ore JHR 39: 119-153 (2014) JOURNAL OF *0eerrvewed opevaccets ural doi: 10.3897/JHR.39.784 | (Met Hymenopter a http://jhr.pensoft.net/ The insertional Society of ymenoptersts. RESEARCH First contribution to the bionomics of the pollen wasp Celonites fischeri Spinola, 1838 (Hymenoptera, Vespidae, Masarinae) in Cyprus In memory of Friedrich W. Gess Volker Mauss!, Andreas Miiller? I Staatliches Museum fur Naturkunde, Abt. Entomologie, Rosenstein 1, D-70191 Stuttgart, Germany 2 ETH Liirich, Institute of Agricultural Sciences, Biocommunication and Entomology, Schmelzberestrafse 9/LFO, CH- 8092 Liirich, Switzerland Corresponding author: Volker Mauss (volker.mauss@gmx.de) Academic editor: Jack Neff| Received 4 May 2014 | Accepted 19 August 2014 | Published 26 September 2014 Attp.//zoobank. org/13D25DFD-B7F6-42FF-9EF2-258E574DDCAA Citation: Mauss V, Miiller A (2014) First contribution to the bionomics of the pollen wasp Celonites fischeri Spinola, 1838 (Hymenoptera, Vespidae, Masarinae) in Cyprus. Journal of Hymenoptera Research 39: 119-153. doi: 10.3897/ JHR.39.7841 Abstract Celonites fischeri was recorded from ten localities in various open, disturbed habitats in North-West Cy- prus. The species is probably narrowly oligolectic exploiting exclusively flowers of Echium (Boraginaceae) as the sole pollen and nectar source. Females perform a pollen collecting strategy hitherto unknown in pollen wasps; they ingest pollen from fresh anthers of Echium flowers that have just started to open by forcing their head into the only slightly opened corolla. Males patrol along Echium plants in search for females. Mating was mainly observed at Echium flowers but also occurred in the area of a male sleeping ageregation. The aerial nest, consisting of 2—5 earthen cells sometimes covered with an additional thin layer of earth, is attached to stones or plants. Nest building and soil collection behaviour are described and an ethogram of a nesting female observed during three consecutive days is given. Males form sleep- ing aggregations at particular sites that are continuously used over at least eleven consecutive nights, even though the size of the male groups may vary from day to day. During sleeping, the males characteristically curl their bodies around withered stems. Keywords Palaearctic, Echium, flower association, oligolecty, mating behaviour, nest construction, sleeping aggregation Copyright Volker Mauss, Andreas Miiller. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 120 Volker Mauss & Andreas Miiller / Journal of Hymenoptera Research 39: 119-153 (2014) Introduction The knowledge of the bionomics of Palaearctic species of the pollen wasp genus Ce- lonites is still very limited. Hitherto, forty-six species of Celonites have been recorded in the Palaearctic region (Carpenter 2001; Gusenleitner 2002, 2007, 2012; Mauss 2013), but detailed bionomical information has been published only for Celonites ab- breviatus (Villers, 1789). Studies on this species refer to mating (Mauss 2006), nesting behaviour (Lichtenstein 1869; Ferton 1901, 1910; Bellmann 1984, 1995), flower as- sociation and flower visiting behaviour (Bequaert 1940; Schremmer 1959; Bliithgen 1961; Bellmann 1995; Miiller 1996; Mauss 2006) and male sleeping aggregations (Amiet and Mauss 2003). Further information is restricted to a few flower visiting records for Celonites mayeti Richards, 1962, C. andreasmuelleri Mauss, 2013, C. afer Lepeletier, 1841, one species of the C. phlomis-group and six species of the subgenus Eucelonites (Bequaert 1940; Richards 1962; Gusenleitner 1973; Mauss 2013). Moreo- ver, Lichtenstein (1875) published a short and fragmentary description of a nest of C. mayeti (erroneously named as C. fischeri). Bionomical information about Celonites fischeri is lacking, despite a short, uncon- firmed note of Bingham (1898), who stated that this species had been reared from cylin- drical mud nests in Aden (Yemen). The geographic range of C. fischeri extends over North Africa, Cyprus, the Middle East and the Arabian Peninsula (Richards 1962, 1984; Car- penter 2001). Together with C. afer the species belongs to the C. fischeri-complex. The C. fischeri-complex and the C. abbreviatus-complex form the C. abbreviatus-group within the subgenus Celonites s. str. (Mauss 2013). The C. fischeri-complex is characterized by a normal facial pilosity thereby differing from species of the closely related C. abbreviatus- complex, which are equipped with a specialised pollen collecting apparatus on the frons consisting of knobbed setae (Mauss 2013). In C. abbreviatus, these knobbed setae serve to remove pollen from the nototribic anthers of various species of Lamiaceae (Schremmer 1959; Bellmann 1995; Miiller 1996; Mauss 2006). Other members of the C. abbreviatus- complex like C. mayeti and C. andreasmuelleri were also observed to visit flowers of this plant family (Bequaert 1940; Mauss 2013). Due to