Plain Tiger African Queen

Appearance

"D. chrysippus" is a medium-sized butterfly with a wingspan of about 7–8 cm. The body is black with many white spots. The wings are orange, the upperside brighter and richer than the underside. The apical half of the forewing is black with a white band. The hindwing has three black spots in the center. The wings are bordered in black and outlined with semicircular white spots. This species exhibits slight sexual dimorphism, as the Male has large scent glands on his hindwings, which the female lacks. They appear as a large black spot with a white centre if viewed from the underside

"D. chrysippus" is a polymorphic species, so the exact coloring and patterning vary within and between populations.

It is similar in appearance to the Indian fritillary, which may coexist with it.

Naming

Despite the external similarity, the common tiger is not closely related to the plain tiger. Three subspecies were considered valid in a 2005 review:

⤷  "Danaus chrysippus chrysippus"
⟶  Asia, Mediterranean region, northern tropical Africa
⤷  "Danaus chrysippus alcippus" - formerly "D. c. aegyptius"
⟶  From the Cape Verde Islands through tropical Africa to Yemen and Oman. Browner with broader white forewing spots.
⤷  "Danaus chrysippus orientis" - formerly "D. c. liboria"
⟶  Saint Helena, southern tropical Africa to South Africa, Madagascar, Comoros, Seychelles and Mascarenes. Small white forewing spots.

"D. c. alcippus" is well on the way of becoming a distinct species.

On the other hand, the former subspecies "petilia" is nowadays recognized as a good species, the lesser wanderer. More enigmatic is the status of the former subspecies "dorippus" and "bataviana". These are tentatively also regarded as a distinct species, the dorippus tiger.

However, it appears that the dorippus tiger is the product of an ancient lineage of "Danaus" hybridizing with plain tiger females. As the plain tiger is known to be parasitized at least occasionally by "Spiroplasma" bacteria which selectively kill off male hosts, a subsequent scarcity of plain tiger males might have led to this hybridization and the evolution of the dorippus tiger. From the colour pattern of this species, it can be assumed that the ancient lineage had no black apex on the forewings, as this characteristic is still absent in "D. dorippus".

The presumed subspecies "cratippus" most likely belongs to either the lesser wanderer or the dorippus tiger, but confirmation of its taxonomic status requires more research. In any case, these three species are closely related; their closest relatives, in turn, might be the soldier and queen butterflies.

Several local forms have been described from Asia:

⤷  "Danaus chrysippus chrysippus" f. "alcippoides"
⟶  The upper hindwing is more or less very white; about half of the individuals have a second submarginal spot in the forewing. Occasionally found in South-East Asia, very rarely in India.
⤷  "Danaus chrysippus chrysippus" f. "gelderi"
⟶  The upper hindwing has white markings. Occasionally found on Sulawesi.
⤷  "Danaus chrysippus chrysippus" f. "bowringi"
⟶  The upper hindwing has a subapical band composed of somewhat larger spots, and an additional forewing spot as in f. "alcippoides" is always present. Found throughout the eastern parts of this subspecies' range.

On the other hand, the plethora of named taxa from Africa are apparently F1 or F2 hybrids between the plain tiger subspecies and/or "D. dorippus":

⤷  "Danaus chrysippus" × "alcippoides"
⟶  is "D. c. chrysippus" × "D. c. alcippus"
⤷  "Danaus" × "transiens", "Danaus" × "klugii", "Danaus" × "albinus" and "Danaus" × "semialbinus"
⟶  are "D. c. alcippus" × "D. dorippus"

Behavior

The plain tiger is mimicked by several species due to its unpalatability to potential predators. Previously, it was thought that cardenolides obtained from food sources during the larval stage were responsible for the aversive nature of adult "D. chrysippus", but many larval food sources lack cardenolides, and some adult West African populations of "D. chrysippus" do not store cardenolides well, yet still repel predators. More recently, pyrrolizidine alkaloids have been proposed to be also responsible for the unpalatability of "D. chrysippus". Adult male danaines often feed on plants containing pyrrolizidine alkaloids, and although females rarely do, they may be protected simply through their resemblance to males of the same species. The ability of "D. chrysippus" to store cardenolides varies across populations, so likely both cardenolides and pyrrolizidine alkaloids contribute to the unpalatability of "D. chrysippus" to different extents depending on the population.

