Grylloblatta marmoreus, Schoville, Sean D., 2012

Schoville, Sean D., 2012, Three new species of Grylloblatta Walker (Insecta: Grylloblattodea: Grylloblattidae), from southern Oregon and northern California, Zootaxa 3412, pp. 42-52 : 49-50

Grylloblatta marmoreus new species

( Figs. 1 C, 2E–H)

Type material. Holotype male in ethanol, deposited in CAS, labeled: “Big Foot Cave, Marble Mountain Wilderness Area, Siskiyou Co., CA, G. O. Graening & Guy Graening, 3 Sept. 2010 ” [white label]/ “ HOLOTYPE Grylloblatta marmoreus Schoville det. S.D. Schoville 2011” [red label]; Big Foot Cave, located in Marble Valley, approximately 41.5628o North and - 123.1899o West, elevation 5,935 ft, Marble Mountain Wilderness Area, Siskiyou County, California.

Other specimens. Juvenile in ethanol, deposited in CAS, labeled: “Planetary Dairy Cave, G. O. Graening and David Weaver, 4 July 2010 ” [white label]/ “ Grylloblatta marmoreus Schoville det. S.D. Schoville 2011” [white label]; Planetary Dairy Cave, approximately 41.560o North and - 123.197o West, elevation 5,621ft, Marble Mountain Wilderness Area, Siskiyou County, California near the headwaters of the Canyon Creek watershed.

Etymology. The specific epithet, marmoreus , means “of marble” in Latin and is named for the Marble Mountains of California where this specimen was collected.

Diagnosis. Adult males of this species can be distinguished from those of all other Nearctic Grylloblatta species by the following combination of character states: color buff yellow; small body size for genus; relatively short limbs; fewer than 30 antennomeres; ratio of antennomere lengths 2 and 1 1.5; head wider than pronotum; compound eyes well-developed and medium size; pronotum trapezoidal with rounded proximal end and forming soft triangular point at posterior end; subgenital plate with slight rounded tooth; right coxopodite with sharply curved process; left coxopodite with short, stubby stylus; cercus short with short cercomeres.

Description of holotype male. Antennomere count on right antennae 27 and broken left antennae 25. Antennomere 2 1.5X larger than antennomere 1. Compound eyes well developed, length greater along body axis than width, and pigmentation black. Head slightly broader than pronotum but narrower than interorbital distance. Pronotum gently curved in anterior end and triangular at posterior end, overall trapezoidal as width at anterior end greater than posterior end, posterior end forming soft triangular point, transverse sulcus at anterior end curving slightly towards anterior end, length greater than width. Leg coloration amber yellow, slightly lighter than dorsal body color, and small brown setae present. Legs relatively short. Portion of right mid leg below femur removed and destroyed during DNA extraction. Cercus length short with short cercomeres. Subgenital plate more than twice as wide as long, distal edge hardened, distal end forming very slight rounded tooth. Right coxopodite longer than wide with a strong curve towards the ventral side of the body, a short process strongly curved towards anterior on dorsal side near base, stylus borne directly on distal end approximately 30% of the length of coxopodite, and heavily pubescent. Left coxopodite width greater than length, stylus at distal end short and stubby (0.021cm). Dorsal and ventral body color buff yellow (87), appendages lighter amber yellow (83), antennomeres and cercomeres amber yellow fading to white at distal ends, subgenital plate and coxopodites amber yellow.

Measurements of holotype male (cm). BL 1.256, HL 0.228, HW 0.255, EL 0.054, EW 0.034, ID 0.208, Ant1L 0.02, Ant2L 0.03, AntRatio 1.5, PL 0.235, PW 0.214, FL front 0.295, FL mid 0.268, FL rear 0.3886, TL front 0.235, TL mid 0.275, TL rear 0.402, TrL front 0.067, TrL mid 0.1005, TrL rear 0.154, PTrL front 0.201, PTrL mid 0.201, PTrL rear 0.214, SbgL 0.0536, SbgW 0.1273, RCxL 0.1005, RCxW 0.0804, LCxL 0.1139, LCxW 0.134, CL 0.4104.

Description of other specimens. Juvenile specimen is amber yellow (83) on the head and pronotum, with a white abdomen and appendages.

Comparisons. Grylloblatta marmoreus n. sp. can be distinguished from G. oregonensis n. sp. in having smaller body size, pronotum narrowing at posterior end and forming soft triangular point, and smaller antennomere 2:1 ratio. It can be distinguished from G. siskiyouensis n. sp. in having fewer antennomeres, buff yellow coloration and weaker point at posterior end of pronotum. It can be distinguished from G. ro t h i in having a subgenital plate without a lobelike projection on distal end and right coxopodite with a strongly down-curved process. It differs from G. chandleri in having a subgenital plate with a more rounded tooth at distal end and right coxopodite with strongly down-curved process. It can be distinguished from G. sculleni in having smaller body size and fewer antennomeres; from G. gurneyi in having a subgenital plate with a single rounded tooth at distal end and right coxopodite with strongly down-curved process; and from G. b a r b e r i in smaller body size and having less than 30 antennomeres.

Habitat distribution. The type specimen was found in the twilight zone of a cave habitat, on a rock near ice. The juvenile was found on a rock at the bottom of a pit near the cave entrance.

Geographical distribution. Grylloblatta marmoreus n. sp. is known from multiple cave sites in the Marble Valley of Marble Mountains, California ( Fig. 3 ).

Phylogenetic relationships. Based on mitochondrial cytochrome oxidase subunit II data, G. marmoreus n. sp. (GenBank Accession JN612963 & JN612964 ) is distinct from (minimum ~10%) other nearby grylloblattid species ( Table 1 ). The adult type specimen and the juvenile from Planetary Dairy Cave differ by 0.4%. In a neighbor-joining analysis, it is grouped with G. oregonensis n. sp. and G. siskiyouensis n. sp. in an unresolved polytomy ( Fig. 4 ).

Figures

FIGURE 1. Differences in size and coloration observed in type specimens. A) Grylloblatta oregonensis n. sp. B) G. siskiyouensis n. sp. C) G. m a r m o re u s n. sp.

FIGURE 3. Geographical distribution of grylloblattid populations (dots) and type localities (crosses and asterisks) in California and Oregon, USA.

FIGURE 4. Relationships of new Grylloblatta species based on mitochondrial cytochrome oxidase subunit II gene data.