this difference in facial pilosity, host plant choice and flower visiting behaviour are expected to differ between the members of the two closely related Palaearctic species complexes of the C. abbreviatus-group. The aim of this study is to perform a detailed investigation of flower association and flower visiting behaviour, mating, female brood care and male behaviour in Ce- lonites fischeri and to compare the biology of this species with that of other members of the C. abbreviatus-group, some Ethiopian species of Ce/onites as well as other aerial nesting members of the Masarini. Material and methods Investigations were carried out from 20 May to 30 May 2013 in the vicinity of Paphos in north-western Cyprus. The study area has a Mediterranean climate with hot, dry First contribution to the bionomics of the pollen wasp Celonites fischeri Spinola, 1838... 121 summers and mild, rainy and rather changeable winters (Meteorological Service 2014). The average annual precipitation in Paphos is about 370 mm (Baier et al. 2009). The mean temperature in the hottest (August) and coldest month (February) is 26 °C and 13 °C, respectively (Flint and Stewart 1992). During the study period, the weather was mainly sunny and warm with maximum air temperatures above 25 °C, reaching 30 °C on three days (suboptimal conditions with clouds or haze predominated in the after- noon of 24 May and in the morning of 26 May and 29 May). On 22 May and 24 May, Celonites fischeri was searched for systematically in the vicinity of Paphos by checking promising sites with large Echium populations. Geographic coordinates (WGS 84) were measured using a Garmin GPS 12. Celonites fischeri was found at 10 localities [I Kato Paphos 34°44.495'N 32°26.004'E; II 0.5 km north of Agios Georgios 34°54.528'N 32°19.606'E; III 1 km south-east of Coral Bay 34°50.582'N 32°23.232'E; IV 1.5km south-east of Drousia 34°57.683'N 32°24.834'E; V Prodromi 35°01.779'N 32°24.798'E; VI 3 km south-west of Prodromi 35°00.760'N 32°23.584'E; VII 2 km south-west of Nikoklia 34°43.007'N 32°32.956'E; VIII 1 km north of Choletria 34°46.462'N 32°36.448'E; IX 0.5 km south-south-west of Praitori 34°50.672'N 32°44.500'E; X 0.5 km south of Pachna 34°46.120'N 32°47.334'E]. Most studies were conducted at locality II at the northern periphery of Agios Georgios, a disturbed Phrygana fragment of about 900 m7’, which was irregularly grazed by goats and rarely also by donkeys (Fig. 3). The area was delimited in the east by large thick bushes and in the south by a small track and an adjoining banana plantation. To the west and the north, the area was separated from the adjacent costal Phrygana of the Akamas Peninsula by two small tarred roads. In the area, 26 richly flowering patches of Echium angustifolium Mill. (Boraginaceae) were present varying in size between 0.25 to 2 m? (Fig. 46). In addition, fifteen other plant species were in flower [Asteraceae: Calendula arvensis L., Carduus nutans L., Centaurea hyalolepis Boiss., Chrysanthemum coronarium L., Pallenis spinosa (L.) Cass, Scolymus hispanicus L., Asteraceae spec.; Boraginaceae: Heliotropium hirsutissimum Grau.; Bras- sicaceae: Sisymbrium irio L.; Fabaceae: cf. Lotus spec.; Lamiaceae: Ajuga chamaepitys (L.) Schreb. palaestina (Boiss.) Bornm., Teucrium micropodioides Rouy; Malvaceae: Malva cretica Cav.; Primulaceae: Anagallis foemina Mill.; Ranunculaceae: Delphinium peregrinum L.]. For all documentations of observations the local time (= Greenwich Mean Time + 3h) was used. Sunrise was approximately at 5h35, sun’s zenith at 12h45 and sunset at 19h50. Time intervals were measured using a digital stop-watch. Observations were made with a close-up binocular (Pentax Papilio 8.5x21) and documented by using a Canon EOS camera with a 180 mm or 100 mm macro-lens (scale up to 1:1, resolution 18 mega pixel) and macro flash-lights. Specimens of all plant species flowering at locality II were collected and pre- served dried. The material was placed in the herbarium of the Staatliches Museum ftir Naturkunde Stuttgart (Herbarium STU). The plant taxa were identified following Meikle (1977-1985) and Tutin et al. (1964-1980). Flower preferences of imagines were studied by counting the number of sightings (= first observations) of flower visiting 122 Volker Mauss & Andreas Miiller / Journal of Hymenoptera Research 39: 119-153 (2014) Figures 1-5. Habitat of Celonites fischeri at locality 1 0.5 km north of Agios Georgios, Cyprus: | Nest site of nest F attached to a dwarf shrub (Asteraceae) 2 Bare area in the centre used by females of C. fischeri as a quarry site (qs) 3 Disturbed Phrygana (viewed from the south-west; with patches of Echium angusti- folium (E), sites of three nests (D, F, S), quarry site (qs) and male sleeping aggregation m,) 4 Nest D and nest S attached to the same stone (viewed from the north, nest S not visible behind the side of the stone) 5 Nest GB attached to stone. First contribution to the bionomics of the pollen wasp Celonites fischeri Spinola, 1838... 