XXIII LEUCOSPIS 543 



excursions is, Fabre believes, to ascertain if another Zeucospis egg 

 has been laid in the cell, and in that case to destroy it. For 

 the food, as we have said, being only enough for one larva, and 

 the mother Zeucospis frequently laying more than one egg in a 

 cell, it is necessary that all the eggs except one should be destroyed. 

 Fabre did not actually observe the act of destruction, but he 

 found repeatedly in his glass tubes that the supernumerary eggs 

 were destroyed, being, in fact, wounded by the mandibles of the 

 lirst-hatched larva. After several days of this wandering life 

 the tiny destroyer undergoes a first moult, changing its skin 

 and appearing as a very different creature (Fig. 357, C) ; it 

 is now completely destitute of any means of locomotion, very 

 deeply segmented, curved at one extremity, with a very small 

 head, bearing extremely minute, scarcely perceptible, mandibles. 

 The sole object of its existence in this state is to extract the 

 contents of the Chalicodoma larva, and appropriate this material 

 to the purposes of its own organisation. This it accomplishes 

 not by wounding, tearing, or destroying the larva, for that ap- 

 parently would not answer the purpose ; the contents must be 

 conveyed while still in their vital state to itself ; and this it 

 effects by applying its mouth to the extremely delicate skin of 

 the victim, the contents of whose body then gradually pass to 

 the destroyer, without any visible destruction of the continuity 

 of the integument. Thus the Ijcucospis larva gradually grows, 

 while the bee larva shrinks and shrivels, without, however, 

 actually suffering death. The process of emptying the bee larva 

 apparently does not occupy the Zeucospis more than two or three 

 weeks, being completed by about the middle of the month of 

 August ; afterwards the larva remains in the cell by the side of 

 the shrivelled skin of its victim for ten or eleven months, at the 

 end of which time it assumes the pupal condition, and very 

 shortly thereafter appears as a perfect Insect. 



Monodontomerus cupreus is another member of the Chalcididae 

 that lives parasitically at the expense of bees of the genus Chali- 

 codoma. Its habits have been sketched by Fabre,^ and exhibit 

 considerable difference from those of Zeucospis. It is much less 

 in size, and can accommodate itself to a greater variety of food ; 

 it will, in fact, eat not only the larva of Chalicodoma, but also 

 that of another bee, of the genus Stelis, that is frequently found 

 ^ Souvenirs entomologiques. Troisieme serie, 1886, p. 179. 



