A New Earwig in the Genus Vostox (Dermaptera: Labiidae) from the Southwestern United States and Mexico.
Psyche 68:45-52, 1961.
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Vol, 68 JUNE-SEPTEMBER! 1961 Nos. 2-3
A NEW EARJVIG IN THE GENUS llOSTOX
( DERMAPTERA : LABIIDAE)
FROAI THE SOUTHWESTERN
UNITED STATES AND 3fEXICO1
BY Tv. L. NUTTING~ AND ASHLEY B. GURNEY^ During the summer of 1958 a single male earwig was taken from a light trap in southwestern New &Iexico and selit to the U. S. National Museum for identification. Apparently a new species of lfostox, it was put aside with the hope that moi-e specin~ens might be collected. In the fall of 1959, during a study of the Dermaptera in the Univer- sity of Arizona collection, six adults and three nyn~phs of this same earwig were discovered anlong some ~mdetermined specimens. A fur- ther search finally resulted in the completion of the series of six males, seven females, and three nymphs upon which the following description is based. This new earwig brings the total number of Dermaptera in the United States, both native and adventive, to 19 species and I subspecies.* Probably not more than six or seven of then1 are repre- sentatives of our endemic fauna.
There are about seven previously described species of lfostox, of which only brunneiflcnnis (Sei-ville) occurs in the United States; the others are all Neotropical. Tf. brunneiflennis ranges from Virginia Indiana, and Illinois south to Florida and westward to eastern Texas, with a few records from Panama and the states of Vera Cruz and Sinaloa in Mexico. So far as the available nlaterial demonstrates! the new species ranges from southem New Mexico and Arizona into the Mexican states of Sinaloa and Baja California. Neither of the species 'Arizona Agric~~ltural Experiment Station Technical Paper No. 642. 'Department of Entomology, University of Arizona, Tucson. 'Entomology Research Di~ision, Agricultural Research Service, U. S. De- partment of Agriculture, JVashington, D. C. 4Several changes, which have occurred in the list of United States Dermap- tera since the paper by Gurney (1950) appeared, may be noted. Prolabia has been found to be a synonym of ilfarava, and M. wallacci (Dohrn) a synonym of A[. arachidis (Yersin), the latter current combination replacing Prolabia arachidis (see Hincks, 1954). Pyragropsis buscki (Caudell), a recent addition to the list, occurs in Florida
(Gurney, 1959). Prolabia ~ulchella (Serville) has been transferred to Lafrobia, a genus described as new by Hincks (1960).
46 Psyche [June-September
of P'ostox found in the United States is apparently very common over most of its range) though fairly numesous specimens of bmmneipennis have been seen from Floi-ida and other southeastei-n states) where it occurs beneath loose bark of trees. Spongovostox upicedentatus (Cau- dell) is similai- superficially to the new species and is one of the commonest enwigs native to the southwestel-n United States and northwestem Mexico.
The following keys serve to distinguish the latter and the two United States species of Vostox, in spite of their general similarity in habitus) size,, and coloration. Keys to Species of lfostox and S~ongovostox Found in Continental United States
Forceps armed with a conspicuous subapical tooth 8pongovo~tox apicedentabus (Caudell)
Forceps armed with at least one conspic~~ous tooth at or consider- ably anterior to middle (if tooth is absent) forceps are definitely concave internally on basal third) ........................................ 2 2. Forceps spa-sely tuberculate beneath) not concave internally, typically bearing a prominent, rounded tooth considerably an- tei-ior to middle (if two pro~ninent teeth occur) the smaller) secondasy tooth is at the middle) ; pygidium as in Figs. 10 or I I ,; paramel-es with conspic~ious preapical curvatui-e, Fig. 9. ............................................... Vost~x brunneipe,nnis (Serville) Forceps smooth beneath) genei-ally conspicuously concave internal- Iy on basal third, lai-ger specimens with tooth near middle; pygidium as in Figs. 2, 3 01- 7; paramel-es less conspicuously .......................
cui-ved, Fig. 8.
Vostox excavatus) new species
Forceps armed with a basal) quadrate tooth, projecting but little beyond dorso-intei-nal margin ; abdominal sterna model-ately clothed with fine yellow-brown setae and bearing many long, brown setae on posterior margins (males and nymphs as well) ; suggestions of lateral folds on segments foui-) five, and some- times six (sometimes subtle but) when pi-ominent) each fold bearing a long, light brown seta) ; pygidium much like Fig. 5, Spo:ngovostox upicedentatus (Caudell)
Forceps armed with a large) basal) quadrate tooth, projecting well beyond dorso-internal margin (Fig. I ) ............................... 2 2.
