Metepeira arizonica

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Current valid name

Metepeira arizonica Chamberlin and Ivie (family Araneidae)

Recognition and diagnostic features

Orb-weaving spider with unique marking on middle of ventral surface of abdomen: a white longitudinal line surrounded by black longitudinal lines, leaf-like pattern on dorsal surface of abdomen.

Related or similar species

Immatures of Neoscona oaxacensis

Spider

Body lengths when mature: male: 2.7 - 3.8 mm, female: 4.7 - 8.4 mm

Immatures resemble miniature adults.

Egg sac

Description: oblong sac suspended in web, often with others in tandem, looks like a seed pod or piece of dead vegetation, eggs are longer than wide (bean-shaped)

Number of eggs per sac: 30.4 (range 18 to 45)

Size of egg: 0.94 ± 0.029 mm for greatest length

Time of year eggs are likely to be laid: late summer

Distribution

In California: southern half of state

Elsewhere: Arizona, southwestern New Mexico, western Texas, Mexico

Native to North America

This species has not been transported or become established outside of its range.

Biology

Orb weaving. Makes retreat of silk and debris a short distance away from the catching orb web where it hides waiting for prey to fall into web. Collected from March to December. Common in citrus in the Central Valley, but not common in grapes.

Status in table grapes

Level of Incidence: uncommon

Level of Concern in New Zealand: WPNZ (May 2010) nr, BORIC (Dec 2011) nr (not listed), MAF-BPRA (2002) nr (coding definition)

Level of Concern in Australia: WPAU (2006) nr (coding definition)

Level of Medical importance: none

Common name

None for species, orb weavers for family

Taxonomic history

Stable

Selected references

Levi, H. W. 1977. The orb-weaver genera Metepeira, Kaira, and Aculepeira in America north of Mexico (Araneae: Araneidae). Bull. Mus. Comp. Zool. 148: 185-238.