123 individuals while walking randomly across the area at all localities (total investigation time 18.25 h). Flower visiting behaviour of Celonites fischeri at Echium angustifolium was investigated at various patches of this plant at the localities I and II for 15 h in total. Pollen samples from two brood cell provisions of nest F (see below) from locality II were prepared using the method outlined by Westrich and Schmidt (1986). In addi- tion, pooled pollen samples from four localities (II, III, VI and IX) were prepared each with pollen from the crops of five females previously fixed in Duboscq-Brasil solution (Romeis 1989). The different pollen types were ascertained under a light microscope at magnifications of 400x or 1000x and determined to generic level with the aid of a refer- ence collection consisting of pollen samples of 500 mainly Mediterranean plant species. The behaviour of a female at one of the nests (nest F; see below) was continu- ously investigated from 27 May until 30 May except for the individual’s resting period during the night (total observation time 27.5 h). Spatial and temporal behavioural patterns were reconstructed in more detail by analysis of sequences of photographies repeatedly taken during the observation period. Activities inside the cell were observed with the aid of a magnifying hand mirror. The nests were marked in the field with little ice-cream national flags and named after the country code of the flag used (Fig. 5). Nest GB was removed on 26 May, nest S and D on 27 May, and nest F on 30 May. In the field, cell dimensions were meas- ured using a strip of millimetre paper (accuracy 1 mm). The brood cells were opened on June | and investigated under a stereomicroscope (Wild M3, magnification up to 40x, ocular micrometer with a maximum accuracy of 0.024 mm). The remnants of the nests as well as dry specimens of males and females from all localities were placed in the collection of Volker Mauss. Behaviour and activity of males at sleeping aggregations were recorded at locality I both by point observations and during random searching on 20 May between 15h00 and 17h30, and at locality II by short observations on eight days. The number of males in each group (defined as all males sleeping together on the same stem end for a night) and the number of male groups were systematically counted in the evening, when male activity had completely stopped and all males remained motionless in sleeping position (at locality I from 20 to 30 May between 19h20 and 20h00; at locality II on 21, 23 and from 25 to 30 May between 17h40 and 19h00). Results Habitat Celonites fischeri was found in various open and disturbed areas, including Phrygana fragments, coastal dunes, abandoned building areas and olive groves, as well as road sides. The localities were situated at altitudes between 10 m and 660 m above sea level. They were characterized by a considerable quantity of Echium angustifolium. Open water sources were always lacking. 124 Volker Mauss & Andreas Miller / Journal of Hymenoptera Research 39: 119-153 (2014) Flower association During random searching, all 46 sightings of flower visiting females and all 8 sightings of flower visiting males of Celonites fischeri were exclusively recorded at Echium angus- tifolium. Likewise, 68 females and 13 males recorded during point observations visited flowers of E. angustifolium. Visits to flowers of other plant species were not observed. Both males and females showed two different types of behaviour at the flowers. The first behaviour served presumably for nectar uptake. The wasp alighted on the upper margin of the corolla and moved quickly head first deep into the corolla tube so that only distal parts of the metasoma remained visible in the flower opening (Figs 6, 8). Within the flower, the ventral side of the wasp was always orientated towards the upper wall of the corolla and its dorsal side towards the filaments and the style (Fig. 8). The wasp stayed in this position for a moment before it moved backwards out of the corolla tube and flew off. On a few occasions, when the wasp was leaving the flower, distal parts of the protruded proboscis were visible for a moment before the proboscis was complete- ly retracted, indicating nectar uptake (Fig. 7). The median duration of nectar uptake by females was 3.2 s (range 1.6—9.8 s, n = 18). Nectar uptake was observed only at com- pletely open flowers in full blossom. The second behaviour served apparently for pollen collection. The wasp alighted on the corolla and worked an anther with mandibles and maxillae (Figs 9, 13), while the proboscis remained retracted. At the same time, the fore legs made brushing movements from the anther towards the mouth and were repeat- edly moved between the moving mouthparts. During the whole process the wasp held