Ancistrocerus waldenii waldenii (Viereck 1906)

Wahlberg, Emma, Baião, Guilherme C., Häggqvist, Sibylle, Martinsson, Svante, Pistone, Dario & Pape, Thomas, 2014, Ancistrocerus waldenii waldenii (Viereck 1906) (Hymenoptera: Vespidae, Eumeninae), a new addition to the fauna of Greenland, Zootaxa 3838 (1), pp. 143-150 : 144-148

Ancistrocerus waldenii waldenii (Viereck 1906)

Odynerus waldonii Viereck 1906a: 304 , ♀.

Odynerus waldenii Viereck 1906b: 350 (emendation).

Ancistrocerus waldenii waldenii: Krombein 1979: 1505 ; Buck et al. 2008: 113.

Examined material: GREENLAND: Kangerlussuaq/Sdr Strømfjord (67°00′ N 50°41′ W), 2 Aug. 1992 ( ZMUC, Leg. J, Böcher)—4 ♀, 4 ♂; Itilleq, eastern end (66°33′ N, 52°26′ W), 22–23 Jul. 2003 ( ZMUC, Leg. Kissavik Expedition ZMUC)—7 ♀, 2 ♂; Søndre Isortoq, Nuk (65°28′ N, 52°12′ W), 13–14 Jul. 2003 ( ZMUC Leg. Kissavik Expedition ZMUC)—1 ♀; Kangerlussuatsiaq/Evighedsfjord, Taterat (66°00′ N, 52°33′ W), 19 Jul. 2003 ( ZMUC Leg. Kissavik Expedition ZMUC)—1 ♀; Ikamiut Kangerdluarssuaq, Tasersuaq (65°47' N, 52°39' W), 17–18 Jul. 2003 ( ZMUC Leg. Kissavik Expedition ZMUC)—2 ♀, 2 ♂; Kangerlussuaq/Sdr Strømfjord (67° 1'19"N, 50°40'16"W), 20 Jul. 2013 ( ZMUC, Leg. T. Pape)—4 ♀, 3 ♂; Qeqertarsuaq/Godhavn, Lyngmarksbugten (69°15'35"N, 53°32'35"W), 24 Jul. 2013 ( ZMUC, Leg. T. Pape)—2 ♀.

Distribution. Nearctic. In Canada except in NU ( Buck et al. 2008). In the USA in AZ, CA, CO, IL, MI, MT, NM, SD, VA and WY. Greenland (new record). Subspecies A. w. excavatus Bequaert 1944 and A. w. flavidulus Bequaert 1944 from BC and CA to MT, WY, CO, AZ ( Krombein 1979).

All specimens were identified as Ancistrocerus waldenii (Viereck 1906) ( Fig. 1 ). This species is most similar to A. albophalerathus (de Saussure 1855) and an undescribed Ancistrocerus sp. A ( Buck et al. 2008). Males of A. waldenii are separated from similar species in North America by the deeply emarginated clypeal margin. Females can be distinguished from similar species by the completely black scape and by the presence of a pale apical spot on tergum 6 ( Buck et al. 2008). Overall, colour patterns are rather variable ( Buck et al. 2008) and the Greenland specimens tend to have reduced pale markings compared to North American specimens. A detailed description of the species is available in Buck et al. (2008).

Ancistrocerus waldenii was seen to be abundant in the area around Kangerlussuaq, and specimens were repeatedly seen flying over low vegetation or on open paths and dirt roads where females were seen collecting clay for nest building. On Disko Island, several specimens were observed flying along an open path near a stream in a low mountain meadow (69° 15'34''N, 53° 32'34''W) ( Fig. 2a ) close to Qeqertarsuaq. The vegetation in the area was composed mostly of glaucous willow ( Salix glauca L.) and dwarf shrubs, with mosses, sedges, and lush stands of dwarf fireweed ( Chamerion latifolium (L.) Holub) along the stream flowing through the area.

