Research Article |
Corresponding author: Brandon Woo ( magicicadaseptendecim@gmail.com ) Academic editor: Hugh Rowell
© 2021 Brandon Woo.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Woo B (2021) A new species of pygmy mole cricket (Orthoptera: Tridactylidae) from the Lake Wales ridge of Florida and new records of Ellipes eisneri from the northern Brooksville ridge. Journal of Orthoptera Research 30(2): 131-143. https://doi.org/10.3897/jor.30.65603
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Pygmy mole crickets (Orthoptera: Tridactylidae) are usually associated with the edges of ponds and streams, but in the sandy uplands of Florida, at least two lineages of these insects have evolved to live in xeric scrub and sandhill habitats. Very little work has been done with scrub tridactylids since they are tiny and often difficult to collect. In this paper, the pygmy mole cricket Ellipes deyrupi sp. nov. is described from the northern Lake Wales Ridge of Florida. It is sympatric at all known locations with another scrub tridactylid, Neotridactylus archboldi Deyrup & Eisner, but has not been found co-occurring with the closely related Ellipes eisneri Deyrup. The habits of this new species are convergent with both N. archboldi and E. eisneri. In addition, new records of Ellipes eisneri are presented, extending this species’ known distribution to the Northern Brooksville Ridge. Both species of scrub Ellipes are found in restricted geographic ranges and suffer from a lack of study and recognition. Conservation implications for these two species are discussed.
Distribution, Florida endemics, sandhill, scrub, taxonomy, Tridactylinae
The pygmy mole crickets, or Tridactylidae (Orthoptera: Caelifera: Tridactyloidea), are a family of small, burrowing orthopterans with a worldwide distribution (
The Florida scrub is a unique and threatened habitat restricted to a series of ridges and dunes formed from Miocene, Pliocene, or Pleistocene shorelines, during which time the rest of the state was underwater (
The oldest and longest of Florida’s sand ridges, and the one with the highest levels of endemism, is the Lake Wales Ridge (LWR), which extends in central Florida from just south of the Orlando area to just north of Lake Okeechobee (
Most Florida scrub endemic arthropods are poorly known due to their small sizes, restricted geographic ranges, and habitat specializations (
Collection.—Initial specimens of the new species were collected in yellow bowl traps (always following rain) during a 2009 survey of arthropods endemic to the Lake Wales Ridge. Additional material was collected by the author in August 2018 at the Tiger Creek Preserve and in August 2019 at two roadside sites east of Lake Marion. These two localities, as well as roadside sites on the Brooksville Ridge that might harbor Ellipes eisneri populations, were located using Google Maps. The author made several trips to the Brooksville Ridge during June and July 2018 in search of E. eisneri, but dry conditions kept the insects deep underground and out of reach. On July 28 and 29, 2018, the weather was more favorable, and specimens of E. eisneri were collected at five sites. All tridactylid specimens were collected either by carefully digging up the raised burrows immediately after rain or by sifting dry sand around the tumuli.
