568 



PHYSIOLOGY. 



Acheta and Gryllotalpa, which excavate holes for their dwelling- 

 places. Some, as the cockroaches (Blattaria), are true nocturnal 

 animals, which conceal themselves during the day, and only at night 

 run about upon the ground. 



The habitats of beetles are as different as their entire organisation. 

 Large families, as the Melanosomata and Helopodea, are strictly fixed 

 to the earth, and scarcely ever quit it. The majority of the Melanoso- 

 mata have consequently lost the organs of flight with its capability. 

 Others, as the capricorns, Chrysomelfs, ladybirds, and cockchafers, are 

 found only upon plants, and consequently seek the air, although they, 

 and chiefly the former, but seldom fly. The Curculios are partly fixed 

 to the earth, as BracJiycerus, Plintlius, Meleus, Cleonis, Thylacites, 

 Sitona, &c. ; others live upon plants, as Ceutorhynchus, Clonus, Or- 

 chestes, Phyllobius, Apion, Rhynchites, &c. ; a few, as some species 

 of Bagous, Hydronomus, Alismatis, Schon., &c. are found also in the 

 water upon roots, but they do not swim. The true water beetles are 

 the Dytici, Gyrimis, Hydrophihis, Helopliorus, Elmis, and the other 

 Macrodactyli. The larvae of these also are found only in the water, 

 whereas the larvae of the preceding families, as far as they are known, 

 seek remote and concealed places, for instance, the earth and the in- 

 terior of plants. The larvae of the Chrysomeloz and CoccineUce live 

 chiefly upon plants, partly from which they support themselves, and 

 partly from the plant lice found upon them. Many insects also seek 

 dark remote places removed from the open air ; some therefore live in 

 dung, as the Coprophagi, some in carrion, as the Peltodea, or in both 

 substances, as the Brachyptera : their larvae also live partly in these 

 substances or in the earth in their vicinity. Some perfect beetles like- 

 wise, as the genera Heterocerus and Prognathus, live in the earth, 

 particularly in the moist sand of the sea coast, but towards evening 

 they quit these places of abode, and fly about in the dusk. The ma- 

 jority of the small Carabodea do the same, seeking for prey, although 

 they but rarely quit the earth during the day. The larger ones are for 

 ever fixed to the earth, for they have no wings, although the genus 

 Calosoma forms an exception, the species of which are winged, and 

 frequently fly. The last family of the beetles, the Cicindelacea, live 

 chiefly upon sand, but the majority of them can fly as well as they 

 can run, and immediately exercise this faculty Avhen in danger or if 

 pursued. 



