20 



THE MOUTH-PARTS OF CULEX, MALE. 



The mouth-parts of the male of Culex have not been described, as far as I 

 know, with any degree of accuracy, altho, since Swammerdatnm's time, the males 

 have been distinguished from the females, by all scientific entomological writers 

 on the subject, by means of their feather-lifte antennae and maxillary palpi. 

 Jordens 18 (Bd. 1, p. 165) thinks, contrary to the opinion of most writers, that 

 the male mosquito can bite, and writes "But since the male is also provided with 

 a sucking seta, it is not comprehensible why it should not use it for the same 

 purpose." * He describes (p. 162), however, the setae of the male Culex as four 

 in number, the same as he describes those of the female. 



The proboscis of the male of Culex pipiens, the only species the male of which 

 I have studied, is slightly longer and slenderer than the corresponding organ in 

 the female. The five-jointed maxillary palpi are covered with long hair at the tip. 

 The setae are fewer in number and less completely sheathed by the labium than 

 in the female; they consist of a well-developed labrum-epipharynx and two slightly 

 developed maxillae. The mandibles are absent, and the hypopharynx coalesces 

 with the labium (fig. 12, h and /). The labium and maxillary palpi are more 

 densely covered with hair and scales than they are in the females, and they 

 contain muscles; the other mouth-parts, the setae proper, are naked, chitinous, 

 and contain no muscles. In comparative length the mouth-parts may be arranged, 

 longest first: maxillary palpi, labium and labrum-epipharynx, maxillae; in 

 comparative size they may be arranged, largest first: labium, maxillary palpi, 

 labrum-epipharynx, maxillae. The relative position of the mouth-parts of the 

 male, determined in the same way as for the female, is different from that in 

 the female (compare fig. 8-U with 13-15) in that the short, rudimentary maxillae 

 are pushed out sidewise to allow the hypopharynx to coalesce with the labium. 

 In the male the oesophageal pump, or bulb, behind the nerve-ring fails, and the 

 sucking of fluids must be done by the pharynx alone, as it is done in most diptera. 



The labrum-epipharynx is nearly the same in general form and structure in 

 the male Culex as it is in the female, it is a trifle longer and slenderer, but 

 the same figures (5 lr-e, and 6) will serve for the tips of both. In section (fig. 

 12, I >'-?), the labrum shows a groove on its upper surface, which deepens as it 

 nears the base (fig. 13, lr-e). At its base the labrum-epipharynx unites with the 



* " Da aber auch die mannliche mit ebcn dm Sau-stachel versehen ist, so ist nicht 

 einzusehen, warum sie sich desselben nicht zu gleicher Absirht bcdienen sollte." 



