Cheiracanthium mildei (Longlegged Sac Spider)

About Cheiracanthium mildei

Taxonomic Hierarchy

→ Kingdom: Animalia
→ Phylum: Arthropoda
→ Class: Arachnida
→ Order: Araneae
→ Family: Eutichuridae
→ Genus: Cheiracanthium
→ Species: Cheiracanthium mildei

Common Name (Official / AAS)

Longlegged Sac Spider

Other Common Names

Sac Spider, Yellow Sac Spider, Black-footed Spider, Prowling Spider, Slender Sac Spider, Yellow House Spider

Author

Author of species name: Ludwig Carl Christian Koch (abbreviated L. Koch, not to be confused with his father, Carl Ludwig Koch, abbreviated C. L. Koch). First year published: 1864, as Cheiracanthium mildei.

Pronunciation

ky-ruh-KAN-thee-um MILL-dee-eye

Meaning

Cheiracanthium is a Greek combination that means “hand spinelet” (Cameron 2005). This is a description of part of the male spider’s pedipalp. Based on L. Koch’s original description of the species, we believe the specific epithet mildei is in recognition of the botanist Dr. Carl August Julius Milde (often called Julius Milde).

Notable Previous Names

It is good to note that the genus Cheiracanthium was previously included within the families Clubionidae and Miturgidae. Also, the genus name has occasionally been misspelled in the literature as Chiracanthium.

Identifying Traits of Cheiracanthium mildei

Size

Body length (excluding legs) of adult female ranges from 7-10 mm; adult males range from 5-9 mm.

Female Primary Colors

Male Primary Colors

Eye diagram of Cheiracanthium mildei

Eyes

Total of eight eyes. When viewed from the front, there are two horizontal rows of four. Bottom (anterior) eye row is nearly straight across, while the top (posterior) row is very slightly procurved. All eight eyes are circular and of relatively equal size. See eye diagram for clarification.

Legs

Legs are proportionately long for the size of the body, very long in adult male specimens. They are all one color, usually the same as the rest of the body (yellow, pale green, or tan). The “toes” of this spider may appear black, owing to the tuft of dense hairs beneath the claws. This tarsal pad allows the spider to easily climb smooth surfaces. The tarsi (tips of legs) have 2 claws.

Body

Cephalothorax and abdomen are roughly the same size, although well-fed or gravid (egg-laden) females may have a very large abdomen. The abdomen is oval in shape, widest in the middle. The spinnerets are usually visible when the spider is viewed from above. Both the male and the female have similar coloration: shades of pale green, tan, or yellow.

Range of Cheiracanthium mildei

Cheiracanthium mildei can be found in the following states, provinces and territories across the United States and Canada. Our current understanding of each spider's distribution is drawn from numerous scientific publications and online spider submissions, in order to be as accurate as possible. It is important to remember that spiders do not adhere to the territorial lines decided on by humans, therefore these ranges are subject to change.

Important Range Notes

This species is native to southern Europe but has become widespread in the Northern Hemisphere (it has also established itself in Argentina). The first official North American records were from Massachusetts and New York in 1947 (Bryant 1951). We have listed every U.S. state (except Hawaii) and Canadian province in our range; there are surely some states and provinces where this non-native spider may not be recorded from yet, but anything is possible with this quick spreading species. In North America, it is easily transported via commerce because of its synanthropic nature.

United States

Canada

Additional Information

Habitat

It is found mostly indoors in North America where it prowls ceilings and walls at night. A special pad of dense hairs beneath the claws of each foot allow this spider to navigate easily on smooth surfaces. This is a spider of scrub lands and open fields of heather in its native European range.

Web

This is a spider that hunts “on foot.” It does not spin a web to ensnare prey. The spider does spin a silken “sleeping bag” where it rests during daylight hours. Look for these retreats where walls meet the ceilings. The spider spins a new retreat at the end of each night. Should the spider fall off or leap away from danger, it descends on a silken dragline.

Season

Mature individuals may be found at any time of year since this species typically lives indoors in human habitations.

Food

Prey is any insect or other invertebrate that the spider can overpower. They are sometimes encountered around outdoor lights, stalking insects that are attracted there.

Lifecycle

The male spider, facing the female, crawls beneath her, upside down, to insert his pedipalps into her genital opening. Females mate only once, but create one to five egg sacs during their lifetime, each about a month apart. The female encloses herself in a silken sac and then lays her eggs inside it, covering them with a thin sheet of silk; essentially creating a sac within a sac. She stays inside the outer sac and stands guard over the eggs until the spiderlings emerge. Each brood is typically 30-40 eggs, however, Kaston (1977) notes as few as 16 eggs in a single sac and as many as 70. The eggs are light yellow and each one is roughly 0.5 millimeters in diameter (Bryant 1951). The lifespan of the male is close to one year, usually less, whereas that of the female may be 1.5 years.

