Certain Holoptilini (Reduviidae: Holoptilinae) have long been believed to attract and paralyze ants through secretions released from a sternal structure on the abdomen termed a “trichome.” In this study, the trichome for adults of Ptilocnemus lemur is examined in detail, the first time in any Holoptilini. The trichome comprises a median elevation on abdominal sternite 2, a transverse groove, a median projection on sternite 3, and four groups of setae and hair-like projections. The hair-like projections (hairs of group 3 and 4) are shown to be associated with a layer of glandular units, which may be the source of ant-attracting or paralyzing secretions. Apart from these glandular units, a second type of glands is present on the sternum. These so far undocumented glandular units are arranged in distinct areas on the pregenitalic sternites, and are conspicuous by their large pores. Nymphs of P. lemur do not possess a trichome, but the glandular areas on the pregenitalic segments are already present.