Canadian Journal of Arthropod Identification
 
 

Taxonomic revision of the Nearctic erosa species group of Phymata Latreille, 1802 (Heteroptera: Reduviidae: Phymatinae)

CJAI 41 -- October 1, 2020
doi:10.3752/cjai.2020.41

Paul Masonick & Christiane Weirauch

| Abstract | Introduction | Checklist | Materials & Methods | Species Key | Taxonomy | Acknowledgments | References | PDF | Cite |
| Appendix |
 
 

Materials & Methods

Specimens, depositories, and databasing: A total of 4,125 databased erosa group specimens were examined, of which 1,694 were adult females and 2,385 adult males. Table 2 lists the collections from which material was borrowed and/or is now deposited. Specimens examined are listed by species in the Appendix. We only report material which has been georeferenced: several aberrant individuals which could not be identified or were labeled as being collected drastically out of their known/previously documented range were excluded. We georeferenced older specimens for which geographic coordinates and elevation had not been recorded with locality information using GEOLocate software (https://www.geo-locate.org/) and Google Earth Pro v7.3.2.5776. Specimens were each affixed with a unique specimen identifier (USI) and databased using the Planetary Biodiversity Inventory instance of the Arthropod Easy Capture Database (https://research.amnh.org/pbi/locality/index.php). Specimen information and images can be accessed through the Heteroptera Species Pages (http://research.amnh.org/pbi/heteropteraspeciespage).

Measurements and imaging: Specimen measurements (in mm, Table 3) were taken using a dissecting scope mounted to a digital micrometer positioning system which was connected to a Microcode II® RS-232 digital readout (Boeckeler Instruments®). We recorded measurements of the total body length, the distances across the lateral and posterior pronotal angles (either of which may represent the widest portion of the thorax), and the individual lengths of the pedicel, basiflagellomere, and distiflagellomere (of the left antenna for all specimens in which it was intact). The ratio of the length of the distiflagellomere to that of the pedicel + basiflagellomere is reported for each taxon. This was calculated by taking the mean across ratios for individual specimens of a given sex. While past taxonomists who dealt with this genus often recorded the maximal width of the abdomen, we omitted this trait from study because it is rather contextual and strongly influenced by how the specimen died and whether it had recently fed and/or was carrying mature eggs. Specimen photographs were taken using a Leica Microsystems imaging system (LAS software v4.3.0), stacked with Zerene Stacker v1.04 to create composite images, and then edited in Adobe Photoshop® CC 2017. Figures were prepared in Adobe Illustrator® CC 2017.

Distribution maps and citizen science data: Specimen-associated locality data and observational data (i.e., geocoordinates and images) shared by the general public with our iNaturalist project “Uncovering the ambush bugs” (https://www.inaturalist.org/projects/uncovering-the-ambush-bugs) were used in conjunction to create more complete estimates of current taxon distributions (data last accessed October 9, 2019). This data is provided in a supplementary spreadsheet (iNaturalist_observations.xlsx) and image archive (iNaturalist_images.zip). Distribution maps (Maps 1-17) were generated with the available coordinate data for each erosa group species in SimpleMappr (https://www.simplemappr.net/).

Taxonomic descriptions: Descriptions were partially produced using a WinClada v1.61 (Nixon 1999) based character matrix and then manually edited to accommodate variability and any unique traits for each species. Outlines displaying the consensus pronotal shape were generated following the geometric morphometric approach outlined in Masonick and Weirauch (2020) and are included for each sex in all taxon plates. The curvature of the pronotal lobes are best viewed from a dorsolateral perspective with the lateral margin placed roughly perpendicular to the optical axis. Pronotal shape variation is described from this position unless otherwise noted. Adult males are described in their entirety, but for females, only sexually dimorphic traits are described. Based on combined molecular data, we recently showed that the erosa group likely comprises three main species complexes, the americana, borica, and fasciata species complexes (see Masonick and Weirauch, 2020, Fig. 3). While these complexes are fairly well-defined using DNA, no morphological synapomorphies are apparent. Due to the lack of diagnostic characters, we only provide a general description for all erosa group taxa and not the individual species complexes themselves. Species descriptions are each accompanied with a plate highlighting their key diagnostic characters. Given their morphological variability and the fact that both age and diet influence color pattern traits in adults (see Punzalan et al. 2008a), we strongly recommend that readers assess multiple characters when making identifications.