Ancistrocerus waldenii is a solitary wasp constructing mud nests on vertical rock surfaces ( Fig. 2 b), and each nest is provisioned with several Lepidoptera larvae ( Fig. 2 c). The female attends to several mud cells, laying one egg per cell and then providing it with several caterpillars before the cell is sealed. The number of caterpillars provided for the nests is similar to records from other species of Ancistrocerus Wesmael (Bequaert 1944, Krombein 1967), and in three excavated cells from the Qeqertarsuaq population 13, 9 and 6 caterpillars were found ( Tab. 1). The caterpillars were identified as belonging to the Plutellidae, Gelechioidea (probably Oecophoridae ) and Noctuidae , with individual female wasps apparently acquiring a ‘search image ′ for a narrow range of prey caterpillars. The taxonomic composition of caterpillars from the Greenland nests differs from that mentioned by Krombein (1979), who found A. waldenii to prey on caterpillars of the family Tortricidae . Species of Torticidae are known from Greenland, however studies have been concentrated to the southern parts ( Downes 1966, Johannesen 1990) and the northern distribution of this moth family is less well known. The adult wasps are reported to feed on nectar from various flowers and from honeydew ( Spradbery 1973). When searching for nests during a moist and cold day near Qeqertarsuaq, several females were observed resting in the nests on the rock surfaces ( Fig. 3 ), a behaviour known to occur in several other solitary wasps during night or in unfavourable weather ( Evans 1966). The nests in Qeqertarsuaq were built on rock surfaces facing south-southeast (153.4±6.6°, mean of 25 nests at 13 different sites). The observations of Morris (1959) where some nests were facing west are somewhat incongruous to our south-southeast findings. Local factors like prevailing wind direction and availability of suitable surfaces may play a part, and onshore winds could be a factor affecting the orientation of individual nests, especially in the Arctic where temperature is one of the main influences of arthropod activity ( Downes 1965, Høye & Forchhammer 2008). Previous observations of nesting sites are sparse regarding Ancistrocerus in general, and while we can corroborate the general prey preference regarding caterpillars ( Tab. 1) with data from our study, data also indicate that prey species and nest site preferences vary somewhat according to the local situation.

