Holcocera plagatola is a moth in the family Blastobasidae. It is found in Guatemala. The length of the forewings is 9.5–9.7 mm. The forewings are greyish brown intermixed with a few dark-brown scales. The hindwings are translucent brown basally, gradually darkening to the apex. The larvae feed on Persea americana. They were found feeding in the fruit pulp surrounding the seed and possibly the seed itself.