Terminology and abbreviations: Anatomical terminology roughly follows that used in Kormilev’s (1962) revision of the genus. Morphological features of Phymata are illustrated in Figures 1, 2, and 20R. The following abbreviations are included in keys, plates, and/or text: aa, anterior angle; af, antennal furrow; apd, anterior pronotal disk; apl, anterior pronotal lobe; bflg, basiflagellomere; cas2–7, connexiva of abdominal segments 2–7; dflg, distiflagellomere; fcx, forecoxa; ffm, forefemur; fp, frontal process; ftb, foretibia; gp, granulation patch; la, lateral angle; lc, longitudinal carina; ln, lateral notch; mspl, mesopleuron; mtpl, metapleuron; op, ocellar process; pa, posterior angle; pd, pedicel; pop, preocellar process; pp, posterior process; ppd, posterior pronotal disk; ppl, posterior pronotal lobe; prpl, propleuron; py, pygophore; sc, scutellum; sppl, shoulder of the posterior pronotal lobe; tb, transverse band of the corium; tlc, tubercles of longitudinal carina.

Botanical taxonomy: Plant names and authors listed in this revision are based on the Integrated Taxonomic Information System database (itis.gov).

Nomenclature: The nomenclatural acts contained within this work have been registered in ZooBank (http://www.zoobank.org), the official registry of the International Commission on Zoological Nomenclature. The LSID (Life Science Identifier) number of the publication is: urn:lsid:zoobank.org:pub:2E2263AA-F7B4-46B6-A26B-97A9F9CE3628.

Table 2. List of specimen depositories and their collection codes.

Collection Location Code
American Museum of Natural History New York City, NY USA AMNH
California Academy of Sciences San Francisco, CA USA CAS
Illinois Natural History Survey Insect Collection Champaign, IL USA INHS
University of Kansas Snow Entomological Museum Lawrence, KS USA KU
Natural History Museum of Los Angeles County Los Angeles, CA USA LACM
Museum of Northern Arizona Flagstaff, AZ USA MNA
Montana State University Montana Entomology Collection Bozeman, MT USA MTEC
Natural History Museum Vienna Vienna, Austria NHMW
Swedish Museum of Natural History Stockholm, Sweden NRM
San Diego Natural History Museum San Diego, CA USA SDNHM
University of California Riverside Entomology Research Museum Riverside, CA USA UCR
Universidad Autonoma de Mexico Instituto de Biologia Mexico City, Mexico UNAM
United States National Museum of Natural History District of Colombia, USA USNM
University of Idaho William F. Barr Entomological Museum Moscow, ID USA WFBM


Table 3. Measurements in mm of erosa group taxa. Abbreviations: body, total body length; pd, pedicel; bflg, basiflagellomere; dflg, distiflagellomere; la, lateral angle of pronotum; pa, posterior angle of pronotum.

    Length   Width
Species   body pd bflg dflg dflg: pd+bflg la pa
Phymata americana              
males (N=8) Mean 8.81 0.62 0.66 1.15 0.89 3.37 3.42
  SD 0.30 0.06 0.02 0.09   0.18 0.20
  Range 1.00 0.16 0.07 0.25   0.59 0.48
  Min. 8.15 0.56 0.64 1.05   3.08 3.17
  Max. 9.15 0.72 0.71 1.30   3.67 3.65
females (N=8) Mean 10.06 0.65 0.70 1.03 0.76 3.74 3.86
  SD 0.42 0.04 0.07 0.09   0.33 0.21
  Range 1.14 0.11 0.22 0.23   0.93 0.64
  Min. 9.59 0.59 0.54 0.92   3.38 3.63
  Max. 10.73 0.70 0.76 1.14   4.31 4.27
                 
Phymata arctostaphylae              
males (N=5) Mean 8.08 0.56 0.63 1.23 1.04 3.40 3.30
  SD 0.41 0.03 0.01 0.05   0.23 0.19
  Range 0.91 0.07 0.02 0.11   0.59 0.51
  Min. 7.70 0.52 0.62 1.18   3.06 3.05
  Max. 8.61 0.59 0.64 1.29   3.65 3.56
females (N=5) Mean 9.47 0.62 0.68 1.02 0.78 3.73 3.71
  SD 0.46 0.04 0.05 0.10   0.27 0.23
  Range 1.18 0.11 0.13 0.27   0.66 0.58
  Min. 8.96 0.57 0.64 0.92   3.43 3.40
  Max. 10.14 0.68 0.76 1.20   4.09 3.97
                 
