Hemming (1967) stated:-
For a long time there was considerable difficulty in determining the nominal species to be accepted as the type-species of this genus. This was due in part to the rather obscure nature of the type-selection made by Scudder in 1875 and in part to the ambiguity in the Code as to the species to be accepted as the originally included species of any given genus. Fortunately, as will be seen below, these difficulties disappeared with the publication of the present revised Code. The details of this case are set out below.
Hübner recognized seven species as belonging to the genus Colotis. Of these the first five are currently treated as belonging to the genus Colias Fabricius, the last two to the present genus. Of these, the first (Species No. 1033) Hübner called by the name calais, which he attributed to Cramer, though in fact it was published by Stoll after Cramer's death and for this he cited the plate and figure reference "351.A.B.". The second of Hübner's species (No. 1034) he called by the name cypraea Fabricius. Throughout his work Scudder followed the taxonomic disposition made by Kirby in his Syn. Cat. diurn. Lep. of 1871. When dealing with the nominal species here in question Kirby (: 499) identified Papilio calais, as figured by Stoll on plate 351, and also as previously figured by Cramer himself on plate 53, with the nominal species Papilio amata Fabricius, 1775. He identified with that species also the nominal species Papilio cypraea Fabricius ; 1787. Thus, the nominal species recognized by Hübner as belonging to his genus Colotis were treated by Kirby as representing the same taxon, being united under the name amata Fabricius. Scudder, following the same course stated that amata Fabricius was the type-species of this genus. Scudder's action was accepted by later authors as constituting the selection of the first of Hübner's species (i.e. that to which he applied the name calais Cramer and for which he cited figs A & B on plate 351) as the type-species of Colotis, this view being considered justifiable because he had cited amata Fabricius in the synonymy of calais.
At this point it is necessary briefly to leave the strictly nomenclatorial field, in order to examine the interpretation of the nominal species Papilio calais Cramer owing to the bearing of this question on the interpretation of the present genus. First, it must be noted that according to long-established taxonomic opinion two different taxa were described and figured under the name Papilio calais in Cramer's Uitl. Kapellen. These taxa are considered to be subspecies of a single species, the name usually used for the collective-species so recognized being calais Cramer. The taxon recognized as the nominate subspecies of this collective species occurs over a wide area in Tropical Africa, outside which it has only been recorded from Aden. The second taxon figured under the name calais in the Uitl. Kapellen is currently known by the name amata Fabricius and occurs from Syria through Persia to Central and Southern India. On the basis of the foregoing taxonomic analysis the figures given in Cramer's Uitl. Kapellen may be examined as follows : The specific name calais as published by Cramer in 1775 (Uitl. Kapellen 1 (5) : 84, pl. 53, figs C, D) is a nomenclatorially available name and is the oldest such name applicable to the taxon occurring in Tropical Africa. The taxon described and figured as Papilio calais by Stoll in 1781 (in Cramer, Uitl. Kapellen 4 (30) : 118, pl. 351) is that which, as explained above, occurs from Syria to Southern India and is currently identified with the taxon named Papilio amata by Fabricius in 1775. It is this taxon which Scudder in 1875 selected as the type-species of Colotis Hübner.
For many years it was considered that the type-species of a nominal genus must be one which the author of the generic name in question had accepted as a taxonomically good species. On this basis the genus Colotis Hübner was considered to have been based upon a misidentified type-species. Its type-species was commonly cited - as it was by myself in 1934 (Gen. Names hol. Butts 1 : 133) - as Papilio calais Cramer, Stoll, , nec Cramer, that name being synonymized simultaneously with the name Papilio amata Fabricius. Luckily, this difficulty disappeared on the publication of the present revised Code which embodies in Article 69 (a) (i) a decision taken by the Thirteenth International Congress of Zoology in Paris in 1948, under which a nominal species, the name of which is cited in the synonymy of an included species at the time of the establishment of a genus, itself ranks as an originally included species. Under this provision the nominal species Papilio amata Fabricius, the name of which (as already noted) was cited by Hübner in the synonymy of the first of the species included by him in Colotis - i.e. Species No. 1033, to which Hübner erroneously applied the specific name calais Cramer, itself acquires the rank of an originally included species. Further, in view of the action (already described) taken by Scudder in 1875 the nominal species Papilio amata Fabricius becomes the unchallengeable type-species of the genus Colotis Hübner.
Finally, there is a point which requires examination in connection with the relative precedence to be accorded to the names Papilio calais Cramer and Papilio amata Fabricius which (as already explained) are considered subjectively to apply to two subspecies of a single specific unit. These names were both published in the year 1775 and there was until recently no means for determining which of these names was the first to be published. This difficulty was overcome in 1958 (Opin. int. Comm. zool. Nom. 19 : 1-44) when the Commission precedence its Opinion 516, in which it was ruled under the Commission's Plenary Powers that the Syst. Ent. of Fabricius is to be accorded precedence above the portions of Cramer's, Uitl. Kapellen also published in 1775. Under this ruling the name Papilio amata Fabricius 1775, takes precedence over the name Papilio calais Cramer, . It thus becomes the oldest nomenclatorially available name subjectively available to the present species. It also becomes automatically the name for the nominate subspecies, and the name calais Cramer while ceasing to be the specific name of the collective species (as it has hitherto commonly been treated as being), becomes the name for the Tropical African subspecies of that species.
Madais Swinhoe in Moore, 1909 was established to denote a subgenus of Colotis Hubner,  and was raised to generic level by Larsen, 1983, Fauna of Saudi Arabia 5 : 370.
COLOTIS was included within the subfamily PIERIDAE: PIERINAE by Ackery et al., in Kristensen (1999).
The higher classification used here follows Lamas (2008).
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Search the Biodiversity Heritage Library (BHL) for references to COLOTIS and included species.