368 ARACHNIDA ARANEAE CHAP. 



Mimetus interfector, of still more ferocious and piratical habits. 

 Its special quarry is Theridion tepidariorum. Sometimes the 

 Theridion overcomes the invader, and one case was observed in 

 which a second Mimetus was devouring a Theridion beside the 

 dead body of its predecessor, who had come off the worse in the 

 combat. 



The eggs of Theridion tepidariorum are also sometimes 

 devoured by this spider, and a similar propensity has been 

 observed in some English species, for Staveley 1 states that it is 

 common to see certain spiders of the genus Clubiona feeding upon 

 the eggs which have been laid by their neighbours. The larvae 

 of some Hymenopterous insects are parasitic upon Spiders them- 

 selves, and not upon their eggs. Blackwall found this to be the 

 case with the larvae of Polysphincta carbonaria, an Ichneumon 

 which selects spiders of the genera Epeira and Linyphia on 

 which to deposit its eggs. 2 The spider thus infested does not 

 moult, and is soon destroyed by the parasite which it is unable 

 to dislodge from its back. Menge, in his Preussische Spinnen, 

 enumerates several cases of parasitism in which the larva, as 

 soon as it has developed from the egg, enters the spider's body, 

 there to continue its growth. Spiders are also subject to the 

 attack of a parasitic worm, Gordius (cf. vol. ii. p. 173). 



Some of the most deadly foes of Spiders are the Solitary 

 Wasps. There are many species of Pompilus (vol. vi. p. 101), 

 which, having excavated holes in clay banks, store them with 

 spiders or other creatures which they have paralysed by their sting. 

 They then deposit an egg in the hole, and immediately seal up the 

 orifice. This habit is found to characterise the solitary wasps of all 

 parts of the world. Belt 3 relates the capture of a large Australian 

 spider by a wasp. While dragging its victim along, it was much 

 annoyed by the persistent presence of two minute flies, which it 

 repeatedly left its prey to attempt to drive away. When 

 the burrow was reached and the spider dragged into it, the two 

 flies took up a position on either side of the entrance, doubtless 

 with the intention of descending and laying their own eggs as soon 

 as the wasp went away in search of a new victim. Fabre 4 gives 

 an interesting account of one of the largest European Pompilidae, 



1 British Spiders, 1861, p. 102. 2 Ann. Nat. Hist. (1), xi., 1843, p. 1. 



3 Naturalist in Nicaragua, 2nd ed., 1888, p. 134. 



- Nouveaux souvenirs entomologiques, ch. xii. 



