imported>Battmutler: /* Behaviour */

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Behaviour

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{{Short description|Species of cockroach}}
{{Speciesbox
| name = Asian cockroach
| image = Blattella asahinai the Asian cockroach - adult 05.jpg
| image_caption = [[Adult (insect)|Adult]]
| taxon = Blattella asahinai
| authority = Mizukubo, 1981
}}

'''''Blattella asahinai''''', the '''Asian cockroach''', is a [[species]] of [[cockroach]] that was first described in 1981 from insects collected on [[Okinawa Island]], Japan.<ref name = "richman" >
{{ Cite web
| language = en
| access-date = 2022-12-05
| year = 2020
| last = Richman
| first = D.
| department = Urban Entomology - Featured Creatures
| website = [[University of Florida Department of Entomology and Nematology|Department of Entomology and Nematology]]
| publisher = [[University of Florida College of Agricultural and Life Sciences]] (UFl CALS)
| url = https://entnemdept.ufl.edu/creatures/urban/roaches/asian_cockroach.htm
| title = Asian cockroach - ''Blattella asahinai'' Mizukubo
}}
</ref> It is a small species of cockroach, typically {{ Convert | 1.3 to 1.6 | cm | frac = 8 }} long and tan to dark brown in colour with dark parallel stripes on the back of their heads.<ref>{{Cite web|title=Asian Cockroach Facts & Control: Get Rid of Asian Roaches|url=https://www.orkin.com/cockroaches/asian-cockroach|website=[[Orkin]]|date=11 April 2018|access-date=2020-05-29}}</ref> It is commonly mistaken for the [[German cockroach]] (''B. germanica'') due to their similar appearance. It is now commonly found in the [[United States]] in and around houses.

==Characteristics and appearance==
The Asian cockroach is nearly identical to the [[Blattella germanica|German cockroach]] (''B. germanica'') except for a few minor [[morphology (biology)|morphological]] differences. Like the German cockroach, it is about {{ Convert | 1.6 | cm | in | abbr = on | frac = 16 }} long, is tan to brown in color, and has wings. However, its wings are longer than the German cockroach, and a difference is seen in a groove in the abdomen in the two species. The quickest way to tell the difference between them is that the Asian is a strong flyer and is attracted to light, unlike the German.<ref name="richman"/> This species tends to prefer the outdoors, whereas the German prefers living indoors. The almost identical appearance has caused concerns and issues with the [[pest management industry in the United States|pest management industries]] when determining the strategies of pest control, as pesticides for the German are not always effective for the Asian.<ref name = "Morphological" >
{{ Unbulleted list citebundle
| This review...
|{{*}} {{ Cite journal
| language = en
| year = 2001
| volume = 33
| issue = 3
| first4 = J.
| first3 = George
| pages = 363–92
| first2 = John
| first1 = Alan
| last4 = Bryce
| last1 = Olsen
| publisher = [[Academic Press]] (AP) ([[International Society of Regulatory Toxicology & Pharmacology]])
| issn = 0273-2300
| lccn = 81646304
| oclc = 485750423
| journal = [[Regulatory Toxicology and Pharmacology]]
| last3 = Ziobro
| last2 = Gecan
| title = Regulatory action criteria for filth and other extraneous materials v. strategy for evaluating hazardous and nonhazardous filth
| s2cid = 17134205
| pmid = 11407939
| doi = 10.1006/RTPH.2001.1472
}}
| ...cites this study:
|{{*}} {{ Cite journal
| language = en
| year = 1999
| issue = 1
| volume = 92
| first = Lori
| publisher = [[Oxford University Press]] (OUP) ([[Entomological Society of America]] (ESA))
| journal = [[Annals of the Entomological Society of America]]
| issn = 0013-8746
| eissn = 1938-2901
| last = Lawless
| pages = 139–143
| title = Morphological Comparisons between Two Species of ''Blattella'' (Dictyoptera: Blattellidae)
| s2cid = 87611296
| doi = 10.1093/aesa/92.1.139
}}
}}
</ref> To differentiate between the two cockroaches with the naked eye, there are noticeable parts of each cockroach. The ventral surface of the left mandible, the vein coloration of the right [[tegmen]], the [[wing (insect)|wing]] size and venation as well as the [[seta]]l marginal bristles on the [[cercus|cerci]] are the slight morphological differences between the Asian and German.<ref name = "Morphological" />

