Pardosa lapidicina

Emerton, 1885

Stone Spider

Pardosa lapidicina, commonly known as the stone , is a small wolf spider in the Lycosidae. It inhabits cobble beaches and rocky shorelines near water, particularly above the tide . The exhibits distinctive patterns tied to tidal cycles and seasonal temperature changes. Research has documented its use of sit-and-wait foraging combined with sun-basking, and its diet includes small such as dipterans, collembolans, and amphipods. Males recognize females through a contact located on the female's and legs, requiring physical contact for .

Pardosa lapidicina by (c) Dan MacNeal, some rights reserved (CC BY), uploaded by Dan MacNeal. Used under a CC-BY license.

Pardosa lapidicina by (c) Tom Kennedy, some rights reserved (CC BY), uploaded by Tom Kennedy. Used under a CC-BY license.

Pardosa lapidicina by (c) Toby, some rights reserved (CC BY), uploaded by Toby. Used under a CC-BY license.

Pronunciation

How to pronounce Pardosa lapidicina: /pɑrˈdoʊsə ˌlæpɪˈdɪsɪnə/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from other wolf by the perpendicular long on the legs, particularly visible on the hind pair. identification requires microscopic examination of : females possess a paired , while males have modified resembling small boxing gloves. Mature males may exhibit different color patterns from females. Distinguished from the related species Pardosa milvina by species-specific contact chemistry, to which P. lapidicina males do not respond.

Images

Habitat

Primarily found near water, including cobble beaches above the tide , rocky streambeds, and shorelines of lakes and bays. Occupies both open beach areas and beaches with salt-marsh grass. In Rhode Island, documented at of 30 individuals per 0.5 m along shorelines. Also found in woodland areas and fields near water.

Distribution

United States and Canada. Documented in Rhode Island (Narragansett Bay area), with records from Vermont and other states. North distribution.

Seasonality

Active year-round with seasonal movement patterns. During winter months (April-November in study area), remain close to the beach. In warmer months, approximately one-third of the population moves with tides. Overwinters as or immatures.

Diet

Active feeding on small . Documented includes (), (), and amphipods. Captures more than one prey item per day under observed conditions.

Behavior

Employs a sit-and-wait foraging strategy combined with frequent sun-basking. Exhibits tidal patterns: remains near the beach during cooler months, with approximately one-third of the moving with tides during warmer months. Males detect females through a contact located on the female's and legs; the requires physical contact and is not volatile. Upon contact with pheromone-bearing females, males perform including leg tapping and palpal drumming. The pheromone is -specific—males do not respond to females of Pardosa milvina—and remains detectable after mating.

Ecological Role

Small in shoreline and riparian . Documented at high in suitable (30 individuals per 0.5 m), suggesting significant predatory impact on small in these environments.

Similar Taxa

Pardosa milvinaClosely related in same ; distinguished by species-specific contact to which P. lapidicina males do not respond
Other Pardosa speciesRequires microscopic examination of ( in females, modified in males) for definitive identification; many species overlap in general appearance and preference

More Details

Research History

Subject of behavioral research by Douglass Morse at University, who documented , patterns, and foraging at cobble beaches in Rhode Island.

Pheromone Biology

Contact is quickly inactivated by water, suggesting an to the moist shoreline where this occurs. The system represents a facultative sexual stimulus that can be bypassed if the male directly contacts the female.