Isturgia, HUBNER, 1823

Scoble, Malcolm J. & Krüger, Martin, 2002, A review of the genera of Macariini with a revised classification of the tribe (Geometridae: Ennominae), Zoological Journal of the Linnean Society 134 (3), pp. 257-315 : 273-279

publication ID	https://doi.org/ 10.1046/j.1096-3642.2002.00008.x
persistent identifier	https://treatment.plazi.org/id/03F16A20-1E0F-FFB4-FEC0-A1CBFDD0DD63
treatment provided by	Carolina
scientific name	Isturgia
status

Treatment

ISTURGIA HÜBNER View in CoL

(Figs 7–10, 84–110)

Isturgia Hübner, [1823] . Type species: Geometra conspicuata (Denis & Schiffermüller], 1775, a junior subjective synonym of G. limbaria Fabricius, 1775 . Austria.

Bichroma Gumppenberg, 1887 View in CoL . Type species: Noctua famula Esper, 1787 . Europe. [Listed as junior subjective synonym of Isturgia View in CoL by Parsons et al. (1999): 523.]

Enconista Lederer, 1853 View in CoL . Type species: Fidonia perspersaria Duponchel, [1829] View in CoL , a junior subjective synonym of miniosaria Duponchel, 1829 View in CoL ; France: Montpellier. [Listed as junior subjective synonym of Isturgia View in CoL by Parsons et al. (1999): 523.]

Tephrina Guenée, [1854] . Type species: Geometra murinaria [Denis & Schiffermüller], 1775. Austria. Syn. nov .

Description

Head. Antenna bipectinate in male. Chaetosemata oval, not strongly extended.

Wings (Figs 7–10). Isturgia limbaria and its close relative I. roraria (Esper) are distinctive species with sternum A8 of ♂; 88, 89, I. famula , 88, ♂ genitalia, 89, sternum A8 of ♂. both wings yellow, flecked with black and with a black termen in the forewing. I. famula (Esper) (comb. nov.), previously in Bichroma , is also distinctive (Fig. 8). The species previously assigned to Enconista have a grey or buff background (e.g. Fig. 9). In I. murinaria (Fig. 10) and its relatives, which were previously assigned to Tephrina , the wings are mostly greyish or purplish brown to ochreous.

Male genitalia ( Figs 84–86, 88 View Figures 84–89 , 90, 92, 94 View Figures 90–95 , 96, 98, 100 View Figures 96–101 , 102–104, 106 View Figures 102–107 ). Uncus pointed; horns lacking. Gnathos with medial element prominent in type species and grooved; in many other species medial element reduced, in some (particularly in murinaria ( Figs 102, 104, 106 View Figures 102–107 ) and relatives) gnathos band-like, lacking triangular medial element. Valva: excavated; in murinaria and relatives sacculus pointed. Vinculum: saccus extended slightly, in murinaria and relatives extended prominently; ventral plate convex. Juxta: lower corners almost forming pockets.

Pregenital abdomen of male ( Figs 87, 89 View Figures 84–89 , 91, 93, 95 View Figures 90–95 , 97, 99, 101 View Figures 96–101 , 105, 107 View Figures 102–107 ). Sternum A8 weakly emarginated, unsclerotized (e.g. type species and close relatives), or with small sclerotized projections (as in Figs 95 View Figures 90–95 , 97 View Figures 96–101 ).

Female genitalia ( Figs 108–110 View Figures 108–110 ). Too variable to provide a useful diagnosis for the genus; diagnostic characters important for Afrotropical species-groups ( Krüger, 2001).

Diagnosis. Included in Isturgia are species with genitalia similar to those illustrated, and which differ from those of other smaller and more tightly defined genera (see discussion under ‘Tribe Macariini Guenée, [1858] ’).

Distribution. Palaearctic and mainland Oriental (including Tibet); Australia if penthearia Guenée is included in Isturgia . In addition many Afrotropical species dealt with by Krüger (2001) are included in Isturgia as adopted here.

Habits. I. limbaria flies in sunshine and rests with the wings closed over the body ( South, 1961).

Foodplants. Other than for Salvia (Labiatae) , all records are on Leguminosae ( Fabaceae ). (For the limbaria -group, Prout (1915 –16) recorded ‘broom’ ( Cytisus ) for limbaria and Genista and Spartium for roraria and Emmet (1991) cited Cytisus scoparius for limbaria . I. famula (Bichroma) feeds mainly on Cytisus scoparius (as Sarothamnus , see Rödel & Trusch, 1997). Of the species assigned previously to Enconista , the foodplant of I. exustaria (Staudinger) (comb. nov.) is given as Retama raetam and that of I. berytaria (Staudinger) (comb. nov.) as Calicotome villosa by Sauter (1992). There exists several published records for species previously assigned to Tephrina : e.g. I. disputaria (Guenée) comb. nov. on Acacia (see Fletcher, 1963) and Acacia nilotica (see Wiltshire, 1949); I. pulinda deeraria (Walker) comb. nov. on Acacia (see Herbulot in Rougeot, 1977); I. perviaria (Lederer) comb. nov. on Acacia and Prosopis ( Wiltshire 1988) ; I. arenacearia ([Denis & Schiffermüller]) comb. nov. on Coronilla varia and other Papilionaceae ( Dufay, 1971) ; I. murinaria ([Denis & Schiffermüller]) comb. nov. on Medicago sativa , Trifolium , Vicia , Genista and Salvia (see Lhomme 1935) and Glycine max (see Zandigiacomo & Dalla Montà, 1982). Other records particularly of Leguminosae have been made for some of the South African species ( Krüger, 2001).

Comments. The range of variation in the male genitalia of Isturgia , Bichroma , Enconista and Tephrina makes it impossible to distinguish these nominal taxa from each other, and they are treated in this work as synonymic. Furthermore, I. famula (Bichroma) shares similarities in habitat, foodplant and appearance of the larva with I. limbaria (see Rödel & Trusch, 1997).

There is one other species, I. roraria (Fabricius) , which is very similar to the type species of Isturgia . Prout (1915 –16) included carbonaria Clerck (see under Macaria , below) and cretaria Staudinger. We have not examined material of cretaria but from Prout’s description it does not resemble limbaria or roraria .

Also included in Isturgia by us are those species treated under this name by Krüger (2001) and by Parsons et al. (1999). Although we are uncertain that all species united under Isturgia in the sense of the present work form a monophyletic group, the similarity in valva shape, uncus and gnathos suggests that these species are best assigned to this genus, at least provisionally.

Species previously assigned to Enconista Lederer are grey and occur in southern Europe, North Africa and the Middle East, with one species on the Canary Islands and one in southern North America. Diagnoses of four of these species were presented by Hausmann (1990) and further information on the group was given by Sauter (1992).

The type species of Tephrina ( murinaria ) and at least its close relatives form a species-group within Isturgia . They are characterized by a pointed sacculus in the male genitalia and a band-like gnathos that lacks the triangular medial element typical of most species of Isturgia .

Number of species. It is difficult to estimate the number of species in the genus because its boundaries and monophyly are not established. There are approximately 60 species, including those described as new in Krüger (2001), currently assigned.