Vespula akrei Landolt

Landolt, Peter J., Sierra, José Monzón, Unruh, Thomas R. & Zack, Richard S., 2010, A new species of Ve s p u l a, and first record of Vespa crabro L. (Hymenoptera: Vespidae) from Guatemala, Central America, Zootaxa 2629, pp. 61-68 : 62-65

Vespula akrei Landolt sp. nov.

( Figs. 1 A, B, C, D)

Diagnosis. Vespula akrei can be differentiated from V. squamosa , the only other currently known species of Vespu la in Guatemala, by the all black mesonotum, all black antennae, absence of an orange tinge to the yellow of the gaster, black forecoxae, and differing gastral pattern ( Fig. 1 A). Vespula akrei can be differentiated from V. maculifrons , which is genetically close, generally by the oval to oblong yellow marks within the black band of the first gastral tergum, and by the all black forecoxae, all black sixth gastral sternum and tergum, and relatively heavy black margin of the clypeal apex. There is much variation in the coloration of V. maculifrons , including a coloration pattern on the first gastral tergum like that of V. a k re i ( Jacobson et al. 1978). Gastral terga 2 to 5 of V. maculifrons also possess lateral black spots that are partially enclosed within the anterior black band of each tergum (figured by Jacobson et al. 1978). Such lateral black spots are mostly absent in V. a k re i. Vespula akrei can be differentiated from V. inexpectata by the yellow spots within the black band on gastral tergum 1, by the absence of lateral black spots partially enclosed within the black bands of gastral terga 2 to 5, the complete yellow genal band, and the ocular sinus completely filled with yellow.

Description. Worker female: Head yellow and black. Vertex mostly black, with ocular sinus completely yellow and continuing downward along the inner margin of eye to clypeus. Gena yellow anteriorly from vertex to base of mandible and black along posterior margin. Carina of gena complete from vertex to base of mandible. Antenna black. Frons mostly yellow with medial black marking contiguous with black marking on clypeus, and vertical black stripe encompassing each antennal lobe. Clypeus yellow with a medial vertical black mark extending from near antennal base to 2/3 of distance to bottom or distal margin of clypeus. Lower clypeal margin heavily marked with black on the protruding apex. Oculo-malar space short, less than width of antennal scape, black. Mandible yellow. Vertex, frons, clypeus, gena, and mandible dorsally with long black hairs.

Thorax mostly black with yellow markings. Pronotum black with yellow border along mesonotum. Mesonotum entirely black. Dorsal-most area of mesepisternum adjacent to posterior-most pronotal margin yellow. Fore wing tegula yellow posteriorly. Two elongate yellow markings on anterior of scutellum and two elongate yellow markings on anterior of metanotum. Hind wing tegula yellow. Fore coxa black to dark brown, femur yellow except black mark on dorsum of femoral base and black stripe anteriorly, tibia orange-yellow with light brown marking dorsally, tarsus orange-yellow. Mid coxa yellow, femur yellow except black marking on dorsum of femoral base, tibia yellow, tarsus orange-yellow. Hind coxa black with yellow marking dorsally, femur yellow except ventral black area at base, tibia yellow-brown with longitudinal dark brown area dorsally, tarsus light orange-yellow. Thorax and femur with long black hairs. Propodeum black. Forewing length 6.4 ± 0.2 (? ± SE) mm, range 6.0 to 6.9 mm (n = 5).

Gaster black and yellow, with segments 1 to 5 black proximally and yellow distally. Yellow tergal bands of segments 1 to 4 of roughly equal width. First tergum with two yellow oval spots on either side of midline of black band dorsally. Midline of dorsum of each black band of terga 1 to 5 with narrow posterior extension into the yellow band. Gastral sterna 2–5 with black spots extending posteriorly from each black band well into yellow band. For gastral sternum 2, this black spot is connected to the black band with an area of red-brown. Tergum 1 of gaster with long light brown hairs.

Queen: Coloration as in worker with the following exceptions. Pronotum posteriorly with yellow mark bordering yellow area of mesopleuron. Yellow areas of scutellum and metanotum expanded compared to workers, with metanotum yellow marks meeting at mid-line of dorsum, forming single transverse yellow band narrowed medially. Gastral tergum and sternum 6 black with yellow distally. Forewing length 8.2 ± 0.1 (mean ± SE) mm, range 7.7 to 8.5 mm (n = 5).

