Micropsectra Kieffer Micropsectra contracta, Reiss, 1965Micropsectra insignilobus, Kieffer, 1924Micropsectra junci (Meigen, 1818)Micropsectra radialis, Goetghebuer, 1939Micropsectra

Chamutiová, Tímea, Hamerlík, Ladislav & Bitušík, Peter, 2020, Subfossil chironomids (Diptera, Chironomidae) of lakes in the Tatra Mountains an illustrated guide, Zootaxa 4819 (2), pp. 216-264 : 255-256

Micropsectra Kieffer ( Figs 93–98 )

Head capsule yellow to brown. Occipital margin usually with well-developed occipital plate. Antenna placed on elongate pedestal, often with apical tooth or spur. Lauterborn organs on long pedicels that extend beyond flagellum. Premandible bifid. Mandible with apical tooth, dorsal tooth and 3 inner teeth, all teeth brown. Mentum with the median tooth rounded, laterally notched to crenate, usually slightly paler than 5 lateral teeth. Ventromental plates close together medially, a little wider than mentum, with fine striation.

Remarks: Micropsectra head capsules closely resemble Tanytarsus . The best character for separating is the form of premandible (unfortunately often missing from subfossils), which is bifid in Micropsectra , while consisting 3–5 teeth in Tanytarsus . A projection on the antennal pedestal is characteristic for Micropsectra . However, some Tanytarsus species may also have a spur. On the other hand, spur is not always visible or is missing in some Micropsectra (very rarely though). The shape of spur can be also indicative, since it is sharp in Micropsectra , but always of different shape in Tanytarsus (e.g., long, broad and rounded apically) ( Brooks et al. 2007). Micropsectra can be confused with Paratanytarsus as well, but Paratanytarsus has uniformly dark mentum, while in Micropsectra there is a pale area in the middle part of mentum.

Species of the genus Micropsectra are common inhabitants of the Tatra Mts. lakes. Up to now, 8 species were recorded: Micropsectra apposita (Walker, 1856) , M. atrofasciata (Kieffer, 1911) , M. junci (Meigen, 1818) , M. lindrothi Goetghebuer, 1931 , M. notescens (Walker, 1856) , M. radialis Goetghebuer, 1939 , M. roseiventris (Kieffer, 1909) and M. sofiae Stur & Ekrem, 2006 ( Bitušík et al. 2006a; Giłka 2007; Novikmec et al. 2015).

Five morphotypes were identified in the subfossil material following Brooks et al. (2007).

Micropsectra contracta - type ( Fig. 93 )

Head capsule pale brown. Arch of occipital margin narrower. Spurs at antennae pedestals distinctive and noticeably point outwards.

Micropsectra insignilobus - type ( Fig. 94 )

Head capsule pale brown. Long antennae pedestals with short, pointed spurs. Occipital plate well-developed, arch of occipital margin relatively broad.

Micropsectra junci - type ( Figs 95, 96 )

Head capsule yellow. Similar to M. insignilobus - type, but first pair of lateral teeth of mentum clearly shorter than the second laterals.

Micropsectra radialis - type ( Fig. 97 )

Head capsule brown. Short rounded spurs present at relatively short (about as long as broad) antennae pedestal. Occipital plate strongly reduced. This morphotype was found most frequently with high abundance both in the lakes situated at higher altitude and in deep sub-alpine lakes.

Micropsectra type A ( Fig. 98 )

Head capsule yellow. Similar taxon to M. insignilobus - type, but occipital plate greatly enlarged and convex. The second most abundant morphotype in the surveyed lakes.

Micropsectra contracta - type ( Fig. 93 )

Head capsule pale brown. Arch of occipital margin narrower. Spurs at antennae pedestals distinctive and noticeably point outwards.

Micropsectra insignilobus - type ( Fig. 94 )

Head capsule pale brown. Long antennae pedestals with short, pointed spurs. Occipital plate well-developed, arch of occipital margin relatively broad.

Micropsectra junci - type ( Figs 95, 96 )

Head capsule yellow. Similar to M. insignilobus - type, but first pair of lateral teeth of mentum clearly shorter than the second laterals.

Micropsectra radialis - type ( Fig. 97 )

Head capsule brown. Short rounded spurs present at relatively short (about as long as broad) antennae pedestal. Occipital plate strongly reduced. This morphotype was found most frequently with high abundance both in the lakes situated at higher altitude and in deep sub-alpine lakes.

Micropsectra type A ( Fig. 98 )

Head capsule yellow. Similar taxon to M. insignilobus - type, but occipital plate greatly enlarged and convex. The second most abundant morphotype in the surveyed lakes.

Figures

FIGURES 93–98. Micropsectra contracta-type: 93—head capsule (arrow indicates spur). Micropsectra insignilobus-type: 94—head capsule. Micropsectra junci-type: 95—head capsule. M. junci-type: 96—mentum (arrow indicates shorter first pair of laterals). Micropsectra radialis-type: 97—head capsule. Micropsectra type A: 98—head capsule (arrow indicates greatly enlarged and convex occipital plate).