I am familiar with numerous specimens in various stages, collected in
Sardinia by Dr. Staudinger, and preserved by inflation.
The first stage is blackish, and shows no kind of marking; thus
agreeing with the corresponding stage of _Euphorbiæ_. The second stage
is unfortunately not represented in Staudinger’s collection.
The third stage shows a row of ring-spots, which are, however,
connected by a very distinct and sharply defined subdorsal line. In the
fourth stage a second row of (under) ring-spots is added, whilst the
subdorsal line generally at the same time disappears.
The caterpillar remains unchanged during the fifth stage, when it shows
a great resemblance in marking to _Euphorbiæ_; neither does it appear
to differ essentially from this species in colour, so far as can be
judged from preserved specimens and single figures (in Duponchel and
Hübner). I have, moreover, seen several larvæ in the last stage, and
the subdorsal could be distinctly recognized as a broad light stripe.
Of the four groups, the second (that of _Galii_), appears to me to be
of but very little importance, as I shall now proceed to show from the
development of _D. Vespertilio_.