … The average surface of calyx is 0.10 mm to 1.04 mm clubs and spindles”. Melthaea delicata is probably endemic to the Red Sea.