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)

turret, and maybe carried on its construction (observations made in the summer of 1956 and during the recent investigation). The problem must be cleared up bv further observations. As is to be seen from the aboves, Odynerus spiricornis breeds on the loess wall of Tihany from the middle of June till the beginning of August. The highest number of their population was active on 6 and on 21 July. Their numbers were still on the increase in the first part of July, while it was considerably diminished in the cold and rainy weather in the middle of the month. III. The habits of Odynerus spiricornis Spin. R e y (1946) designates the three following phases in the life of 0. spinipes L.: the excavating of the nest, the depositing of the eggs, and the provisioning of the brood. Enlarging this classification to a certain extent, I distinguish the following phases in the nest-building activities of 0. spiricornis : 1. The search for a suitable nesting place, 2. The digging of the nest, 3. The depositing of the eggs, 4. Provisioning, 5. The closing of the nest, 6. Feeding. I have discussed the activities of the wasp in another paper of mine (L. Móczár 1960). The search for the nesting place Odynerus Nr. 3. The specimen hegan to scratch the wall hy its mandibles at 10 : 35, after a search for 14 minutes on 21 July. It flew away after 3 minutes. It returned at 10 : 45, and dug farther. At 10 : 48, I marked it by blue lacquer paint on its back during its work ; it departed, but appeared again at 11 : 25 and began to dig a fresh nest 80 cm away. It again flew off after 3 minutes, and again returned in 2. First, it hegan to excavate the wall, gnawing a small hollow in it, pasting the dug-out material onto the lower part of the hollow. Not much later, it had inadvertently brushed off the small ledge. At 11 : 40, it flew away toward the Balaton, returning at 11 : 44, then dug for a time, departing several times from its work. At 11 : 46, it was examining the darker, harder, sedimentary, lower-lying part of the loess wall, alighting on it repeatedly, abandoning the former place. It flew off after 10 minutes. At 12 : 35, it was hovering before the above site. Then it departed again, but shortly returned. It was still looking for a suitable nesting place at 13 : 16, commencinsi the construction of its final nest at 13 : 50 (cf. p. 389.). Odynerus Nr. 4. This specimen began scratching the wall at 11 : 25 on 21 July. Having excavated a semisphaerical hollow, it brought some water at 12 : 01. However, it wetted the loess wall 4 cm beside the former excavation, began digging in the softened place, then returned to the original nest. It departed at 12 : 01, continuing its digging after 1 minute. Then it flew away at 12 : 08, returning after 20 minutes, but it dug again beside the initial nest. Not much later, it returned to the original nest, scraping its minute ledge. It. flew away at 12 : 09, but when it returned, it flew into a burrow 9 em away. It hardly wetted it or spent any time there when it returned again to the original hollow. It flew away at 12 : 10, returning after 40 seconds, scraping again around the alien burrow. It flew off again at 12 : 13, returning after 42", and — after a hovering about for 20" — it dug out some material further away from the former diggings, and sealed up the above burrow. It finished this work at 12 : 14, then flew away, and after a minute pasted a fresh layer from the material of the first digging on the seal mentioned above. Then it was just flying around. It is improbable that this wasp would have begun the digging of its fresh nest before the sealing up of its earlier nest. It is much more probable that it was still so much in the state of uncertainty of looking for a fresh nest that the perception of the (alien) burrow elicited in it the recently executed reflex series of activity, the necessity of sealing up the burrow. Odynerus Nr. 7. This wasp was digging its nest on a projecting ledge at 12 : 35 on 21 July. It flew away at 12 : 37, but it was again working in 35 seconds. It. departed at 12 : 38, returning after 56", but it Avas scraping in the vicinity of the burrow, as if it wanted to make the surface more even. It