Arachnids of North Carolina
Order:
Scientific Name: Common Name: Family (Alpha):
« »
View Araneidae Members: NC Records

Eustala anastera (Walckenaer, 1841) - Humpbacked orbweaver


Male
Taxonomy
Order: ARANEAEInfraorder: AraneomorphaeFamily: Araneidae                                                                                 
Identification
Online Description/Photos: The prosoma is variable in color, usually matching the opisthosoma. The opisthosoma is triangular and tallest at the posterior end; this humped appearance leads to the common name. The coloration and pattern can vary from shades of tan and brown to vivid greens. Some have a pair of spots on the lateral sides of the humped area of the opisthosoma; some have a dark line down the median. Many have a foliate pattern. The ventral opisthosoma has a light central mark that runs from the epigastric furrow to the spinnerets; the mark is bordered in black. The scape of the female epigynum is directed anteriorly. The legs also vary in color and are covered with short spines in the female; the spines are more pronounced in the mature males. More than a dozen species of Eustala are in North America, and identification to species level is difficult without a specimen. (Rose, 2022) BugGuide Google, iNaturalist, Wikipedia, GBIFTechnical Description: Spiders of North America - Bradley; Spiders of the Carolinas – Gaddy; Bugguide; an examination of the structure and genitalia of Cyclose and Eustala: http://www.biodiversitylibrary.org/page/4314711#page/79/mode/1up
Comments: Abdomen longer than wide with a distinct dorsal hump. Varies in color and pattern, but it is usually dark brown to reddish brown. Some individuals have a dark folium or spots on abdomen. Cephalathorax is completely covered with light hairs. larger and darker than emertoni & cepina. Males differ from emertoni & cepina by having a row of three to five short macrosetae on the venter of the second femur. Color forms include a mottled lichen coloration, dark reddish brown with varying cream/white patch on dorsal surface, with or without pair of black wavy lines on abdomen, a gray form with a black vertical striped on the dorsal surface of abdomen and several other color morphs. Can resemble E. anastera, but the three species reportedly in NC can be generally determined by their abdominal profiles: anastera is separated from cepina and emertoni by tip of abdomen upturned, and neither rounded nor blunt in side view (see illustration under "Structural photos," below).
Total Length: Small, female total body length 5.4-10mm, male total body length 3.9-9.5mmAdult ID: identifiable by photo
Structural photos

Illustrations by Levi, H. W. (1977). The American orb-weaver genera Cyclosa, Metazygia and Eustala north of Mexico (Araneae, Araneidae). Bulletin of the Museum of Comparative Zoology 148: 61-127.
Distribution in North Carolina
Comments: Common throughout North Caorlina and the eastern United States. Adults spring through fall.
County Map: Clicking on a county returns the records for the species in that county.
Adult phenology:
 High Mountains (HM) ≥ 4,000 ft.
 Low Mountains (LM) < 4,000 ft.
 Piedmont (Pd)
 Coastal Plain (CP)

Click on graph to enlarge
Habitats and Life History
Habitats: forest edge, understory of pine and hardwood forests, goldenrod fields and marshes.
Observation Methods: Sweep netting.
Abundance/Frequency: Common.
Silk / Web: Orb web, rebuilt each evening and removed before dawn.
Behavior: Nocturnal. Webs are usually built among dead branches in the understory of conifer and broadleaf forest, or in open woodlands. The young emerge from the egg case, grow during the summer and then overwinter as subadults. Spider waits in the web at night with her legs slightly spread apart. The spider does not build a retreat but rests curled up on branches, looking like a piece of bark. If disturbed, the spider may run a short distance then resume this cryptic pose.
Status in North Carolina
Natural Heritage Program Status:
Natural Heritage Program Ranks:
State Protection:
Comments:

 Photo Gallery for Eustala anastera - Humpbacked orbweaver

63 photos are available. Only the most recent 30 are shown.

Recorded by: Mark Basinger on 2024-03-31
Lee Co.
Comment: 		Recorded by: Mark Basinger on 2024-03-31
Lee Co.
Comment:
Recorded by: Brian Bockhahn on 2023-10-19
Dare Co.
Comment: 		Recorded by: Brian Bockhahn on 2023-08-23
Stokes Co.
Comment:
Recorded by: Tracy S. Feldman on 2023-04-11
Scotland Co.
Comment: 		Recorded by: Tracy S. Feldman on 2023-04-11
Scotland Co.
Comment:
Recorded by: Jim Petranka on 2022-09-26
Moore Co.
Comment: 		Recorded by: Brian Bockhahn on 2022-07-04
Avery Co.
Comment:
Recorded by: Brian Bockhahn on 2022-07-04
Avery Co.
Comment: 		Recorded by: Brian Bockhahn on 2022-07-04
Avery Co.
Comment:
Recorded by: Donald Zepp on 2022-06-27
Johnston Co.
Comment: 		Recorded by: Donald Zepp on 2022-06-27
Johnston Co.
Comment:
Recorded by: Brian Bockhahn on 2022-04-26
Wake Co.
Comment: 		Recorded by: Brian Bockhahn on 2022-03-22
New Hanover Co.
Comment:
Recorded by: Brian Bockhahn on 2022-03-22
New Hanover Co.
Comment: 		Recorded by: Erich Hofmann and Kayla Weinfurther on 2022-03-07
Buncombe Co.
Comment:
Recorded by: Brian Bockhahn on 2021-09-29
Durham Co.
Comment: 		Recorded by: Brian Bockhahn on 2021-09-29
Durham Co.
Comment:
Recorded by: R. Newman on 2021-05-27
Carteret Co.
Comment: 		Recorded by: Brian Bockhahn on 2021-04-30
Rockingham Co.
Comment:
Recorded by: R. Newman on 2020-11-25
Carteret Co.
Comment: 		Recorded by: R. Newman on 2020-11-25
Carteret Co.
Comment:
Recorded by: R. Newman on 2020-11-03
Carteret Co.
Comment: 		Recorded by: R. Newman on 2020-11-03
Carteret Co.
Comment:
Recorded by: Brian Bockhahn on 2020-09-16
Ashe Co.
Comment: 		Recorded by: Brian Bockhahn on 2020-07-17
Polk Co.
Comment:
Recorded by: B. McRae on 2020-06-17
Macon Co.
Comment: 		Recorded by: Brian Bockhahn, Kyle Kittelberger on 2020-06-03
Alleghany Co.
Comment:
Recorded by: Brian Bockhahn on 2019-05-08
Stokes Co.
Comment: 		Recorded by: Brian Bockhahn on 2019-04-22
New Hanover Co.
Comment: