Pseudoanthidium (Pseudoanthidium) jacobii Vereecken & Litman, 2023

Vereecken, Nicolas J., Ruiz, Carlos, Marshall, Leon, Perez-Gil, Monica, Molenberg, Jean-Marc, Jacobi, Bernhard, La Roche, Francisco & Litman, Jessica R., 2023, A new small carder bee species from the eastern Canary Islands (Hymenoptera, Megachilidae, Anthidiini), Journal of Hymenoptera Research 96, pp. 983-1015 : 983

Pseudoanthidium (Pseudoanthidium) jacobii Vereecken & Litman sp. nov.

Type material.

Holotype. Spain • 1♂; Lanzarote, Haría, 19 Apr. 2021; NJ Vereecken leg.; DZUL.

Paratypes. Spain • 1♀; Lanzarote, Haría, 18 Apr. 2021; J-M Molenberg leg.; ULB • Spain • 1♂; same collection data as for preceding, 19 Apr. 2021; J-M Molenberg leg.; ULB • 1♂; same collection data as for preceding, 18 Apr. 2021; J-M Molenberg leg.; DZUL.

Other material.

Spain • 1♂; Lanzarote , Haría; 21 Feb. 2023; M Pérez-Gil leg.; DZUL • 1♀; Haría, 16 Apr. 2023; M Pérez-Gil leg.; DZUL • 1♀; Haría, 19 Apr. 2023; C Ruiz leg.; DZUL • 1♀; Lanzarote , Guatiza, 25 Mar. 1997, F La Roche leg.; FLR .

Diagnosis.

Besides differences in their distribution pattern across the Canary Islands archipelago (Fig. 1 ), males and females of P. canariense and the newly described P. jacobii can be unambiguously identified based on a number of morphological criteria described below, including their relative size, as well as the density of the punctuation, the colour and the shininess of their cuticle as shown on Figs 2 - 4 . Fig. 5 illustrates the structure of specialized hooked and waved hairs on the metasomal sterna (S3-S4-S5) in males, as well as their apicolateral combs on each lateral arm of S5.

Female. The female of P. jacobii may be distinguished from P. canariense by the following combination of characters: BL minimally only half size (4-7 mm in P. jacobii , 6-9 mm in P. canariense ), ITD shorter (on average: 2.13 mm in P. jacobii , 2.91 mm in P. canariense ), OOD shorter (~ 1 ocellar diameter in P. jacobii , ~ 1.5-2 ocellar diameters in P. canariense ), TPD lower (spaces between points at least ~ 1-1.5 diameter of a single point in P. jacobii , <0.5 diameter of a single point in P. canariense ), SSPD slightly higher (~ 0.5 diameter of a single point in P. jacobii , <0.5 diameter of a single point in P. canariense ), TEG brighter (orange-yellow in P. jacobii , black in P. canariense ), ProN brighter (orange-yellow in P. jacobii , black in P. canariense ), ProLo mostly brighter (orange-yellow like the tegulae in P. jacobii , black in P. canariense , but more specimens of each species should be examined), TCP wider, brighter (wide and orange-yellow in P. jacobii , narrower and dark orange in P. canariense ), and with a better defined maculation margin (gradual infiltration of the black colour into the orange yellow maculations of the integument in P. jacobii , well-defined colour boundary/contrast between darker orange maculations and black cuticule in P. canariense ), FACE brighter (orange-yellow clypeus, mandibles, lower part of paraoccular region in P. jacobii , all black in P. canariense ) and wider (face broader than long in P. jacobii , face longer than broad in P. canariense ), LEGS brighter (all legs black only from the coxa to the very base of the femur black, the rest of the femur and other leg segments are orangish yellow in P. jacobii , all coxae, femurs but only posterior tibiae black in P. canariense ).

