(common names: Blue worm, India Blue, Malaysian Blue, and Traveling worm)
Published by University of Hawaii Manoa, Cooperative Extension Service/College of Tropical Agriculture and Human Resources
Piper Selden, Michael DuPonte, Brent Sipes, and Kelly Dinges
Origin: Over 4,400 distinct species of earthworms have been identified and named by researchers. Perionyx excavatus (Perrier, 1872) is found over large areas of tropical Asia, including India, Malaysia, the Phillippines, and Australia. It is also found in parts of South America, Puerto Rico, and some areas of the United States (south of the Mason Dixon line and Gulf Coast region). Naturalized populations of P.excavatus have been identified in Hawaii. Specific date of origin is unknown.
Description: Perionyx excavatus is a small earthworm, averaging 1.2 to 2.7 inches in length, with a deep purple anterior and dark red or brown posterior. It has an iridescent blue-violet sheen on its skin that is visible in bright light. These worms are highly active and twitch when disturbed. The clitellum, or "collar," of the mature P. excavatus begins approximately 12 segments from its mouth and covers segments 12 to 17.
Environment: P. excavatus is a tropical earthworm species. It is a rapid decomposer that breaks down organic wastes and is used in vermicomposting systems worldwide. Temperature range: 45˚F to 90˚F. Preferred: 70˚F to 80˚F. P. excavatus has little tolerance for low temperatures.
Life cycle: Growth stages: cocoon, immature worm, adult. Earthworms are hermaphrodites, having both male and female reproductive organs. Worms release small, lemon-shaped cocoons after mating. Each cocoon contains several fertilized eggs, hatching in approximately 15 to 21 days under ideal conditions. Reproductive rates vary according to temperature and system maintenance with as many as 19 young hatched per worm per week. Time to sexual maturity is approximately 17 to 35 days under ideal conditions.
Uses: Perionyx excavatus is a prolific breeder with proper feeding and maintenance. It is an excellent composting worm in tropical and subtropical locations.