Chilo auricilius Dudgeon 1905

Chilo auricilius Dudgeon, 1905 Figs. 35, 95, 153. Chilo auricilia Dudgeon, 1905: 405. Type locality: India, Burogah, N. Bihar. = Diatraea auricilia (Dudgeon): Fletcher 1928: 58; Gupta 1940: 799. = Chilotraea auricilia (Dudgeon): Kapur 1950: 408. = Chilo popescugorji Błeszyński, 1963: 179, fig. 63, type locality: Taiwan, China; Bleszynski, 1970: 135 (syn.). MATERIAL 7 ♀ (detailed information on Table S1; https://doi.org/ 10.5061/dryad.b8gtht7mh). SIMILAR SPECIES Chilo polychrysus (Meyrick, 1932). DIAGNOSIS Chilo auricilius, also known as the Gold-fringed Stemborer, is a widespread species in South-East Asia. It can be recognized by the silver suffusion as well as the thickly marked silver median line in males and females (Fig. 35). This species is highly similar to Chilo polychrysus in habitus, which led to erroneous reports from the Philippines (Barrion et al., 1990). Examination of male genitalia (Fig. 95) enables unambiguous identification of this species: pars basalis at base of valva absent (thorn-shaped pars basalis at base of valva in C. polychrysus); saccus narrow, conspicuously protruding anterad; juxta with two medium-length symmetrical arms not extending beyond basal-costal angle of valva, straight (two arms curved around the phallus in C. polychrysus); phallus with ventro-lateral arms roughly curved, reaching subapical part of phallus (strongly curved, reaching apex of phallus in C. polychrysus); phallus with subapical conical bump and small bulbose basal projection (both absent in C. polychrysus). In female genitalia (Fig. 153), the following characters distinguish this species from congeneric species: short ring-shaped sclerotized antrum; ductus bursae narrow, ca 1.5 X length of corpus bursae; corpus bursae progressively widening, pear-shaped, without signum. Chilo polychrysus exhibits a conspicuous C-shaped sclerotization at antrum, on each side of ductus opening, which enables unambiguous recognition of the species. DISTRIBUTION Most of South-East Asia (Sugar Research Australia). PHILIPPINES: Luzon (Batangas, Cagayan, Laguna, Quezon, Zambales), Panay (Iloilo), Mindanao (Davao Oriental, Misamis Oriental, Sirugao del Sur) (Litsinger et al., 2011). Collected at altitudes between 50 and 850 m on the Philippines. DNA BARCODING A maximum p-distance of 0.33% is observed between specimens MFNLEP-PYRALPHIL07-B08 from Mindanao (Surigao) and MFNLEP-PYRALPHIL07-H09 from Luzon (Quezon). Haplotype network reconstruction including all available BOLD sequences reveal that the Philippine haplotype is identical to a haplotype found elsewhere in Australia and India. REMARKS This Chilo species is a pest of sugarcane in South-East Asia. It also feeds on rice, maize, and sorghum (Bleszynski, 1970c; Litsinger et al., 2011; Maes, 2022). In a survey of Chilo species on rice in the Philippines, C. auricilius accounted for 73% of the total number of specimens collected, while C. polychrysus was not recorded (Barrion et al., 1990). Broad distribution of Chilo auricilius over the Philippines is the result of rice culture expansion over the archipelago.