Dorsal surface of anal segment with a scattering of prominent tubercles ovei- posterior third (Fig, I 3) ; ventro-internal margin of forceps prominent and crenulate) dorso-intei-nal margin
Nutting and Gur,ney - Genus lfostox
broadly rounded and beset with a few widely spaced tubercles, innei- face thus scarcely concave for more than half its length; pygidiu~n as in Fig. 12, but scarcely diagnostic. Vostox brun,nmeipennis (Sei-ville)
.................................................. Dorsal surface of anal segment comparatively smooth; dorso- and ventso-internal ~nai-gins of forceps prominent and closely set with small tubercles (almost crenulate), inner face thus dis- tinctly concave as a longitudinal groove nearly to tip ; pygidium as in Fig. 4. ......................... F'ostox excavatus, new species Vostox excavatus, new species
Description. ilfale (holotype) : Size medium, foi-1n usual for genus; body depressed with sides of abdomen (except foi- slightly narrower segments I and 10) subparallel and as wide as elytra; abdomen minutely punctulate above and bdow, less so on segments 1-3, in- creasingly so posteriorly, body practically smooth elsewhese; fine, shoi-t setae sathes densely covering labrum, antennae and limbs, but sparse on 1-emainder of body including forceps, elytra and wing scales; a few longes setae on postesior mai-gin of head, anterior margin of pronotum, cephalic faces of femoi-a, near bases of coxae, and on the posterior margins of all abdominal stei-na except the last. Head cordate in dossal outline, with greatest width through the eyes equal to the median length; occipital margin broadly and obtusely emarginate ; caudal angle of genae broadly rounded ; eyes not especially prominent, slightly shorter in length than the postocular portions of genae ; ecdysial cleavage lines very faintly impressed ; antennae broken, one with I I, the othei- with 12 segments, the first segment equal to the sixth in length, considesably shorter than the fourth and fifth together. Pronotum subquadrate, with greatest width at caudal thii-d nearly equal to its median length, cephalic margin produced mesad to form a narrow cervical flange, laterocephalic angles obtuse and narrowly rounded, lateral margins straight and diverging slightly to the broadly rounded caudal margin, anterior two-thirds of disc convex with lateral margins flaring upward, thus forming shallow furrows which broaden and become confluent with the flattened posterios third of disc; median longitudinal sulcus moderately impressed on convex portion of disc, but becoming obsolete in posterior third. Elytra with median length 2.1 times the greatest width of a single elytron ; lateral margins nearly straight and subparallel, humeral angles bsoadly rounded, distal ~nargin subtruncate. Exposed portions
of wings projecting posteriorly almost one-half the median elytsal length with external margins converging gradually to the truncated distal extrenlities.
Abdomen broadened slightly in the middlr, with basal seg~nent notably narrower than anal segment; lateral folds model-ately promi- nent on second and third terga; posterior margin of tei-ga four, five, and six borderrd with small tubercles, becoming obsolete laterad ; anal segment ti-ansversely sectangulate with sides subparallel, posterior ~nargin truncated, but with a ~11~11 lobe laterad above dorso-hternal margin of each forceps.
Forceps, as in figuse 7, about thi-ee-fourths as long as the normallj- exposed portion of abdomen, relatively smooth, slender, and straight except for gentle incui-ving of the apical third, a pro~ninent, slightly rounded tooth just anterior to middle on dorso-internal margin ; inncr faces rather stsongly excavate anteriorly, this becoming obsolete proximad from tooth ; ventro-internal ~nargin bearing a few irregular- ly spaccd tubercles anterior to tooth; pygidium, as in figure 7, with sides parallel at base, converging acutely to the nai-1-owly rounded apex; subgenital plate slightly less exposed than the last tergum, its lateral margins oblique and broadly rounded into the somewhat con- cave distal margin; concealed genitalia as in figure 8. Femora moderately inflated, anterior pair most strongly so, md subequal in length to anterior tibiae; tarsi long, slendcr, their ventral :mi-gins (particularly of metatarsi) bearing numerous, stiff setae; posterior metatam~s subequal to the co~nbined length of the rmmining two tarsal segments, the ventral surface with 2 rows of setae along the outer (lateral) margin, inns (mesal) ~nargin with 2 longitudinal rows and nun1erous shorter marginal setae which are arranged in about 12 to 15 short, oblique, conlblike rows to give a "stepped" or "staircase" effect. (The co~nbs are best seen on clean specimens, in a mesa1 view, with magnification of 50 01- more times, in a strong light.) Coloration: Similar to hrunncificnn;~; head) pi-onotum, median third of wing scales and abdon~en dai-k chestnut brown, paler on antennae, clytra, anal segment and forceps; outer two-thirds of wing scales yellowish-white ; limbs honey yellow ; eyes black. lleasurements (in millimetess) : Body length (exclusive of forceps and pygidium), 9; median length of head, I -5 ; length of prono-
tum, 1.5 ; median length of elyti-on, 2.5 ; internal length of exposed wing scale, I .I ; length of forceps, 4.3. Fernale (allotype) : General form as in male) but somewhat more robust and differing as follows: head broader and longer; eyes larger
Nutting and Gurney - Genus Vostox
and slightly longer than cheeks; antennae broken) one with 9, the other with 12 segments; abdomen notably wider) but with anal segment considerably narrower than the basal segment; marginal tubercles absent from terga four, five) and six; forceps typically shorter, stouter, and shaped as in figui-e I) with a large quadrate tooth on dorso-internal margin at base) both dorso- and ventro-internal margins pro~ninent and irregularly but closely set with s1na11 tubercles, inner faces thus distinctly concave nearly to tips; pygidiuin shaped as in figure 4. Coloration: Differs from male in no important respect except for being a shade darker over-dl, especiaIIy 011 the anal segment and forceps.
