Bird nests occupied by Sphecidae wasps in Brazil

The present paper reports on additional ins tances of nest cells of a wasp (Pison sp., Sphecidae} in nests of a hummingbird (Phaethornis ruber, Trochilidae) and a new instance in the nest of a flycatcher (Tolmomyas fiaviventris, Tyrannidae).

Wasps of the genus Pison are known to nest in bamboo tubes in Europe (Grandi , 1961). Yosh1moto (1965) reporte on Pison argentatum nesting in holes in lava walls of buildings. Also, Yoshimoto reports that in Thailand P. argentatum nests on walls while P. punctH forms, P. suspiciosum and P. strandi use beetl e burrows or bamboo tubes to build partitionedcelled nests. In Belém. Pará, Brazil, I reported (Oniki, 1970a(Oniki, , 1970b) the occurrence ot nest cells of Pison sp. in ocupied nests of Reddish Hermit, (Phaethornis ruber, Trochilidae). Here I report on nest cells of the same wasp species in oher nests of the same hummingbird, and also from the nest of a Yellow-breasted Flycatcher (Tolmomyias 1/aviventris, Tyrannidae).

MATERIAL AND METHODS
In the course of detailed studies of nesting seasons of birds, I returned to the Área de Pesquisas Ecológicas do Guamá of the Instituto de Pesquisas Agropecuárias no Norte (IPEAN) at Belém , from April 1972to May 1973 In studies of nests of many species of birds, I watched for further occurrences of wasp cells. In some cases. wasps were observed entering a bird 's nest while it contained eggs or young. However, bird nests were only collected after the young bird left the nest or the eggs or young were destroyed . Then wasp cells were cour1'ted , and placed in jars in the laboratory so that adult wasps could emerge .

R.ESULTS
In 1972-1973, I encountered wasp cells in 2 out of 5 nests of Rcddish Hermits, Phaethornis ruber, and in one nest of a Yellow breasted Flycatcher, Tolmomyias flaviventris. Table I indicates that wasp cells were in nests of 0 . 6 to 2. 7 m in height. Wasp cells were found in nests during May, June and July. Earlier I (1970b) found wasp cells in June, July, August and October . The number of wasp cells was 7 and 3 in P. ruber nests and about 20 in the r. flavlventris nest.
The Reddish Hermit nest found on 28 June 1972, had 2 tiny young . Both young developed in the nest but on 16 July only one young was left. On 17 July the nest was empty . This nest was collected on 31 July 1972, when it had severa! half-built wasp cells; I put it in a glass jar to obtain emerging wasps .
The other Reddish Hermit nest, found 4 July 1972, had 2 eggs. Two tiny young were in the nest on 16 July. The young were develop ing in the nest but this was found empty on 27 July . The nest was collected on 1 August. lt had 3 wasp cells and they were placed in a jar. Two adult wasps were found dead on 17 September 1972.
The Yellow-breasted Flycatcher nest ( Fig .  1) found on 9 May 1972 had 2 eggs. A wasp was first noticed carrying mud and entering the si de of the nest on June 6 . One o r two wasps carne 2 times in 2 seconds and cleaned the antenna before leaving the bird nest. On 7 June the wasp was not present but the previous day's cell was closed and another cell was half built. On 8 June the wasp was not present but the second cell was three-fourths completed . On 9 June the wasp was not present but the cells were almost closed. (The two young birds flew out of the nest on 10 June ( • ) -UNICAMP, Instituto de Biologia, Departamento de Zoologia Ac:rA AMAZONICA 5(3) : 301·303 . 1975 as the nest was touehed) . On 13 June the wasp was in and repairing the last cell, whieh was a little damaged by the previous night's rain. On 15 June, the bird nest and an adult wasp were eolleeted soon after it entered the nest with mud. About twenty eells were then separated from the inside of the bird nest and plaeed in a jar. Dates when emerged adults were found in the jar are as follows: From the Yellow-breasted Flyeatcher nest, 18 wasps that emerged were males and 2 were females. The wasp opens one ·lid" of its barrel-shaped eell in emerging. Average dimensions of 8 sueh eells were: 1 .3 em long and 0.6 em wide.

CONCLUSIONS
Aeeording to Table 1, the wasp breeding Oetober. The size of the bird nest seems to season iso now known to extend from May to limit the number of wasp eells, beeause the hummingblrd nests had 7 and 3 eells but the larg flyeateher nest had about 20 eells and ohers were still heing built.