Table Of Content2003. The Journal of Arachnology 31:142-144
SHORT COMMUNICATION
A NEW SUBSPECIES OF PHILODROMUS RUFUS
(ARANEAE, PHILODROMIDAE)
Bruce Cutler: Department of Ecology and Evolutionary Biology, University of
Kansas, 1200 Sunnyside Avenue, Lawrence, Kansas 66045-7534 USA. E-mail:
[email protected]
ABSTRACT. A new subspecies ofPhilodromus rufus, P. r.jenningsiis describedfrom the southcentral
and southeastern United States. It is characterized by a light brown unicolorous carapace, except for dark
semicircular marks at the central rear carapace edge.
Keywords: Philodromus rufusjenningsi, crab spider, philodromid
The Philodromus rufus species-complex consists Paratypes: All with same locality and habitat
of 23 related species in America north of Mexico. data as the holotype: 1$, same data as holotype
Two species, Philodromus exilis Banks 1892, and (deposited in FSCA); 1<5, 8 April 1995, matured 13
P. rufus Walckenaer 1826, are very similar mor- April 1995 (deposited in the American Museum of
phologically. Further, P. rufus comprises three sub- Natural History, New York(AMNH)); 19, 8 April
species in this region, and others in the Palearctic 1995, matured 24 April 1995 (deposited in
(Dondale & Redner 1968). About a decade ago it AMNH); Id, 28 April 1995 (deposited in the Na-
became apparent that an undescribed Philodromus tional Museum ofNatural History, Washington, DC
occurred in northeastern Kansas. While genitalical- (NMNH)); 1$, 2 April 1995, matured 17 April
wlyasinsdtirsitkiinngguliyshdaifbfleerefnrtofmrPo.mrtuhfauts,ofitasnycomloermpbaetrteronf p1o9s9i5te(ddeipnosMiutesdeiunmNoMfNHCo)m;pa1rda,ti2v8eApZroiollo1g9y9,5H(adre--
the P. rufus group, and is closer to that of some
members of the P. aureolus group, such as P. key- vard University (MCZ)); 19,8 April 1995, matured
serlingi Marx 1890. More specimens have become 18 April 1995 (deposited in MCZ); Id, 2 April
available since then from the south central and 1995, matured 12 April 1995 (deposited in the Ca-
south-eastern parts of the United States. Because nadian National Collections, Ottawa (CNC)); 19,2
the genitalia are identical to those ofthe other sub- April 1995, matured 16 April 1995 (deposited in
species of P. rufus, and the males vibrate the front CNC).
legs during courtship, it is appropriate to describe Other material examined: USA: ARKANSAS:
this taxon as a subspecies, since the cuiTently Lonoke County, Prairie County; GEORGIA: For-
known distribution is allopatric to that ofany ofthe syth County (in winter webs ofAnelosimus studio-
other subspecies. I wish to acknowledge Hank sus (Hentz 1850)); KANSAS: Douglas County (10
Guarisco, Lawrence, Kansas and Jamel Sandidge, males and 17 females, same locality data as holo-
Department of Ecology and Evolutionary Biology, type, a few from woody vegetation other than J.
University of Kansas who collected specimens of virginiana), Jefferson County, Shawnee County;
this subspecies and shared information with me, MISSISSIPPI: Lafayette County, Madison County,
and Daniel T Jennings, Garland, Maine who sent Marshall County (in winter webs ofA. stiidiosus);
specimens ofP. exilis andP. rufus vibrans Dondale NORTH CAROLINA: Gaston County (in winter
1964, for comparative study. webs ofA. stiidiosus). Specimens in collections of
Philodromus rufusjenningsi new subspecies the author. Hank Guarisco, and Daniel T. Jennings.
Figs. 1-4 Unless mentio—ned all were from J. virginiana.
Material examined.—Holotype male: U.S.A.: Etymology. This taxon is named forDr. Daniel
KANSAS: Douglas County, Lawrence, University T. Jennings of Garland, Maine, USDA, Forest Ser-
of Kansas, West Campus, 28 April 1995, B. Cutler, vice Insect Ecologist, retired. A well known spider
beating Juniperus virginiana L., deposited in Flor- ecologist and expert on crab spiders, and long time
ida State Collection ofArthropods (FSCA), Gaines- friend and colleague of the author, who first rec-
ville, Florida. ognized these spiders as new.
142
CUTLER—NEW SUBSPECIES OF PHILODROMUS RUFUS 143
—
Figure 4. Distribution of Philodromus rufus
jenningsiin the south central and southeasternUnit-
ed States (filled circles); open circles are localities
for P. r. vibrans from Dondale & Redner (1968).
