NO. 2171. SYNOPKIS OF THE COCCINELLin LARVAE— BOVING. 623 



three rows of dorsal depressions on each side of the body. Some of 

 the lateral setae (cols, fig. 5) are very large, very fragile, and of a pecu- 

 Har structure, emitted from a coUarlike prolongation of the basal 

 cup. The fragile nature and speciaUzation of these hairs suggest that 

 they are defensive, either in a merely mechanical way or possibly con- 

 taining a poison. Undoubtedly protective organs are certain large 

 repugnatorial glands, which can emit drops of bloodhke fluid; these 

 are placed dorsaUy in the intersegmental skin on each side of the first 

 eight abdominal segments (hg, fig's. 1 and 5). Small ring-shaped 

 light brown spiracles (sp, figs. 1 and 5) occur on the mesothorax and 

 on the first eight of the ten abdominal segments ; a rudimentary pair 

 is found on the metathorax. The spiracles are provided with an 

 effective closing mechanism (fig. 5), which prevents the expiration 

 of the air, when the larva contracts the body to press out the blood- 

 like fluid from the glands.^ 



The three thoracic segments bear stout legs (fig. 3), which are in- 

 serted rather close together; their color is dark gray with the ter- 

 minal margin of each joint shiny, black; the small, clawhke tarsi are 

 black, with a seta near the base and are surrounded by cm-ious, club- 

 shaped hairs on the end of tibia (fig. 1). The anal segment (10 ahd, 

 figs. 1,3) is bent downwards and forms a well-developed sucker, which 

 is used in the locomotion. 



STRUCTURAL DETAILS OF THE MATURE LARVA. 



Cranium (figs. 8, 9, 10) symmetrical, rectangular, twice as broad as 

 long; occipital foramen of the same width as the cranium; head 

 reaches further back above than below; ventrally the foramen is 

 without any distinct chitinous margin, because the two epicranial 

 halves are widely separated and the gula region (gu) is without any 

 chitinization (fig. 10); hypostoma (h), strongly chitmized, with a 

 distinct triangular posterior enlargement (htri, fig. 10). Labrum 

 (Zr, fig. 9), very large and semicircular, shaped like an eyeshade; 

 anterior margin distally without any serration, ciliar fringe or mar- 

 ginal setae; clypeus ( = postlabrum Lyonet) (c, fig. 9) indistinct 

 because the chitinization of epistoma (ep) is but slightly developed, 

 and only obvious near the dorsal articulation of the mandibles; frons 

 (f) completely fused with epicranium (ecr), no indication whatever 

 of the frontal sutures nor any epicranial suture; ^ three well developed 

 lateral oceUi (fig. 1, oc, fig. 8) arranged, as the figures show, in a tri- 

 angle just behind the antennal ring. The laterally placed antennal 

 ring (a, figs. 8, 9) is strongly chitinized and smrounds the whole basal 

 membrane of the antenna; the antenna is of about the same length as 



1 Compare A. G. Boving, Natural History of the Larvae of Donaciinae (International Revue der 

 gesamten Hydrobiologie und Hydrographie, vol. 3, Biol. Suppl. 1, 1910, i>. 73). 



2 Compare the first-stage larva, mentioned on page 628. 