on only with its mid and hind legs with the meso- and metasoma remaining outside the corolla. The median duration of pollen uptake by females was 79.6 s (range 5.1—229.9 s, n = 15), which is significantly longer than the time for nectar uptake (Mann-Whitney Test: p (2-tailed) < 0.001). Pollen uptake by females was recorded at flowers with open (Fig. 13), half opened (Fig. 12) and only slightly opened corollae (Fig. 11), depending on the age of the flowers. In the latter case, the females forced their head into the only slightly opened corolla of flowers that had just started to open (Fig. 10, 11). The median duration of pollen uptake by the females did not differ significantly between flowers in different phases of corolla opening (Fig. 47; Kruskal-Wallis Test: Chi? = 0.72, df = 2, p = 0.70). Ona single occasion a male was also observed to take up pollen from a flower with only slightly opened corolla tube while all other visits took place at open flowers. Females were often observed to fly slowly past many flowers within an Echium patch before finally alighting on a particular flower where they started to take up pol- len. During such an “inspection flight”, a female sequentially approached flowers, but shortly before she came into contact with the corolla she changed the course and di- rected her flight towards another flower where the whole process started anew. Inspec- tion flights were infrequently interrupted by perching on twigs or dry leaves, which was accompanied by cleaning behaviour in two instances. Foraging females were oc- casionally observed to switch from nectar uptake to pollen uptake or vice versa during a single flower visit as well as on consecutive visits to different flowers. The crop content of all females investigated and the two brood cell provisions from the same nest consisted exclusively of pollen from Echium (more than 99%). First contribution to the bionomics of the pollen wasp Celonites fischeri Spinola, 1838... 125 Figures 6-13. Flower visiting behaviour of Celonites fischeri at Echium angustifolium: 6 Female entering flower head first for nectar uptake 7 Female leaving flower after nectar uptake with proboscis still protruding 8 Male deeply inside corolla tube during nectar uptake 9 Male feeding on pollen directly from an anther 10-1 1 Female taking up pollen from flower with only slightly opened corolla tube 10 from anther ac- cessible from outside II after forcing her head into the corolla tube from anthers inside the corolla tube 12-13 Females taking up pollen from the same flower at different stages of corolla opening 12 corolla half open 13 9.5 min later corolla completely open. 126 Volker Mauss & Andreas Miiller / Journal of Hymenoptera Research 39: 119-153 (2014) Mating Mating behaviour was observed both at flowering patches of Echium angustifolium and in the area of a male sleeping aggregation. Males were frequently observed to patrol in a constant flight slightly above the Echium plants, sporadically interrupted by perching on inflorescences or on dry, hori- zontal stems near Echium plants (Fig. 21). Patrolling males sometimes approached each other over a short distance, but then continued their flights without any further interaction. On one occasion, two patrolling males flew towards each other, hovered face to face at a distance of about 1 cm and soared up in this position for approximately 5 cm, before they flew off in different directions. Patrolling males were observed several times to pounce on a flower visiting or perching male and, in a few incidents, they performed mating movements (Fig. 19) before flying off. The behavioural sequence during copulation can be subdivided into three phases: 1. initiation, 2. insertion, 3. separation. At flowers, initiation always started by a pa- trolling male pouncing on a flower visiting female. In 12 out of a total of 16 cases, this was unsuccessful, since the female fell to the ground or flew off, remained on the flower without further interaction with the male or the male turned away before reaching the female (Fig. 14). In four cases, pouncing was successful and initiation behaviour was continued. After alighting on the dorsal mesosoma of the female the male held on to it (Fig. 15) and orientated his body axis parallel to hers. This resulted in a position, in which the head of the male was slightly anterior to the female’s head with the male antennae orientated downwards and his fore legs placed on frontal parts of the female’s head (Fig. 16). Then the male protruded the distal end of his proboscis at least for a short moment, raised his antennae and moved backwards on the back of the female (Fig. 20). During this process, the male antennae were orien- tated obliquely upwards and the male genitalia were already visible in the opening of the genital chamber. Finally, the head of the male was positioned above the posterior half of the female mesosoma