"258 ENTOMOLOGICAL SOCIETY 



tion of the wasp, I commenced to dig with my knife, and was 

 rewarded by finding, at a depth of about three inches, a fully 

 grown larva of Heterocampa sub-albicans Pack., as fresh and 

 bright as if it had been placed there but a moment before, and 

 attached to it, at about the middle of the body, glued on to it 

 for a short distance, an elongated and slightly curved white 

 egg, about 3.5 mm. in length, by about i mm. in diameter, which, 

 there can be no doubt, had been deposited there by this wasp, 

 after the caterpillar had been placed in position. The burrow 

 was then filled up and the surface smoothed so nicely that it 

 was impossible for human, and perhaps other eyes, to discover 

 the whereabouts of the precious treasure. Why, however, the 

 wasp should return, after having apparently finished its task ; 

 be able to find the place again, go through such strange actions, 

 and place the pebbles on top of the burrow, is difficult to 

 explain. It may be then that its motherly instinct and love 

 for its offspring urged it to revisit the spot to satisfy itself that 

 everything was secure against intruders, and, to make surety 

 doubly sure, to place obstructions on top by which other insects 

 might be detained from entering the ground at this particular 

 spot. 



Dr. Fox said that he had observed on one occasion the inter 

 mittent action of the female of this species in constructing its 

 burrow in hard ground. The work would be prosecuted with 

 energy for a few minutes and then abandoned, to be taken up 

 again after a short interval. 



Mr. Ash mead said that he had had a similar experience in 

 Florida, but had not seen anything corresponding to the piling 

 up of pebbles described by Mr. Pergande. 



Mr. Schwarz remarked that it would be interesting to know 

 if this insect always takes the same kind of caterpillar with 

 which to store its burrow. 



Dr. Fox said, as opposing this view, that finding in adjacent 

 cells of wasps totally distinct spiders was a common experience, 

 and that in one instance (locality Massachusetts) one cell 

 examined contained almost altogether specimens of Lathro- 

 dectus mactans, interesting as furnishing the most northern 

 range of this spider, and the adjoining cell was filled with 

 Thomisoid spiders. 



Mr. Ashmead remarked that the wide distribution of the 

 Ammophila in question renders a singleness of food-habit very 

 improbable. 