Determination.—Specimens of E. eisneri were identified using
Measurements and terminology.—Measurements were made to the nearest 0.5 mm by hand using a ruler and dissecting microscope (Wild Heerbrugg, Heerbrugg, Switzerland). Terminology follows
Photographs and maps.—Live nymphs and adults of both species were photographed in situ using a Canon EOS Rebel T3 with an attached Canon 100 mm macro lens and an external flash (Sunpak Auto 383 Super connected with a CowboyStudio 4 Channel Wireless Hot Shoe Flash Trigger & Receiver). Collected nymphs and adults were photographed in a whitebox studio setup using the same equipment, with the addition of Canon extension tubes (EF25 and EF12 II) to the camera. Images of the habitat and tumuli were taken with an iPhone. Images of preserved specimens were made using a Canon EOS 6D with attached MPE 65 mm macro lens (20X zoom lens used for the terminalia and stridulatory apparatus) and Macro Twin Lite MT-24EX flash on a Cognisys Stackshot 3X system. Images were stacked using Zerene Stacker v.1.04 (Zerene Systems LLC, Richland, WA). All images were processed using Adobe Lightroom CC 2015.8 to crop and adjust white balance. Composite figures were created using Adobe Photoshop CC, v.14.2.1. Maps were created with SimpleMappr (
Depositories.—
1 | Larger, body length 3.8–10 mm; hind tarsus present | Neotridactylus 2 |
– | Smaller, length 3–5 mm; hind tarsus reduced to a tiny flap concealed between the hind tibial spurs | Ellipes 3 |
2 | Larger, length 5.5–10 mm; fully winged; swimming plates on hind tibia present; color variable; usually found in sandy or muddy areas along water | N. apicialis |
– | Smaller, length 3.8–4.9 mm; tegmina abbreviated, hind wings absent; swimming plates absent; uniformly dark colored; always found in xeric scrub habitats | N. archboldi |
3 | Fully winged; color variable but never uniformly pale; usually found in sandy or muddy areas along water | 4 |
– | Tegmina abbreviated, hind wings absent; coloration pale white and brown; always found in xeric scrub or sandhill habitats | 5 |
4 | Antennae in both sexes 10–segmented | E. minuta |
– | Antennae in the male 11-segmented, in the female 12-segmented | E. gurneyi |
5 | Smaller, length 3.3–3.5 mm; head blackish brown with narrow cream lines along inner orbits and coronal and frontal sutures; found in open sandhill habitat on the Brooksville Ridge | E. eisneri |
– | Larger, length 3.5–4.1 mm; head white with irregular blackish brown band at its base and an irregular line of the same color between the compound eyes; found in yellow sand scrub habitat on the northern Lake Wales Ridge | E. deyrupi sp. nov. |
Family Tridactylidae Brullé, 1835
Subfamily Tridactylinae Brullé, 1835
Ellipes
Scudder, 1902: 309;
—Tridactylus minutus Scudder, 1862 (= Ellipes minuta), by original monotypy.
—Holotype: USA • ♂; Florida: Polk County: Sarasota Court, east of Lake Marion; 28.084972, -81.514889; 07 Aug. 2019; red type label, “Holotype Ellipes deyrupi Woo”; B. Woo leg.;
—Differs from all other known species of Ellipes, except E. eisneri in its flightless condition, pale white and brown coloration, lack of swimming plates, and occurrence in xeric habitat. Easily distinguished from E. eisneri by its larger size, distinctive coloration, and disjunct range.
—Male (holotype). (Fig.
Structural characters: antennae 10-segmented, front tibia with 4 teeth; swimming plates of hind tibiae absent; forewing abbreviated, hind wings absent; scraper present on the underside of the forewing (Fig.
Terminalia as in Fig.
Female. (Fig.
—Male holotype. length of head and body: 3.50; length of pronotum: 0.75; width of pronotum: 1.2; width of head across eyes: 0.75; length of hind femur: 2; length of hind tibia: 1.50; length of forewing: 0.4.
Female allotype. length of head and body: 4.10; length of pronotum: 1.00; width of pronotum: 1.20; width of head across eyes: 0.70; length of hind femur: 2.10; length of hind tibia: 1.60; length of forewing: 0.75.
—This species is named in honor of Dr. Mark Deyrup, Emeritus Research Biologist in Entomology at the Archbold Biological Station, who first collected the species and recognized it as distinct, and who has contributed the bulk of what is known about scrub tridactylid biology. Dr. Deyrup encouraged the author to describe this new species and look for other species across the southeastern U.S. and has been enormously supportive and generous with his knowledge of Florida natural history.
—
—Restricted to the north-central Lake Wales Ridge in Polk County, FL (Fig.
—All specimens were collected in bare sand patches within yellow sand scrub habitat (Fig.
