Orthenches semifasciata

Orthenches semifasciata is a moth of the family Plutellidae. It is known from New Zealand.

The wingspan is 16–18 mm. The head, palpi, and thorax are white mixed with brown and the abdomen is grey. The forewings are elongate, the costa gently arched, the apex subacute, the termen rounded and oblique. They are white, irrorated with shining dark brown, especially on dorsal half. The markings are shining dark brown. The hindwings are light fuscous-grey.