and the basal parts of his fore legs were placed over the base of her wings and tegulae along with the fore tarsi on the sides of her mesosoma (Fig. 17). His mid and hind legs held laterally on to the anterior segments of her metasoma. The posterior end of the male metasoma was well behind the tip of the metasoma of the female (Fig. 18). The male genital chamber remained open and the genitalia were somewhat protruded. The mouthparts of the male were retracted with one exception when the distal end of the proboscis was still in a protruded position. The female usually continued pollen uptake. During the following insertion phase the male genitalia were inserted into the female genital chamber. This was observed only once with certainty at flowers and lasted for about 10 s. Separation was a short process in which the male genitalia were removed from the genital chamber of the female and both partners flew off directly. On two occasions it was observed that a second male alighted on the back of a copulating male (during initiation and inser- tion respectively) for a few seconds (Fig. 20). Mating behaviour away from flowers was only observed once: At the male sleep- ing aggregation m, on 21 May at 15h49 a female alighted on a fine, dry twig where First contribution to the bionomics of the pollen wasp Celonites fischeri Spinola, 1838... 127 Figures 14-21. Mating behaviour of Celonites fischeri: 14 Pouncing male turning off before reaching a flower visiting female 15 Male alighting on the mesosoma of flower visiting female, trying to hold on 16 Anterior position of the male during initiation, in which his head is a little anterior to the head of the female 17 Posterior position of the male during initiation, in which the head of the male is positioned above the posterior half of the mesosoma of the female 18 Male in posterior position during initiation, trying to insert genitalia into the genital chamber of the female. Note protruded male proboscis 19 Male performing mating movements after pouncing on a perching male 20 Male alighting on a pair in initiation phase. Note protruded proboscis of primary male 21 Male perching on dry stem of perennial herbaceous plant. 128 Volker Mauss & Andreas Miller / Journal of Hymenoptera Research 39: 119-153 (2014) she remained for 7 min, while males were absent. In the beginning the female folded her wings under her metasoma. Later on she slightly opened her wings and spread her antennae. Then a flying male appeared and alighted directly on the mesosoma of the female, moved backwards on her back and inserted his genitalia into her genital cham- ber for 8.1 s before the partners separated and flew off. Female brood care Nest structure: Four nests were discovered at locality II (Table 1). All nest sites were less than 5 m away from patches of Echium angustifolium (Fig. 46). Three nests (GB, D and S) were attached to medium sized stones less than 10 cm above the ground. The nests were on oblique to nearly vertical lateral parts of the stones exposed to the west or north and were more or less hidden by vegetation (Fig. 4, 5). A fourth nest (F) was placed approximately 25 cm above the ground on a narrow, almost vertical stem about 10 cm inside of a dwarf shrub of the family Asteraceae, which was situated on the south-western margin of a patch of bushes (Fig. 1). The nests were made of fine clayey soil with a small but variable proportion of tiny stones. The nests consisted of 2.5 cells in the median (n= 4) (Table 1). All the cells were orientated almost vertically with the opening directed towards the ground, but the arrangement of the cells was variable. In three nests, the cells were abutted only longitudinally (Figs 24, 25). In nest F, the third cell was also attached to the first cell longitudinally but the second cell was constructed with its closed end abutting the seal of the completed first cell resulting in a linear arrangement of these cells (Fig. 26). A nest covering was only present in nest GB (Fig. 22). The covering consisted of a smooth, thin layer of the same fine clayey earth as the brood cells and covered the cells completely. The material of the covering could be separated from the cell walls with- out difficulty indicating that it had been applied after the cells had been finished. The covering was only attached to the outer curves of the cells and to the adjacent substrate thus stretching over medial and lateral hollow spaces between the cells and the cell walls and the underlying stone respectively (Fig. 23). The brood cells were cylindrical, rounded at the closed (basal) and truncate at the open (apical) end (Fig. 25). The median dimensions of the cells were: length of com- pleted cells 10.5 mm (n = 10); outer diameter 4.4 mm (n = 4); and inner diameter at the cell opening 3.5 mm (n = 9) (Table 2). The median thickness of the cell wall was 0.29 mm (n = 11), becoming somewhat wider at the basal end of the cell. The outer cell surface showed a distinct “fish scale” pattern while the inner surface was smooth. The cell seal was positioned about 1 mm inwards from the edge of the cell opening. The thickness of the seal varied slightly over its diameter and measured in the median 0.23 mm (n = 8) at the thinnest part. Sealed cells of old nests mainly had a large frontal or lateral opening that covered the apical third of the cell and had probably been made by an emerging imago of Ce/lonites fischeri (Figs 22, 25, Table 2). Brood cell content: The content of the brood cells is summarized in Table 2. First contribution to the bionomics of the pollen wasp Celonites fischeri Spinola, 1838... 