[[Image:Blattella asahinai the Asian cockroach - nymph 06.jpg|thumb|left|150px|[[Nymph (biology)|Nymph]]]]

== History and distribution ==
The Asian cockroach is so similar to the [[German cockroach]] that it was only recognized as a distinct species in 1981 by Dr. [[Takayuki Mizukubo]], from the [[National Institute of Agro-Environmental Sciences]], Japan.<ref name=":1">{{Cite journal|last=Roth|first=Louis M.|date=1986-01-01|title=''Blattella asahinai'' Introduced Into Florida (Blattaria: Blattellidae)|journal=[[Psyche: A Journal of Entomology]]|language=en|volume=93|issue=3–4|pages=371–374|doi=10.1155/1986/60130|issn=0033-2615|doi-access=free}}</ref> Recent genetic analyses indicate that ''B. germanica'' only diverged from ''B. asahinai'' slightly over 2000 years ago, presumed to be the point at which the German cockroach spread to areas where it was no longer in contact with ''B. asahinai''.<ref name=TangEtAl>
Qian Tang, Edward L. Vargo, Intan Ahmad, Theodore A. Evans (2024) Solving the 250-year-old mystery of the origin and global spread of the German cockroach, ''Blattella germanica''. Proceedings of the National Academy of Sciences 121(22) e2401185121. doi:10.1073/pnas.2401185121</ref>

The first reported appearance of the Asian cockroach in the United States was in 1986 in [[Lakeland, Florida]] but at first it was believed to be the German species. It is believed that the Asian came to Florida through the import of goods from Japan. On March 3, 1986, Dr Louis M. Roth received cockroaches of Lakeland, Florida from Dr Philip G. Koehler of [[Florida Extension Services]] of the University of Florida for inspection.<ref name=":1" /> It was noted that a [[pest control worker]] referred to them as "German cockroaches" but they could fly readily and were common outdoors. The only two species of ''Blattella'' present in the United States were the field cockroach (''[[Blattella vaga|B. vaga]]'') and the German. Roth was unaware of the Asian species but discovered it and sent several Lakeland specimens to Dr. Mizukubo and he concluded they were ''B. asahinai''.

Further testing was implemented by the [[Center for Urban and Structural Entomology]] at Texas A&M University in September 2007<ref name=":2">{{Cite journal|last1=Austin|first1=James W.|last2=Glenn|first2=Grady J.|last3=Szalanski|first3=Allen L.|last4=McKern|first4=Jackie A.|last5=Gold|first5=Roger E.|title=Confirmation of Asian Cockroach ''Blatella Asahinai'' (Blattodea: Blattelidae) Introduction to Texas Based on Genetics, Morphology, and Behavior|date=2007|journal=[[Florida Entomologist]]|volume=90|issue=3|pages=574–576|doi=10.1653/0015-4040(2007)90[574:COACBA]2.0.CO;2|issn=0015-4040|doi-access=free}}</ref> where they tested the two species through an ethological, morphological and genetic approach in order to confirm the presence of the Asian cockroach in [[Harris County, Texas]]. [[DNA testing|Evaluations of DNA gene sequences]] showed similarities to the German.<ref name=":2" /> It was found that environmental factors play a significant role in differentiating the two species although there are slight morphological differences. It was confirmed that Asian Cockroaches were discovered in Harris County, Texas in May 2006 around the [[Barker Reservoir]], in both urban and undeveloped areas. These cockroaches were later also found in the [[Hunters Creek Village, Texas|Hunter's Creek subdivision]] in greater Houston. The Asian cockroach has since expanded throughout much of Florida and is spreading into other southern states. In addition to Florida, it is reported in [[Alabama]], [[Georgia (U.S. state)|Georgia]], [[South Carolina]], and [[Texas]].<ref name="richman" /> In [[Dothan, Alabama]] in 2003, there were several reports that stated there were "flying German cockroaches" from [[Alabama Cooperative Extension System]] agents, where specimens were obtained for identification. Using a male specimen and comparing it to the description of Dr. Mizukubo and Dr. Roth, they confirmed that the specimens were in fact Asians.<ref>{{Cite journal|last1=Appel|first1=A|last2=Eva|first2=M|last3=Snoddy|first3=E|date=2009|title=Distribution of the Asian cockroach, ''Blattella asahinai'' (Dictyoptera: Blattellidae), in Dothan, Alabama|journal=[[Journal of the Alabama Academy of Science]]|volume=80|issue=1}}</ref>

