Poisonous (cryptotoxic) or venomous (phanerotoxic), what’s the difference?

Murray S. Blum

While poisonous species are widely distributed throughout the Arthropoda, not all of these invertebrates are venomous. It is important to distinguish cryptotoxic species from phanerotoxic animals which contain a venom apparatus [...]. Cryptotoxic animals, which do not possess an external secretory apparatus, are poisonous only after being ingested, whereas the toxin of phanerotoxic invertebrates are generally delivered into the host by injection as part of an offensive or defensive reaction. Venomous (phanerotoxic) species are characterized by a venom apparatus consisting of a poison gland, reservoir, a venom duct, and generally a device for infecting the venom into another animal. These terminological criteria are used to separate the species with nonvenomous defensive secretions from those with true venoms. Thus, the quinone-rich exudates of tenebrionids may be poisonous, but they are not classified as venomous in the sense that the constituents of bee venoms are.

Fonte: Blum, M. S. 1981. Chemical defense of arthropods. NY, Academic.