Borchsenius, 1949
Appearance in life
Scale cover of adult female mussel-shaped, 1.6 mm long, slightly convex, white, with terminal exuviae. Scale cover of immature male different from that of female; small and elongated, white, felted, tricarinate, with terminal exuviae.
Morphology
Adult female not pupillarial; body oval CHLASS.jpg , widest at metathorax, then tapering to apex of pygidium. Derm membranous except for pygidium; mesothorax, metathorax and free abdominal segments only slightly produced laterally, without marginal sclerotized spurs. Pygidium shallow and rounded, with or without a median notch. Median lobes zygotic, with a strong basal yoke and distinct marginal setae between the bases, either adpressed near their bases (leaf form) or separated by a small gap (twig form), the rest of the lobes divergent. Second lobes bilobed, smaller than median lobes, sometimes reduced or obsolete. Third lobes bilobed, reduced to marginal prominences or serrations, or absent. Ventral paraphyses absent. Gland spines small, present in marginal pairs on the pygidial segments but absent from between the median lobes; short gland spines also present on either side of free abdominal segments, becoming ventral conical duct tubercles towards the anterior, also on thorax. Anus circular to oval, situated between centre and anterior 1/3 of pygidium; vulva situated slightly anterior to centre of pygidium. Marginal macroducts only slightly larger than, or same size as dorsal ducts, each sclerotized around the orifice, with the long axis of the orifice often intermediate between parallel and perpendicular to the margin; arranged in groups along the margin, sometimes associated with pore prominences or marginal serrations; number difficult to determine, but 3 or more present on segments VI-VII; absent from between median lobes. CHLASP.jpg Some dorsal macroducts on pygidium as large as marginal ducts, with sclerotized rims. Dorsal macroducts present in segmental series of submarginal and submedian ducts, as far forward as mesothorax to submedian part of segment VI or VII; orifices of most dorsal macroducts circular. Ventral conical duct tubercles present submarginally anterior to abdominal segment IV. Perivulvar pores present in 5 groups. Stigmatic disc pores few, present by anterior spiracle, present or absent from by posterior spiracle. Antennae each with 1 or 2 setae.