21 



betimes in the morning, or both. Could he only in addition to the real insects make a 

 collection of the huge phantasmagoric spectres that fly and creep about the roadway pro- 

 jected by the intense light, he would have an array of " bugges " that might fairly be 

 called " terrors by night." 



INSECTS IN ARCTIC REGIONS. 



A special interest attaches to the question of the mode of life in insects in relation to 

 their surroundings in high northern latitudes. Knowing, as we do, that the time avail- 

 able for the development of an insect in the extreme north is limited to from four to six 

 weeks in the year, one has felt surprised how it could be possible for certain species to 

 run through all their transformations in so short a time. 



R. McLachlan, in his paper on the insects of Grinnell Land (Jour. Linn. Soc, Zoology, 

 vol. xiv.) refers to the difficulties which the shortness of the summer interposes to the 

 development of insects, and intimates his suspicion that a development which would with 

 us take place in a single summer would there require several summers. 



The correctness of this suspicion has been completely established by the interesting ob- 

 servations on species of Lepidoptera in South Waranger, in latitude 69° 40\ made by G. 

 Sandberg. He was successful in watching the development of some extreme northern 

 species from the egg. 



Let us take as an example (Eneis Bore, Schn., a true hyperborean butterfly, which has 

 never been found outside the Arctic circle*, and even there only occurs in places which 

 bear a truly Arctic stamp. 



The imago flies from the middle of June onwards, and lays its eggs on various species 

 of grass. The eggs are hatched the same summer ; the larva hibernates below the surface 

 of the earth, feeds and. grows all through the following summer, but does not succeed in 

 attaining its full size ; it then hibernates a second time, and does not assume the pupa 

 state till the spring of the following year. 



The pupa, which in the allied forms in more southern localities is freely suspended in 

 the air to a grass stem or some similar object, here reposes in the earth, which in so in- 

 clement a climate must evidently be a great advantage. 



The butterfly escapes from the pupa-skin' after an interval of from 5-6 weeks, a period 

 of unusual length for a diurnal Lepidopteron. In more southern lands the pupal repose 

 of butterflies in summer rarely exceeds a fortnight. Hence, the entire metamorphosis is 

 more tedious than in more temperate regions. ' 



By these and other observations, Sandberg shows that one Arctic summer, in latitude 

 70°, does not suffice for the development of many Lepidoptera, but that two or more sum- 

 mers are required for the purpose. If, therefore, more than one summer is 

 needful for the development of Lepidoptera, it appears to me even more 

 certain that Humble-bees must require more than one summer. With us it is only the 

 fully developed females which survive from one year to the next ; in spring they form the 

 new nest, lay eggs, and bring up the larvse which develop into workers, and thus begin to 

 contribute to the support of the family, whence at last towards autumn males and females 

 are developed. It seems hardly credible that all this can happen each summer in a sim- 

 ilar way at Grinnell Land, in latitude 82°, especially as there the supply of food must be 

 less than with us. Hence, the development of a colony of Humble-bees must the. _ e be 

 something quite different. 



* Mr W. H. Edwards informs us that Mr. David Bruce has taken C'hionobas Taygete Hub., which is 

 syn. of Ocneis Bore Sch., in Colorado, on summits, at high elevation. Mr. Edwards' Catalogue, No. 304, 

 says Taygete Hub. = Bootes Bd., and Staudinger's Cat. says Bore Sch. is the same as these, that is, it is all 

 one species. 



