528 



FuLLAWAY (D. T.). A New Hymenopterous Parasite of the Australian 

 Fern Weevil, Syagrius fulvitarsis, Pase. — Bull. Ent. Res., London, 

 xiii, pt. 2, August 1922, p. 201. 



Ischiogonus syagrii, sp. n., is described from two females and two 

 males reared from larvae of Syagrius fulvitarsis (Australian fern weevil) 

 at Nimbin, New South Wales [cf. R.A.E., A, ix, 517 ; x, 87]. 



Till YARD (R. J.).. The Life-history of the AustraUan Moth-lacewing, 

 Ithone fusca, Newman (Order Neuroptera Planipennia). — Bull. 

 Ent. Res., London, xiii, pt. 2, August 1922, pp. 205-224, 2 plates, 

 11 figs. 



A study of the life-history of Ithone fusca, Newm., during 1918 and 

 1919 has shown that the complete cycle normally requires exactly two 

 years. The adults emerge about sundown from the end of October to 

 mid-November, flight beginning after sunset. Swarming principally 

 occurs on calm, warm evenings, andmanj^ natural enemies lie in wait for 

 them and destroy vast numbers. 



The length of the various stages of /. fusca is on an average 31 days 

 for the egg, 1 year and 9i months for the five larval instars, about three 

 weeks for the larva in cocoon and another three for the pupa in cocoon, 

 while the adults live two or three days. Pairing usually occurs within an 

 hour or two of emergence, and most of the eggs are laid the same night. 

 The female, having located a soft place in the sand, digs down with her 

 abdomen and deposits from 200 to nearly 300 eggs, rolling each one 

 separately in the sand, which adheres to its sticky surface and forms a 

 protective covering. The larva, upon hatching, works down through 

 the top layer of dry soil, until it reaches the zone of slight moisture, 

 where it lives. During dry weather larvae can be found from U- ft. to 

 over 2 ft. below the surface, but after rain they work upwards, always 

 keeping in the zone of shght moisture. When the larva is full-grown, 

 it ceases to feed and penetrates to a lower level in the soil, where it 

 hollows out an elongated oval cell and then spins a silken cocoon. The 

 first cocoon was found on 12th September, and the earhest emergence 

 foUowing that date was on 30th October. The pupa apparently frees 

 itself from the cocoon and then comes to rest at some point in the soil 

 where the warmth of the sun is noticeable, waiting until slight cooling 

 has taken place before it discloses the imago. The stages are described. 



For a long time the food of the larvae remained undiscovered, but 

 experiment has shown that they feed on Coleopterous larvae present in 

 the soil, more than 90 per cent, of these being Scarabaeid grubs. The 

 method seems to be to burrow down underneath their prey and attack 

 it from below, sucking the victim dry. The fact that there is a remark- 

 able resemblance between the larva of Ithone and the Scarabaeid grubs 

 on which it feeds has caused the former to escape notice in the past. 



Various species of Ithonids are widely distributed in Australia, and 

 are therefore evidently capable of withstanding extremes of temperature 

 in the soil. They are most abundant along the sandy foreshores and 

 in light, loose soil, which is also the preferred habitat of the various 

 species of grass grubs. As these grubs are a serious pest in many parts 

 of the world, any addition to their natural enemies is important, and 

 attempts have already been made to introduce /. fusca into New 

 Zealand in the hope of controlling them. 