Male. The male of P. jacobii may be distinguished from P. canariense by the following combination of characters: BL minimally only half size (4-6 mm in P. jacobii , 6-8 mm in P. canariense ), ITD shorter (on average: 2.22 mm in P. jacobii , 2.95 mm in P. canariense ), OOD shorter (~ 1 ocellar diameter in P. jacobii , ~ 1.5-2 ocellar diameters in P. canariense ), TPD lower (spaces between points at least ~ 1-1.5 diameter of a single point in P. jacobii , <0.5 diameter of a single point in P. canariense ), SSPD slightly higher (~ 0.5 diameter of a single point in P. jacobii , <0.5 diameter of a single point in P. canariense ), TEG brighter (orange-yellow in P. jacobii , black in P. canariense ), ProN brighter (orange-yellow in P. jacobii , black in P. canariense ), ProLo mostly brighter (orange-yellow like the tegulae in P. jacobii , black in P. canariense , but more specimens of each species should be examined), TCP wider, brighter (wide and orange-yellow in P. jacobii , narrower and dark orange in P. canariense ), and with a better defined maculation margin (gradual infiltration of the black colour into the orange yellow maculations of the integument in P. jacobii , well-defined colour boundary/contrast between darker orange maculations and black cuticule in P. canariense ), FACE brighter (orange-yellow clypeus, mandibles, lower part of paraoccular region in P. jacobii , all black in P. canariense ) and wider (face broader than long in P. jacobii , face longer than broad in P. canariense ), LEGS brighter (all legs black only from the coxa to the very base of the femur black, the rest of the femur and other leg segments are orangish yellow in P. jacobii , all coxae, femurs but only posterior tibiae black in P. canariense ). Brushes of thickened, wavy hairs on S3, as well as the lateral dark brown comb of S5, identical in both species.

Description.

Female. Head: Mandible orange-yellow, except for teeth and apex of anterior margin, which are reddish-brown. Pilosity on clypeus and tufts at base of antenna white; on anterior margin of clypeus off-white, and on vertex blond. Clypeus dark yellow with black anterior margin. Punctures of clypeus dense and small anteriorly and laterally, with interspaces not larger than diameter of one-half puncture. Punctures become sparser and larger medially and posteriorly, where the maximum distance between punctures reaches two puncture diameters or more in the posterior-medial zone. Interspaces between punctures on clypeus shiny, most notably so where punctures are least dense. Paraocular area dark yellow and densely punctate, with interspaces not over the diameter of one-half puncture. Antenna with scape and pedicel black; flagellar segments dark brown. Flagellar segments shorter than wide, except for the first and the last, which are longer than wide. Frons with punctuation nearly honeycomb areolate, punctuation becoming slightly less dense toward the vertex, with shiny interspaces. Vertex with dark yellow triangle behind each eye, meeting or nearly meeting at midline of vertex. Vertex densely punctate, with interspaces not over 0.5 puncture diameter wide. Punctation on vertex mostly homogenous, with punctures just posterior to median ocellus slightly larger. Gena densely, evenly punctate, with spaces between points less than 0.25 puncture diameter wide.

Mesosoma: Scutum black. Punctuation dense, with spaces between punctures shiny, not more than one-quarter puncture diameter wide. Tegula dark yellow anteriorly, translucent yellow posteriorly. Pronotal lobe dark yellow apically, black basally. Scutellum black with dark yellow band medially on posterior margin. Punctures on black part of scutellum slightly larger and less dense than on scutum, with spaces between punctures on the median part of the scutellum shiny and up to one half a puncture diameter wide; punctation on yellow part of scutellum even less dense, with spaces between punctures over one puncture diameter wide. Mesepisternum densely punctate, punctures becoming smaller and less dense around episternal groove; spaces between punctures shiny. Propodeum laterally and anteriorly finely, densely punctate; medially shiny and without punctuation. On all legs, coxa, trochanter and base of femur black; the rest of the femur, tibia and tarsal segments orange-yellow. Wings infuscate.

Metasoma: T1 anteriorly brownish-yellow, posteriorly reddish-brown. A dark yellow spot present laterally, slightly masked by the colour of the anterior margin of the tergite. Lateral spots vaguely joined medially on the tergite by a faint yellow band connecting the posterior margin of each spot. Punctuation relatively dense, even laterally, with spaces between punctures not greater than the diameter of half a puncture. T1 with unpunctured, shiny, translucent brown posterior margin measuring about two punctures wide. T2 anteriorly black with diffuse dark yellow lateral spots; posteriorly, T2 brownish-yellow. Lateral spots on T2 placed slightly medially to those on T1. Punctation on T2 dense but less so than on T1, with spaces between punctures laterally up to nearly one puncture diameter. Diameter of punctures of T2 greater than those of T1. T2 with unpunctured, shiny, translucent brown posterior margin measuring about two punctures wide. T3 like T2 in colour, with punctation slightly less dense. Punctation of T4 similar to that of T3; T4 mostly black with yellow spots laterally and with shiny, translucent brown posterior margin; anterior edge of this margin with a single row of punctures medially. T5 black, densely punctate, with spaces between punctures shiny and measuring less than 0.25 puncture diameter. T6 black, densely punctate, spaces between punctures less shiny than those of T5 and measuring less than 0.25 puncture diameter, overall texture T6 somewhat rough.