Because the plain tiger is unpalatable, they are aposematic - their bright coloration serves as a warning to predators that they are either distasteful or toxic. Consequently, once a predator has made the mistake of attempting to eat a plain tiger, they will refrain in the future from attacking similarly colored butterflies. This has led to the evolution of a number of other species which mimic the plain tiger in order to co-opt the protection conferred by such bright coloration.

Habitat

The plain tiger prefers arid, open areas, and is found in a variety of habitats, including deserts, mountains, deciduous forests, and human-tended gardens in cities and parks. It is comfortable at altitudes ranging from sea level to around 1,500 m.

Reproduction

The plain tiger's larval host plants are from several families, most importantly Asclepiadoideae :
⤷  "Asclepias" – milkweeds
⤷  "Aspidoglossum interruptum"
⤷  "Calotropis" – mudar
⤷  "Caralluma burchardii"
⤷  "Ceropegia dichotoma"
⤷  "Cryptolepis buchananii"
⤷  "Cynanchum"
⤷  "Gomphocarpus fruticosus"
⤷  "Kanahia laniflora"
⤷  "Leichardtia australis"
⤷  "Leptadenia hastata"
⤷  "Marsdenia leichhardtiana"
⤷  "Metaplexis japonica"
⤷  "Orbea variegata"
⤷  "Oxystelma pulchellum"
⤷  "Pentatropis"
⤷  "Pergularia daemia"
⤷  "Periploca linearifolia"
⤷  "Pleurostelma cernuum"
⤷  "Secamone"
⤷  "Tylophora"
Host plants from other families include "Dyerophytum indicum", "Ficus", "Ipomoea", "Lepisanthes rubiginosa" as well as some Euphorbiaceae, Malvaceae, Poaceae, Rosaceae and Scrophulariaceae.Most predators of the early developmental stages of "D. chrysippus" are arthropods. Such potential predators include various kinds of spiders, assassin bugs, cockroaches, ladybugs, ants, and mantises. The caterpillars will even cannibalize each other. Egg and larval mortality is often high; as many as 84% of eggs may be lost to predation and up to 97% of larvae can be lost by the fifth instar, although most larval deaths occur during the third instar.

Food

The plain tiger's larval host plants are from several families, most importantly Asclepiadoideae :
⤷  "Asclepias" – milkweeds
⤷  "Aspidoglossum interruptum"
⤷  "Calotropis" – mudar
⤷  "Caralluma burchardii"
⤷  "Ceropegia dichotoma"
⤷  "Cryptolepis buchananii"
⤷  "Cynanchum"
⤷  "Gomphocarpus fruticosus"
⤷  "Kanahia laniflora"
⤷  "Leichardtia australis"
⤷  "Leptadenia hastata"
⤷  "Marsdenia leichhardtiana"
⤷  "Metaplexis japonica"
⤷  "Orbea variegata"
⤷  "Oxystelma pulchellum"
⤷  "Pentatropis"
⤷  "Pergularia daemia"
⤷  "Periploca linearifolia"
⤷  "Pleurostelma cernuum"
⤷  "Secamone"
⤷  "Tylophora"
Host plants from other families include "Dyerophytum indicum", "Ficus", "Ipomoea", "Lepisanthes rubiginosa" as well as some Euphorbiaceae, Malvaceae, Poaceae, Rosaceae and Scrophulariaceae.Adult plain tiger butterflies obtain nectar from various flowering plants. The particular plants available vary depending on the geographic range of the butterfly population and the season, as certain plants do not flower throughout the entire year.

Predators

Most predators of the early developmental stages of "D. chrysippus" are arthropods. Such potential predators include various kinds of spiders, assassin bugs, cockroaches, ladybugs, ants, and mantises. The caterpillars will even cannibalize each other. Egg and larval mortality is often high; as many as 84% of eggs may be lost to predation and up to 97% of larvae can be lost by the fifth instar, although most larval deaths occur during the third instar.The most common predator of adult plain tigers are birds. In eastern Africa, the most common predator is the fiscal shrike "L. c. humeralis".