Psectrocladius Kieffer

Description

Introduction

Medium-sized to large larvae, up to 11 mm long. Head capsule usually pale; single labral sclerite rugulose in posterior 2/3.

Antenna

Antenna with 5 segments; segments consecutively smaller. Ring organ low on basal segment. Blade not extending beyond terminal antennal segment. Lauterborn organs small or absent.

Labrum

Labrum with SI distinctive, unique, palmate with 3-10 lobes, either subequal in size or outer lobes smaller, other S setae simple. Pecten epipharyngis of 3 usually subequal spines;. 4-5 pairs of chaetulae laterales present, single. Premandible with 1 apical tooth; brush absent.

Mandible

Mandible with apical tooth slightly shorter than or up to four times longer than combined width of 3 inner teeth. Seta subdentalis with distinct apical hook. Seta interna present in Psectrocladius s.str. and P. (Monopsectrocladius) or absent in P. (Allopsectrocladius) except for P. platypus and in P. (Mesopsectrocladius); when present, then with 5-6 weakly serrate or simple setae.

Mentum

Mentum with 1-2 median teeth; when 1, then either with median or lateral low projections, with triangular median point, trifid, or with pair of nipple-like median projections; 5 pairs of lateral teeth present. Ventromental plate broad, with straight lateral margin, extending beyond outer tooth of flattened mentum; with variable number of distinct setae in beard beneath.

Maxilla

Maxilla with lamellae of galea simple medially, resembling fused spines more ventrally. Pecten galearis with very fine teeth, perhaps occasionally absent. Anterior lacinial chaeta apparently not differentiated.

Body

Body with parapods divided; with simple claws. Procercus large, with 1 to several spurs and/or tubercles on apicoposterior basal margin; 3-7 strong and 0-2 weak apical anal setae present. Supraanal setae normal, not strong. Anal tubules present, shorter or longer than posterior parapods.

Notes

Ecological Notes

Larval Psectrocladius are almost exclusively lentic, living in standing water bodies ranging in size from small pools and cattle troughs to the largest lakes.

The genus is essentially northern hemisphere; records from Australia and the Neotropics appear to be erroneous (e.g. see Parapsectrocladius).

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