== Habitat and behaviour ==
Asian cockroaches are predominantly found outdoors in shaded mulched, composted areas where fresh plant litter accumulates as well as in damp areas.<ref name=":4" /> Large areas of grass or leaf litter are what the Asian cockroach gravitates towards. When the Asian cockroach is happy with the chosen location, they are the dominant cockroach and take over the location where they tend to form hordes of 30,000 to 250,000 cockroaches per acre ({{ Convert | 30,000 to 250,000 | /acre | /ha | disp=out }}).<ref name=":4">{{Cite web|title=Asian cockroach - ''Blattella asahinai'' Mizukubo|url=http://entnemdept.ufl.edu/creatures/urban/roaches/asian_cockroach.htm|website=entnemdept.ufl.edu|access-date=2020-05-29}}</ref> Its population reaches its zenith in late August and declines rapidly with the onset of cool weather.<ref>{{Cite thesis|title=Distribution and Population Dynamics of the Asian Cockroach (''Blattella asahinia'' Mizukubo) in Southern Alabama and Georgia|url=https://etd.auburn.edu/handle/10415/785|date=2007-05-15|degree=Thesis|language=en-US|first=Edward|last=Snoddy}}</ref> Asian cockroaches are the most active at dusk and are attracted to light-coloured surfaces and bright lights. This means at dusk, the Asian cockroach may fly towards the home and enter through open doors and windows but indoor invasions occur rarely. While other cockroaches carry diseases and bacterium, as of today, research has not suggested that the Asian cockroach carries any pathogens or diseases. However, they do come into contact with other bacteria due to their habitat preferences being around homes with outdoor pathogens, animal feces, and fungi.<ref name=":4" />

=== Mulch preferences ===
Leaf litter of all kinds is where the Asian cockroach is most commonly found. In the Southern states of America, typical [[mulch]] types include cypress, oak leaf litter, pine, rubber, and topsoil.<ref name=":7" /> As leaf litter is used as domestic mulching for general purpose landscaping, using this type of mulch can affect how dense indoor populations of the Asian cockroach can be. They are predominantly a nocturnal species of cockroach, although they live and breed outdoors, they are attracted to light sources will find their way into buildings.<ref name=":7" /> These can include homes, office buildings, and restaurants. The Asian cockroach stays clear of topsoil and rubber mulch and has very little interaction with cypress mulch.<ref name=":7">{{Cite journal|last1=Snoddy|first1=Edward T.|last2=Appel|first2=Arthur G.|date=2013-02-01|title=Mulch Preferences of the Asian Cockroach (Dictyoptera: Blattellidae)|journal=[[Journal of Economic Entomology]]|language=en|volume=106|issue=1|pages=322–328|doi=10.1603/EC12032|pmid=23448047|issn=0022-0493|doi-access=free}}</ref> During adverse weather conditions such as cold weather or dry conditions, the Asian cockroach burrows down into the leaf litter.<ref>{{Cite journal|last1=Snoddy|first1=Edward T.|last2=Appel|first2=Arthur G.|date=2008-03-01|title=Distribution of ''Blattella asahinai'' (Dictyoptera: Blattellidae) in Southern Alabama and Georgia|journal=[[Annals of the Entomological Society of America]]|volume=101|issue=2|pages=397–401|doi=10.1603/0013-8746(2008)101[397:dobadb]2.0.co;2|issn=0013-8746|doi-access=free}}</ref>