2 3
—
Figures 1-3. Philodromus rufusjenningsi new (Fig. 4) is allopatric to all other known subspecies
subspecies, female: 1. Dorsal view ofprosoma and of P. rufus except in North Carolina. P. rufus vi-
opisthosoma; 2. Dorsal view of prosoma; 3. Prola- brans occurs in the Smoky Mountains in the ex-
teral view of leg I. treme southwestern partofthat state, butatahigher
elevation, notat the lowerelevations whereP. rufus
— jenningsi was taken.—
Diagnosis. The genitalic characters easily place Natural History. Collector bias is marked in
this taxon in the P. rufus species complex. It may the records ofP. r.jenningsi. Mostrecords arefrom
be distinguished from all other members of the J. virginiana, because of the interest of the author
complex by the solid light brown carapace with al- and H. Guarisco in spiders from this conifer. The
most no markings except for the dark brown semi- records from webs of the social theridiid spider
circular marks at the rear of the carapace, see Fig. Anelosimiis studiosus resulted from the interest of
2. In the key to species and subspecies of the P. Jamel Sandidge in that species. There are a few
rufus group in Dondale and Redner (1968), this records from beating and sweeping broad-leaved
subspecies keys to couplet 3 wherethecolorpattern shrubs and trees, and it is expected that, as in the
does not match. Similarly in Dondale and Redner other subspecies, P. r. jenningsi will be found to
(1978) this subspecies keys to couplet 21 where occur on woody vegetation throughout its range. In
again the color —pattern does not match. the laboratory, specimens of the later instars feed
Description. Male: Carapace 1.48 ± 0.11 readily on species of Drosophila and other small
(range 1.29-1.68) mm long and 1.47 ± 0.08 (range insects and can easily be reared to maturity in small
1.25-1.58) mm wide; femur II 2.08 ± 0.25 (range Petri dishes (55 mm in diameter by 15 mm tall).
mm
1.39-2.34) long (15 specimens). Carapace uni- Courtship and mating observations were conducted
mm
form light brown with two dark semicircularmarks in plastic tissue culture dishes 100 in diameter
at rear center (Fig. 2). Legs I-III brown with dark by 20 mm tall.
speckling at distal end of femur, and at proximal Courtship was initiated by males approaching fe-
ends of tibia and metatarsus (Fig. 3). Leg IV uni- males andrapidly vibrating the first and secondpair
form light brown. Dorsum of opisthosoma in well of legs, see Dondale (1964) for details. Egg sacs
marked individuals with a complex pattern (Fig. 1). made as a result of these laboratory matings were
Female: Carapace 1.58 ± 0.13 (range 1.42-1.91) lenticular, about 10 mm in diameter, and attached
mm long and 1.52 ± 0.08 (range 1.32-1.62) mm to the surfaces of the Petri dishes. Up to three egg
wide; femur II 1.99 ±0.17 (range 1.68-2.18) mm sacs may be made by mated females with the num-
long (15 specimens). Coloration as in male but ber of eggs decreasing in successive egg sacs. For
more clearly demarcated. Genitalia and leg spina- the first egg sac, the mean number of eggs per sac
tion as in other subspecies, see Dondaleand Redner was 16.6 ± 3.8, range 12-25 (15 egg sacs).
(1968). As in other subspecies of P. rufus males Attempts were made to assess fertility as a result
vibrate the first two pairs of legs during courtship of matings between specimens of P. r. jenningsi
and most habitat records are from woody vegeta- and specimens from two populations of P. r. vi-
tion. — brans (MAINE: Penobscot County and MINNE-
Distribution. The range of this subspecies SOTA: Ramsey County). There were some cross
144 THE JOURNAL OF ARACHNOLOGY
population matings, but the numbers were low and LITERATURE CITED
resulted in few fertile eggsacs. Future attempts us- Dondale, C.D. 1964. Sexual behavior and its appli-
ing larger cages such as those utilized by Dondale cation to a species problem in the spider genus
(1964) may b—e more productive. Philodromus (Araneae: Thomisidae). Canadian
Remarks. Pattern intensity varies considerably Journal of Zoology 42:817-827.
in P. r.jenningsi. Well-marked specimens resemble Dondale, C.D. & J.H. Redner. 1968. The imbecillus
those in Figs. 1-3. Other individuals have the pat- and rufus groups of the spider genus Philodro-
tern reduced. Extreme reduction results in a loss of mus in North America (Araneida: Thomisidae).
all pattern, except for the dark semicircular marks Memoirs of the Entomological Society of Can-
at the rear of the carapace. Immature specimens of Donaddaale5,5,C7.8D.pp&. J.H, Redner. 1978. The Insects
Pm.enrs. joefnnPi.ngkseyisecrlloisnegliy, arnedsebmobtlhe airmemafotuunrde osnpecfio-- and Arachnids of Canada; part 5. The crab spi-
ders ofCanada and Alaska. Araneae: Philodrom-
liage ofJ. virginiana. Exceptforthe earliestinstars, idae and Thomisidae. Agriculture Canada, Pub-
specimens of the latter species have a thin black lication 1663, 255 pp.
margin around the carapace which is lacking in the
former species, except at the very rear of the car- Manuscript received 18 January 2002, revised 14
apace. August 2002.
