285 



XIX, 



On Laap, or Lerp, the Cup-lilie Coverings of Psyllidss 

 foufid on the Leaves of certain Eucalypti. By Thomas 

 DoBSON, Esq., B.A., of the High School, Hohart Town. 

 \_Read llth September, 1850.] 



The white saccharine substance called " lerp," by the 

 Aborigines, in the north-western parts of Australia Felix, 

 and which has attracted the attention of chemists, under 

 the imjDression that it is a new species of manna, originates 

 with an insect of the tribe of PsyUidtB, and order Hemiptera. 



According to Latreille, {Diet. Classique d' Hist. Nat. 

 art. Psylla), only six species of this genus are known, and 

 these are all proper to Europe. 



The three species described in this paper are, in all pro- 

 bability, new to entomologists. 



The larva of several insects avail themselves of their 

 peculiar secretions to form a rude tent-like protection from 

 their enemies and the weather. Those of the Crioceres are 

 concealed under an irregular mass, having the appearance 

 of macerated leaves. The Cassidce, Coccidm, and Psyllidce 

 are hidden under a cloak of white cottony filaments flowing 

 from the articulations of the body. The Psylla Eucalypti 

 enjoys a more profuse supply of glutinous pabulum than its 

 European congeners, and is thus enabled to construct a more 

 artificial and effective dwelling. It is, perhaps, owing to the 

 remarkable dryness and mildness of the winter just past that 

 these insects have been obtainable in their various phases 

 of transformation at all times during the last four months. 

 The white conical tents of the larvse and pupse may be 



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