Helcystogramma trijunctum is a moth in the family Gelechiidae. It is found in China (Anhui, Gansu, Guangxi, Guizhou, Hubei, Hunan, Shaanxi, Sichuan, Yunnan) and Taiwan.

The length of the forewings is 6-6.5 mm. The forewings have a fuscous fascia from the base to halfway the length of the anterior margin. There is a large, triangular costal blotch nearly connected to the fuscous fascia arising from the posterior margin at one-fourth the length and the postmedian line is incurved, dark brown beyond it. There is also a well—developed blackish tuft beyond the cell on the fold near the middle, other smaller ones near the middle and end of the cell.

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