== Diet ==
Asian cockroaches are omnivorous, as are most cockroach species : they will eat anything they can find. They have been observed to eat human food, pet food, flowers and agricultural crops, as well as prey such as lepidopteran eggs in soybean and cotton crops.<ref name=":9">{{Cite journal|last1=Pfannenstiel|first1=Robert S.|last2=Booth|first2=Warren|last3=Vargo|first3=Edward L.|author4-link=Coby Schal|last4=Schal|first4=Coby|date=2008-07-01|title=''Blattella asahinai'' (Dictyoptera: Blattellidae): a New Predator of Lepidopteran Eggs in South Texas Soybean|journal=[[Annals of the Entomological Society of America]]|language=en|volume=101|issue=4|pages=763–768|doi=10.1093/aesa/101.4.763|issn=0013-8746|doi-access=free}}</ref> They have also been sighted feeding on lettuce, cabbage, and strawberries.<ref>{{Cite web|title=What Do Cockroaches Eat?|url=https://www.terminix.com/blog/bug-facts/what-do-cockroaches-eat/|website=[[Terminix]]|language=en|access-date=2020-05-29}}</ref>

== German cockroach comparison ==
The Asian cockroach is the presumed ancestor of the German cockroach, the predominant cockroach pest in America and some parts of the world.<ref name=TangEtAl/>

=== Behaviour ===
The Asian cockroach has longer but narrower wings than the German cockroach.<ref name=":4" /> It can be observed flying, predominantly its preferred choice of movement especially when disturbed,<ref>{{Cite journal|last1=Brenner|first1=Richard J.|last2=Patterson|first2=R. S.|last3=Koehler|first3=P. G.|date=1988-05-01|title=Ecology, Behavior, and Distribution of ''Blattella asahinai'' (Orthoptera: Blattellidae) in Central Florida|journal=[[Annals of the Entomological Society of America]]|language=en|volume=81|issue=3|pages=432–436|doi=10.1093/aesa/81.3.432|issn=0013-8746}}</ref> and to move around compared with the German cockroach, which can be rarely seen flying, merely fluttering its wings ineffectively.<ref name=":5">{{Cite web|title=Cockraoch Pest Control Houston |url=https://cycreekpestcontrol.com/blog/identifying-asian-vs-german-cockroaches-in-your-home/|language=en-US|access-date=2020-05-29}}</ref> The other main difference between the two species is its reaction to light sources; the Asian cockroach is naturally attracted to light, whereas the German cockroach scatters away in the presence of bright light.<ref name=":3">{{Cite web|title=Asian Cockroach Control: Facts & Identification|url=https://www.terminix.com/pest-control/cockroaches/asian-cockroach/|website=[[Terminix]]|language=en|access-date=2020-05-29}}</ref>

