on their cervical regions with glands nearby and patterning across the wings that is meant to warn and advertise toxicity (neurotoxic choline esters). Enemies Predators While not often eaten due to its toxicity, naïve birds will on rare occasion consume either the adult or larval stages of this species. Parasites The larval form of A. caja is parasitized by quite a few endoparasites, which usually grow as larvae inside the living host (in this case a caterpillar). Examples include: Carcelia gnava Carcelia lucorum Carcelia tibialis Compsilura concinnata Exorista fasciata Exorista grandis Hubneria affinis Pales pavida Thelaira leucozona Thelaira nigripes Thelymorpha marmorata. All of the listed species of parasites are flies, and they all parasitize during their larval stages. Protective coloration and behavior Müllerian Adult garden tiger moths exhibit clear warning signals, which they share with other tiger moths to advertise very real toxicity upon consumption. Adults can also spray an irritating compound when threatened. The chemical, produced in glands that are exposed when threatened, is a choline ester. A similar compound is found in the tissues of the adults, with the eggs, gonads, and abdomens having the highest concentrations. Genetics Phylogeny Arctia caja is very well adapted to cold temperate climates, and is closely related to many other tiger moths both molecularly and genetically. Although it has variable patterning, it is still quite genetically and molecularly similar to other species that have been separated from A. caja due to appearance, such as A. intercalaris, A. martinhoneyi, A. thibetica, A. brachyptera, and A. opulenta. Evidence for combining some of these species does not seem strong enough to create conclusions in that regard. Physiology Sound generation Adults can make rasping sounds with their wings and can emit high pitched squeaking sounds that are audible to humans. These sounds have been found to affect bat behavior, as the squeaks of this insect cause bats to avoid the noxious moth. Bats that could associate squeaking or clicking sounds as indicative of toxic prey quickly used sound alone as a deterrent. Digestion The digestion of this species is most remarkable in the larval stage. The host plants of this species almost always carry toxins known as pyrrolizidine alkaloids. To deal with this the caterpillars have developed the capacity to metabolize a wide range of toxins using unique enzymes. These enzymes both convert the plant's toxins into a non-toxic form, but they also allow the larval