Hypochrosini

The tribe Hypochrosini derives from the Hypochrosidae of Guenée (1857) and has priority over the Anagogini of Forbes (1948). The type species for the Anagogini is Anagoga pulveraria Linnaeus. The tribe was defined by Forbes (1948) within his group of tribes with a pupal cremaster ending in eight hooked setae. The characters he referred to are: a pupa with callosity, without flange- plates; male genitalia with a double furca, the left arm usually longer than the right; gnathus with a vertically elongate, blade-like tip, usually with a single series of spines; male antennae pectinate, various. The genus Hypochrosis Guenée, type genus of the Hypochrosini, shares (not all species, see Hypochrosis Guenée) the furca character that provides the most reliable definition for the tribe.

In South-east Asia the tribe is more diverse than in North America, hence it is possible to survey the validity of these features more widely. The furca is the most reliable feature, though secondarily lost in some taxa. The vinculum is slender, without a saccus, but looping down on each side to a variable extent from a central point of fusion with the valve bases (also fused together). The loops each contain a single corema, rarely a double one (Mesaster Warren) or none (Anagoga Hübner). The uncus is usually dorsolaterally flattened, often apically spatulate; there are digitate, setose socii associated with it as seen in some other ennomine tribes. The aedeagus shaft terminates asymmetrically, usually acutely; vesica ornamentation is very variable. The comb of setae on male sternite 3 is not present.

The female genitalia are typical of the subfamily, with the ductus bursa often sclerotised and fluted. The signum varies but in many cases is a typical centrally stalked disc bearing spines.

The moths are often brightly coloured and strikingly patterned, though without satiny scales as in some other tribes.

The tribe Scardamiini may be related (See Scardamiini).

Forbes (1948) divided his Anagogini into two subtribes on the basis of male antennal characters, presence or absence of coremata in combination with gnathus spines in a row versus diffuse, and presence or absence of pupal grooves. The combinations of genitalic characters do not hold for the Oriental fauna, and genera without pectinate antennae in the male occur. Therefore no attempt has been made to apply these subtribes here.

The Hypochrosini show some indication of host-plant specialisation in genera where several taxa have been reared. The probable sister-genera FascellinaWalker and Corymica Walker feed on Lauraceae. Heterolocha Lederer species are known mainly from Caprifoliaceae. The few records for Achrosis Guenée are from Rubiaceae. Garaeus Moore species are known to feed on several plant families.

The tribe is one of three geometrid groups where lachryphagy (mammalian tear sucking) is extensively recorded, the others being the Macariini (See Macariini) and the Scopula/Zythos group of genera in the Scopulini (Bänziger, 1973, 1983, 1988). Lachryphagous hypochrosine genera noted by Bänziger are Hypochrosis Guenée, Achrosis Guenée and Fascellina. These geometrid groups are also noted to come to carrion bait in Borneo (Holloway, 1989).