Japanese cockroach

The Japanese cockroach (Crescispina japonica), synonym Periplaneta japonica,^[1][2] also known as the Yamato cockroach,^[3] is a cockroach native to Japan, adapted to cooler northern climates.^[4][5][6] It has a flexible univoltine or semivoltine (one- or two-year) life cycle, depending on the timing of its hatching, and is unusual in being able to spend two winters as diapause nymphs before reaching maturity.^[5]

Japanese cockroach
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Blattodea
Family:	Blattidae
Genus:	Crescispina
Species:	C. japonica
Binomial name
Crescispina japonica (Karny, 1908)

Description

Initial first-instar nymphs are dark brown, with white or brownish white tips of the maxillary and labial palps. Adults measure 25–35 millimetres (2+1⁄2–3+1⁄2 cm) in length, and have a shiny, uniformly black to blackish-brown body, with brown tarsi and maxillary and labial palps. The adult male's wings extend slightly beyond the body's length, while the female's wings are around half the body's length.^[7]

Unlike most cockroaches, the major hydrocarbon in C. japonica’s cuticular lipids is cis-9-nonacosene.^[8] Males have significant amounts of cis-9-heptacosene not found on females, as do V. australasiae and V. fuliginosa males and females.^[8] Glucose, myo-inositol, scyllo-inositol and trehalose were found in overwintering nymphs and are thought to be a factor in their freeze tolerance.^[9]

Freeze tolerance

Nymphs have been observed in the wild hibernating in subfreezing temperatures during winter in snow-covered habitats.^[10] Overwintering nymphs were able to survive laboratory supercooling experiments in the −5 to −8 °C (23 to 18 °F) temperature range, enduring 12 hours of tissue freezing,^[9] as well as recover from burial in ice.^[3] The ability to walk on ice was also found to be unique among several cockroach species tested.^[3]

Habitat

Primarily an outdoors species, populations are adaptable to living indoors in houses and buildings where food is stored, prepared, or served.^[7][11]

Defense

A C. japonica nymph alone or in sparse populations accumulates a viscous secretion along its rear dorsal surface, droplets of which it can be splashed some distance toward a threat through a shaking action. The presence of an aggressive species of ant, Formica exsecta, triggered this defensive response, rendering the ants helpless.^[12]

Presence as an introduced species

Originally from Japan, C. japonica has spread to China, Korea and far eastern Russia, though it is considered a common pest primarily in central and northern Japan.^{[6][7][11][13]}

The species was found in New York City in 2013 by Evangelista et al.,^{[14]: 581 [15]: 40 [16]} the first time the species was found in the United States.^[17] It was found by an exterminator beneath plantings in High Line, a Manhattan park, and was able to survive over a cold winter.^[18] Scientists who confirmed the identity of the species through genetic testing theorize that it may have been imported in the soil of ornamental plants used in the park.^[17] This identification demonstrates the use of DNA barcoding for urban pest control.^[14][15]