31easurements (in millimeters) : Body Iength (exclusive of for- and pygidiun~~) , 9; median length of head, I .5 ; length of pronotum, 1.5; median length of elytron, 2.5 ; internal length of exposed wing scale, I .I ; length of forceps) 4.3.
P'ariution: There are five male paratypes) three of which do not vary sig~~ificantly in size from the type; the length (in nm.) of ~wious parts of the snlallest spech~en (Tucson) follow: body 7.2,
head I -5, pronotum I -2, elytron 2.1, wing scale I .I, forceps 2.8. The ejves of all but the smallest agree with the type in being shorter than the genae, whereas in the smallcst spec.men they are slightly longer. The complete number of antenna1 segments varies from 12 to 16.
The Tucson specin~en also lacks thz marginal tubercles on terga four, five, and six. Although the forceps of all are distinctively excavated, the large tooth is absent in the t~vo s~naller specimens( Fig. 6), and its position marked o111y bj, a tubercle in the third. The shape of the pygiclium apparently varies considerably as in brunneipennis ; in two specimens it is unlike thc type in that it is truncated at the tip (Figs. 2 and 3). All genitalia are preserved in glyccrol and show close agree- ment with those of the type in the shape of the parameres, details of the sclerotizcd armature of the basal vesicle, and the bend of the ejaculatory duct.
The six female paratypes show co~isiderably less variation in size and configuration of characters; the lengths (in mm.) of various parts of the smallest specimen ("Vcnodio") follow: body 8.6, head I .6, pronotum I 4, elytron 2.3, wing scale 1.2, forceps 2.2. The 1e11gth of the eye of two agrees with the allotype in being longer than the cheeks, whereas in three it is shorter, and in the remaining specimcn these measurements are equal. The number of antenna1 segments ranges from 13 to 16. LMost of the paratypes vary but little in the shades of brown described above; however, the two females from
Nutting and Gurney - Genus Vostox
Baja California are a dark, smoky brown over-all, nearly black on the head, and diminishing posteriorly to a dark chestnut brown on the forceps. The appendages and outer portions of the wing scales are a lighter smoky brown.
hTymphs: Three nymphs, presumably collected with one of the adult males, are included with the paratypes. These specimens are probably more than half-grown, for they range in length from 6.5 to 7 mm., and each bears moderately developed, fused wing pads. The antennae are 10- to 12-segmented.
Each of the first six abdominal
sterna bears two long setae, which are conspicuously arranged in con- tralateral rows, one-third of the width of the abdomen from each margin. (This pattern may exist in the adult stage but is not evident in any of our specimens.) The smooth forceps range from 1.8 to 2.2 mm. in length but show none of the specializations of either sex beyond the minute tubercles along the dorso- and ventro-internal margins. Figure 5 shows the configuration of the pygidium which suggests that all three may be females. Their coloration is similar to the holotype, except that the outer two-thirds of both pairs of wing pads are dark brown and the inner third is a lighter, yellow-brown. Holotype: U.S.N.M. No. 65696
Type locality: Santa Catalina Mts. (2000-3000 ft.), Pima Co., Ariz.