Male. Head: Mandible orange-yellow, except for teeth and apex of anterior margin, which are reddish-brown. Pilosity on clypeus and tufts at base of antenna white; on anterior margin of clypeus off-white, and on vertex dark blond to brown. Clypeus rugose-punctate, orange-yellow with black anterior margin. Paraocular area orange-yellow and rugose-punctate, with interspaces not over the diameter of half a puncture. Antenna with scape and pedicel black; flagellar segments dark brown. Flagellar segments shorter than wide, except for the first and the last, which are longer than wide. Frons with punctuation nearly honeycomb areolate, punctuation becoming slightly less dense toward the vertex, with shiny interspaces. Vertex with orange-yellow triangle behind each eye, widely interrupted towards the midline of the vertex by a black punctured space. Vertex densely punctate, with interspaces not over 0.5 puncture diameter wide. Punctation on vertex mostly homogenous, with interspaces between punctures increasing towards the eye margin and the latero-posterior part of the vertex. Gena densely, evenly punctate, with spaces between points less than 0.25 puncture diameter wide.

Mesosoma: Scutum black. Punctuation dense, with spaces between punctures shiny, not more than one-quarter puncture diameter wide. Tegula orange-yellow anteriorly, translucent orange brown posteriorly. Pronotal lobe orange-yellow apically, black basally. Scutellum black with orange-yellow band medially on posterior margin. Punctures on black part of scutellum slightly larger and less dense than on scutum, with spaces between punctures on the median part of the scutellum shiny and up to one half a puncture diameter wide; punctation on yellow part of scutellum even less dense, with spaces between punctures over one puncture diameter wide. Mesepisternum densely punctate, punctures becoming smaller and less dense around episternal groove; spaces between punctures shiny. Propodeum laterally and anteriorly finely, densely punctate; medially shiny and without punctuation. On all legs, coxa, trochanter and base of femur black; the rest of the femur, tibia and tarsal segments orange-yellow. Wings infuscate.

Metasoma: T1 brownish-orange on its anterior half, with an orange-yellow spot present laterally, slightly masked by the colour of the anterior margin of T1. Lateral spots joined medially on the tergite by a brownish-orange band connecting each spot. Punctuation relatively dense, even laterally, with spaces between punctures not greater than the diameter of half a puncture. T1 with unpunctured, shiny, translucent brown posterior margin measuring about two punctures wide. T2 anteriorly black with diffuse orange-yellow lateral spots; posteriorly, T2 brownish. Lateral spots on T2 placed slightly medially to those on T1. Punctation on T2 dense but less so than on T1, with spaces between punctures laterally up to nearly one puncture diameter. Diameter of punctures of T2 greater than those of T1. T2 with unpunctured, shiny, translucent brown posterior margin measuring about two punctures wide. Lateral spots on T3 placed slightly medially to those on T2. T3 similar to T2 in colour, with punctation slightly less dense. Punctation of T4 similar to that of T3; T4 mostly black with less diffuse orange-yellow spots laterally and with shiny, translucent brown posterior margin; anterior edge of this margin with a single row of punctures medially. T5 black, densely punctate, with spaces between punctures shiny and measuring less than 0.25 puncture diameter. T6 black, densely punctate, spaces between punctures less shiny than those of T5 and measuring less than 0.25 puncture diameter, overall texture T6 somewhat rough. T7 black, densely punctate, with rounded notch on posterior margin. Genitalia with semi-translucent, apically rounded (i.e., unnotched) and flattened gonostyli; penis valves flattened and rounded. S3 with short, dense, velvety pubescence anteriorly, posteriorly with premarginal brush of hairs, hooked at the tips, as well as an underlying comb of thickened, wavy hairs. S5 laterally with dark brown comb.

Etymology.

