Minettia punctiventris (Rondani, 1868)

Ebejer, Martin J., 2019, Taxonomic notes on West Palaearctic species of Lauxania Latreille, Sapromyza Fallén, Calliopum Strand and Minettia Robineau-Desvoidy, with a description of a new species of Minettia (Diptera, Acalyptrata: Lauxaniidae) from Morocco, Zootaxa 4543 (1), pp. 37-51 : 43-45

The Minettia punctiventris group of species

In the West Palaearctic, there are several species of Minettia that are yellow, with or without scutal or abdominal vittae or spots, have long plumosity on the arista and 0+3 dorsocentral setae, the biseriata group of Papp (1981). Within this assemblage of species there is a small subgroup, here called—the punctiventris group—that is easily separated from the rest by the following combination of characters: mid tibia with two dorsal preapical setae, face with a brown spot between the antennal bases and between the antennae and eye margin ( Fig. 35 ), and hind femur at extreme apex with a small dark spot on both sides ( Fig. 36 ). In the male terminalia, the right gonite has two arms as in other species of Minettia , but in this subgroup, the tips of the arms are not so heavily sclerotized nor sharply pointed or hooked, but rather spatulate.

Papp (1981) studied the types of this group of species, namely: M. punctiventris ( Rondani, 1868) , M. tinctiventris ( Rondani, 1868) and M. suillorum ( Robineau-Desvoidy, 1830) and he described M. subtinctiventris . Rondani’s description (1868) of M. tinctiventris suggested diffuse, dark abdominal markings, but Papp who examined Rondani’s specimens specifically mentioned a spot on the sixth tergite. Through the kind collaboration of Dr Luca Bartolozzi of "La Specola", Natural History Museum, University of Florence, I received photographs of the lectotype series of this species ( Figs 31–33 ) and can confirm that Rondani’s description probably refers to postmortem changes in colour of the abdomen and Papp's description is accurate. This was a necessary check since a new species, which belongs to this group and which is described below, has similar male postabdominal features but quite different abdominal colour pattern. Separating the species of this group is difficult, more so in the female sex. In the key to species, Shatalkin (2000) separates M. suillorum and M. tinctiventris from M. muricata on the basis of the latter having brown spots at the apex of the hind femur. However, this character is present in both M. tinctiventris and M. punctiventris , as was indeed emphasized by Rondani and can be seen in the types of M. tinctiventris .

Papp (1981) examined only the terminalia of the male type of M. suillorum and gave very brief notes on the differences between this and his M. subtinctiventris . He did not comment on any similarities or differences between M. suillorum and M. tinctiventris nor did he provide an illustration of the terminalia of M. suillorum . This species was described from a specimen taken in Algeria. The extremely brief description by Robineau-Desvoidy in essence states that the species is yellow and the wings are hyaline. The holotype is in Paris and photographs are available on the museum website (http://coldb.mnhn.fr/catalognumber/mnhn/ed/ed5956). These show the type to be in too poor a state of preservation to deduce useful external taxonomic characters.

Minettia subtinctiventris was described from two males taken in Tunisia and M. tinctiventris was described from two males and a female taken in Italy. The figures are not orientated exactly to the same angle and this makes comparison difficult, particularly as the proposed species differences are rather minor. Too few specimens were examined at the time. There appear to be no external differences between these species. The postabdominal characters are minor and fall within species variability. The females of all four of them are not separable, at least on external characters. I examined several specimens from Portugal and Morocco that fit between these species’ concepts. The photographs of the types of M. tinctiventris enabled me to examine also the female external features and these show the very long bristles on the middle of the 5th abdominal tergite as well as the folding downwards of the tergite lateral to these setae thus giving the tergite an apparent rhomboidal shape ( Fig. 33 ). This is relevant, as it has exactly the same appearance as that of M. muricata which was described from a single female taken in Croatia. The very long marginal setae on the female fifth tergite are variable in their number (5–8) and degree of development (although always strong) within a population. The degree of sclerotization of the gonites in the male terminalia, the length of the phallapodeme as well as the length and number of setulae on the surstyli also vary, occasionally even within the same specimen they vary in length and number between the right and left surstylus. Therefore, I contend that such variablity does not separate these populations into different taxa and I propose the following synonymies:

Minettia suillorum ( Robineau-Desvoidy, 1830)

Terenia suillorum Robineau-Desvoidy, 1830: 641

Sapromyza tinctiventris Rondani, 1868: 44 — syn. nov.

Sapromyza muricata Becker, 1895: 208 — syn. nov.

Minettia subtinctiventris Papp, 1981: 175 — syn. nov.

Figures

FIGURES 34–36. Minettia aenigmatica sp. n. 34) holotype, male habitus, 35) male paratype, face; 36) same, apex of hind femur.

FIGURES 31–33. Minettia tinctiventris (Rondani), 31) lectotype male, habitus, 32) same, abdomen, postero-dorsal, 33) paralectotype, female abdomen, postero-dorsal.