Matrona, Selys, 1853

Orr, Albert G. W., 2024, A review of present knowledge of larvae of the Calopterygoidea (Zygoptera) of the Oriental realm, including keys to families and known genera, Zootaxa 5497 (2), pp. 209-243 : 225

Matrona

The genus Matrona ranges from islands of southern Japan to China, Indochina, Thailand, Myanmar and north-east India and includes nine species. It has recently undergone substantial revision (Yu et al. 2015) hence although there are several descriptions of the larvae of supposedly Matrona basilaris , based on their range some are obviously of other species, and some may be of uncertain identity. Fraser (1919b) described M. nigripectus Selys larva (as basilaris ) from the Shillong area in Meghalaya, India at about 1400-1500 m, providing a habitus drawing of fair quality and a rather surreal depiction of structural details which nevertheless can be interpreted accurately enough to recognise similarities with other species. Matsuki & Lien (1978) and Ishida (1996) provided detailed descriptions and illustrations including the habitus for M. cyanoptera Hämäläinen & Yeh and M. japonica Förster respectively. Needham (1930), illustrates the basic habitus sketch of ‘ M. basilaris ’ but as it is evidently based on a specimen from mainland China (Hangchow, Zhejiang), its identity must be treated with caution, especially as it depicts exceptionally long legs. Most recently Wang et al. (2017) described and illustrated photographically M. basilaris larvae from Anhui, China. This specimen is a confirmed DNA match with adult M. basilaris hence their description can be considered definitive ( Figs 30 , 48 , 55 ). All species are evidently very similar and direct comparisons of specimens are needed to determine any interspecific differences, preferably paired with confirmatory molecular determination. The revision by Yu et al. (2015) also erected a second subgenus, Matrona ( Divortia but so far no confirmed larvae belonging to this taxon have been documented; but workers should be alert to the possibility that they may display clear differences from subgenus Matrona (Matrona) . The habits and ecology of the species are variously described: for M. cyanoptera , “Distributed in the plains and low hills throughout Taiwan; the larva living in [the] middle section of streams resting on tree roots branches and stems in unshaded slow streams”, ( Matsuki & Lien 1978); for M. basilaris , “...found both in small montane streams with sandy substrates and open rivers with stony substrates). Some [larva] even occurred in very small puddles covered with dense vegetation formed by discontinuous streams. They were usually concealed among stones and gravel, or in water plants, depending on their body colour. The habitat usually had many adults of Mnais tenuis Oguma ”, ( Wang et al. 2017); and for M. nigripectus , “Generally concealed amongst debris, dead twigs etc or lying under cover of rocks. Movements sluggish, ...resembles Ranatra ...” ( Fraser 1919b).

Figures

FIGURES 27–34. 27. Prementum of Calopterygidae showing measurements used in family key (based on Calopteryx japonica, redrawn from Miyakawa 1983). 28. Neurobasis chinensis, prementum and left labial palp (redrawn from Lieftinck 1965). 29. Matronoides cyaneipennis, prementum and labial palps (ventral view). 30. Matrona basilaris, prementum (dorsal view, drawn from Wang et al. 2017). 31. Atrocalopteryx atrata, prementum (dorsal view, redrawn from Miyakawa 1983). 32. Mnais tenuis, prementum (dorsal view, redrawn from Matsuki & Lien 1977). 33. Echo uniformis, prementum and left labial palp dorsal view (redrawn from Lieftinck 1965). 34. Psolodesmus mandarinus, prementum (dorsal view, redrawn from Matsuki & Lien 1978).

FIGURES 42–51. 42. Archineura incarnata: caudal gills; left lateral above, median below (drawn from Yang et al. 2022). 43. Echo modesta: caudal gills; left lateral above, median below, with baso-dorsal shield arrowed (original illustration). 44. Psolodesmus mandarinus, dorsal view of caudal gills, with baso-dorsal shield of median gill arrowed (redrawn from Matsuki & Lien 1978). 45. Mnais andersoni, left lateral caudal gill with upper margin of median gill visible; baso-dorsal shield of median gill arrowed (original illustration). 46. Mnais gregoryi: caudal gills; left lateral above, median below, with baso-dorsal shield arrowed (drawn from Yang et al. 2021). 47. Caliphaea angka: caudal gills; left lateral above, median below (drawn from Yang et al. 2021). 48. Matrona basilaris: caudal gills; left lateral above, median below (drawn from Wang et al. 2017). 49. Vestalaria venusta: caudal gills; left lateral above, median below (drawn from Wang et al. 2017). 50. Vestalis amoena group: caudal gills; left lateral above, median below (redrawn from Lieftinck 1965). 51. Vestalis melania: caudal gills; left lateral above, median below (redrawn from Guadalquiver et al. 2022).

FIGURES 52–56. 52. Caliphaea angka, habitus (based on Yang et al. 2021). 53. Vestalis gracilis, habitus (redrawn from Rattanachan et al. 2022). 54. Neurobasis chinensis, habitus (original drawing). 55. Matrona basilaris, habitus (drawn from Wang et al. 2017). 56. Echo uniformis, habitus (redrawn from Lieftinck 1965).