Pseudoanthidium (Pseudoanthidium) jacobii is dedicated to Mr. Bernhard Jacobi (Oberhausen, Germany), naturalist extraordinaire and talented macrophotographer who has a genuine and boundless passion for wild bees, particularly for species found in Europe and Australia. Bernhard’s interest for the Canary Islands has grown steadily and uninterrupted ever since the publication of Hohmann et al.'s (1993) landmark volume on the bees, wasps and ants of the archipelago. He has since then investigated the entomofauna of all of the Canary Islands in situ, reporting and illustrating the occurrence and distribution of the European Beewolf, Philanthus triangulum (Fabricius, 1775) on the archipelago ( Jacobi et al. 2013), as well as new records on the distribution and phenology of Colletes perezi Morice, 1904 on Fuerteventura ( Jacobi and Suárez 2018) and the first record of the American species Megachile (Chelostomoides) otomita Cresson, 1878 established on Tenerife ( Strudwick and Jacobi 2018). Bernhard and his wife have been regular visitors to Lanzarote for over three decades, particularly during the winter months, and he was the third person (after authors NJV on 18.iv.2021 and MPG 12.ii.2023) to photograph a live specimen of P. jacobii in Lanzarote on 12.iii.2023 (Fig. 1D ). Bernhard has also recently contributed new occurrence records of the widespread small carder bee P. nanum near his home in the German state of North Rhine-Westphalia ( Jacobi et al. 2021).

Genetic differentiation between P. jacobii and other Pseudoanthidium species

The results of CO1 analyses demonstrate that P. jacobii is strongly supported as the sister species to P. canariense (ML bootstrap value = 96%) (Fig. 6 ). The two species are separated by a K2P-corrected genetic distance of 2.7%. Furthermore, P. jacobii exhibits an average K2P-corrected genetic distance of 5.9% from the clade consisting of P. nanum - P. scapulare - P. palestinicum ; of 5.1% from P. stigmaticorne ; and of 5.3% from the clade consisting of P. tenellum - P. cribratum .

Ecology, distribution and ecological niche differentiation

Habitat and host plant associations

In Lanzarote, the vegetation at the localities of Haría and Bco. de Elvira Sánchez where males and females of P. jacobii were recorded was composed of a chamaephytic substitutional flowering plant community established on old agricultural land with deep soils, generally on eroded slopes and on stony slopes, ravines, ledges physiognomically characterised by the presence of Asteriscus intermedius (DC.) Pit. & Proust ( Asteraceae ) and Lavandula pinnata L. ( Lamiaceae ) among others (see also Rámon Arévalo et al. 2016). By contrast, the localities of Teguise and Macher are peri-urban or rural anthropic areas with sparse natural vegetation, and the locality of Valle del Palomo is composed of xeric shrubland with a physiognomy of dendroid spurge shrubland, dominated by Euphorbia regis-jubae J. Gay ( Euphorbiaceae ). This is secondary vegetation typically found on abandoned arable or pastureland, roadsides and watercourse-beds ( Reyes-Betancourt et al. 2001). In Fuerteventura, the locality of Betancuria where a female of P. jacobii was photographed is characterised by a flowering plant community consisting of dwarf chamaephytes exposed to strong winds and heavily grazed, where Helianthemum canariense (Jacq.) Pers. ( Asteraceae ) and Spergularia fimbriata Boiss. & Reut. ( Caryophyllaceae ) are dominant ( del Arco Aguilar et al. 2018). Females of P. (P.) jacobii were observed collecting pollen on A. intermedius (DC.) Pit. & Proust (endemic to Fuerteventura and Lanzarote) (Fig. 1 ), Pulicaria canariensis subsp. lanata (Font Quer & Svent.) Bramwell & G. Kunkel (endemic to Lanzarote), and Glebionis coronaria (L.) Cass. ex Spach (syn. Chrysanthemum coronarium L., native and of Mediterranean origin) ( Asteraceae ). Males were also observed nectaring and patrolling for females on and around the same flowering plant species.

Nesting behaviour

A single observation by co-author BJ in Lanzarote on 16.iii.2023 of a female nesting in a pre-existing cavity formed in a lava rock (Fig. 1D ). All Pseudoanthidium species are reported to nest in pre-existing cavities or in pithy plant stems (see Litman et al. 2021 and references therein; Bogusch et al. 2022).

