Oxidus gracilis, known as the greenhouse millipede, the hothouse millipede, common garden millipede or the short-flange millipede, is a member of the flat-backed family of millipedes (Paradoxosomatidae).Thought originally native to tropical Japan, human movement has widely introduced it to every continent except Antarctica, probably along with plants. It is found in abundance throughout the Americas, especially in the southeast and western United States, as well as Europe, and across the south Pacific islands.It is the most common flat millipede in Hawaii and in the Cook Islands and French Polynesia.Shelley (2007) suggests it is among the most widespread and abundant metazoan animals in the world.
Greenhouse millipedes require moist soil, as they are prone to dessication.They are nocturnal; during the day they can be found in leaf litter, under rocks and decaying logs.Often they make their way into basements.Millipedes such as Oxidus gracilis are important decomposers in their ecosystems. Vegetarians, they feed mostly on decaying plant matter, although when this is not available they will eat live plants.Populations can occur in huge numbers.Whitaker et al. (2012), for example, describe some populations in Indianna caves that cover the walls and floor.Heavy rains sometimes drive them out of water saturated soil, and they become more noticed by people.They are found in greenhouses everywhere, where they can be a significant pest.
Unlike centipedes, greenhouse millipedes cannot bite (nor can any millipede species). However, when disturbed they emit an unpleasant smell, as do other members of the polydesmid family.Analyses have identified six different noxious compounds they secrete in different quantities depending on their environment.These compounds include phenol and a cyanide derivative, and presumably are effective for defense from predation, and also for resisting colonization by bacteria and fungi in the soil.
The Greenhouse millipede grows to 2cm (0.8 inches) long.Adults are thought to live for a year.Males have one fewer pair of legs (31) than do females.Adults are dark brown or black, sometimes with a yellow stripe. Females reach maturity at 5 - 6 months old.The have no breeding session, but lay batches of 40-300 sticky, white or brown eggs all year long, in chambers they create about 7-15 mm (0.3- 0.6 inches) below the soil surface.First instar larvae have just 3 pairs of legs, and they grow more segments and legs as they molt and mature.Younger instars are light in color, and get darker as they age.
(Bertone 2013; Capinera 2008; Cook Islands Biodiversity Database 2007; Davenport 2015; Duffey and Blum 1997; Ebeling 2002; Ruane 1990; Shelley 2007; Taira, Nakamura and Higa 2003; Whitaker et al. 2012)
The greenhouse millipede (Oxidus gracilis), also known as the hothouse millipede, short-flange millipede, or garden millipede, is a species of millipede in the family Paradoxosomatidae that has been widely introduced around the world, and is sometimes a pest in greenhouses.[3]
Greenhouse millipedes achieve lengths of 18 to 23 mm (0.71 to 0.91 in) as adults, and widths from 2 to 2.5 mm (0.079 to 0.098 in). The dorsal section of each segment has a transverse groove, a trait found in most paradoxosomatids. They are brown in color with pale cream-colored legs and paranota (lateral "keels" extending from each segment).[4]
Greenhouse millipedes are thought to be native to Japan, but have been introduced globally. They are found in the tropics as well as temperate North and South America,North of Iran, and all of Europe.[4][2]
Mating pair The greenhouse millipede (Oxidus gracilis), also known as the hothouse millipede, short-flange millipede, or garden millipede, is a species of millipede in the family Paradoxosomatidae that has been widely introduced around the world, and is sometimes a pest in greenhouses.
