280 MEMOmS OF THE QUEENSLAND MUSEUM. 



ON THE EMERGENCE OF TWO TUBE-DWELLING 

 HOMOPTEROUS INSECTS. 



By Henry Hacker, F.E.S. 



(Plates XVII and XVIII). 



PECTINARIOPHYES PECTINARIA Kirk. 



A good account of the calcareous tubes made by this and an alHed species, 

 together Avith the curious nymphs that inhabit them, was given by F. Ratte,^ in 1884 ; 

 but the method of emergence was very briefly mentioned by this author. Kirkaldy- 

 in 1906, placed these insects in the subfamily Cercopince and erected two new genera 

 Pol i/chcefo2)hyes and Pedinariojihyes for their accommodation. Subsequently^ he 

 placed them in the subfamily Machcerotince. 



These calcareous ' tubes have been frequently observed by me, attached to 

 small Eucalyptus saplings, and during the last two years I have included them 

 amongst other studies in the life histories of Australian Homoptera. As far as I 

 am aware the final ecdysis of these insects is not paralleled by that known of any 

 other group. All the tubes seen, however, do not contain living nymphs, as those 

 deserted in previous seasons, owing to their durable nature, remain on the twigs for 

 an indefinite time. The empty tubes have a bleached appearance in comparison 

 with those that are occupied. The occupied tubes contain a clear liquid, and in 

 it the nymphs liv3 submerged with their heads downwards. Their suctorial apparatus 

 is inserted through a longitudinal slit on the inner side of the tube into the twig to 

 which the tube is attached. 



The first indication that the insect is about to emerge is the appearance of 

 small bubbles at the mouth of the tube. This occurs in early spring, generally in 

 the evening or at night. Viewed through a lens at this stage, the posterior end of the 

 nymph is seen continually moving from side to side ; this end protrudes for about 

 a second, evidently to obtain a supply of air, and then retracts, after which fresh 

 bubbles are blown ; this renewing of the air supply takes place at intervals. The 

 operation continues for about an hour, by which time a large mass of froth has been 

 produced, covering the mouth of the tube and hanging over the side. When about 

 to emerge, the nymph forces its way to the top of the tube, protruding its posterior 

 end first until the legs have reached the lip. It then swings itself over, and with 

 the 1 exd now upward it climbs down the outer side of the tube until it is merged 



1 Prcc. Linn. Soc. N.S.W., Vol. IX, p. 1164, 1884. 



2 Bull. Haw. Sugar Plant. Exp. Sta. i, pp. 384-386, 1906. 

 » Bull. Haw. Sugar Plant. Exp. Sta. xii, p. 10, 1913. 