=== Reproduction and life cycle ===
Asian cockroaches and field cockroaches are similar ecologically in comparison to the German cockroach due to both these species breeding outdoors. Both the female Asian and German cockroach carry their egg capsules ([[ootheca]]e) with them until the eggs hatch<ref name=":6">{{Cite journal|last1=Atkinson|first1=Thomas H.|last2=Koehler|first2=Philip G.|last3=Patterson|first3=Richard S.|date=1991-08-01|title=Reproduction and Development of ''Blattella asahinai'' (Dictyoptera: Blattellidae)|journal=[[Journal of Economic Entomology]]|language=en|volume=84|issue=4|pages=1251–1256|doi=10.1093/jee/84.4.1251|pmid=1842796|issn=0022-0493|doi-access=free}}</ref> but female Asian cockroaches produces fewer oothecae in comparison to the German cockroach, producing approximately four oothecae in their lifetime, each averaging 35 - 40 eggs.<ref name=":4" /> Asian Cockroaches have longer initial and subsequent pre-oviposition periods than its German counterpart, and their eggs require slightly longer time to hatch. Asian adult females produce their first egg ootheca approximately 13 days after becoming an adult, and the period from when the ootheca first appeared to hatching is approximately 19 days. The female German cockroach can produce an Ootheca after approximately 8 days after becoming an adult with an incubation period of approximately 17 days.<ref name=":6" /> The oothecae of the Asian cockroach appears slightly smaller than that of the German cockroach as well as once hatched, the Asian cockroach is notably smaller than the German cockroach at the time of its first [[instar]].<ref>{{Cite journal|last1=Ross|first1=Mary H.|last2=Mullins|first2=Donald E.|date=1988-12-01|title=Nymphal and Oöthecal Comparisons of ''Blattella asahinai'' and ''Blattella germanica'' (Dictyoptera: Blattellidae)|journal=[[Journal of Economic Entomology]]|language=en|volume=81|issue=6|pages=1645–1647|doi=10.1093/jee/81.6.1645|issn=0022-0493}}</ref> The Asian cockroach is most fertile from February to May as well as in August through to September. <ref name=":6" />

Shortly after hatching, nymph cockroaches turn from white to brown and their skin hardens.<ref>{{Cite web|title=How Cockroaches Work|url=https://animals.howstuffworks.com/insects/cockroach.htm|date=2006-12-19|website=HowStuffWorks|language=en|access-date=2020-05-30}}</ref> Asian cockroach females requires 60 - 70 days to become an adult, slightly longer than the males. The lifetime of male and female Asian Cockroaches are approximately 50 and 100 days respectively, compared with the German cockroach which lives on average 130 for males and 150 days for females.<ref name=":6" />

An occasion where an Asian and a German mate with one another is extremely rare due to the behavioural differences of the two species but this can occur. On the rare occasion they produce viable offspring, it has the ability to fly and [[Pesticide resistance|inherits the insecticide resistance]] the German possesses.<ref name=":8">{{Cite web|title=Asian Cockroach, Blattella asahinai|url=https://urbanentomology.tamu.edu/cockroaches/asian-cockroach/|website=[[Urban and Structural Entomology Program at Texas A&M University]]|language=en-US|access-date=2020-05-30}}</ref>

==Beneficial insect==
[[File:ARS Blattella asahinai.jpg|thumb|[[Soybean]] leaf]]
[[File:An Asian cockroach (Blattella asahinai; possibly).jpg|thumb|[[Calabash]] leaf]]
In 2006, entomologist [[Robert Pfannenstiel]] conducted research on the ecology of predators of crop pests in Texas, in particular the Asian cockroach. Asian cockroaches ventured west into Texas in 2006, and became the most common predator of [[bollworm]] eggs in the state's [[Lower Rio Grande Valley|Rio Grande Valley]] region. The bollworm threatens [[cotton]], [[soybean]], [[maize]], and [[tomato]] crops.<ref name=":0">{{Cite web|title=Asian Cockroaches Could Aid Texas Growers|url=https://www.sciencedaily.com/releases/2008/01/080106132313.htm|website=ScienceDaily|language=en|access-date=2020-05-30}}</ref> ''[[Helicoverpa zea]]'' (Boddie) and ''[[Spodoptera exigua]]'' (Hubner) are leading [[insect crop pest|pests]] of soybean crops in Southern Texas. Their eggs were placed on the leaves of soybean crops, without pesticides, and were observed in 3-hour increments over 24 hours to observe both the night and day behaviour of predators towards the pests of the crops.<ref>{{Cite journal|journal=[[Annals of the Entomological Society of America]]|language=en|doi=10.1603/0013-8746(2008)101[763:badban]2.0.co;2|title = ''Blattella asahinai'' (Dictyoptera: Blattellidae): A New Predator of Lepidopteran Eggs in South Texas Soybean|year = 2008|last1 = Pfannenstiel|first1 = Robert S.|last2 = Booth|first2 = Warren|last3 = Vargo|first3 = Edward L.|last4 = Schal|first4 = Coby|volume = 101|issue = 4|pages = 763–768|s2cid=38613040 }}</ref> From 2001 to 2005 similar tests were conducted on the predation of [[Lepidoptera]]n eggs but no observations of the Asian cockroach were made. In 2006, nymph and adult Asian cockroaches were observed feeding on ''H. zea'' and ''S. exigua'' from both the canopy and leaf litter of the crops and made up 53.7% of all predators feeding on the eggs.<ref name=":9" />

