See also: fusula, sericose. 2. (Arthropoda: Insecta) An external apparatus from which silk exudes and is spun; produced by dermal gland openings on the abdomen in Coleoptera; fore tarsi in Embioptera and some Diptera; by the Malpighian tubes discharging at the anus in Neuroptera, some Coleoptera and Hymenoptera; discharged from the mouth cavity, usually modified salivary glands in Psocoptera, Siphonaptera, some Diptera, Trichoptera, Lepidoptera and Hymenoptera; in larval bees, the salivarium. 3. (NEMATA: Adenophorea) The terminal pore of the caudal glands; the cement glands.