Abiskomyia Edwards

Description

Introduction

Small larvae, 4 mm long.

Dorsal Head

Dorsal surface of head with frontoclypeal apotome. Head capsule setae simple.

Antenna

Antenna borne on pedestal with pointed apico-mesal projection. 4 segmented; segment 2 weakly to strongly subdivided, when strong appearing as 2 segments; segments 3 and 4 short. Ring organ situated at basal 1/4 of basal segment, antennal seta present. Blade arising from apex of 2nd segment, extending to 4th segment. Lauterborn organs alternate on apices of subdivisions of 2nd segment, style arising from apex of distal division of 2nd segment.

Labrum

Labrum with single labral sclerite, SI plumose, remaining S setae simple. Labral lamellae consisting of a single, smooth subtriangular scale abutting sockets of SI. Chaetae plumose; spinulae simple, elongate. Pecten epipharyngis of 3 narrow pointed scales. Chaetulae laterales serrate, 4-5 pairs of apparently simple, elongate chaetulae dorsal to serrate chaetulae. Chaetulae basales present. Ungula U-shaped. Premandible with 2 apical and 2 shorter inner teeth; brush well developed, some branches plumose.

Mandible

Mandible with apical tooth shorter than combined width of 3 inner teeth. Seta subdentalis straight, apically pointed. Seta interna of 4 plumose branches.

Mentum

Mentum with 2 median and 6 pairs of lateral teeth; median and 1st laterals subequal in size, weakly separated from each other and forming a truncate apex to the mentum, 2nd laterals small and appressed to 1st laterals. Ventromental plate broad, subtriangular, with short spine-like projections on ventral surface. Setae submenti plumose, arising close to mentum.

Body

Anterior parapods separate, each bearing an apical and a subapical group of fine claws. Posterior parapods separate, each bearing claws arranged in a circle; some claws pectinate. Procercus about as high as wide, bearing 7 apical anal setae; 2 of apical anal setae longer and thicker than remaining setae. Anal end truncate directed posteriorly. Body with plumose and simple setae.

Notes

Ecological Notes

Larval Abiskomyia live on the benthos of oligotrophic lakes and smaller bodies of standing water. Larvae construct cylindrical tubes of substrate resembling those of Heterotanytarsus and some Tanytarsini (Stempellina, Zavrelliella, etc).

Two species are described from the arctic/subarctic of the Holarctic, with a possible 3rd undescribed species.

Palaeo-head capsules of Abiskomyia can be abundant in Holocene lake sediments throughout the Arctic.

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