THE ANIMAL FILES

Northern golden orb weaver

Nephila pilipes

The large spider and the tiny one on a web can be female and male of the same species.

Northern golden orb weavers show pronounced size differences between the sexes. Females build large vertical webs with an off-centre hub, while males remain much smaller. Silk structure and prey handling show how a web is a working capture device rather than a rigid ornament.[1]

Follow the evidence ↓
Northern golden orb weaver
Image: Charles J. Sharp · Commons · CC BY-SA 4.0
Sexes
Females much larger than males[1]
Web
Vertical, with hub commonly above centre[1]
Silk
Elastic capture regions with structural supports[1]

Different sizes, one species

Female-biased size dimorphism occurs across studied populations. Explanations include selection on female reproduction and on male mate-finding, but those hypotheses are not interchangeable with direct observations. A small adult male should not automatically be called a juvenile female just because it shares a web with a much larger spider.[1]

A net with different jobs

Elastic silk absorbs energy as an insect hits, while firmer structures anchor the web. Feeding experiments report changes in silk and mesh under different prey treatments. A web is therefore a material system with components, and “strong” alone does not explain how it stops a moving insect without immediately breaking.[1]

Eggs at ground level

Females place their eggs in small pits in the ground and cover them with plant debris or soil. The egg site is separate from the aerial web that captures food.[1]

A COMMON MIX-UP

Does every small spider on a female’s web have to be her offspring?

No. An adult male can be far smaller than the female.[1]

TRY A LITTLE REASONING

Why combine elastic capture silk with firmer supports?

Reveal the explanation

Elastic regions absorb impact while supports hold the net in position; the components solve different mechanical tasks.[1]

Sources & editorial notes

Adapted and translated from the cited Wikipedia revisions, with source-linked reasoning. Image credit and licence are listed separately above.

Adapted and translated from Wikipedia contributors; exact revisions are linked below. CC BY-SA 4.0

  1. Wikipedia contributors — Nephila pilipes (adapted and translated; exact revision)
  2. NCBI Taxonomy — Nephila pilipes (identity and game lineage)

Last fact check:

One discovery leads to another

Southern black widowA tangled web is organised around catching and wrapping.Latrodectus mactans ↗Mediterranean black widowThirteen spots are a clue, not a complete identification.Latrodectus tredecimguttatus ↗Wasp spiderThe stripes resemble a wasp; the prey-catching machine is silk.Argiope bruennichi ↗