Genus Cryptostigma Ferris 1922

Type species: Cryptostigma ingae Ferris, by original designation and monotypy [= Cryptostigma inquilina (Newstead)].

Generic diagnosis of adult female. In life: body oval, elongate oval, or subcircular, convex, rarely cylindrical (only when found inside narrow hollow twigs); usually with a thin glassy wax cover, rarely with rather thicker wax cover, sometimes with very long white waxy threads protruding from stigmatic areas; not producing an ovisac. Slide-mounted specimens: dorsal derm usually becoming heavily sclerotized at maturity; dorsal setae present or absent, when present, each spinose with apex pointed, blunt, knobbed, rounded, or occasionally spatulate; dorsal tubercles and dorsal tubular ducts absent; sclerotic pores, simple pores and preopercular pores present or absent; dorsal microducts present, each with opening single or bilocular, outer and inner ductules either short or long; orbicular pores present or absent; when present, each pore composed of a thin membrane with membranous or mildly to heavily sclerotized margins, sometimes associated with setae, simple pores and microducts; cribriform plates absent; cribriform platelets (very small cribriform plates generally less than 20 μm at widest point, found singly or in groups) present or absent; anal plates together quadrate, rarely pyriform, with rounded angles, each plate with 4–21 setae on dorsal surface, and 0–6 ventral subapical setae; anal ring commonly bearing 10 setae, but with up to 20 setae in C. serratum; eyes absent; marginal setae present or absent, when present each spinose or conical, stout, usually with apex pointed, often numerous; stigmatic clefts deep; spiracular sclerotizations present, each closely associated with a spiracle, each spiracular sclerotization either short or long, often enclosing spiracle; stigmatic setae numbering 0–3 per stigmatic area, present on each stigmatic sclerotization, setae often broken off, each seta bluntly or sharply spinose, or conical, all subequal in length; spiracles large, width of peritreme usually greater than length of legs, spiracular opening generally facing dorsally or towards body margin; antennae reduced, each usually 1–4 segmented, mostly 1 segmented or represented by a flattened segment bearing numerous setae, rarely with up to 8 fused segments in C. melissophilum Kondo; legs greatly reduced, with segments usually indistinct or fused, in many species represented by clusters of setae usually associated with a tiny sclerotic plate or claw; spiracular disc-pores each with 3–9 loculi; mouthparts well developed, labium with 8 labial setae; multilocular disc-pores each about same size or larger than a spiracular disc-pore, with 3–11 loculi (mostly with 5–8 loculi), distribution of multilocular disc-pores variable; ventral setae slender, pointed, usually abundant on posterior abdominal segments; ventral tubular ducts usually absent, but present in C. saundersi Laing and C. chacoense Kondo.

Generic diagnosis of slide-mounted first-instar nymphs. Most first-instar nymphs of Cryptostigma can be diagnosed by the following combination of features (adapted and modified from Kondo 2010): dorsum with 1 or 2 membranous folds just anterior to anal plates, always showing signs of sclerotization; venter with antennae each 5 or 6 segmented; without a seta present near each coxa; ventral submedian setae usually numbering 3 (rarely up to 5) pairs, or with many setae on all abdominal segments and thorax, never arranged in 6 pairs.

Remarks. With the description of the new species, Cryptostigma is now composed of 18 species. The above diagnosis was adapted and modified from character states given by Kondo 2010).