MOTIONS OF INSECTS. 455 



see flies and spiders do upon our ceilings, and up perpendicular surfaces 

 even when of glass, it affords room for much interesting and curious in- 

 quiry. Climbing insects may be divided into four classes. Those that 

 climb by means of their claws ; those that climb by a soft cushion of dense 

 hairs, that, more or less, lines the underside of the joints of their tarsi, 

 the claw -joint excepted ; those that climb by the aid of suckers, which 

 adhere (a vacuum being produced between them and the plane of position) 

 by the pressure of the atmosphere ; and those that are enabled to climb 

 by means of some substance which they have the power of secreting. 



The first order of climbers those that climb by means of their claws 

 includes a large proportion of insects, especially in the Coleoptera order 

 the majority of those that have five joints in their tarsi being of this de- 

 scription. The predaceous tribes, particularly the numerous and prowling 

 ground- beetles (Eutrechina), often thus ascend the plants and trees after 

 their prey. Thus one of them, the beautiful but ferocious Calosoma syco- 

 phanta, mounts the trunk and branches of the oak to commit fearful 

 ravages amongst the hordes of caterpillars that inhabit it 1 . By these the 

 less savage but equally destructive tree-chafers (Melolonthce), and those 

 enemies of vegetable beauty the rose-chafers (Cetonia auratd), are enabled 

 to maintain their station on the trees and shrubs that they lay waste. 

 And by these also the water-beetles (Dytiscus, Hydrophilus, &c.) climb the 

 aquatic plants. But it is unnecessary further to enlarge upon this head ; 

 I shall only observe, that in most of the insects here enumerated the claws 

 appear to be aided by stiff hairs or bristles. 



Other climbers ascend by means of foot-cushions (pulvilli) composed 

 of hairs, as thick set as in plush or velvet, with which the under sides 

 of the joints of their tarsi the claw -joint, which is always naked, ex- 

 cepted are covered. These cushions are particularly conspicuous 

 in the beautiful tribe of plant-beetles (Chrysomelidts). A common in- 

 sect of this kind before mentioned, called the bloody-nose beetle 

 (Timarcha tenebricosa), by the aid of these is enabled to adhere to the 

 trailing plants, the various species of bed-straw (Galium), on which it 

 feeds ; and by these will support itself against gravity ; for both this and 

 Chrysomela Goettingensis will walk upon the hand with their back down- 

 wards, and it then requires a rather strong pull to disengage them from 

 their station. The whole tribe of weevils (lihynchophora Latr.) are also 

 furnished with these cushions, but not always upon all their joints, some 

 having them only at their apex ; and the palm-weevil (Cordylia Palmarum) 

 at the extremity solely of the last joint but one. Those brilliant beetles the 

 Buprestes have also these cushions, as have likewise the numerous tribes 

 of Capricorn -beetles (Longicornes Latr.). The larvae of these being timber- 

 borers, the parent insect is probably thus enabled to adhere to this sub- 

 stance whilst it deposits its eggs. Indeed, in some species of the former 

 genus the cushions wear the appearance of suckers. While the linear 

 species of Helops are without them, they clothe all the tarsi of H. ceneus 

 (Chalcites K. Ms). 2 In two other genera of the same order, Silpha and 

 Cicindela, the anterior tarsi of the males are furnished with them ; in these, 

 therefore, they may be regarded, like the suckers of the large water-beetles 



i Reaum. ii. 457. 



8 The insect here alluded to is figured by Olivier under the name of Tenebrio 

 nitens (No. 57. t. i. f. 4.) : his Hdops ceneus (No 58. t. i. f. 7.) is a different insect. 



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