The worker was officially described by myrmecologist David Emmanuel M. General of the University of the Philippines in a 2016 Halteres paper.

General coined the specific epithet as a patronym honoring entomologist Gary Alpert who acted as a mentor and friend.

[2] Overall the Harpegnathos alperti is 19.45 mm (0.766 in) long, with an overall black coloration to the body grading to patchy yellowish chocolate-brown on the leg while the mandibles and antennae are a darker chocolate.

Each antennae has sort erect to suberect hairs sparsely scattered along the scape which extends beyond the posterior margin.

[2] The holotype was trapped during the process of general insect collection on a Pterocarpus indicus ("narra") plantation with an understory consisting of Musa textilis Abacá banana.