Author: (Oku, 1963)
Mint rhizome worm
Adult: 15-18 mm wingspan; forewing ground colour light greyish-ochreous, faintly striated with grey and brown, with dark greyish mottling on basal third of wing; with rather broad median fascia, an elongate, pale-edged patch from termen above tornus towards costa before apex and another smaller patch on dorsum before tornus.
Egg: deposited singly on the leaf of the host plant.
Larva: head orange-brown, with irregular dark markings; caudo-lateral patch and region of stemmata blackish; body creamy white; prothoracic shield yellowish-brown, irregularly lined with dark brown along caudal margin; anal shield yellowish-brown.
Pupa: in a cocoon in the soil, about 1 cm below the surface.
Endothenia menthivora male
External characters: 18-22 mm wingspan; forewing gradually dilated posteriorly, without costal fold; termen almost straight; ground colour light greyish-ochreous, faintly striated with grey and brown, with dark greyish mottling on basal third of wing, often extending over to middle of wing; markings dark grey, mixed with brown; median fascia rather broad, irregular, expanding from about middle of costa to just below fold, with anterior margin abruptly concave at end of cell; subterminal marking an elongate patch, from termen above tornus towards costa before apex; dorsal patch raised towards apex; both patches often edged with paler colour; some darker dots on apex and apical part of costa; cilia ochreous-grey, with a darker basal line and a paler subbasal shade. Hindwing grey, with a narrow and short dorsal fold (Oku, 1963).
male genitalia E. menthivora
Genitalia: Tegumen rounded and extremely bulging; uncus constricted at base, with strong spines ventrally, arranged in two rows; socii strongly chitinized, triangular, fused with tegumen; gnathos absent; valva long, with notch in margin before cucullus; the latter covered with long hairs; caudal process of sacculus curving inwards; a sclerotic lobe armed with spines beyond basal cavity. Aedeagus acutely pointed.
Endothenia menthivora female
External characters: Similar to male.
female genitalia E. menthivora
Genitalia: Postvaginal plate of sterigma complicated, presenting concavities and transverse ribs; antevaginal plate broad, posterior margin concave medially; antrum broad; corpus bursae with single basket-shaped signum.
The winter is passed in the larval stage within the rhizome of mint. In the following spring the larvae leave the rhizome to pupate in a cocoon in the soil, about 1 cm below the surface. Moths emerge from early July until mid August. The eggs are deposited one by one on the leaf of the host plant, and hatch in about one week. The larvae bore into the stem and finally reach the rhizome. The species seems to be univoltine (Oku, 1963).
The larvae bore into the stem and rhizomes of mint.