== Pest status ==
The Asian cockroach is a foreign pest with a peak in adult population during summer and spring in Florida. It lives in the garden where it is in contact with animal [[feces]], [[soil-borne pathogen]]s and other disease-causing microorganisms.<ref name=":8" /><ref name=":7" /> The German cockroach has feces and body parts that can possibly be [[allergen]]ic to humans and the Asian cockroach may possess similar traits and pose the same health issue to these individuals.

== Control and management ==
Although the Asian cockroach prefers the outdoors as its habitat, they are often drawn to houses due to light sources. [[Restaurant industry in the United States|Restaurants]] have implemented control measures such as [[Integrated Pest Management]] programs (IPM) which target the German cockroach. Due to the similarities to the German and if proper identification is not made of the Asian species, restaurants and homeowners may use pesticide treatments that are ineffective against the Asian, exposing the individuals to unnecessary [[pesticide residue]]s and other control measures.<ref name=":7" /> Indoor cockroach insecticides are generally ineffective in killing the Asian and will only control the ones that have entered the house but are difficult to contain once penetrating a location.{{ Clarify | date = December 2022 }} They are fast and nimble, and are difficult to kill on the spot. In order to control and manage the Asian, garden or outdoor area maintenance of homes {{endash}} including removal of excess [[mulch]] and plant debris {{endash}} is an effective approach to reduce population.<ref name=":3" />

Preventative measures for insects including sealing cracks or crevices in the floor or walls are unnecessary for Asian cockroaches as they can fly into buildings through open windows or doors anyway.<ref name=":8" /> The use of outdoor insecticides offers another option to Asian cockroach management. [[Cyfluthrin|ß-cyfluthrin]] and [[fipronil]] granules are insecticides that are highly toxic to the Asian cockroach taking on average 20 minutes and 11 hours respectively to kill the cockroach compared to a MotherEarth Exempt Concentrate natural essential oil which can take up to 11.45 days to kill the cockroach.<ref>{{Cite journal|last1=Snoddy|first1=Edward T.|last2=Appel|first2=Arthur G.|date=2014-02-01|title=Field and Laboratory Efficacy of Three Insecticides for Population Management of the Asian Cockroach (Dictyoptera: Blattellidae)|journal=[[Journal of Economic Entomology]]|volume=107|issue=1|pages=326–332|doi=10.1603/ec13342|pmid=24665717|issn=0022-0493|doi-access=free}}</ref> [[Scatter bait]]s have been purposely developed for the control of the Asian cockroach and have proven to be effective whereas indoor applications of insecticides have proven to be ineffective.<ref name=":8" />

==References==
{{Reflist}}

==External links==
{{Commons category|Blattella asahinai}}
{{Wikispecies}}
* [http://entomology.ifas.ufl.edu/creatures/urban/roaches/asian_cockroach.htm Asian cockroach] on the [[University of Florida|UF]] / [[Institute of Food and Agricultural Sciences|IFAS]] Featured Creatures Web site.

{{Taxonbar|from=Q1884775}}

{{DEFAULTSORT:Blattella asahinai}}
[[Category:Cockroaches]]
[[Category:Insects described in 1981]]
[[Category:Household pest insects]]

Blattella asahinai - Revision history

imported>Battmutler: /* Behaviour */