Photographs of nymphs and adults of E. deyrupi are posted by the author to BugGuide.net for public viewing, at https://bugguide.net/node/view/1575492/bgimage
Ellipes eisneri Deyrup, 2005: 142.
—Holotype: USA • ♂; Florida: Citrus County: near Inverness, Withlacoochee Forest, Citrus Area, Forest Road 13, 1.3 mi. south State Road 44; 03 Apr. 1995; sandhill habitat with bare sand, dug from vertical burrow; M. Deyrup leg.;
—USA, Florida • 2 ♀;Citrus County: Floral City, side of road on Bedford Dr.; 28.746, -82.299; 28 Jul. 2018; specimens in ethanol; B. Woo leg.;
—These are the only two sites from which the species has been known prior to this work. Herein, I present the following specimen data and localities. For photographs of living and preserved specimens of E. eisneri, see Figs
—Found on the Brooksville Ridge in Levy, Marion, and Citrus Counties, FL (Fig.
—Specimens were collected in bare sand patches within open sandhill habitats (Fig.
Ellipes deyrupi represents the third species of Tridactylidae known to be restricted to sandy Florida uplands. Its discovery vindicates Deyrup’s 1996 and
The situation of the two species of scrub Ellipes, in which there is one species (E. eisneri) on the Brooksville Ridge and another species (E. deyrupi) on the northern LWR, shares several similarities with that of Florida Geopsammodius Gordon & Pittino, 1992 scarab beetles. These blind, flightless beetles also live just below the surface of the sand in scrub and sandhill habitats, and the author often found and collected them while searching for tridactylids (specimens are in the
The ecology and behavior of scrub tridactylids is largely unknown. The only species that has been studied in any detail at all is Neotridactylus archboldi, which feeds on a layer of subsurface algae (
Ellipes deyrupi may be a species of conservation concern. If the species occurred further south on the LWR,
The new records for E. eisneri reported here extend its range to the Northern Brooksville Ridge, and my suspicion is that it likely occurs across the entire ridge in suitable habitat. Its occurrence on the northern part of the ridge is interesting because the other Brooksville Ridge endemic Orthopteran, the flightless grasshopper Melanoplus withlacoocheensis
Ellipes eisneri was relatively abundant wherever found, judging by the number of tumuli and burrows present at all sites, so it is most likely not a rare species within its known range. While its distribution appears to be wider than previously known, the fact remains that it has not been found on any other of Florida’s sand ridges, and that most of the open sandhill habitat on the Brooksville ridge is under threat from human development. The Withlacoochee State Forest (Citrus Tract) is still the only known protected site for E. eisneri, as the new localities reported here are all roadside sandhill habitats. The Bronson site, however, is adjacent to the Watermelon Pond Wildlife and Environmental Area, owned by the Florida Fish and Wildlife Conservation Commission. It is almost certain that there are populations of E. eisneri present in the extensive sandhills of this protected area. The nearby Goethe State Forest and Goethe Wildlife Management Area are also likely to hold populations of E. eisneri. It would be prudent to sample within these localities during rainy weather to determine whether E. eisneri occurs there.
I am extremely grateful to Mark Deyrup for offering me the chance to describe this species and for encouraging and supporting my work on Florida tridactylids. I thank the staff of Archbold Biological Station for providing food and housing. Thanks are also due to Beatriz Pace-Aldana of the Nature Conservancy for granting me permission to collect specimens at the Tiger Creek Preserve and for providing helpful information about the area. Jason Dombroskie reviewed the original manuscript and has supported my studies of tridactylids for several years. Kyhl Austin assisted with the Cognisys focus-stacking system and zoom lens. Ann Dunn accompanied me on various collecting trips and shared my enthusiasm for tiny, understudied animals. Angela Soto, Seth Raynor, and Scott Ward provided plant and lichen identifications. A portion of this work was supported by a summer internship at the Archbold Biological Station to B. Woo. I thank the two reviewers for their comments on the manuscript. The Orthopterists’ Society provided funding for publishing this paper.