OF THE MALTESE ISLANDS. 75 
In captivity this insect is much more restless than P. perniciosus, so much 
so that after a few hours one may readily distinguish the two species by this alone, 
apart from the other characters ; 7.e., the generally larger size, paler colour, and 
much longer legs of P. papatasii. 
Ovum (PI. I, figs. 1-5).—When forcibly expelled from the body a day or 
so before the cuticle has become opaque the interior (oolemm) can be seen ; and 
in such examples also the micropyle is distinctly visible as a short ring-like 
extension at the anterior pole of the egg. The oolemm at this stage is filled with 
globular particles of fatty matter, suspended in a structureless matrix. When 
first laid the egg is translucent white and covered with a thin coating of viscous 
matter by which it readily adheres to the surface upon which it may fall ; five 
hours after it has been laid it assumes its normal form and colour, which may be 
described as follows :—Form very elongate, dark brown, shining, with longitudinal 
black wavy lines, which in certain lights give the periphery of the egg a faintly 
rugose appearance ; these black lines are slightly raised and are joined by slender 
cross-lines so that a faint but rather coarse reticulation is formed. The transverse 
lines are however, very difficult to trace unless they are illuminated by a strong 
beam of light. 
The incubation period lasts for about nine days ; but unlesskept ina moistened 
atmosphere the eggs will not hatch. 
Larva.—First instar (PI. I, fig. 8). Cylindrical and distinetly caterpillar- 
like in its general form; head black ; body white or ochreous white ; caudal 
bristles, long, black. Head (fig. 19) very broadly pyriform ; frontal hairs two 
in number, simple; dorsally there are three similar hairs on each side; one 
arising from the mid-region of the mandibles, one near the base, and a slightly 
longer one towards the centre of the head, near the margin ; besides these there 
are at least four hairy spines on each side, arranged as shown in the illustration. 
Antennae (fig. 19, ant.) composed apparently of three segments, the first two 
being quite rudimentary and ring-like ; third segment broad, flat and ovate in 
outline, the anterior edge faintly emarginate and furnished with a centrally placed 
hair. Mandibles (fig. 19, md) large and provided with four distinct but rather 
blunt teeth, of which the apical one is much the largest. Labial plate (fig. 19, /p) 
somewhat triangular in outline, with four teeth on each side, the median ones 
being much the largest; in its general form the labial plate resembles those 
found in the larvae of the CuLictpar. Articulations of the body clearly 
defined ; each segment bears from four to five hairy spines on each side, all of 
which are broadly dilated apically. Caudal bristles in two pairs, one of which is 
much the longer, almost equalling the length of the body, the other pair 
extremely short. 
Last instar (Pl. 1, fig. 7). Form resembling that of the first instar; colour 
pale ochreous white ; head black; caudal bristles black, arranged in two pairs, 
each pair being attached to a large tuberculous process ; the inner bristle is much 
the longer, almost equalling one-half the length of the body of the larva ; all of 
these bristles, under a high magnification, present a number of extremely fine, 
equidistant, and intensely black surface lines, the intervening spaces being dis- 
tinctly pale ; it is highly probable therefore that these bristles are finely striated, 