Phymata borica                
males (N=4) Mean 7.31 0.51 0.59 1.03 0.95 2.61 2.64
  SD 0.38 0.04 0.06 0.09   0.04 0.05
  Range 0.76 0.10 0.14 0.20   0.08 0.12
  Min. 6.93 0.46 0.52 0.91   2.56 2.57
  Max. 7.69 0.56 0.66 1.11   2.65 2.69
females (N=3) Mean 8.40 0.55 0.62 0.91 0.78 2.99 2.99
  SD 0.22 0.05 0.02 0.01   0.09 0.09
  Range 0.43 0.09 0.04 0.02   0.18 0.17
  Min. 8.19 0.52 0.60 0.91   2.89 2.90
  Max. 8.62 0.61 0.64 0.92   3.07 3.07
                 
Phymata fasciata              
males (N=6) Mean 8.21 0.56 0.65 1.08 0.89 3.14 3.24
  SD 0.49 0.03 0.03 0.06   0.15 0.18
  Range 1.46 0.07 0.09 0.14   0.43 0.44
  Min. 7.61 0.53 0.61 1.01   2.97 3.07
  Max. 9.07 0.60 0.70 1.15   3.40 3.51
females (N=4) Mean 9.18 0.58 0.69 0.89 0.7 3.45 3.60
  SD 0.47 0.08 0.05 0.13   0.22 0.22
  Range 0.98 0.17 0.11 0.27   0.48 0.46
  Min. 8.62 0.52 0.65 0.74   3.25 3.37
  Max. 9.60 0.69 0.76 1.01   3.73 3.83
Phymata granulosa              
males (N=5) Mean 8.50 0.56 0.69 1.09 0.87 3.38 3.48
  SD 0.61 0.03 0.04 0.10   0.26 0.26
  Range 1.63 0.08 0.11 0.25   0.61 0.65
  Min. 7.89 0.53 0.65 0.99   3.18 3.25
  Max. 9.52 0.60 0.76 1.24   3.78 3.90
females (N=5) Mean 9.61 0.66 0.79 1.06 0.74 3.90 4.08
  SD 0.51 0.05 0.03 0.10   0.28 0.24
  Range 1.22 0.14 0.08 0.23   0.71 0.60
  Min. 8.89 0.59 0.75 0.93   3.57 3.81
  Max. 10.11 0.73 0.83 1.16   4.28 4.42
                 
Phymata luteomarginata        
males (N=5) Mean 6.99 0.51 0.49 0.96 0.96 2.71 2.80
  SD 0.44 0.05 0.05 0.13   0.28 0.27
  Range 1.15 0.12 0.12 0.32   0.72 0.62
  Min. 6.30 0.44 0.46 0.75   2.27 2.37
  Max. 7.45 0.56 0.57 1.06   2.99 2.99
females (N=5) Mean 7.75 0.49 0.56 0.77 0.73 2.86 2.97
  SD 0.82 0.06 0.06 0.09   0.25 0.25
  Range 1.99 0.14 0.14 0.19   0.60 0.60
  Min. 6.99 0.42 0.51 0.66   2.63 2.72
  Max. 8.97 0.56 0.64 0.85   3.23 3.32
                 
Phymata metcalfi              
males (N=6) Mean 7.73 0.54 0.58 0.96 0.86 3.01 3.04
  SD 0.54 0.03 0.04 0.12   0.30 0.28
  Range 1.34 0.09 0.10 0.30   0.75 0.76
  Min. 7.16 0.51 0.53 0.83   2.68 2.68
  Max. 8.49 0.60 0.63 1.13   3.43 3.43
females (N=6) Mean 8.53 0.55 0.61 0.82 0.71 3.23 3.27
  SD 0.68 0.05 0.04 0.07   0.29 0.32
  Range 1.78 0.13 0.12 0.16   0.64 0.80
  Min. 7.47 0.51 0.53 0.74   2.79 2.78
  Max. 9.25 0.64 0.65 0.90   3.44 3.58
                 
