Plate XXX. fig. 1. [male].--2. [female].
ORDER: Coleoptera. SECTION: Lamellicornes. FAMILY: Dynastidæ, _MacLeay_.
GENUS. DYNASTES, _MacLeay_. Geotrupes, _Fabricius_. Scarabæus,
_Latreille_, _Linnæus_, _&c._
DYNASTES HERCULES. Thoracis [male] cornu incurvo longissimo subtus
barbato utrinque unidentato, capitis recurvato dentato. (Long. Corp. 5
unc. 9 lin. [male].)
SYN. Scarabæus Hercules, _Linn. Syst. Nat._ 2. 541. 1. _Oliv. Ins._ 1. 3.
_b._ 1. _tab._ 1. _f._ 1. _tab._ 23. _fig._ 1. _Fabr. Ent. Syst._ 1. _p._
2. _No._ 1. _Naturalists' Library, Beetles, pl._ 11. _Edwards, Birds, t._
334. _Gronov. Zooph._ 412. _Johnst. Ins. t._ 16. _f._ 1. _Petiv. Gaz. t._
70. _f._ 1. _Roesel. Scar. tom._ iv. _t._ 5. _f._ 3. _Pal. Beauv. Ins.
d'Afr. & d'Amer. Col. Pl._ 1. c. _f._ 1. _Marcgr. Braz._ 247. _fig._ 3.
HABITAT: Gaudaloupe (_Drury_). South America.
_Male._ Black, except the elytra, which are of an olive colour; having a
number of black spots on them of different shapes and sizes, varying
considerably in different individuals. Thorax, above, smooth, and
shining, the sides covered with a multitude of small punctures. Its front
is produced into a long shining horn, near three inches in length, which
gradually bends downwards from the base to the extremity, where it is
slightly forked; the under side being covered with short fine hairs of a
yellowish colour, resembling the pile of velvet, and having about two
inches from its extremity a strong short spine placed on each side. The
head is furnished with another horn, about two-thirds the length of the
first, sharp and thin on its upper side, and towards the end bending
upwards; having on the upper edge, near the middle, three or four teeth
or strong spines, and another near the extremity. Eyes shining, red
brown. Tibiæ armed with spines, particularly the anterior pair, which
have four; three near the tips, and one near the middle. The middle and
hinder tibiæ have each two strong spurs, and several smaller spines,
surrounded with hair on the other parts. The edge of the abdomen is
covered with a row of dark orange-coloured hairs. Several other parts of
the body, joints, &c. are also clothed with the same {60}coloured hairs.
Each of the ungues has a little tuft of strong hairs issuing from the
extremity of the terminal joint of the tarsi.
_Female._ This sex is unfurnished with horns. The elytra are the same
colour as in the male, not spotted so much, if at all, and more rugose.
Thorax black, with a few yellowish spots, formed like stars or rays on
it. In other respects it resembles the male.
Drury adds to this insect the following remark--"I have observed many
species of beetles whose males have been furnished with horns, either on
the head or thorax, but in which the females have none, but have those
parts quite smooth and plain; and my observations incline me strongly to
think that this rule subsists in every one of them, through the whole
class. The instances I could bring in support of this opinion are too many
to be admitted in this place."
The circumstance observed upon in the preceding note is certainly very
interesting in a physiological point of view. In quadrupeds we find both
sexes of cornuted species armed with horns; but in insects almost
universally the males alone are provided with these appendages. It is also
worthy of remark, that although in the majority of insects the females
considerably surpass the males in size, yet in those species in which the
males are cornuted, the females are almost invariably smaller than their
partners.
Burmeister lays it down as a rule, that with regard to the differences of
the sexes, their whole character may be thus distinguished; viz. that the
male displays a preponderance of evolution, and the female a preponderance
of involution; and observes, "that some beetles have processes upon the
head and thorax, which, like the mandibles, can meet, like tongs, and thus
serve as a weapon. This is asserted of Hercules and its large comrades."
This opinion as to the uses of these horns can, however, scarcely be
maintained, since the number of species in which the horns really meet is
very few. Kirby and Spence observe, "What may be the use of these
extraordinary appendages to the males, has not yet been ascertained.
Whether the individuals of this sex are more exposed to the attack of birds
and other enemies, in consequence of being more on the wing than the
females, and are therefore thus provided with numerous projecting points of
defence, is a question worth considering." It is also to be observed that
these appendages, instead of being deciduous, as in many of the higher
animals, are in insects component parts of the external skeleton.
There are a few exceptions to the observation of Drury; thus in the
Lamellicorn genus Hoplites Dej. Catal. (Scarabæus Pan,) the females are
cornuted as well as the males; and in the genus Osmia, belonging to the
section of wild bees, Dasygastres, Latr., the females alone have the head
furnished with two porrected horns.
{61}BUPRESTIS (CHALCOPHORA) VIRGINIENSIS.
Plate XXX. fig. 3.
ORDER: Coleoptera. SECTION: Serricornes. FAMILY: Buprestidæ.
GENUS. BUPRESTIS, _Linn._ SUBGENUS. Chalcophora, _Solier_.
BUPRESTIS (CHALCOPHORA) VIRGINIENSIS. Thorace lato fusco, punctis
cupreis; elytris serratis atris, maculis cupreis, saturâque metallicâ.
(Long. Corp. 1 unc. 1½ lin.)
SYN. Buprestis Virginiensis, _Drury, App. vol._ 2. _Herbst. Col._ ix.
_p._ 114. 63. _t._ 148. _f._ 1.
Buprestis Virginica, _Linn. (Gmel.)_ 1. iv. _p._ 1940. _No._ 110. _Rossi
(Hellw.) Fn. Etr._ 1. _p._ 211. _not._
HABITAT: Virginia.
Head small and broad. Antennæ about the length of the thorax, and small.
Thorax broad and rugged, having the elevated parts of a dark coppery
colour; but the depressed ones lighter, covered with very small
punctures, and joining close to the wing-cases. Scutellum very small and
triangular. Elytra of the same colour with the thorax; the dark parts in
the figure being those that lie highest. They are margined on the sides
and suture, extending even with the anus; which near their edges are
slightly serrated. Under side shining and coppery, but on the sides with
a tincture of flesh colour. Legs the same; with two tibial spurs.