The Japanese cockroach (Periplaneta japonica), also known as the Yamato cockroach,[1] is a cockroach native to Japan, adapted to cooler northern climates.[2][3][4] It has a flexible univoltine or semivoltine (one- or two-year) lifecycle, depending on the timing of its hatching, and is unusual in being able to spend two winters as diapausenymphs before reaching maturity.[3]
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.[5]
Unlike most cockroaches, the major hydrocarbon in P. japonica’s cuticular lipids is cis-9-nonacosene.[6] Males have significant amounts of cis-9-heptacosene not found on females, as do P. australasiae and P. fuliginosa males and females.[6]Glucose, myo-inositol, scyllo-inositol and trehalose were found in overwintering nymphs and are thought to be a factor in their freeze tolerance.[7]
Freeze tolerance
Nymphs have been observed in the wild hibernating in subfreezing temperatures during winter in snow-covered habitats.[8] 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,[7] as well as recover from burial in ice.[1] The ability to walk on ice was also found to be unique among several cockroach species tested.[1]
Habitat
Primarily an outdoors species, populations are adaptable to living indoors in houses and buildings where food is stored, prepared, or served.[5][9]
Defense
A P. 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.[10]
Presence as an introduced species
Originally from Japan, P. japonica has spread to China, Korea and far eastern Russia, though it is considered a common pest primarily in central and northern Japan.[4][5][9][11]
The species was found in New York City in 2013 by Evangelista et al.,[12]: 581 [13]: 40 [14] the first time the species was found in the United States.[15] It was found by an exterminator beneath plantings in High Line, a Manhattan park, and was able to survive over a cold winter.[16] 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.[15] This identification demonstrates the use of DNA barcoding for urban pest control.[12][13]
References
^ abcTanaka, S (May 2002). "Temperature acclimation in overwintering nymphs of a cockroach, Periplaneta japonica: walking on ice". Journal of Insect Physiology. 48 (5): 571–583. doi:10.1016/s0022-1910(02)00077-x. PMID12770085.
^ abTanaka, Seiji; Uemura, Yoshinobu (August 1996). "Flexible Life Cycle of a Cockroach Periplaneta japonica with Nymphal Diapause". Journal of Orthoptera Research. Orthopterists’ Society (5): 213–219. doi:10.2307/3503596. JSTOR3503596.