Phymata mexicana              
males (N=5) Mean 8.43 0.62 0.66 1.14 0.89 3.55 3.35
  SD 0.35 0.02 0.04 0.08   0.29 0.28
  Range 0.88 0.05 0.12 0.18   0.77 0.67
  Min. 8.14 0.59 0.61 1.05   3.29 3.17
  Max. 9.03 0.64 0.73 1.24   4.06 3.84
females (N=5) Mean 9.40 0.64 0.73 1.00 0.73 3.88 3.76
  SD 0.26 0.06 0.05 0.09   0.27 0.29
  Range 0.67 0.15 0.11 0.20   0.68 0.78
  Min. 9.12 0.59 0.68 0.91   3.51 3.34
  Max. 9.80 0.73 0.79 1.11   4.19 4.13
                 
Phymata mystica              
males (N=5) Mean 8.26 0.62 0.63 1.05 0.84 3.29 3.36
  SD 0.49 0.05 0.05 0.05   0.12 0.17
  Range 1.00 0.12 0.13 0.11   0.27 0.40
  Min. 7.73 0.57 0.57 0.99   3.16 3.14
  Max. 8.72 0.69 0.70 1.10   3.43 3.54
females (N=5) Mean 9.19 0.62 0.67 0.88 0.68 3.57 3.61
  SD 0.44 0.05 0.03 0.07   0.16 0.23
  Range 1.05 0.12 0.07 0.15   0.34 0.53
  Min. 8.63 0.56 0.65 0.79   3.40 3.37
  Max. 9.67 0.68 0.71 0.94   3.75 3.90
                 
Phymata obscura              
males (N=4) Mean 8.35 0.57 0.63 1.05 0.87 3.23 3.21
  SD 0.58 0.05 0.04 0.07   0.32 0.29
  Range 1.31 0.11 0.10 0.18   0.76 0.71
  Min. 7.57 0.51 0.58 0.95   2.90 2.85
  Max. 8.88 0.62 0.68 1.13   3.66 3.56
females (N=4) Mean 9.93 0.61 0.68 1.00 0.77 3.66 3.79
  SD 0.33 0.04 0.04 0.08   0.35 0.34
  Range 0.79 0.10 0.09 0.18   0.84 0.82
  Min. 9.52 0.56 0.65 0.89   3.31 3.44
  Max. 10.31 0.66 0.74 1.07   4.16 4.26
                 
Phymata pacifica              
males (N=5) Mean 6.60 0.46 0.56 0.82 0.81 2.66 2.53
  SD 0.17 0.04 0.04 0.04   0.08 0.07
  Range 0.36 0.09 0.09 0.10   0.18 0.15
  Min. 6.40 0.43 0.51 0.77   2.57 2.46
  Max. 6.76 0.52 0.60 0.87   2.75 2.61
females (N=5) Mean 7.85 0.52 0.63 0.70 0.61 3.17 3.05
  SD 0.58 0.07 0.04 0.06   0.20 0.17
  Range 1.59 0.18 0.08 0.13   0.44 0.38
  Min. 7.18 0.44 0.60 0.63   2.96 2.88
  Max. 8.77 0.61 0.68 0.76   3.40 3.26
                 
Phymata paraborica              
males (N=8) Mean 6.84 0.52 0.54 0.90 0.86 2.54 2.54
  SD 0.18 0.03 0.03 0.05   0.09 0.09
  Range 0.56 0.08 0.08 0.13   0.28 0.28
  Min. 6.59 0.48 0.50 0.84   2.38 2.40
  Max. 7.15 0.56 0.57 0.97   2.66 2.69
females (N=8) Mean 7.42 0.52 0.55 0.74 0.69 2.71 2.70
  SD 0.32 0.05 0.02 0.04   0.13 0.13
  Range 1.05 0.11 0.08 0.12   0.42 0.35
  Min. 6.89 0.46 0.51 0.65   2.47 2.52
  Max. 7.94 0.56 0.59 0.78   2.88 2.87
                 
Phymata pennsylvanica              
males (N=5) Mean 8.19 0.56 0.59 1.32 1.15 2.92 2.96
  SD 0.35 0.02 0.06 0.10   0.14 0.18
  Range 0.94 0.05 0.16 0.25   0.34 0.47
  Min. 7.73 0.53 0.52 1.15   2.75 2.73
  Max. 8.67 0.58 0.68 1.41   3.09 3.20
females (N=5) Mean 9.27 0.57 0.63 1.04 0.88 3.27 3.36
  SD 0.22 0.05 0.09 0.04   0.13 0.17
  Range 0.58 0.13 0.26 0.10   0.35 0.45
  Min. 8.97 0.51 0.50 1.01   3.16 3.20
  Max. 9.55 0.63 0.76 1.11   3.50 3.65
                 
