

Observations on an Australian Mud Dauber etc. 31 
reopening them the next morning) which were attacking the inclosed cater- 
pillars; shortly, the wasp arrived at the nest (I did not see her behavior upon 
arrival), closing the etrance of the cell at once (hardly, I think saving its con- 
tents, because some of the ants were most probably shut in and would be quite 
capable oi destroying what was leit) and then daubing pellets of mud over the 
line of cells, continuing this up to noon (thus this disturbance by ants, at once 
stimulated the instinct of self preservation; the wasp discontinued her building 
operations at once and made eiforts to insure the safety of the progency already 
provided for) and through the afiternoon up to 5.30 p. m., July 4, as early as 
8.30 a. m., the mothes wasp was at work, continuing to cover the „flat“ row of 
cells with earth until noon. 
At this time, I distincetly saw her make two trips to a spot beneath the 
verandah and gather dry earth, applying it each time to a dry place on the nest; 
yet when these spots were examined after the female leit, they were wet and 
pliable and therefore the female must use some sort of saliva. Consequently, | 
went below to the spot which she was visiting and saw her make six successive 
trips to it; after each trip, [I examined the exact spot from which she had been 
gathering and at each place there was a small round concavity made by the 
mandibles periectly wet. But, under each of these it was dry and afterward I 
dug up with my knife all ihe earth near the spot and under it without encounte- 
ring moisture above the depth of two inches; the nature ofthe earth was sandy. 
The wasp was gathering sand from one little area which had become a grooved 
semicircle. Within an area oi several square feet at this place were many of 
these shallow cavities, most of them quite irregularly situated but at this time 
this wasp was visiting one particular spot where her gathering operations had 
iormed one of these cavities as noted, a shallow groove, crescentic in shape and 
resembling one which would be formed by drawing the tip of the middle finger 
gently over the sandy ground for a short distance and semicircularly. When the 
wasp was away at the nest, aiter her second trip during this observation, I ob- 
literated the individual, sınall pits making up the grooved semicircle (and made 
by the mandibles at each gathering) by gently drawing the tip ofa finger through 
them; when she returned her actions denoted that she sensed a ditierence — 
she hesitated and turned aside several times before finding the spot; this 
was repeated on her sixth return, immediately before which I had excavated 
the groove down to some distance with a knife. This did not disturb her much, 
however, as alter a few seconds she gathered the pellet of sand irom one edge 
oi the little excavation. Hence, this species has developed a habit of using her 
own saliva for the purpose of wetting the pellets of earth used in building ope- 
rations, an extremely useful adaptation in a country where (at least beiore the 
white man’s settlement) much time may elapse at one particular spot before a 
suitable mudhole could be found or elsewhere it would be necessary to restrict 
reproduction to the vicinity of permanent watercourses. 
This mother wasp continued to daub over her nest with earth pellets for 
a.while in the afternoon but left later; she was still visiting the dry spot beneath 
the verandah (a soit muddy spot was not thirty feet away in the roadway). At 
ll a. m., July 6 she returned and daubed the nest cluster for a short while, soon 
leaving. It was not seen again until 11.30 a. m., July 9, when the nest was daubed 
intermittently for an hour or two. 
I was absent until July 31. I was informed that the nest remained unchanged 
until the day before my return when the nest had heen broken off On the 
morning of July 31 I found that the eight upper cells had fallen to the floor of 
the verandah in one piece; these cells were empty but all were lined with silk, 
showing that they had contained grown larvae; this was probably the work of some 
bird. I removed the remaining three cells (1,2 and 3), all of which contained pupae, 
enclosed within stiff but very thin, white cocoons; the pupa of cell I was colored 
considerably, the others pale. The adult of cell I emerged on August 6 at noon; 
by this date, the two other pupae were more colored and fully so on August 12, 
emerging on August 14, 1912. 
The following significant facts were observed. 
(1). Variation in the situation, arrangement and form of the cells is usual 
and common. 
(2). The mother wasp has not learned that a partly filled cell leit open 
during the night is a source of danger; at any rate, that it would be more 
economical to close it, even if the egg is not placed in first. 