Male: Coloration of vertex, gena and mandibles as in worker. Frons mostly yellow with black diamondshaped mark midway between antennal sockets. Clypeus yellow except for brown distal edge and black distal lateral extensions. Ocular malar space black, equal in length to width of antennal scape. Antennae black, except for small yellow spot distally on anterior of scape. Thorax black, as in worker. No yellow at posteriormost margin of the pronotum. Yellow on scutellum and metanotum reduced in comparison to worker and queen, with considerable black at mid-dorsum separating yellow markings. Gaster black and yellow, with each segment black anteriorly and yellow posteriorly. Yellow gastral bands of similar widths for segments 2– 6. Gastral tergum 7 black with two small round yellow spots. Unlike females, there are no yellow spots within black area of gastral tergum 1. First gaster tergum with numerous long light colored hairs. Broad lateral reddish colored area bordering black area of first gastral sternum, and less pronounced red coloration in the black areas of other gastral sterna, as well as the most lateral area of tergum 2. Forewing length 7.3 mm (n = 1).

Type material. Holotype. The holotype worker is labeled “ GUATEMALA, Zacapa, 12 km north of San Lorenzo, N15 0 06.86 ' W89 0 40.82 ', 2200 m. elev. Jose Monzon 14–20 April 2008 / HOLOTYPE Vespula akrei Landolt 2010 [red label].” The Holotype is deposited in the entomological collection of the Universidad del Valle de Guatemala, Guatemala City, Guatemala.

Paratypes. Four workers, same data as holotype; 1 worker, GUATEMALA, Zacapa, above San Lorenzo, 2100 m elev, Sept. 1986, M. Sharkey; 1 worker, GUATEMALA, Zacapa Sierra de las Minas 12 km N of San Lorenzo, N15 0 06.86 ' W89 0 40.82 ', 2200 m elev., May 4–6, 2008, Peter J. Landolt, collector; 28 workers, GUATEMALA, Zacapa, Sierra de las Minas, 2250 m, San Lorenzo, Cerro Monos, 19–21 May 2010, N0 15 116' W0 89.685', J. Monzon, B. Sutton, G. Steck, and P. Skelley; 4 workers, GUATEMALA, El Progresso, Cerro Piñalon, Bosque pino, 2,219 m, 16–18 May 2010, N0 15.073' W0 89.948', J. Monzon, B. Sutton, G. Steck, and P. Skelley; 3 queens, GUATEMALA, Zacapa Dept., ca 8 km NW of San Lorenzo, ca 27 km from CA-9 turn-off N15 0 06.959 ' W89 0 40.686 ', 4 May 2008, 2130 m, R. S. Zack, P. J. Landolt, & J. Monzon, coll.; 1 queen, same data as preceding except 5 May 2008; 2 queens, GUATEMALA, Zacapa, Sierra de las Minas, 2250 m, San Lorenzo, Cerro Monos, 19–21 May 2010, N0 15 116' W0 89.685', J. Monzon, B. Sutton, G. Steck, and P. Skelley, Paratypes are deposited in the James Entomological Collection, Washington State University, the Universidad del Valle de Guatemala, the Smithsonian Institution, the American Museum of Natural History, Florida State Collection of Arthropods, the Royal Alberta Museum, and the collections of Peter J. Landolt and José Monzón Sierra.

Other specimens examined. One worker. GUATEMALA, Zacapa, Jones, Rio Colorado, 500 m, F. Garcia 23/III/1996. One male. GUATEMALA, Zacapa, Sierra de las Minas 16-V-1987. L. M. Giron. Both specimens are in the entomological collection of the Universidad del Valle de Guatemala, Guatemala City.

Distribution and habitat notes. Nearctic: Guatemala. The species currently is known only from the Sierra de las Minas mountain range, Zacapa and El Progresso Departments within the Reserva de Biósfera de las Minas. The type habitat is at an elevation near 2200 m in a cloud forest with primarily broad leaf trees with some pines and a dense woody understory. The habitat at Cerro Piñalon is similar but with more extensive pine trees. The label localities for the two specimens collected previous to the type series are the towns of San Lorenzo and Jones. San Lorenzo is at an elevation of 1800 m but its surrounding habitat is open pine forest and grassland with little other vegetation. Jones is much lower in elevation, circa 500 m, and is in a dry rain shadow of the mountain range, with the dominant vegetation comprised of short seasonally deciduous trees and shrubs. It is doubtful that the specimens were collected in these towns and the locality labels for these two specimens probably indicate the towns that are nearest to the collection sites, rather than the specific collection sites themselves.

Most of the workers of V. a k re i were captured in a malaise-type interception trap suspended across small dirt roads. One worker was netted while it hovered in thick underbrush in a forested area along a road. Three queens collected in 2008 were on flowers of a single unidentified shrub, while queens collected in 2010 were in the interception trap.

Vespula squamosa was also present at the type locality.

V. a k re i currently is known only from a small area in Zacapa and adjacent El Progresso Departments, with the distribution at high elevations within the Sierra de las Minas mountain range, and within the Reserva de la Biósfera Sierra de las Minas. The species may also occur at other moist, high elevation sites in Guatemala but access to these areas generally is difficult.

Etymology. The species epithet, akrei , is in honor of our (PJL & RSZ) late mentor and friend, Roger D. Akre, who added so much to our understanding of the genus Ves p ul a.

