Canadian Journal of Arthropod Identification
 
 

Orthoptera of Alaska: A photographic key, new records, and synonymy of Melanoplus gordonae

CJAI 44 -- April 23, 2021
doi:10.3752/cjai.2021.44

Adam Haberski, Derek A. Woller, and Derek S. Sikes

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

Materials & Methods

The key presented here is for adult Orthoptera and is based largely on the works of Vickery and Kevan (1985 (1986)) and Catling (2008) who covered the Alaskan species in their keys to the Canadian fauna. Adults for all Alaskan species can be distinguished from nymphs by the presence of fully developed wings, except in the case of the two Rhaphidophoridae species whose life stages all resemble one another with the exception of relative size (adults being the largest and most robust) and presence of fully developed cerci and genitalia. Taxonomy used here follows that of the most current Orthoptera Species File (Cigliano et al. 2020). Morphological terminology is consistent with that of Catling (2008). An informational overview for each species follows the key and is organized alphabetically by genus and then specific name. A list of institutions that contributed specimens, photographs, and distribution data can be found in Table 2.

Table 2. List of institutions that provided specimens, photographs, and GBIF.org distribution data.

Abbreviation Institution Specimens Photos GBIF data
ANSP The Academy of Natural Sciences of Drexel University, Philadelphia, PA, USA - yes -
ASUHIC Arizona State University Hasbrouck Insect Collection, Tempe, AZ, USA yes yes -
BYUC Brigham Young University Monte L. Bean Life Science Museum, Provo, UT, USA - - yes
CSUC Colorado State University C. P. Gillette Museum of Arthropod Diversity, Fort Collins, CO, USA - - yes
KNWR Kenai National Wildlife Refuge, Soldotna, AK, USA - - yes
LEMQ McGill University Lyman Entomological Museum and Research Laboratory, Ste. Anne de Bellevue, Quebec, Canada yes yes yes
OMNH University of Oklahoma, Oklahoma Museum of Natural History, Norman, OK, USA - - yes
OSUM Ohio State University Museum of Biological Diversity, Oberlin, OH, USA - - yes
UAM University of Alaska Museum of the North, Fairbanks, AK, USA yes yes yes
UBCZ University of British Columbia Spencer Museum, Vancouver, British Columbia, Canada - - yes
UMMZ University of Michigan Museum of Zoology, Ann Arbor, MI, USA - yes yes
USDA APHIS PPQ S&T Phoenix Lab Rangeland Orthoptera Collection, Phoenix, AZ, USA yes yes -
USNM National Museum of Natural History, Washington, D.C., USA - yes yes
UWBM University of Washington Burke Museum of Natural History and Culture, Seattle, WA, USA - - yes

This key should correctly identify males and short-winged females of all species. However, difficulty may arise for some long-winged females, specifically for the species M. bruneri, M. sanguinipes, and Melanoplus fasciatus (Walker, 1870). To explain, both Vickery and Kevan (1985 (1986)), and Catling (2008) relied on a combination of ventral coloration of the hind femur and cercus shape to distinguish females of M. bruneri and M. sanguinipes. Catling (2008) describes M. bruneri as having a “hind femur entirely yellowish below; upper side of cercus straight” and M. sanquinipes as having a “hind femur with pink or reddish stripe below; upper side of cercus convex.” However, we found these characters to be variable in the Alaskan specimens we examined. For example, many specimens of M. sanguinipes in the UAM collection have straight cerci, and the undersides of their femora are yellow, red, pink, or pink-striped. Furthermore, preserved specimens are often faded or discolored, limiting the usefulness of this color-based character. Thus, our key is not designed to distinguish between females of M. bruneri and M. sanguinipe meaning some specimens will key out inconclusively. This issue will only be rectified by collecting and examining a longer series of Alaskan M. bruneri in order to develop more reliable characters. Like M. buneri, reliable identification of M. fasciatus females will only be possible with more specimens because, as of yet, insufficient numbers have been collected from Alaska. Therefore, the current best methods for identifying females of these species are either examining hind femora coloration in newly collected specimens or by association with males.

We identified UAM specimens by use of the prior mentioned keys in combination with identifications made by the following orthopterists: A. B. Gurney, P. Naskrecki, D. Nickle, and J. Rehn. Specimen data were compiled from the literature, UAM records, and by searching GBIF.org (https://doi.org/10.15468/dl.h86qrh) (GBIF.org 2020). UAM specimen data are publicly available via the Arctos database (http://arctos.database.museum/saved/Orthoptera), which serves data to GBIF.org among other data aggregators. GBIF.org records were limited to those based on preserved specimens and those with verifiable photographs. Literature records were georeferenced following the MaNIS georeferencing guidelines (Chapman and Wieczorek 2006), and distribution maps were then created in R (R Core Team 2018). DNA barcode data were archived on the Barcode of Life Database (BOLD) website (http://www.boldsystems.org) (Ratnasingham and Hebert 2007).

Body length measurements for the acridids and tetrigids were taken from Catling (2008). Specimens of the two rhaphidophorids were measured from the front of the head (excluding the antennae) to the tip of the abdomen and the mean length for each sex is reported. For Pristoceuthophilus cercalis Caudell, 1916, ten UAM specimens of each sex were measured. For Tropidischia xanthostoma (Scudder, 1861) males, only one Alaskan specimen was available, and its length is reported. Female length was based on nine specimens from California as no specimens from Alaska or Canada were available.

Except for living specimens, images for the key were taken with either a Leica Microsystems DFC425 camera attached to a Leica MZ16 microscope or a Macroscopic solutions Macropod Pro 3D imaging system attached to a Canon EOS 6D Mark II DSLR camera with a 65 mm lens. Multiple images were taken at different focal lengths and then stacked into a single composite image. Images from the Leica DFC425 were processed with Leica Application Suite V3.8, and images from the Macropod system were processed using Zerene Stacker (Build T2020-05-22-1330). Adobe Photoshop was used to add scale bars and adjust light levels. All images were taken using UAM specimens unless otherwise noted.

Morphological Terms

Figs. 2–3

  • Abdomen: the third and posterior body segment.
  • Antennae: paired, segmented sensory organs on the head.
  • Carina: an elevated ridge, notably on the head and pronotum.
  • Cercus(i): paired posterior-directed appendages emerging from the tenth abdominal segment.
  • Fastigium: a flat surface at the extreme front of the head.
  • Femur: the third segment of the leg, exceptionally large on the hind leg.
  • Foveolae: a depression with well-marked sides.
  • Furculae: paired posterior-directed appendages emerging from the ninth abdominal segment.
  • Ovipositor: paired blade-like structures protruding from the tip of females’ abdomens, used to lay eggs.
  • Pronotum: the dorsal plate of the first thoracic segment.
  • Prosternum: the first ventral thoracic segment, located between the forelegs.
  • Subgenital plate: the terminal ventral plate of the abdomen, covers the internal male and female genitalia.
  • Supra-anal plate: the terminal dorsal plate of the abdomen, covers the internal male genitalia.
  • Tegmen(ina): the sclerotized forewing(s).
  • Thorax: the second body segment bearing the legs, pronotum, and wings.
  • Tibia: the fourth leg segment, exceptionally long and thin on the hind leg.
  • Tubercles: small, rounded buttons or bumps.
  • Figure 2. Left lateral view of a female grasshopper (Acrididae) illustrating characters used in the key.

    Figure 3. Dorsal view of the male terminalia of a grasshopper (Acrididae) illustrating characters used in the key.