1880.] PROF. WESTWOOD ON THE GENUS PERGA. 375 



attendance on the Larva by an Insect of the Tribe of Terebrantia, be- 

 longing to the Genus Perga, observed at Hobarton, Tasmania." The 

 female insect deposits her eggs in a longitudinal incision between the 

 two surfaces of the leaves of one of the Eucalypti, adjoining the mid- 

 rib. The eggs, about eighty in number, are placed transversely in a 

 double series. They are of an oblong form, two lines in length and 

 half a hne in breadth. On this leaf the mother sits till the exclusion 

 of the larvae (which takes place in a few davs) ; nor can she be made 

 to leave the spot except by actual force, clinging to the edges of 

 the leaf by her flexible tarsi. The larvse, when hatched, are of a 

 dirty-green colour, with shining black heads : they keep together in 

 the brood, arranging themselves in oval masses with their heads 

 pointing outwards. They appear to feed chiefly by night ; the 

 mother insect sitting with outstretched legs over her brood, preserving 

 them from the heat of the sun and attacks of their enemies with 

 admirable perseverance, never ofifering to use her wings (even when 

 disturbed) or moving from the spot. Instances are mentioned 

 where two mother insects were found tending one large brood, a 

 smaller adjacent one being without the parent; and, although so 

 anxious in the defence of the young, they allowed themselves to be 

 transposed to other broods, which they tended with equal assiduity 

 for a period of from four to six weeks. They were, however, never 

 observed to render any direct assistance to the larvae ; indeed the 

 broods which had been accidentally deprived of their mothers were 

 still in a thriving state. Previously to casting their skins, the larvae 

 arrange themselves in an oval mass with their heads pointing out- 

 wards, and the anterior legs elevated, resting on the four posterior 

 only. The remainder of the body is hkewise thrown upwards ; 

 and their tails meet in the centre, forming a conical mass, concealed 

 in the midst of which are the small and feeble individuals of the 

 brood. In a subsequent communication Mr. Lewis states that there 

 is but one brood in the year, and the earliest portion of their lives is 

 passed during the winter season, when they are subject to heavy rains. 

 When resting in the day the larvae, like those of most other Tere- 

 brantia, carry their heads erect, emitting a drop of a yellow gummy 

 fluid from the mouth ; and if touched they throw their heads back and 

 vomit this fluid in some quantity. It is very thick, and seems to be 

 given to them as a protection against Ichneumonidae, one of which 

 tribe preys upon them ; but the author had seen one of the Ichneu- 

 mons dead with tlie wings and legs covered and glued together by 

 this gummy matter. 



29. Perga smithii, Westw. (Plate XXXVI. fig. 6.) 



Fcemiua gracilis. P. lewisii similis, at multo minor, pallidior, ah- 

 domine nitido luteseente, dimidio apicali castaneo, tibiarum posti- 

 carum apice et articulis tarsormn posticorum ajncibus nigris. 



Long. Corp. lin. 6-7. Expans. alar, antic, lin. lOg-12. 



Hab. in Australasia. In Mus. Hopeiano. 



P.ferruginece, Leach, affinis, differt corpore graciliore, abdominis 

 dimidio apicali obscure castaneo ; tarsis elongatis, posticis nigro an- 



