The humble earthworm: memento mori extraordinaire: "Remember that thou shalt die." The Conqueror Worm, devourer of prince and peasant.  Metaphor for the frailty of the flesh, subverter of monuments, levelerof empires. Emblem of the vanity, the evanescence, and the end of all human endeavour. And yet, paradoxically, this earthworm, this great destroyer, is also a great builder- a builder of fertile topsoil, itself the sustainer of all civilization.

To learn more about this paradoxical critter, follow the links below. We have included several newsletter and review articles, profiles of eight key species of earthworm, images, and links to other web sites with information about earthworms.

Articles

Matthew R. Werner, Center for Agroecology and Sustainable Food Systems, UC Santa Cruz Robert L. Bugg, UC SAREP

Matthew R. Werner, Center for Agroecology and Sustainable Food Systems, UC Santa Cruz

Robert L. Bugg, UC SAREP

Robert L. Bugg, UC SAREP

Species Profiles

The following key characteristics of eight earthworm species found in California orchards and vineyards are based on accounts in Gates (1972) and Reynolds (1977).

Green Worm

Allolobophora chlorotica (Savigny) (Lumbricidae)

green worm
Photograph by Suzanne Paisley.

Green worm (Allolobophora chlorotica) is an endogeic, geophagous earthworm that often inhabits heavy, poorly drained soils.

  • Palaearctic origin
  • Color varies from green to yellow, pink, or gray
  • 30-70 x 3-5 mm
  • Found in a wide range of soil types, mainly on wet, highly organic or polluted sites
  • Endogeic, largely geophagous
  • Matures at 120-130 days
  • Lives 447-587 days
  • 25-27 cocoons per worm per year, 1 hatchling per cocoon
  • Casting and mating occur beneath the soil
  • Facultative diapause
  • Sluggish; rolls into spiral when disturbed
  • Believed unpalatable to many fish
 

Snake Worm, Crazy Worm, Black Wriggler

Amynthas corticis (Kinberg, 1867) (Megascolecidae)

 

crazy worm
Photographs by Suzanne Paisley.
crazy
Photographs by Suzanne Paisley.

 

Crazy worm, snake worm, or squirmy Burmese worm (Amynthas diffringens) is common in warm parts of California in permanent beds with abundant surface litter. It can squirm violently when handled, sometimes actually leaping from one’s hand. When handled, it often sheds its tail, which continues to squirm while the rest of the earthworm tries to escape.

 

  • Origin in Southern Asia including part of China
  • Found in warm climates, including Central Valley
  • 45-170 x 3-6 mm
  • Parthenogenetic
  • Some detritivory at soil surface
  • Excretory system in part enteroic: most nephridia discharge into gut
  • Very fast moving, lashes about when disturbed, often sheds "tail" which continues to lash about while the rest of the earthworm escapes
  • Found in clayey and sandy soils, tolerates heat, drought

 

Southern Worm

Aporrectodea trapezoides (Dugés) (Lumbricidae)

southern wormsouthern 

Southern worm (Aporrectodea trapezoides) feeds on soil and detritus, and is often abundant in both orchards and field crops that receive abundant inputs of organic matter.

Photographs by Suzanne Paisley (left) and Robert L. Bugg (right).

  • One of a complex of closely related species including A. tuberculata and A. turgida (often referred to collectively as A. caliginosa)
  • Color variable, from slate gray to pink, flattenable posterior
  • 80-137 mm x 3-7 mm contracted, 220 x 3-5 mm relaxed
  • Parthenogenetic reproduction
  • Dormancy spent rolled in a ball in an oval chamber
  • Palaearctic origin
  • Found in heavy or sandy soil
  • Endogeic habit, and mainly geophagous, but some individuals forage on surface detritus; casting at soil surface
  • A common earthworm in Central Valley orchards
  • Tolerates immersion in water: persists in tailwater ponds that are flooded twice per week during summer

Canadian Worm

Aporrectodea tuberculata (Eisen) (Lumbricidae)

  • 90-150 x 4-8 mm
  • 146-194 segments
  • Palaearctic origin
  • Sexual reproduction; copulates below ground
  • Aestivation and hibernation are climatically imposed
  • Not pigmented, mainly endogeic habit
  • Much soil ingested; also organic matter, including plant material
  • Casting at the soil surface
  • A common earthworm in Central Valley orchards

Manure Worm, Compost Worm

Eisenia fetida (Savigny) (Lumbricidae)

manuremanureworm

Compost worm (Eisenia fetida) is an important organism for the reduction of urban and animal wastes. It also serves as fish bait.

Photographs by Suzanne Paisley.

  • Body cylindrical, 35-130 x 3-5 mm
  • Color purple, red, dark red, brownish red. There are unicolored forms and forms that have alternating bands of red-brown on dorsum with pigmentless yellow intersegmental areas.
  • Epigeic habit; detritivorous; very little soil consumed
  • Principal earthworm for composting kitchen wastes, animal manures, etc.
  • Live a maximum of 4-5 years, 1-2 more frequent
  • Reproduce sexually, up to about 900 eggs per year per worm
  • Little tendency to burrow into mineral soil

Nightcrawler

Lumbricus terrestris L. (Lumbricidae)

hands

Nightcrawler (Lumbricus terrestris) is an anecic earthworm that constructs burrows up to 2.5 m (ca 8 feet) deep.

Photograph by Jack Kelly Clark.

bush

Middens of nightcrawler (Lumbricus terrestris) in an organic walnut orchard. Middens are turret-like structures of mud and vegetational litter, and sit atop burrows that can be as deep as 2.5 m (ca 8 feet).

Photo by Robert L. Bugg.

nightcrawler

Middens of nightcrawler (Lumbricus terrestris) in a citrus orchard.

Photo by Robert L. Bugg.

night crawler

 As observed in San Joaquin and Solano counties, densely shaded sprinkler- or flood-irrigated walnut orchards appear especially conducive to the establishment and spread of nightcrawler (Lumbricus terrestris).

Photo by Robert L. Bugg.

  • Palaearctic Origin
  • 90-300 mm x 6-10 mm
  • Dark anterior; pale, flattenable posterior
  • Anecic habit
  • Detrivorous: Leaf litter taken below ground, little soil consumed
  • No dormancy
  • Permanent burrows are up to 2.5 m deep
  • Lives 862-887 days or up to 6 years
  • Matures in 350 days
  • Obligate sexual reproduction
  • 38 cocoons per year per worm
  • Colonies spread about 3-5 m per year

Red Marsh Worm, Red Wriggler

Lumbricus rubellus Hoffmeister, 1843 (Lumbricidae)

redwormredworm

Red wriggler or red marsh worm (Lumbricus rubellus) is an epigeic detritivorous earthworm that is common in apple orchards with permanent cover crops. Photographs by Suzanne Paisley.

  • 60-150 x 4-6 mm
  • Dorsum is red-brown or red-violet and iridescent
  • Ventral surface is pale
  • Epigeic habit; mating and casting below ground, commonly burrows into mineral soil
  • Obligate sexual reproduction
  • Mature in 179 days; longevity 682-719 days
  • 79-106 cocoons per year per worm
  • Diapause spent in a ball 0.45 m deep in soil

Microscolex dubius

Microscolex dubius (Fletcher) (Megascolecidae)

  • Origin in southern South America
  • 35-90 x 2-5 mm
  • Endogeic, detritivorous
  • Parthenogenetic
  • Found in warm climates
  • Found in both clayey and sandy soils
  • Collected from almond orchards in the San Joaquin Valley
  • Small individuals appear to be associated as commensals in middens of Lumbricus terrestris

 

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