Publ. 17. in. 1921. HESPERIDAE. General Topics by Dr. A. Seitz. 833 



B. Grypocera, broad-headed day-butterflies. 



As has already been stated in Vol. I, p. 329, this second Division (Haase denominates it Netrocera) 

 is not equivalent to the first to wliich all the families of day-butterflies belong excej^t the Hesperidae *), inasmuch 

 as it comprises only a single group of relatively homogeneous butterflies, whereas the Bhopalocera comprehend 

 very heterogeneous formations, such as Morpho, Chrysophanus, Leucidia, Leptocircus etc. The differences 

 of the two divisions have already been briefly stated at some other places **) and are here once more classified 

 in the following characterization of the Hesperidae, to which we may, therefore, refer. 



1. Family: Hesperidae, Skippers. 



The Hesperidae are mainly distinguished from the other day-butterflies by the forehead being very 

 broad, for which reason the eyes are farther remote from each other than in any Rhopaloceron. This conspicuous 

 mark, together with the robust structure of the body and a great uniformity in the shape and venation of the 

 wings served Latreille as the foundation for his thoroughgoing separation of this family from the stock of 

 the other day-butterflies. Latreille's grouping is also aided by special morphological examinations; as for 

 instance Retjter's palpal spot exhibits great conformity with all the Hesperidae, but differs entii-ely from 

 that of all the other day-butterflies ***). Moreover, the venation strikingly deviates from that of the Bhopalo- 

 cera, so that all the systematizing authors, although they did not give expression to it in the scheme of their 

 systems, still laid great stress upon the caesura between the Hesperidae and the other day-butterflies, e. g. 

 Herrigh-Schafeer, Scttdder, Trimen a. o. 



The number of Hesperid forms enumerated by Mabille *), about 2150, has since that time increased by 

 several hundreds, although numerous species having often expressly been quoted as doubtful by the said excellent 

 expert of this family turned out to be synonymous or not maintainable for some other reason. The general 

 geographical range has been dealt with already in Vol. I, p. 329; we may once more state here that America is 

 extraordinarily favoured in the distribution of the Hesperidae. In spite of the great flying power of the butter- 

 flies, they are still absent in a comparatively great number of islands, and consequently seem to be entirely 

 unfit for flying across the ocean. But where compact tracts of land allowed them to rest temporarily from 

 their flight, which seems to be a necessity to them, they were able to spread across enormous districts. Thus 

 Calpodes ethlius is distributed over more than 70 degrees of latitude, some Hesperia (e. g. alveiis) over 150 

 degrees of longitude. As the Hesperids are besides very fond of flying much and far and to a certain degree 

 even of wandering, it is natural that they vary little in the countries connected by strips of land even at great 

 distances ; but as they never fly very unintermittingly, there had to be formed particular local forms in all 

 the places separated by the sea. In the far remote New Zealand the Hesperidae, being yet well represented 

 in Australia, are entirely absent, and even in the Canary Islands, which are not difficult to reach for palearctics, 

 there is but 1 species, Adopaea actaeon, however in the form christi regarded by many as a separate species. 



We have already pointed out (Vol. I, p. 329) that the Hesperidae are extremely heliophile. This explains 

 their immense preponderance in the Tropics, which decreases rapidly as soon as we come to the temperate 

 zones, while on proceeding farther towards the polar regions the state of things is reversed. Only one single 

 Hesperid can be regarded as an arctic butterfly, Hesperia centaureae, and since in the north there is a less inter- 

 rupted connection of countries between the New and Old World, this species is also the only one which America 

 has in common with any of the other faunae of the world, i. e. with the palearctic fauna. All the other, 

 almost 2000 Americans are separate species, although some North Americans can yet be recognized to be 

 representatives of certain palearctics. 



The e g g s of the Hesperidae vary greatly in their size, but in their exterior shape they are rather exactly 

 conformable. They are hemispherical, above more or less flattened, ribbed radiately, and often distinctly reticu- 

 lated. The $$ deposit them always singly and, as far as is known to me, also always in moderate numbers on 

 the food-plant or its surroundings. The food-plant itself may belong to nearly all the families of plants; .very 

 many species live on the most highly developed plants, such as Papilionaceae, Caesalpineae and Mimosae, whilst on 



*) Some writers spell the name ,,Hesperiidae" so as to distinguish it from the mythological name of the daughters 

 of Atlas. But since both words are equally derived from the name ,, Hesperia", they may as well be homonymous. 

 *') Vol. I, p. 329. 

 ***) Cirtain resemblances in the exterior of the palpi between the Hesperidae and some genera of other groups of day- 

 butterflies {Eurybia, Allotinus etc.) prove to be merely externally morphological. 

 *) WYTSMAN. Genera Insectorum, Fasc. 17 (1904)- 



V 105 



