Agrotera Schrank, 1802

Chen, Kai, Horak, Marianne, Du, Xicui & Zhang, Dandan, 2017, Revision of the Australian species of Agrotera Schrank (Lepidoptera: Pyraloidea: Crambidae: Spilomelinae), Zootaxa 4362 (2), pp. 213-224 : 214-215

Agrotera Schrank, 1802

Agrotera Schrank, 1802: 163 . Type species: Phalaena nemoralis Scopoli, 1763 , by monotypy.

Diagnosis. External diagnostic characters of Agrotera comprise a modified labial palpus with the third segment triangularly scaled with a very narrow base, a relatively broad triangular forewing with a usually sinuate termen, the purplish grey wing ground colour, a pale yellow forewing base sprinkled with orange scales, often a similar yellowish patch on the hindwing base, and a yellowish dorsal base of the abdomen. The male genitalia are characterized by a small, weakly sclerotized uncus with few simple, hair-like setae, a deeply divided or simple, distally pointed valva with a large, hook-like sclerotized fibula-like process from below the base of the costa, a large, shield-shaped, dorsally bifid juxta, and a well-developed saccus varying from short and triangular to long and rod- or band-shaped.

Description. Head. Frons rounded, with short scales, vertex with moderately raised scales projecting between antennae. Labial palpus upcurved, sickle-shaped, ventral margin with strongly projecting scales, often as three distinct, triangular tufts, with the third segment triangularly scaled ( Figs. 2, 3 ). Maxillary palpus small. Proboscis well-developed. Antenna in male with cilia as long as or slightly longer than diameter of antenna. Thorax. With appressed scales, pale yellow sprinkled with orange scales. Legs usually not modified. Forewing. Subtriangular, costa straight to 3/4, then curved to apex, termen usually sinuate. Retinaculum a tuft of curved bristles from within discal cell, no frenulum hook in male. Ground colour purplish grey, base always pale yellow sprinkled with orange scales, distally edged by antemedial line, often a variably developed purplish grey spot beyond base on costa. Venation ( Fig. 6 ) with R1 free, R2 free but adjacent to stem of R3+R 4 in basal 2/3, R3 and R4 stalked to just beyond 2/ 3, R4 to just before apex, R5 parallel to stalked R3+R4 at base, then curved and diverging; M1 moderately close to R5 at base, M2 widely separate from M1, closing vein concavely curved; M2, M3 and CuA1 equidistant and parallel from posterior angle of cell, then diverging; CuA2 distant from CuA1; only trace of CuP near wing margin; 1A faintly sinuate to tornus, 2A forming complete loop and distally recurved before joining 1A. Hindwing. Nearly fanshaped or triangular. Frenulum single in male, with 2 acanthae in female. Ground colour purplish grey, basal 1/3 usually pale, sometimes pale yellow patch sprinkled with orange scales. Venation ( Fig. 6 ) with Sc+R1 and Rs anastomosing for 1/3 beyond end of discal cell, Rs and M1 short-stalked, closing vein concave, angled; M2 and M3 close and parallel at base, M3 and CuA1 adjacent to each other from posterior angle of cell; CuA2 from below 3/4 of cell; CuP complete but weaker towards base; 1A+2A without basal loop; 3A present. Male genitalia. Anal tube long, often extending beyond uncus. Uncus short to elongate conical, weakly sclerotized, set with few hair-like setae. Vinculum V- to U-shaped, saccus well-developed, sometimes very long. Valva deeply divided with projecting costa and sacculus processes, or simple, elliptic with narrow and pointed apex; always with a long and slender, hook-like sclerotized fibula-like process from inner surface near base of valva. Transtilla arms usually triangular, meeting medially, sometimes with thin hairs. Juxta large shield-shaped, distally bifid and with spinulose caulis. Phallus with cornuti in vesica. Female genitalia. Hind margin of 7th sternite unmodified. Ovipositor lobes narrowly crescent-shaped, evenly set with setae. Posterior apophysis short and slender, anterior apophysis longer than posterior apophysis, sometimes thickened in basal part with a lateral process. Antrum membraneous or sclerotized, cup- or funnel-shaped, colliculum ring-shaped, sometimes with spike-shaped posterior processes. Bursae copulatrix variously divided into ductus bursae and corpus bursae, but nearly always with an area of sclerotized spinules at posterior end and anterior end of corpus bursae; ductus seminalis usually originating from anterior end of colliculum.

Biology. Larvae of A. nemoralis feed in spun leaves mainly of Carpinus betulus , Carpinus japonica , Castanea sativa, Corylus heterophylla, Deutzia crenata , Quercus pubescens ( Simchuk et al. 2012) , Sorbus spp. and Betula spp. ( Slamka 2013), and pupate in a shelter of leaves spun together with silk ( Slamka 2013). Agrotera basinotata feeds on Melastoma malabathricum , Lagerstroemia spp., Castanopsis , Cleistocalyx operculatus, Eugenia aquea and Pavetta indica ( Krauss 1965; Robinson et al. 2010; Gupta & Lokhande 2013).

Distribution. Agrotera occurs in the Palaearctic, Oriental and Australian regions. Additional six African species are placed in Agrotera , but as yet they have not been revised regarding their correct placement in this genus.

Monophyly of Agrotera and putative apomorphies. Investigation of the genitalia revealed an unexpected morphological diversity among the externally superficially similar Agrotera species, indicating that the genus represents a polyphyletic group rather than a monophylum. Consequently, those investigated species that were found to be in disagreement with the diagnosis of Agrotera given above were removed from the genus.

