OP 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 ; i.e., the generally larger size, paler colour, and 

 much longer legs of /'. 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 vmless they are illuminated by a strong 

 beam of light. 



The incubation period lasts for about nine days ; but unless kept in a moistened 

 atmosphere the eggs will not hatch. 



Larva. — First instar (PI. I, fig. 8). Cylindrical and distinctly 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, fiat 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, Ip) 

 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 Culicidae. 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 (PI. I, 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, 