Ecological niche differentiation

The environmental niche space occupied by P. canariense encompasses a large part of the total environmental niche space available in the Canary Islands, covering wide elevation (from 70 m to 2,046 m with a mean of 952 m), mean annual temperature (8.3 °C to 20.9°C, µ =15.2 °C), and mean annual rainfall (135 kg m-2 to 534 kg m-2, µ =354.7 mm) gradients with greater temperature (1.9 °C to 2.2 °C, µ =2.1 °C) and lower precipitation seasonality (73 kg m-2, 90 kg m-2, µ =81.2 kg m-2) gradients and occupying a variety of land cover types (Fig. 7 ). The environmental niche space of PB is almost entirely separate from the niche space occupied by P. canariense and is driven by low elevation (204 m to 460 m, µ =268 m) (Fig. 7 ), warmer (17.6 °C to 19.5 °C, µ =18.7 °C), and drier (101 kg m-2 to 170 kg m-2, µ =138.9 kg m-2) areas with less variation in temperature (1.9 °C to 2.0°C, µ =2.0 °C) and more varied rainfall (92 kg m-2, 100 kg m-2, µ =96.9 kg m-2) (Fig. 7 ). This comparison, as hypothesised, strongly represents the climatic and elevational differences between the islands where the species occur. The overlap between the two species represents the limits of the niche for P. canariense . As shown on Fig. 8 , overall niche overlap between the two species is less than 1% and we can accept the alternative hypothesis that the two niches are less equivalent than random (p=<0.001).

Distribution and threats

Due to a lack of historical baseline data, we could not evaluate P. jacobii using IUCN Criterion A (population reduction). However, with an EOO of 326 km2 and an AOO of 28 km2, P. jacobii fulfils both Criteria B1 and B2 (restricted geographic range; EOO <5,000 km2 and AOO <500 km2, respectively) (IUCN 2023).

Our current knowledge suggests that P. jacobii is known only from Mediterranean type shrubland vegetation localities on the islands of Lanzarote and Fuerteventura (Fig. 1 ). The key host plants exclusively visited by P. jacobii females for the collection of pollen include the herbaceous single-island endemic Pulicaria canariensis subsp. lanata (Font Quer & Svent.) Bramwell & G. Kunkel (endemic to Lanzarote), the archipelago endemic Asteriscus intermedius (DC.) Pit. & Proust (endemic to Fuerteventura and Lanzarote) and the native non-endemic Glebionis coronaria (L.) Cass. ex Spach, all belonging to the family Asteraceae . According to a recent study by Hanz et al. (2023), climate change will severely restrict the climatically suitable area of Canarian herbaceous plant species, particularly archipelago endemics and single-island endemic species, and particularly on the islands of Lanzarote and Fuerteventura, which are expected to experience less annual precipitation in the future. This phenomenon along with the negative impacts of invasive flowering plant species in the archipelago ( del Arco Aguilar et al. 2018; but see Fernandez-Palacios et al. 2022), is very likely going to affect the availability of floral resources used by P. jacobii females, with cascading impacts on their population size and distribution.

According to the IUCN, populations are considered "severely fragmented" if most individuals are found in small and relatively isolated subpopulations, where the probability of recolonization is reduced, should these subpopulations go extinct (IUCN 2023). Under this strict definition, populations of P. jacobii , restricted to extremely isolated pockets on Lanzarote and Fuerteventura, may be considered severely fragmented, thus fulfilling both criteria B1a and B2a. Furthermore, the continuous development of touristic infrastructures on both islands, the increase of pollution brought about by new roads facilitating transport and tourism across the islands ( Martín-Cejas and Ramírez Sánchez 2010), the increase in car ownership and usage ( Martín-Cejas 2015), and other pervasive forms of anthropogenic disturbance such as irresponsible off-roading practices (with associated pollution, damages on plant and animal life, and increased soil erosion rates), sand extraction, wind farms, and increased goat grazing ( Nogales et al. 2006; Banos-González et al. 2016; Cubas et al. 2019) are all likely to have a severely negative impact on the extent and/or the quality of Mediterranean-type shrubland vegetation favoured by P. jacobii and its key host plants. This, in turn, might lead to a continuous reduction of EOO, AOO, the number of subpopulations and the number of mature individuals stemming from a reduction in foraging resources. Following this scenario, P. jacobii also fulfils criteria B1ab(i,ii,iii,iv,v) and B2ab(i,ii,iii,iv,v).

Our field experience further suggests that P. jacobii is characterised by very small population sizes: this can be argued based on the fact (i) that we failed to collect more than two specimens at each sampled locality when the number of specimens should have been at its peak, (ii) that P. jacobii has been completely overlooked up to the present day, and (iii) that females and males are relatively conspicuous in colour, sharing their pollen host plant species with other Canarian bee species active at the same time of the year, namely in early Spring. Hence, P. jacobii also fulfils Criterion C2a(i) based on a conservative estimation of the total number of mature individuals <2,500 across its distribution, as well as an estimated, projected, or inferred decline for reasons detailed above and <250 mature specimens per subpopulation (IUCN 2023).

