THK HABITATS OF INSECTS. 569 



313. 



With respect to the several seasons of insects, in cold and temperate 

 climates, they first present themselves during the warm days of spring 

 but, in hot climates, it is during and immediately after the rainy season, 

 which there supplants winter, that they are seen. We know but little of 

 the appearance of insects in the highest latitudes. Otto Fabricius men- 

 tions in his " Fauna Grcenlandica " sixty-two species of insects observed 

 by him in Greenland, of which eleven were beetles, nine Lepidoptera, two 

 Hytnenoptera, nineteen Diptera, seventeen Dictyotoptera (one Libel- 

 lula, seven Poduree, and nine Mallophaga}, two Neuroptera, and two 

 Hemiptera (lice), the most of which he caught in the months of July 

 and August. But we may readily admit that many escaped him, as may 

 be presumed from Zetterstedt's " Fauna Lapponica," where very many 

 more are enumerated. In temperate climates the number of species in- 

 creases considerably, for in Europe only there are doubtlessly more than 

 20,000 species, at a moderate calculation. Their time of appearance 

 varies considerably, yet the time of their greatest activity is the summer: 

 during the whole of winter there are but few insects in the open air. 

 The reason of this we may, with Kirby and Spence, consider to be the 

 deficiency of their aliment, for although many insects do not feed upon 

 vegetable substances, yet the majority of the flesh feeders obtain their 

 nutriment from the herbivorous ones, and whose existence is thus there- 

 fore bound to the vegetable kingdom. It therefore thence happens that 

 winter, by putting aside the green vesture of the earth, likewise chases 

 the insects that feed upon it. If we examine this more closely we shall 

 find that this relation of insects to plants is very absolute, for the 

 majority of those insects which hybernate in their perfect state are flesh 

 eaters, which find food even in the young larvae just escaped from 

 the egg-shell, whilst the latter are feeding sparingly upon the just 

 developed leaves. If we look to those insects which pass through their 

 earlier stages during the winter, we may assert generally that all insects 

 likewise exist during the winter, but in very different states. Some 

 hybernate as eggs only, others as larva?, others again, and perhaps the 

 majority, as pupae, and the fewest doubtlessly as perfect insects. From 

 all these very different states they all assemble as perfect insects in 

 the summer, and this also is truly the season in which insects are 

 consequently most active. 



As eggs, insects of all orders hybernate, yet these arc but few 



