21G 
HEl'OKT ON ECONOMIC KNTOMOLOdY 
inverted notes of interrogation with the concavity directed towards the median ridge. The 
segments of the body are transversely wrinkled on the dorsal and ventral surfaces (especially 
on the latter) and puckered on the sides. From the third to the eleventh segment, the body 
is thickly covered with minute recurved spines of brownish chitin (darker in the case of 
larvie ready to leave the host), usually arranged in transverse series or groups of two or 
more, which can be seen to form more or less distinct, undulating or irregular, transverse 
rows. Tliese spines will be described in somewhat greater detail below. 
“ Above and to the outer side of each mouth-hook is an antenna-like protuberance 
(‘maxilla’ of Lowne), which, as in the case of the larva of the Blow-fly (Cal/iplidni 
enithrocepliiiht, Mg.), exhibits a pair of light brown, ocellus-like spots, or rathei' papilla;, 
placed one above the other ; according to Lowne's interpretation in the case of the Blow-fly, 
these are sensory in function. In a small larva, 5 mm. in length, from Lagos, the papilla; 
are very clearly visible; each jiapilla is surrounded by a ring of pale lirownish chitin, and 
its shape, when viewed from the side, is exactly that of the muzzle of an old-fashioned 
muzzle-loading cannon. 
“ This small larva also shows on the basal segments of each antenna, or antenna-like 
protuberance, below and a little to the outer side of the mouth-hook, a prominence bearing 
a series of about six small, brown-tipped, chitinous spines. These prominences are 
evidently the same as those referred to by Coipierel and Modiere^ as ‘ deux appendices 
analogues (palpes'?) plus petits, munis de quelques epines tres fines vers leur liord interne,’ 
and clearly shown in their figure (Plate 3, 1 b). In the same larva, the siiines on the body 
are most conspicuous, and most strongly developed and chitiuised on the fifth, sixth and 
seventh segments. The tenth and eleventh segments are also covered with spines, but since 
the chitin of which they are composed is not tinged with brown, these segments appear 
bare. In the adult larva also, the spines in the tenth and eleventh are less conspicuous 
than those on the preceding segments ; on the twelfth segment, which bears the posterior 
stigmatic plates, the spines are very minute. Fully chitinised spines are dark brown, but 
this colour is generally confined to the apical half of the spine, or may be absent from the 
extreme liase. In shape, each spine is a short cone with the apex recurved, pointing 
towards the hinder end of the body. The spines are broad at the base in proportion to 
their length and not infrequently, especially on the under side of the body, are bifid at the 
tip. They are closest together and most strongly developed on the anterior portion of each 
segment, becoming smaller and showing a tendency to disappear towards the hind margin. 
They are arranged in irregular transverse rows, which are usually seen to be composed of 
groups of from two to five spines, placed side by side. 
“ In the adult larva the median area of the ventral surface of segments five (or six) 
to eleven inclusive is marked with a series of three transverse ridges, which are most 
prominently developed on the seventh and following segments. On eacli segment the 
foremost ridge is the shortest ; next in length conies tlie hindmost ; and the middle 
ridge is the longest of the three, curling round the posterior ridge at each end. Similar 
but less strongly marked ridges are seen on the dorsal surface. 
“ I'liiKii'iinii Of the usual barrel-shaped Muscid type. Average dimensions ; length, 
10.\ mm., greatest breadth Ij; mm. Though at first of a ferruginous or light chestnut 
tint, the puparium gradually darkens until it becomes ‘ seal brown ’ or practically black. 
“ Perfect Insect. thick-set, compactly built fly, of an average length of about 9^ mm.; 
sjieeimens as small as mm. or as large as lOJ mm. in length are occasionally met with. 
' Anmdr.s dr, ta SocUti EntDiiioIinjiqnc dr France, 4 ieme .seric, t. ii. (18(j’2), p. 'J7. 