Species of Agrotera share these synapomorphies, the relatively broad triangular forewing with pale yellow base sprinkled with orange scales and with sinuate termen, the small, weakly sclerotized uncus set with sparse setae, the large, hook-like sclerotized fibula-like process from below the base of the costa, a large, shield-shaped, dorsally bifid juxta and the long, well-developed saccus. Based on the generic synapomorphies, we consider A. nemoralis , A. genuflexa , A. longitabulata , A. basinotata , A. discinotata Swinhoe, 1894 and A. posticalis to form the monophyletic Agrotera core group, to which we also refer as the nemoralis group.

Taxonomic status of taxa misplaced in Agrotera . Leucinodella Strand, 1918, Nistra Walker, 1859, Sagariphora Meyrick, 1894 and Tetracona Meyrick, 1884 were treated as synonyms of Agrotera ( Hampson 1899, Shaffer et al. 1996). None of the type species of the four genera agrees with the diagnosis of Agrotera sensu stricto, as given above, and the four genera are consequently removed from synonymy with Agrotera and reinstated as valid genera:

Leucinodella agroterodes Strand, 1918, type species of Leucinodella stat. rev. and synonym of Leucinodella leucostola ( Hampson, 1896) comb. nov. ( Figs 11 , 17 , image of cotype could be found at http:// www.imdap.entomol.ntu.edu.tw/InsectSampleImage.php?TI_ID=955&L=E), differs from Agrotera by the arched forewing termen and the whitish forewing without a pale yellowish wing base with orange scales, as well as in the male genitalia by the short, rod-like, bilobate, distally rounded uncus, apically densely set with flat, short setae, and the tongue-shaped valva without a sclerotized fibula-like process emerging from near the costa base.

Nistra coelatalis Walker, 1859 comb. rev. ( Fig. 12 , image of cotype could be found at http:// www.imdap.entomol.ntu.edu.tw/InsectSampleImage.php?TI_ID=954&L=E), type species of Nistra stat. rev., has a wing pattern similar to L. leucostola , with an arched forewing termen and the absence of the pale yellowish forewing base sprinkled with orange scales. The genitalia of N. coelatalis were not investigated.

Sagariphora heliochlaena Meyrick, 1894 ( Figs 13 , 18 ), type species of Sagariphora stat. rev. is a junior synonym ( Hampson 1896) of Sagariphora magnificalis (Hampson, 1893) comb. nov. ( Fig. 14 , illustration of adult could be found at https://www.biodiversitylibrary.org/item/180014#page/229/mode/1up). This species differs from Agrotera in the arched forewing termen and in the large, lobe-shaped, laterally setose uncus and the presence of several patches of dense setae on the valva of the male genitalia.

Tetracona amathealis (Walker, 1859) comb. rev. ( Figs 15 , 19 ), type species of Tetracona stat. rev., differs from Agrotera in the lobe-shaped, laterally densely setose uncus, the presence of a bundle of bristles emerging from near the valva base, and the weakly sclerotized fibula-like process emerging from the base of the valva. Tetracona amathealis shares with A. pictalis and an unnamed species the narrow triangular forewing with an arched termen, the large lobe-shaped, laterally densely setose uncus, the bundle of bristles emerging from near the valva base and the weakly sclerotized fibula-like process from the base of the valva. We consider all three species congeneric, and consequently transfer A. pictalis back to its original combination with Tetracona, as T. pictalis Warren, 1896 , comb. rev. ( Figs 16 , 20 ). The species of Tetracona resemble Aetholix flavibasalis (Guenée, 1854) , the type species of Aetholix Lederer, 1863 . Aetholix flavibasalis (image of adult could be found at http:// www1.ala.org.au/gallery2/main.php?g2_itemId=11696), which also occurs in Australia, is distinguished from the externally similar Agrotera by the large lobe-shaped uncus with dense, persistent scales on the ventral surface and along the lateral margins, by the bundle of bristles arising from near the valva base, by the weakly sclerotized fibula-like process emerging from the base of the valva and by the ventrally narrow and dorsally complete (nonbifid) juxta. A future taxonomic revision of Aetholix and Tetracona might find the two genera synonymic with each other.

Figures

FIGURES2–6. 2–3.Inverted, triangularlyscaled third segment of labial palpus of Agrotera spp.. 2. A.genuflexasp. nov.. 3. A. longitabulata sp. nov.. 4–5. Adults of Agrotera spp. 4. A. genuflexa sp. nov., paratype, ♂, 6 km SSW of Oenpelli. 5. A. longitabulatasp. nov., paratype, ♂,Iron Range.6. Venation of A. nemoralis. Scale bars = 2.0 mm.

FIGURES 11–16. Adult specimens of some species misplaced in Agrotera. 11. Leucinodella leucostola comb. nov., ♂, Jiangxi, China (SYSBM). 12. Nistra coelatalis comb. rev., holotype (green-circled label), abdomen lost, Ceylon (NHMUK), A. left side; B. right side. 13. Sagariphora heliochlaena (junior synonym of S. magnificalis comb. nov.), holotype (red-circled label), ♂, Sumbawa, Indonesia (NHMUK). 14. Sagariphora magnificalis comb. nov., holotype (red-circled label), ♀ Ceylon (NHMUK). 15. Tetracona amathealis comb. rev., ♂, Mt. Borradaile, Australia. 16. T. pictalis comb. rev., ♂, Kuranda, Australia.Scale bars = 2.0 mm.

FIGURES 17–20. Male genitalia of some species misplaced in Agrotera. 17. Leucinodella leucostola comb. nov., genitalia slide no. SYSU0146 (SYSUBM). 18. Sagariphora heliochlaena (junior synonym of S. magnificalis comb. nov.), Pyralidae Brit. Slide no.2137(NHMUK).19.Tetracona amathealis comb. rev., genitalia slide no. ANIC 8900. 20.T. pictaliscomb. rev., genitalia slide no.ANIC 8828. Scale bars = 0.5 mm.