I'M. 17. III. 1921. HESPERIDAE. General Topics by Dr. A. Seitz. 833 



li. Grypocera, broad-headed day-l)ntterflies. 



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

 is not equivalent to the first to which all the families of day-butterflies belong except the Hesperidae *), inasmuch 

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

 very heterogeneous formations, such as Morpho, Chri/.sophnnu.s, 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 He.speridae are mainly distinguished fi'om the otlier day-butterflies by the forehead being very 

 broad, for which reason the eyes are fai ther remote from each other than in any Rhoj)aloceron. 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 sejDaration of this family from the stock of 

 the other day-bulterflie=*. Latreille's grouping is also aided by special morpliological examinations; as for 

 instance Reuter's palpal spot exhibit-; great conformity with all the Hesperiditc, but differs entirely from 

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

 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. 

 Herrich-Schaffer, ScroDER, Trimen a. o. 



The number of He^perid 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 ethliv.s is distributed over more than 70 degrees of latitude, some He.'iperia (e. g. alveus) over 150 

 degrees of longitude. As the Hesperid* 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 

 distance-;; 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 rejaresented 

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

 there is but 1 species, Adopae'i actueon, however in the form christi regarded by nuxny as a separate species. 



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

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

 zone^, 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, He.speria 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 

 representative > 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 specie? live on the most highly developed plants, such as Papilionaceae, Caesalpineae and Mimosae, whilst on 



*) Some writers spell the name ..Ilespeiiidae" so as to distinguish it Iroin the mytholo^iral najue of (lie daughters 

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

 **) Vol. 1, p. 32!). 

 ***) C Ttain resemlilances in the exterior ot the palpi between the Hesperidae and some genera of other groups of day- 

 butterflies (Eurybia, AUotinus etc.) prove to be merely externally morphological. 

 *) WYTSMAN. Genera Insectorum, Fasc. 17 (UMH). 



V 105 