Because of a lack of population size estimation or comprehensive evaluation of the number of extant populations and their trends, we were unable to classify P. jacobii under Criteria D and E (IUCN 2023).

Last, we obtained convergent results through the parallel calculation of the IUCN rating based on EOO Area (in km2) with the “EOORating” function in the rCAT package, which suggests that P. jacobii should be classified as “EN” (endangered).

Given the above results, P. jacobii thus qualifies for “EN” (endangered) conservation status under IUCN Criteria B1ab(i,ii,iii,iv,v), B2ab(i,ii,iii,iv,v) and Criterion C2a(i); this status is also supported by the results of the “EOORating” analysis mentioned above. We thus propose an IUCN conservation status of “EN” (endangered) for this species.

Figures

Figure 1. Ecology and distribution of Pseudoanthidium jacobii in the Canary Islands A, B male nectaring on an inflorescence of Asteriscus intermedius (Asteraceae) (Photos NJ Vereecken) C female collecting pollen on an inflorescence of A. intermedius (Photo B Jacobi) D female nesting in a pre-existing cavity located in a volcanic lava rock (Photo B Jacobi) E distribution map showing all occurrence records available to us and relevant to both P. canariense and P. jacobii in the Canary Islands.

Figure 2. Illustration of some key morphological traits that characterise females of Pseudoanthidium jacobii A head capsule and first half of the mesonotum in dorsal view B abdomen in dorsal view C tergites 1 - 2 (from top to bottom) in dorsal view D face in frontal view E mandibles and clypeus in frontal view. Photos NJ Vereecken; see description of each sex and the diagnosis in the text for more details.

Figure 4. Illustration of some structural diagnostic morphological traits that help discriminate between Pseudoanthidium canariense (Mavromoustakis) (A, C) and P. jacobii (B, D). Photos NJ Vereecken; see description of each sex and the diagnosis in the text for more details.

Figure 5. Both Pseudoanthidium jacobii and P. canariense share the same overall structure of specialized hooked and waved hairs on their metasomal sterna (S 3 - S 4 - S 5) in males, as well as their dark brown to black apicolateral combs on each lateral arm of S 5. The present photo illustrates the structure in a male P. jacobii where S 3 also exhibits a short, dense, velvety pubescence anteriorly, posteriorly with pre-marginal brush of hairs, hooked at the tips, as well as an underlying comb of thickened, wavy hairs (Photo NJ Vereecken).

Figure 6. Maximum likelihood-based tree based on analysis of a 658 base pair fragment of COI sequenced from selected Pseudoanthidium species in the P. scapulare complex. Maximum likelihood bootstrap support values, based on 1,000 replicates, are shown over nodes; only nodes with support values> 90 % are shown. Terminals are labelled with species names, as well as the BOLD sample IDs corresponding to each specimen. Outgroup removed from figure for convenience. Individuals shown in photographs were not those sequenced for analysis A P. scapulare (Photo NJ Vereecken) B P. nanum (Photo NJ Vereecken) C P. tenellum (Photo B Jacobi) D P. stigmaticorne (Photo H Wallays) E P. canariense (Photo G Pena); and F P. jacobii (Photo NJ Vereecken).

Figure 7. Distribution of elevation records relevant to A Pseudoanthidium jacobii and B P. canariense in the Canary Islands. Different letters right to the boxplots indicate highly significant differences in the elevation range and mean elevation of occurrence (black dot in boxplots) of both species (Kruskal-Wallis test: x 2 = 12.425, df = 1, p - value <0.0005). Photo of P. jacobii M Perez-Gil and of P. canariense G Pena.

Figure 8. Ecological niche overlap between Pseudoanthidium jacobii and P. canariense in the Canary Islands represented by a principal component analysis (PCA). Light grey diamonds represent occurrence records of P. jacobii, and the small underlying dark grey area represents its niche space. Black triangles represent occurrence records of P. canariense and the light grey underlying area represents its niche space. The small black area represents shared niche space between the two species. Small grey dots are background environmental samples from the Canary Islands. Schoener's D statistics and the p - value from the niche equivalence test are also shown. See methods and results sections for more details.