The holotype male was collected by Andrew A. Nichol on Au- gust 15, 1924. In reply to a recent inquiry as to the exact locality, Dr. Nichol has recalled that it was in the lower parts of either Sabino Canyon (south slope of the range) or Canada del Oro (north and west slopes), probably the former. The allotype (U.S.N.M.) was taken under lights on the bridge over the Salt River (dry), Tempe, Maricopa Co., Ariz., on July 18, 1947, by Floyd G. Werner. Paratypes: U. S. National Museum (I d, I?, 2 nymphs) ; Depart- ment of Entomology, College of Agriculture, University of Arizona, EXPLANATION OF PLATE 6.
Figs. 1-8, Fostox excawatus, new species. 1. Forceps of female allotype,
dorsal view. 2. Male pygidium (Tucson), dorsal view. 3. Male pygidium (Virden), dorsal view. 4. Pygidium of female allotype, ventral view. 5. Nymphal pygidium ventral view. 6. Male forceps (Tucson), dorsal view. 7. Forceps and pygidium of male holotype, dorsal view. 8. Concealed genitalia of male holotype: Pm, paramere; Pn, penis; BV, basal vesicle; EjD, ejacula- tory duct. Figs. 9-14, Vostox brztnnezpennis (Serv.). 9. Left penis and para- mere (Gainesville, Fla.), dorsal view. 10. Male pygidium (Dallas, Tex.), dorsal view. 11. Male pygidium (Gainesville), dorsal view. 12. Female pygidium (Paris, Tex.), ventral view. 13. Female forceps (Mobile, Ala.), dorsal view. 14. Male forceps (Gainesville), dorsal view. Figs. 1-7, 10-14, xl5 ; Figs. 8 and 9, x34. (Drawings by senior author).
5 2 Psyche i' [June-September
Tucson (I d, 29, I nymph) ; Arizona State University, Tempe ( I d ) ; Museum of Comparative Zoology, Cambridge. Mass. ( I d, I$) ; California Academy of Sciences, San Francisco, Calif. (I 3) ; Academy of Natural Sciences of Philadelphia ( I$) ; British Museum (N. H.), London, England (I?).
The paratypes are from the following localities : NEW MEXICO: Virden, Hidalgo Co., one male, Aug. 27, 1958. light trap, G. L. Nielsen.
ARIZONA: Tempe, one male, Nov. 22, 1955, Jones; Tucson, Pima Co., one male and three nymphs, Dec. 4, 1924, C. T. Vorhies ; one female, Nov. 7, 1939, Wayne Enloe; two females, Dec. 29, 1939, Tom Embleton; Sabino Canyon, Sta. Catalina Alts., Pima Co., one male, July 25, 1955, at light, G. D. Butler and F. G. Werner; 2 mi. sw. Patagonia (4050 ft., Sonoita Creek bottom, willow-cottonwood), Sta. Cruz Co., one male, Aug. 21, 1949, F. H. Parker.
MEXICO : SINALOA, "Venodio", one female, I 91 8, Kusche ; BAJA CALIFORNIA, 25 mi. w. La Paz (ca. 500-foot plateau, relatively rich shrubby vegetation), one female, light trap, Aug. 30, 1959, K. W. Radfoi-d and F. G. Werner; 10 mi. sw. San Jose del Cabo (100 yd. from ocean in sandy wash, sparse shrubs), one female, light trap, Sept. I, 1959, K. W. Radfoi-d and F. G. Werner. Aside from the few notes appended to the above localities, there is no information of any sort available on this apparently rare earwig. Morgan Hebard ( 1923, and other papers) described many Orthop- tera collected by J. A. Kusche in Sinaloa, at "Venvidio", which probably is our "Venodio." Workers have been unable to locate either locality since, and Irving J. Cantrall, of the University of Michigan, has written us of having prepared a manuscript dealing with the Kusche locality. Thanks to Dr. Cantrall's cooperation, we are able to report that Venadillo apparently is the correct name. This small town is 5 miles northeast of Mazatla'n on Mexican Highway 15, which goes to Culiacan.
GURNEY, A. B.
An African earwig new to the United States, and a corrected list of the Nearctic Dermaptera. Proc. Ent. Soc. Washington 52: 200-203. 1959. New records of Orthoptera and Dermaptera from the United States. Fla. Ent. 42: 75-80.
Dermaptera and Orthoptera from the State of Sinaloa, Mexico, Part I. Trans. Amer. Ent. Soc. 48: 157-196. HINCKS, W. D.
Notes on Dermaptera, I. Proc. R.Ent. Ìàoc Lond. (B), 23 : 159-163. 1960. Notes on Dermaptera, IV. Ibid. 29: 155-159. c
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