THE AUSTRALIAN MUSEUM MAGAZINE. 



85 



tlanj^er. Tliey roll a leaf, find a craok 

 or f-revieo, or construct a bole to pro- 

 tect themselves from the larger preda- 

 tory animals. They also fall a prey to 

 various insects, but usually only one 

 sjiecios is preyed ujion by any spider- 

 eating' insect. 



A certain large yellow wasp which 

 belongs to the family Pompilidae hunts 

 for one of those species that makes a 

 hole in the ground. These wasps can 

 be seen entering hole after hole until a 

 spider is found. The wasp boldly en- 

 ters. l)ut the spider, by far the more 

 active of the two, slips past, and, with 

 the Avasp close behind, an exciting cha-e 

 begins. As quick as a stroke of lightn- 

 ing will the spider seek and find shel- 

 ter, behind a stone, under a leaf, or any- 

 where that affords cover. The wasp is 

 usually left far behind, but, with tbe 

 persistance that is typical of its kind, 

 it will visit stone, stick, leaf, or hole, 

 along the line the spider took, and, 

 routing the refugee out of its hiding 

 place, Avill continue the cliase. 



Tliese liglitning darts of the spider, 

 whose usual habit is to sit motionless 

 liour after hour, require such excessive 

 energy that the harassed creature final- 

 ly becomes exhausted and is overtaken. 

 Should the spider enter a hole wherein 

 another spider is at home, the intruder 

 immediately makes a further lightning- 

 dart, perhaps towards its pursuer, in an 

 endeavour to escape falling a victim 

 to cannibalism. It is usual for the 

 wasp to win the cliase, but the quarry 

 may escape, if, as sometimes happens, 

 the wasp seeks it in another occupied 

 hole. In this case the wasp will ]u\r- 

 sue the new spider with the same fer- 

 vour and insistance, whilst the original 

 one is left to its own devices. The cap- 

 tured spider forms the food of the new 

 generation of wasps, as an egg is des- 

 tined to be buried with it. 



These observations, which differ in 

 several respects from those recorded of 

 other sjiecies of the family in various 

 parts of the world, were carried out at 

 Lindisfarne, near Hobart, Tasmania, 

 where these spiders with sapper-ways 

 are very plentiful. Doubtless similar 

 habits Avill be found under similar cir- 

 cumstances on the mainland of Aus- 

 tralia. 



There are at least two species of 



ichneumon flies that prey upon spiders 

 in the form of extei'nal parasites. The 

 larvae lie along the upper side of the 

 abdomen of their prey, attached near 

 the base, and with the head lying away 

 from the head of the spider. A larva 

 of the ichneumon has not been found in 

 a stage prior to tliis, where it remains 

 one or two days; within a niglit it 

 feeds, l)ecoming more and more bloated, 

 till finally nothing is left of the spider 

 ))ut skin. The larva then spins a cocoon 

 while hanging in the spider's web, and, 

 in a fortnight, there emerges the winged 

 form of the ichneumon. One species 

 occurs in Tasmania, a second in New 

 South Wales, and a third in Queens- 

 land, so probably other ichneumons Avitli 

 tliis lial)it will be found distributed over 

 Australia. 



The iHitboT wild wrote '" 'Coiuc into 

 my jiai Irtiiv' said th;' sjiidcr to ihv l1y" 

 could scarcely have been aware that 

 some flies enter the "parlour" of the 

 spider witli impunity; sometimes the 

 host and not the guest is the victim. In 

 Western Australia it is not an uncom- 

 mon siglit to see a robber-fl}^ dart at a 

 spider in the centre of a web, and, 

 seizing it in a most dexterous manner, 

 carry it away to feed upon at leisure. 

 The habit is apparently limited to one 

 species of I'obber-fly, which is rather 

 common in the vicinity of Perth. In 

 this case it is the fly itself and not the 

 larva that feeds upon the spider, and 

 it appears to form the only diet this 

 ]iarticular fly partakes of in the mati: 

 stage of its existence. 



A family of flies that also plays havoc 

 in the spider world contains species of 

 rather sluggish habits. They are known 

 as "bladder-flies" on account of the 

 blown out, bladder-like shape of many 

 of the species. The larvae of these flies 

 are internal parasites on spiders. 



The eggs of spiders also contribute 

 to the commissariat of the insect world 

 as witnessed in case of the mantispids 

 (not to be confused with "'mantids" to 

 which family they bear a close resem- 

 blance in form as well as name). The 

 larvae of these creatures feed upon 

 either tiie eggs or the newly-emerge(J 

 s]iiders I^efore they leave the egg-sac. 

 Recently in Queensland a small moth has 

 ])een found to feed upon the egg-sac of 

 spiders. 



