* 
32 
NATURE 
which, as already mentioned, feed on the bark of the elm, 
closely resemble those just described, as also do those of 
Brachytarsus (Fig. 7). On the other hand the larva of 
certain beetles feed on leaves, like the caterpillars of 
Lepidoptera ; thus the larva of Crzoceris Asparagi (Fig. 8), 
which, as its name denotes, feeds on the asparagus, closely 
resembles that of certain Lepidoptera, as for instance of 
Thecla spini. A striking illustration of this is afforded 
by the genus Sitaris (PI. 3, Fig. 4), a small beetle allied 
to Cantharis, the blister-fly, and Meloe, the oil-beetle. 
The habits of this species have been very carefully investi- 
gated by M. Fabre.* ‘ 
The genus Sitaris is parasitic on Anthophora, in the 
galleries in which it lays its eggs. These are hatched at 
the end of September or beginning of October; and 
M. Fabre not unnaturally expected that the young 
larvee, which, as already mentioned, are active little 
Fic. 23, Larva ot Platygaster (after Ganin)—o0, mouth; a, antenna; 
J, hocked feet ; 7, toothed process; 2/g, lateral process ; /, branches 
of the tail. 24, Larva of another speciesof Platygaster. The letters in- 
dicate the same parts as in the preceding figure. 25, Larva of a third 
species of Platygaster The letters indicate the same parts as in the pre- 
ceding figures. : 6, Larva of Platygasterinthesecor d stage—z 0, mouth; 
slkj7, cesophagus; gs@e, supra-cesophagal ganglion; 77, muscles; 
(sm, nervous system ; gag/, rudiments of the reproductive glands. 
27, Larva of Platygaster in the third stage—#z 0, mouth; md, 
mandibles; gsa@e, supra-cesophagal ganglion; s24, cesophagus; ag, 
ducts of the salivary glands ; 4, ventral nervous system ; sf, salivary 
glands ; #s/, stomach; 7, imaginal discs; ¢7, trachee; (4, fatty 
tissue ; ed, intestine ; ga, rudiments of reproductive organs ; e w, wider 
portion of intestine ; a 0, posterior opening. 
creatures with six serviceable legs (Fig. 9), would at once 
eat their way into the cells of the Anthophora. No such 
thing: till the month of April following they remain 
without leaving their birth-place, and consequently with- 
out food ; nor do they in this long time change either in 
form or size. M. Fabre ascertained this, not only by 
examining the burrows of the Anthophoras, but also by 
direct observation of some young larve kept in captivity, 
In April, however, his specimens at last threw off their 
long lethargy, and hurried anxiously about their prisons. 
Naturally inferring that they were in search of food, 
M. Fabre supposed that this would consist either of the 
larvze or pupz of the Anthophora, or of the honey with 
which it stores its cell. All three were tried without 
* Ann. das. Sc, Nat, V, vii. T. 4. See also Natural History Review, 
April +862, 
success, The two first were neglected, and when placed 
on the latter the larve hurried away, or perished in the 
attempt, being evidently unable to deal with the sticky 
substance. M. Fabre was in despair : “ Jamais experience,” 
he says, “n’a éprouvé pareille déconfiture. Larves, 
nymphes, cellules, miel, je vous ai tous offert; que 
voulez-vous donc, bestioles maudites?” The first ray of 
light came to him from our countryman, Newport, who 
ascertained that a small parasite found by Léon Dufour 
on one of the wild bees, and named by him Triungulinus, 
was, in fact, the larva of the Meloe. The larve of 
Sitaris much resembled Dufour’s Triungulinus; and acting 
on this hint, M. Fabre examined maany specimens of 
Anthophora, and at last found on them the larve of his 
Sitaris. The males of Anthophora emerge from the pup 
before the females, and he ascertained that as they come 
out of their galleries, the little larva fasten upon them. 
Not, however, for long: their instinct teaches them that | 
they are not yet in the straight path of development ; and, 
watching their opportunity, they pass from the male to 
the female bee. Guided by these indications, M. Fabre 
examined several cells of Anthophora: in some, the egg 
of the Anthophora floated by itself on the surface of the 
honey ; in others, on the egg, as on a raft, sat the still 
more minute larva of the Sitaris. The mystery was 
solved. At the moment when the egg is laid, the Sitaris- 
larva springs upon it. Even while the poor mother is 
carefully fastening up her cell, her mortal enemy is be- 
ginning to devour her offspring. For the egg of the 
Anthophora serves not only as a raft, but as a repast. 
The honey, which is enough for either, would be too little 
for both; and the Sitaris, therefore, in its first meal, 
relieves itself from its only rival. After etght days the 
egg is consumed, and on the empty shell the Sitaris under- 
goes its first transformation, and makes its appearance 
in a very different form as shown in Fig. to. 
The honey which was fatal before is now necessary ; 
the activity which before was necessary, is now useless ; 
consequently, with the change of skin the active, slim 
larva changes into a white, fleshy grub, so organised as 
to float on the surface of the honey, with the mouth 
below, and the spiracles above the surface ; “grace a 
lembonpoint du ventre,” says M. Fabre, “la larve est & 
Yabri. de l’asphyxie.” In this state it remains till the 
honey is consumed ; then the animal contracts, and.de- 
taches itself from its skin, within which the other trans- 
formations take place. In the next stage, which M. 
Fabre calls the pseudo-chrysalis (Fig. 11), the larva has a 
solid corneous envelope and an oval shape, and in its 
colour, consistency, and immobility reminds one of a 
Dipterous pupa. The time passed in that condition 
varies much. When it has elapsed, the animal moults 
again, and again changes its form, and assumes that shown 
in Fig. 12; after this it becomes a pupa (Fig. 13) without 
any remarkable peculiarities; and finally, after these 
wonderful changes and adventures, in the month of 
August the perfect Sitaris (Pl. 3, Fig. 4) makes its 
appearance. : 
q,Qn the other hand, there are cases in which larvae 
iverge remarkably from the ordinary type of the group 
to which they belong, without, as it seems in our present — 
imperfect state of information, any sufficient reason. 
Thus the ordinary type of Hymenopterous larvz, as we 
have already seen, is a fleshy apod grub ; replaced however 
in the leaf-eating and wood-boring groups, Tenthredinidz 
and Sirecidz (Fig. 14) by caterpillars, more or less closely 
resembling those of Lepidoptera. There is, however, a 
group of minute Hymenoptera, the larvze of which reside 
within the eggs or larve of other insects. It is difficult to 
understand why these larvz should differ from those of 
Ichneumons, but as will be seen by the accompanying 
figures, they assume very remarkable and grotesque forms, 
The first of these curiouslarvee was observed by De Filippi,” 
* Ann, and Mag.fof Nat, His., 1852. 
