Observations on an Australian Mud Daiiber etc. 29 



land. Tlie second story was surrounded by the verandah usually present on 

 tropical residences. 



I. The wasp was first observed in June 11 (1912), thus in the winter. It 

 was working upon a nest on the floor oi the north verandah, several 

 inches from the wall. One cell had been built. stocked and closed; a second 

 cell was just about half built and was finished by 1 1 50 a. ni. It was exactly 

 like a carafe or flat water-bottle, neck nearly sessile and central and with an 

 opening through it with a diameter of not more than an eighth of an inch. At 

 noon, the foUowing day, the female was observed to return to this second cell 

 carrying with her a long, slender, green noctuid Caterpillar which she passed 

 through the entrance by paying it out through her legs, using the mandibles- 

 ior power. She left straightway. At 2 p. m./the second cell was plugged; it 

 was open at 9 a. m. The mother wasp was not seen again that day; she did 

 not pass the night at the nest. At ten o'clock. June 13, a third cell had been 

 commenced, tilted against the bottom side of the first; the walls were being 

 built up uiiiformly. in successive rings, gradually arching over and forming a 

 roof; at 10. a. m. they had been raised about a tenth of an inch; at 10 33',2. 

 the cell was roofed, leaving the entrance in the centre; eleven minutes later, the 

 neck or mouth was completed; its axis was inclined to the east and a quarter 

 way to the horizon. As soon as completed, the female left at once. While 

 bui'lding this cell, she visited two different places, making a longer trip around 

 the back of the house, presumably to a small field of maize where the soil was 

 moist and a shorter one to a place beneath the verandah (nearly under the 

 nest) where the soil was sandy and perfectly dry. On the longer trips, she 

 probably obtained wet earth but on the shorter ones certainly only dry sand. 

 Sometimes, she stopped at the sand and gathered it en route home from the 

 longer trip. I saw her make two trips in succession to the sand, adding the 

 bürden of each to the cell and then leaving for the longer trip. The addition of 

 each load of sand did not absorb all of the moisture of the cell's wall and thus 

 was workable. The wasp returned to the third cell at 11.25 a. m. and added to 

 it a green noctuid caterpillar about two thirds grown; I carefuUy extracted this 

 after she left but it contained no egg. It was lying curved around the bottom 

 of the cell (the floor of the verandah) and was alive, quite lively when disturbed 

 but not able to crawl; it seemed in much the same condition as a parasitized 

 larva. At 1.20 p. m., the cell contained another caterpillar; at 2.45 p. m. a 

 second one w^is added, the fomale immediately flying off, returning at 2.47 and 

 capping the entrance with mud; several trips were made for this purpose; it 

 seems that the absence of the first caterpillar was not at all noticed. Upon my 

 return at 5.30 p. m., the nest was unchanged as far as additions to it were 

 concerned, the wasp apparently absent but it was noticed that the roof of the 

 third cell had been broken, presumably by a bird or some rodent. On the 

 foUowing morning (June 14), the second cell had also been broken, one of its 

 contained caterpillars exposed; it had already been attacked by ants; the third 

 cell was now broken down entirely, its Contents missing. This was, to all 

 appearamces. the work of mice, several of which had been seen in the building. 

 A few pellets of excrement resembling that of mice were found scattered near 

 the nest and the cells appear to have been gnawed rather than pecked at. The 

 mother wasp first appeared at the nest at 10 a. m. but I did not see her behavior. 

 However, she flew off and returned with earth, covering the irregulär break in 

 the second cell, continuing to daub the nest until 12.30 p.m., until the first and 

 second cells had been covered by a coating of mud. The third cell was entirely 

 neglected. The female then deserted the nest. On the morning of June 15, I 

 again iound that a hole had been gnawed through the top of the second cell; 

 the female did not return to cover it. The hole was narrow as if made by 

 long teeth. 



II. A second female of this species was observed at 10 o'clock June 19, 

 1912 building a nest near the first one but against one of the uprights of the 

 wall of the house, about three feet up from the floor of the verandah. Half of 

 a second cell had been finished, above and against the first; these cells have 

 their long axis at right angles to the axis of the joist; they were not rounded 

 in outline like those of the""first nest but cylindrical oval or oven-shaped with a 

 central entrance, the whole not unlike in form those of the North American 

 Scelip/iroii cL'mentarius Drury. Thus, this Australian species seemingly adapts the 

 form of its cells to the Situation in which the nest is being built; at any rate. 



