Helcystogramma trigonella is a moth in the family Gelechiidae. It was described by Walsingham in 1892. It is found in the West Indies.[1]
The wingspan is about 11 mm. The forewings are greyish brown, with a small ferruginous spot at the end of the discal cell, margined on its upper and outer side with whitish-ochreous scales. There is a whitish-ochreous line from the base along the dorsal margin to the bulge of the wing, but not continued where the margin becomes straight. A faint whitish-ochreous spot or group of scales is found on the extreme costal margin at one-fifth from the apex. The hindwings are brownish grey, with a tuft of greyish-ochreous hairs above at the base.[2]