Nest Number of larvae Taxa

1 2 Plutellidae , possibly Plutella xylostella

7 Gelechioidea, possibly Agonopterix antenariella (Oecophoridae)

2 1 Plutellidae , possibly Plutella xylostella

5 Gelechioidea, possibly Agonopterix antenariella (Oecophoridae)

3 13 Noctuidae , possibly Polia richardsoni

Ancistrocerus waldenii (Viereck 1906) is exclusively Nearctic and has been recorded from all Canadian provinces except Nunavut ( Buck et al. 2008). In the USA it is recorded from northern or mountainous states; Alaska, Arizona, California, Colorado, Illinois, Michigan, Montana, New Mexico, South Dakota, Virginia and Wyoming. The western populations are usually divided into the two subspecies Ancistrocerus waldenii excavatus Bequaert 1944 and Ancistrocerus waldenii flavidulus Bequaert 1944 ( Krombein 1979; Buck et al. 2008) and the eastern population belongs to the nominotypical subspecies. The earliest capture of A. waldenii in Greenland is from Kangerlussuaq (67°00'31''N, 50°41'21''W, Fig. 4 ) in 1992, an inland region with moderate precipitation ( Tab. 2 ). South of Kangerlussuaq several individuals have been collected during the Kissavik Expedition arranged by the Zoological Museum of Copenhagen (ZMUC) in 2003 at the localities Itilleq, Kangerlussuatsiaq, Ikamiut Kangerdluarssuaq and Isortoq Fjord ( Fig. 4 ); all considerably wetter locations ( Tab. 2 ). The new finding near Qeqertarsuaq represents the northernmost occurrence of A. waldenii in Greenland and is the globally northernmost occurrence of this species, thereby giving evidence of a new northern distribution limit. Previously published records indicated a northern limit at Rampart House, Yukon, Canada, at approximately 67°25'26''N, 140°59'00''W ( Finnamore 1997), and compared to our findings at the 69th parallel north this constitutes a range extension of over 200 km. The finding of a population of A. waldenii at Qeqertarsuaq, Disko, is remarkable as the transition from a low arctic to a high arctic biome takes place across this island, with several homothermic springs in the southern half providing for some amelioration of the local climate (Kristensen 2006). It is also noteworthy that the fauna on the southern part of this island is relatively well studied due to the presence of a permanent research station in Qeqertarsuaq since 1906: Arktisk Station, which from 1953 has been managed by the University of Copenhagen ( Bruun et al. 2006). It seems unlikely that the presence of such a conspicuous insect would go unnoticed for a long period of time; it seems more likely that this population has recently become established. The oldest specimens examined are from Kangerlussuaq 1992, and as Kangerlussuaq Airport is the international hub for Air Greenland and one of only two airports in Greenland large enough for larger airliners, introduction from USA or Canada, possibly via nests constructed on heavy machinery or vehicles, would seem very likely. Based on the material available and the fact that both Kangerlussuaq and Qeqertarsuaq have many observant biologists, including entomologists, passing through, it may be hypothesised that A. waldenii was established first in Kangerlussuaq and only later in Qeqertarsuaq. It remains to be investigated if this introduction can be seen as a result of more traffic by heavy machinery carrying inhabited nests, and how it fits into the general trend of poleward range extensions documented for many taxonomic groups ( Hughes 2000, Hickling et al. 2006). It is noteworthy in this context that the Greenland specimens examined by us have yellow rather than ivory markings on the body ( Figs. 1 & 3 ). The two western subspecies ( A. w. excavatus and A. w. flavidulus ) used to contain the only known yellow-marked populations of this species, but Buck et al. (2008) also mention two males from Virginia, i.e., from the southeastern part of the range. It would seem that yellow-marked populations in general inhabit warmer climates, and other species of Eumeninae (e.g., the closely related A. catskill (de Saussure 1853) and A. albophalerathus (de Saussure 1855) have ivory-marked northern and yellow-marked southern colour forms ( Buck et al. 2008).

We want to express our thanks to Dr H. Solstad, NTNU Trondheim, for a well-organized course and smooth logistics, Professor emeritus R. Elven, Natural History Museum, Oslo, for sharing his massive knowledge about arctic ecosystems, and not the least the botanical students for motivating companionship. Professor emeritus N.P. Kristensen and Dr J. Böcher, both at the Natural History Museum of Denmark, Copenhagen, generously shared chapters from their still unpublished handbook of the Greenland entomofauna, and N.P. Kristensen identified the Lepidoptera larvae. Dr M. Buck, Royal Alberta Museum, Edmonton, provided valuable comments on the manuscript and English language improvements. The Norwegian Research School in Biosystematics (ForBio) is acknowledged for funding the course.

Figures

FIGURE 1. Ancistrocerus waldenii. Female specimen collected near Qeqertarsuaq, Greenland. Photo: E. Wahlberg.

FIGURE 3. Female of Ancistrocerus waldenii resting in its nest during unfavourable weather conditions. Photo: E. Wahlberg.

FIGURE 4. Localities where Ancistrocerus waldenii has been collected in Greenland, base map provided by Esri et al. (2013).

FIGURE 2. A. Low mountain meadow near Qeqertarsuaq, Disko Island, Greenland, where a population of A. waldenii was discovered. B. Clay nests found on vertical rock surfaces. C. Lepidoptera larvae excavated from nest # 2; note newly hatched wasp larva below. Photos: E. Wahlberg.

Tables

TABLE 2. Mean annual temperature and precipitation, values retrieved from (1) Hijmans et al. (2005), (2) Environment Canada (2013) and (3) World Meteorological Organization (2010).

Location	Mean annual temperature (°C)	Mean annual precipitation (mm)
Qeqertarsuaq1	−5.0	279.0
Rampart House2	−9.0	265.5
Kangerlussuaq3	−5.7	140.0
Itilleq1	−3.5	351.0
Kangerlussuatsiaq1	−3.9	447.0
Ikamiut Kangerdluarssuaq1	−3.4	458.0
Isortoq Fjord1	−3.1	487.0
Acknowledgements