Another Prober 



That she should bore through the cocoons 

 of the Stelis, a parasite of the Mason-bee, 

 does not surprise me at all: I know how in- 

 different my bold visitor is to the nature of 

 the victuals destined for her family. I have 

 noticed her presence in the homes of Bees 

 differing greatly in size and habits: Antho- 

 phorae, Osmise, Chalicodomae, Anthidia. The 

 Stelis exploited on my table is one victim 

 more; and that is all. The interest does not 

 lie there. The interest lies in the manoeuvres 

 of the insect, which I am able to follow under 

 the most favourable conditions. 



Bent sharply at right angles, like a couple 

 of broken matches, the antennae feel the co- 

 coon with their tips alone. The terminal 

 joint is the home of this strange sense which 

 discerns from afar what no eye sees, no scent 

 distinguishes and no ear hears. If the point 

 explored be found suitable, the insect hoists 

 itself on tiptoe so as to give full scope to the 

 play of its mechanism; it brings the tip of the 

 belly a little forward; and the entire ovi- 

 positor — inoculating-needle and scabbard — 

 stands perpendicular to the cocoon, in the 

 centre of the quadrilateral described by the 

 four hind-legs, an eminently favourable po- 

 sition for obtaining the maximum effect. For 



67 



