186 
Observations on the various Insects 
with such force, that the point is jerked out of the cavitv that 
holds it; bringing- the centre of the back suddenly upon the plane, 
a spring- is created which raises the beetle many inches from the 
ground, and turning over in the air it alights on its feet; the 
height of the leap depending greatly upon the hardness and 
smoothness of the surface of the plane, and some species can 
bound much higher than others. 
The mouth of the perfect beetle varies considerably from that 
of the larva or Wireworm ; the upper-lip or lahrum is rather 
large (fig. 21), and nearly concealed beneath the projecting fore- 
head ; it is transverse-oval, the anterior margin is pubescent, with 
a membranous edge, and it is ciliated with long hairs. The two 
mandibles or jaws (fig. 22) close over the rest of the mouth, which 
is sometimes scarcely discoverable in repose ; they aire strong and 
horny, clawed at the apex, with a strong tooth on the inside ; to- 
wards the base is a leathery oval lobe, the margin of which is 
densely hairy. The chin or menftim is transverse and narrowed in 
front (fig. 'i3), from whence arises the labium or under-lip (z), 
which is leathery, somewhat quadrate, the anterior margin Irigo- 
nate ; to the centre of this is attached a pair of small palpi (a) of 
three joints, the two basal ones are small and pear-shaped, the 
third is larger and hatchet-shaped. On either side of the chin is 
attached a maxilla (fig. 24), which is terminated by two broadish 
lobes that are densely pubescent at their extremities ; and on the 
outer edge arises a palpus or feeler (b), larger than the labial and 
four-jointed; the basal joint is small, second and third much larger 
and stouter, especially at the apex, the fourth joint the largest and 
more or less hatchet-shaped ; they are slightly hairy. 
Amongst these Elaters, which are the parents of the Wire- 
worms, just as the Turnip Saw-fly is of the Black Caterpillar,* 
there are four species which are most common in corn-fields : 
their metamorphoses have been traced from the worm to the per- 
fect beetle, and these we will first describe. Owing to a differ- 
ence in their structure, they are not included in the same genera 
by modern naturalists; one group being called AoiiiorES by 
Eschscholtz, the other Athous by the same author :| but they are 
all Elaters of Linnaeus. In Agriotrs there are three species, 
unless one be a variety only, which afl'ect the crops; one is called 
1. E. sputator by lAnnmis, and is tlie smallest of them : it is 
shining, piceous, and clothed with very short ochreous pubescence : 
head and thorax black, thickly and distinctly punctured; the 
latter orljirular, convex, the liindcr angles forming short stout 
teeth, sometimes rufous ; down the centre is a channel : scutel 
subovate : elytra or wing-cases not broader than the thorax, but 
* Vide Royal Agr. Journ. vol. ii. pi. B, figs. 2, 6, and 7. 
+ Curtis's Guide, Gen. 309, Nos. ;«), :n, and 32. 