Phymata rossi                
males (N=3) Mean 7.47 0.57 0.59 1.01 0.87 2.90 2.88
  SD 0.77 0.07 0.04 0.03   0.29 0.24
  Range 1.41 0.14 0.07 0.05   0.58 0.47
  Min. 6.59 0.52 0.57 0.98   2.61 2.61
  Max. 8.00 0.65 0.64 1.03   3.18 3.08
females (N=3) Mean 8.52 0.59 0.64 0.87 0.71 3.21 3.28
  SD 0.31 0.07 0.02 0.04   0.14 0.19
  Range 0.62 0.14 0.03 0.07   0.25 0.37
  Min. 8.21 0.51 0.62 0.83   3.12 3.11
  Max. 8.82 0.65 0.66 0.90   3.38 3.48
                 
Phymata saileri                
males (N=1) Meas. 8.01 0.58 0.56 1.04 0.91 2.86 3.25
females (N=1) Meas. 8.08 0.51 0.55 0.8 0.75 3.03 3.30
                 
Phymata salicis                
males (N=2) Mean 7.96 0.59 0.59 0.69 0.59 2.77 2.63
  SD 0.27 0.05 0.07 0.07   0.12 0.02
  Range 0.38 0.07 0.10 0.10   0.17 0.03
  Min. 7.77 0.55 0.54 0.64   2.69 2.62
  Max. 8.15 0.63 0.64 0.74   2.85 2.65
females (N=3) Mean 8.34 0.54 0.59 0.59 0.52 2.84 2.76
  SD 0.57 0.03 0.03 0.04   0.18 0.13
  Range 0.99 0.06 0.06 0.07   0.33 0.25
  Min. 8.01 0.51 0.56 0.56   2.71 2.66
  Max. 9.00 0.57 0.62 0.63   3.04 2.91
                 
Phymata stanfordi              
males (N=5) Mean 7.59 0.55 0.58 0.96 0.84 2.77 2.81
  SD 0.39 0.02 0.03 0.05   0.13 0.11
  Range 1.09 0.04 0.08 0.11   0.30 0.26
  Min. 7.03 0.53 0.55 0.90   2.61 2.63
  Max. 8.13 0.57 0.63 1.01   2.92 2.89
females (N=5) Mean 8.40 0.62 0.65 0.81 0.65 3.07 3.09
  SD 0.69 0.04 0.06 0.06   0.25 0.27
  Range 1.60 0.09 0.16 0.11   0.64 0.65
  Min. 7.69 0.56 0.58 0.75   2.77 2.77
  Max. 9.29 0.66 0.73 0.86   3.41 3.42

Figure 1. General morphology of Nearctic erosa group taxa (P. granulosa ♂).
Morphological features are abbreviated as follows: aa, anterior angle; af, antennal furrow; apd, anterior pronotal disk; apl, anterior pronotal lobe; bflg, basiflagellomere; cas2–7, connexiva of abdominal segments 2–7; dflg, distiflagellomere; fcx, forecoxa; ffm, forefemur; fp, frontal process; ftb, foretibia; gp, granulation patch; la, lateral angle; lc, longitudinal carina; ln, lateral notch; mspl, mesopleuron; mtpl, metapleuron; op, ocellar process; pa, posterior angle; pd, pedicel; pop, preocellar process; pp, posterior process; ppd, posterior pronotal disk; ppl, posterior pronotal lobe; prpl, propleuron; py, pygophore; sc, scutellum; tb, transverse band of the corium.

Figure 2. Pronotal morphology from dorsolateral view (P. fasciata ♂).
Morphological features are abbreviated as follows: aa, anterior angle; apd, anterior pronotal disk; apl, anterior pronotal lobe; gp, granulation patch; la, lateral angle; lc, longitudinal carina; ln, lateral notch; pa, posterior angle; pp, posterior process;  ppd, posterior pronotal disk; ppl, posterior pronotal lobe; sppl, shoulder of the posterior pronotal lobe; tlc, tubercles of longitudinal carina.