244 



INSECTS. PHYLUM ARTHROPODA 



ant.niKc that, has the female. The houseflies and blowflies are 

 incapable of piercing, and can only suck at a surface which is 

 already liciuid, or one which can easily be made so. The general 

 p-ittorn of the mouth-parts is similar to that m the gnat, but the 



an. 



l'"iG. 179. — Head and mouth-parts of a honey bee. — From Borradaile and Potts, 

 The Invertebrata, 2nd edition, 1935. Cambridge University Press, after Cheshire. 



an., antenna ; gal., galea ; gs., glossa ; Ibr., labrum ; Ip., labial palp ; md., mandible ; mxp., maxillary 



palp ; oc, ocellus; pg., paraglossa. 



mandibles and maxillae (except the palps) are missing, and the 

 labella are greatly enlarged and covered with grooves called 

 pseudotracheai, which act like a sponge (Fig. 177 F). Solid food is 

 liquefied by the regurgitation of fluid from the gut, and small teeth 

 on the labella can scrape the surface to assist the enzyme action. 

 The butterflies and moths also have mouth-parts suitable for 

 drinking only , their food being the nectar from flowers. The proboscis 