129 ea Sao tk Ss er es ee ares h he Figures 22-26. Nest structure of Celonites fischeri: 22-24 Nest GB 22 Original condition on 26 May with frontal emergence hole probably made by C. fischeri. 23 Nest covering partly removed to show hol- Be “ee: oe low spaces underneath; cell GB, opened containing meconium of C. fischeri at basal end 24 Cell GB, opened, showing brittle brown cocoon of unidentified holometabolic insect in basal half and small emer- gence hole apical in the cell wall 25 Nest S on 27 May. Cells 33 S;> Sy S, (ordered from the left) with frontal emergence holes probably made by C. fischeri 26 Nest F on 1 June after dissection of cells F, and F, (cell content summarized in Table 2). The provision was a purple, firm, but somewhat viscous pollen mass with shining surface. Contact of the provision with the cell walls was variable: In cell F, the surface of the pollen mass was characteristically papillated (Fig. 26), so that it barely touched 130 Volker Mauss & Andreas Miiller / Journal of Hymenoptera Research 39: 119-153 (2014) Table |. Parameters of four nests of Celonites fischeri recorded at locality II 0.5 km north of Agios Georgios, Cyprus. Height above | Orientation Thclinttien ae Contact Nace Nest} Condition Nest substrate cells} between nest substrate (°) covering adjacent cells stone (base 38x31 cm, height 19 cm) stone (base 40x29 GB old 43 20 longitudinal | present D old TT 20 enc oar longitudinal | absent stone (base 40x29 Sreiit S old 280 sraahcnlicoe ea longitudinal | absent under plant (narrow stem linear or a construction 72 of Asteraceae scrub) longitudinal apsent ‘measured from the lowest part of the nest the cell walls. In cell F, the provision broadly adhered to the wall and apparently mois- tened it. However, this could have been an artefact, since the cell had to be removed and transported only a few hours after provisioning had been completed. The outer cell surface appeared to be dry when the cell was removed but was wet two days later, when the cell was opened, suggesting an artificial situation. The egg of Celonites fischeri from cell F, was whitish, curved and measured 1.88 mm in length. It was situated on top of the provision close to the basal end of the cell (Fig. 26). Remnants of fibrous material were attached to one pole of the egg indicat- ing that it had been fixed to the original cell wall before this had been removed during the dissection of the cell. In the same way the small larva from cell F, was also situated basally on top of the pollen mass, where it fed on the provision (Fig. 26). As in the egg there was some light fibrous material adhering to the posterior end of the larva that was distally fixed to the cell wall. The cocoon of C. fischeri consisted of whitish to yellow- whitish shining threads thinly covering the inner cell walls and the seal (Fig. 23). The threads became more sparse towards the basal end of the cell and in 50% of the cases (n = G) threads were completely lacking at the basal end of the cell. The meconium was situated at the basal end more or less inside the cocoon. The cocoon threads were more brownish in this part of the cell indicating the secretion of a fluid component during the discharge of the meconium (Fig. 24). The solid fraction of the meconium com- prised about 50 little, spherical, blackish packs containing pollen exines. The packs were loosely connected to each other by short threads. Behaviour at the nest: The temporal pattern of the behaviour of the focally observed female at nest F is summarized in Fig. 48. The behavioural sequence during brood cell preparation can be subdivided into four phases: 1. cell building, 2. oviposition, 3. provisioning, 4. sealing. At the beginning of the construction of a new brood cell, when already one or more cells had been constructed, the female alighted without a soil pellet on the stem just below the nest. Then she walked upwards and downwards, randomly across the cell(s) and also back on the stem again for approximately 1—2 min. Finally she 131 First contribution to the bionomics of the pollen wasp Celonites fischeri Spinola, 1838... ]]22 Jo pus yeorde ye Jouressos ur osye syoed asayi Jo may v ‘souTxo uayjod Sururey0s pimby snoosta