Boros István (szerk.): A Magyar Természettudományi Múzeum évkönyve 52. (Budapest 1960)

Móczár, L.: The loess wall of Tihany and the nesting of Odynerus spiricornis Spin. (Hymenoptera, Eumenidae)

mencement and during his work without narcotizing or cooling (it had constructed but a small ledge yet). It flew away immediately and never returned. Another dauber took also to wings when marked in a similar way during its work, but it returned and continued its activity after 15 minutes. Then I cooled down a third was]) 13 minutes after the start of its nest-constructing work, replacing it at its working site. It appeared in 37 minutes, and began to dig a fresh nest 80 cm away. Having narcotized by acetic ether and then marking a wasp intent on making its turret, I put it back into its edifice. It began clearing itself after 2 minutes, then flew away, but it reappeared again after 48 minutes and continued its work. Later, however, it was away for always longer periods, so that its turret was hardly longer than 15 mm even after 2 hours. A wasp, carrying a sawfly larve, was narcotized by acetic ether and then marked on 6 July ; it brought the next sawfly larve into its nest after the lapse of 55 minutes. It may be deduced from the above, and similar, findings that the wasps, at the commencement of their nest-building activities, are still very sensitive to external, disturbing effects. A narcotization by acetic ether is disagreeable, and those molested in the course of their work will generally leave their incipient nests. The first to return to their former activities are those which had been marked after the cooling down process. A wasp more immersed in its nest-building is less sensitive. This is still more true for a larve-carrying dauber. This is supported also by the fact that the sawfly larve can be taken away from it even by hand, and it will still return to its nest. It must be noted that Rey (1946) failed to observe a similar sensitivity on 0. spinipes. He captured four 0. spinipes specimens digging their nests, three others carrying food, and still another one just closing up its nest, setting them free, partly after 2—4, partly after 20 hours. According to him, all of them had speedily returned to their work. By the use of the markings, I was able to establish that they visited 11 turrets on 20 July, 18 ones on 21, 12 on 22, 15 on 23, and 4 on 24 (Plate I, fig. 2). If we suppose that they were active on a single turret during a given day, then there were the above mentioned wasps on the wall. We may add another 20 percent to this number, due to the wasps working on the higher, unattainable parts of the wall. We may also infer, on the basis of the markings, on the number of days spent in activity in the several nests. It was found by the observation of 34 nests that they visited 1 turret for 5 days, 4 turrets for 4 days, 3 for 3 days, 10 for 2 days, and 14 turrets for 1 day. The red spots of the markings on 6 July at the bases of two turrets were indubitably recognizable also later, and these buildings were still visited by the wasps. But it could not be established for certain weather the visitors of the sixth, that is, the twentieth-twentyfirst of July were the same, because I did not observe a single red-marked wasp after the seventeenth of July. I may well be possible that the india ink markings had tracelessly worn off during the two weeks, and that the identical wasp was constructing a fresh cell in the nest. This is the more probable as it had added one and a half cm to the turret on the twentyfirst, obviously from the content of the fresh cell. On the other hand, the „quarreis" (Table III, fig. 10) occasionally observed around the entrances of the turrets — when a wasp will drive away the other one — may render probable the assumption that an alien wasp trespassed into the