Remarks

Pictures of Cheiracanthium mildei (Longlegged Sac Spider)

General

Female Spiders

Male Spiders

Filtering options are grayed out when we do not have pictures for the given perspective. If you are a spider photographer, you can submit pictures of spiders to help fill any voids in our ever expanding library.
  • Cheiracanthium mildei
  • Sex: FemaleFemale
  • Maturity: Adult
  • Attributes: Dorsal
  • City/Region: South Deerfield
  • State: Massachusetts
  • Country: United States
  • Cheiracanthium mildei
  • Sex: MaleMale
  • Maturity: Adult
  • Attributes: Dorsal
  • City/Region: South Deerfield
  • State: Massachusetts
  • Country: United States
  • Cheiracanthium mildei
  • Attributes: Dorsal, Webs
  • City/Region: Rome, Lazio
  • Country: Italy
  • Cheiracanthium mildei
  • Sex: MaleMale
  • Maturity: Adult
  • Attributes: Dorsal
  • City/Region: Milton, Norfolk County
  • State: Massachusetts
  • Country: United States
  • Cheiracanthium mildei
  • Sex: FemaleFemale
  • Maturity: Adult
  • Attributes: Dorsal, Gravid
  • City/Region: Milton, Norfolk County
  • State: Massachusetts
  • Country: United States
  • Cheiracanthium mildei
  • Sex: FemaleFemale
  • Maturity: Adult
  • Attributes: Lateral
  • City/Region: Fremont
  • State: California
  • Country: United States
  • Cheiracanthium mildei
  • Sex: FemaleFemale
  • Maturity: Adult
  • Attributes: Lateral
  • City/Region: Fremont
  • State: California
  • Country: United States
  • Cheiracanthium mildei
  • Sex: MaleMale
  • Maturity: Adult
  • Attributes: Dorsal
  • City/Region: Hayward, Alameda County
  • State: California
  • Country: United States
  • Cheiracanthium mildei
  • Sex: FemaleFemale
  • Maturity: Adult
  • Attributes: Lateral
  • City/Region: Olomouc, Olomoucký
  • Cheiracanthium mildei
  • Sex: MaleMale
  • Maturity: Immature
  • Attributes: Dorsal
  • City/Region: Olomouc Region
  • Country: Czech Republic
  • Cheiracanthium mildei
  • Sex: MaleMale
  • Maturity: Immature
  • Attributes: Eyes
  • Country: United States
  • Cheiracanthium mildei
  • Sex: FemaleFemale
  • Maturity: Immature
  • Attributes: Dorsal
  • City/Region: Cross Plains, Dane County
  • State: Wisconsin
  • Country: United States
  • Cheiracanthium mildei
  • Sex: MaleMale
  • Maturity: Adult
  • Attributes: Dorsal
  • City/Region: Los Angeles
  • State: California
  • Country: United States
  • Cheiracanthium mildei
  • Maturity: Immature
  • Attributes: Dorsal, Spiderlings
  • City/Region: Ypsilanti Township
  • State: Michigan
  • Country: United States
  • Cheiracanthium mildei
  • Sex: MaleMale
  • Maturity: Adult
  • Attributes: Ventral
  • State: New York
  • Country: United States
  • Cheiracanthium mildei
  • Sex: MaleMale
  • Maturity: Adult
  • Attributes: Dorsal
  • City/Region: Ontario
  • Country: Canada
  • Cheiracanthium mildei
  • Sex: FemaleFemale
  • Maturity: Adult
  • Attributes: Egg Sacs, Lateral, Webs
  • City/Region: Loveland
  • State: Ohio
  • Country: United States
  • Cheiracanthium mildei
  • Sex: FemaleFemale
  • Maturity: Adult
  • Attributes: Dorsal, Gravid
  • City/Region: Littleton
  • State: Colorado
  • Country: United States
  • Cheiracanthium mildei
  • Sex: MaleMale
  • Maturity: Adult
  • Attributes: Dorsal
  • City/Region: Indianapolis
  • State: Indiana
  • Country: United States
  • Cheiracanthium mildei
  • Sex: MaleMale
  • Maturity: Adult
  • Attributes: Dorsal
  • State: New York
  • Country: United States
  • Cheiracanthium mildei
  • Sex: FemaleFemale
  • Maturity: Adult
  • Attributes: Gravid, Lateral
  • City/Region: Chicago
  • State: Illinois
  • Country: United States

References and Further Reading

Various Research Papers

Scientific Diagrams and Keys for Identification

References for the Casual Reader

Species guide last updated: May 30, 2016

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