Placement of Vespula akrei . This species is aligned with the V. vulgaris species group ( Bequaert 1930), based on the following key criteria indicated for Paravespula Blüthgen by Archer (1989a, b, c). The occipital carina is complete along the posterior margin of the head from the vertex to the base of the mandible. The first gastral tergum possesses numerous long pale hairs. There are no longitudinal stripes on the mesoscutum and the antennae are completely black. We have no information on the colony cycle, colony size, or foraging habits of V. a k re i.

DNA sequences also assist in the placement of V. a k re i within Vespula . A total of nine specimens, including one V. acadica , two V. a k re i, one V. alascensis , one V. intermedia , two V. maculifrons , one V. squamosa , and one D. arenaria were used for sequencing of portions of two mtDNA genes. Following methods presented in Horton et al. (2008), DNA was extracted from three legs of each specimen with DNAeasy Blood and Tissue Kit (Qiagen Inc., Valencia, CA). Target regions of the genes were amplified using universal primers for CO1 (C-J-1718, C-–2151) and cytB (CB-J-10933, CB-–11367) ( Simon et al. 1994). Products were cleaned with exoSAP (USB Corp., Cleveland, OH) and sequenced using the same primers. Sequences were trimmed and aligned using CLUSTALW in Bioedit ( Hall 1999). DNA sequences are provided in Genbank as accessions HM 031092 - HM 031100 for 472 bp of CO1 and HM 031083 - HM 031091 for 433 bp of cytB.

Phylogenetic hypotheses for the combined 905 bp of mtDNA sequence (CO1 and cvtB genes) were developed using a neighbor joining distance method with MEGA-4 (p distance; gamma distributed substitutions, k-0.07, 10,000 bootstrap replicates [Tamura et al. 2007]) and maximum parsimony as implemented in TNT (one technology sectarian search, find best tree 20 times, 34,540 trees examined, symmetric resampling p=33 and 10,000 replicates; [ Goboloff et al. 2008]). Data were also analyzed with PAUP4 ( Swofford 2003) and MrBayes 3.1 ( Ronquist and Huelsenbeck 2003) testing gene-specific partitions and all base pair combinations. In all cases, D. arenaria was used to root the tree depicted and as an outgroup in parsimony analyses. The single phylogram presented in Fig. 3 , with the shape of the tree (branch distances) defined by the NJ analysis shows the cladogram seen with all four methods of analysis. Statistics along branches of the tree were derived from NJ/TNT analyses. The number above the branch is the number of bp differences/number of synapomorphies. The number below the branch is the bootstrap support calculation/the symmetric sampling support calculation). The results show 100% support for the distinct clade for V. a k re i, for the V. a k re i plus V. maculifrons clade, and for the V. a k re i plus V. maculifrons plus V. alascensis clade, placing V. a k re i in the V. vulgaris species group. Vespula maculifrons and V. alascensis are closely allied to Vespula vulgaris L., and within the V. vulgaris species group ( Bequaert 1930; Carpenter 1987, Carpenter and Perera 2006). The clade containing V. acadica and V. intermedia , members of the V. r u f a species group ( Bequaert 1930; Carpenter 1987) is also well supported. Addition of V. squamosa to this clade reduces support, and is not consistent with the placement of V. squamosa in the V. r u f a group. Carpenter (1987) placed V. squamosa in a separate sister group with Vespula sulphurea (de Saussure). The differences seen between V. a k re i and V. maculifrons were 26 bp substitutions (23 in CO1 and 3 in cytB), 15-16 of which were synapomorphies, and no amino acid substitutions (data not shown). The CO1 473 bp sequence for V. a k re i shows 23 bp differences (4.9%) from the most closely related species that we sequenced ( V. maculifrons ), and similar distances from sequences of five other V. maculifrons in genbank. This represents a significant gap, and is greater than that observed for CO1 differences between V. acadica and V. intermedia (2.75%) for example.

Figures

FIGURE 1. Vespula akrei sp. nov. A. gastral coloration, dorsal view, B. frontal view of head, C. dorsal view of head, and D. lateral view of head.

FIGURE 3. Neighbor joining tree for eight Vespula specimens and Dolichovespula arenaria as an outgroup. Abbreviations for the United States, state where the specimen was collected is shown after the species name; Guat = Guatemala. The top five are all members of the V. vulgaris species group and show the close relationship of V. a k re i to V. maculifrons. The bottom three are all members of the V. rufa species group. Trees were derived from 905 bp of mtDNA (472 bp from CO 1 and 433 bp of cytB). Numbers in bold above a branch are percent support by bootstrap / percent support by symmetric resampling for various clades, and numbers in italics below a branch are the number of substitutions / number of synaporphies along that branch. The tree was rooted on a specimen of Dolichovespula arenaria from Alaska. Tree topologies were qualitatively identical using four distinct phylogenetic algorithms (see text for methods).