MOTIONS OF INSECTS, — 455 
gee 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 (utrechina), 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'. By these the 
less savage but equally destructive tree-chafers (AMelolonthe), and those 
enemies of yegetable beauty the rose-chafers (Cetonia aurata), 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 froneution (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 (Chrysomelide). _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 (thynchophora 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 Palmaruwm) 
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 larvee 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. @neus 
(Chalcites. K. Ms).* In two other genera of the same order, Si/pha 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 
1 Reaum. ii, 457. 
° The insect here alluded to is figured by Olivier under the name of Tenebrio 
nitens (No, 57. t. i. f. 4.): his Helops eneus (No 58. t, i, f. 7.) is a different insect. 
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