Chilo suppressalis (Walker, 1863)

Chilo suppressalis (Walker, 1863) View in CoL

Figs. 39 View Figs 32-39 , 100 View Figs , 158 View Figs 156-159 .

Crambus suppressalis Walker, 1863 . Type locality: [China, Kiangsu], Shanghai

= Chilo oryzae Fletcher, 1928: 59 , pls 3, 4; type locality: India. Pusa; Kawada 1930: 145 (syn.)

= Jartheza simplex Butler, 1880: 690 ; type locality: Taiwan [Formosa]; Hampson, 1896: 957 ( Chilo ); Vinson, 1942: 40 (syn.)

= suppresalis Hampson, 1896: 957

MATERIAL

6 ♀ (detailed information in Table S1; https://doi.org/ 10.5061/dryad.b8gtht7mh) .

DIAGNOSIS

Chilo suppressalis , also known as the Asiatic Rice Borer or Striped Rice Borer , is recognized by the cream/yellow forewing with a conspicuous black rounded discoidal spot in males, while females are similar to those of C. sacchariphagus . Chilo suppressalis can be separated from other Chilo species by the following characters of the male genitalia ( Fig. 100 View Figs ): arms of juxta ca 2/3 of valva length, distincly swollen at midlength; phallus with characteristic long, thin ventral arm ( Bleszynski, 1970c). In female genitalia ( Fig. 158 View Figs 156-159 ), the following characters separate this species: ostial pouch small, slightly demarcated from ductus bursae; ductus bursae basally forming a twist, with sclerotized band; corpus bursae with elongate signum ( Bleszynski, 1970c).

DISTRIBUTION

EAST AND SOUTH AFRICA; BANGLADESH; BRUNEI; CAMDOBIA; CHINA; INDIA; INDONESIA; IRAN; JAPAN; LAOS; MALAYSIA; PAKISTAN; PHILIPPINES: Luzon (Bataan, Batangas, Cagayan, Ifugao, Laguna, Nueva Ecija, Pangasinan, Mountain Province), Marinduque, Mindanao (Misamis Oriental, South Cotabato); SRI LANKA; TAIWAN; THAILAND; VIETNAM.

DNA BARCODING

A maximum intraspecific p-distance of 0.3% is observed between MFNLEP-PYRALPHIL11-A02 from Luzon (Ifugao) and the other three specimens from Luzon and Marinduque. Haplotype network reconstruction reveals that the Philippine haplotype is shared with specimens from China, South Korea, and Iran.

REMARKS

Chilo suppressalis is one of the most severe rice pest species and is present in the whole Oriental region, reaching temperate China and Japan to the North. It has been introduced to Europe and Hawaii ( Maes, 2022). Chilo suppressalis together with Scirpophaga incertulas (Walker, 1863) are the most widespread rice pest species in the Philippines ( Calora & Reyes, 1972). The observed decline of Chilo suppressalis in the past decades could be due to the introduction of narrow-stemmed rice ( Litsinger et al., 2011).