Editing Parent bug

{{Short description|Species of true bug}}
{{Speciesbox
| name = Parent bug
| image = Acanthosomatide - Elasmucha grisea-001.JPG
| image_caption = ''Elasmucha grisea'', upperside
| image2 = 2013-06-04 15-34-47-Hemiptera.JPG
| image2_caption = Front view
| taxon = Elasmucha grisea
| authority = ([[Carl Linnaeus|Linnaeus]], [[Systema Naturae|1758]])
| synonyms =
* ''Cimex grisea'' Linnaeus, 1758<ref name=Fauneur/>
}}

'''''Elasmucha grisea''''', common name '''parent bug''', is a species of [[shield bug]]s or stink bugs belonging to the family [[Acanthosomatidae]]. The term '''parent bugs''' includes also the other species of the genus ''[[Elasmucha]]'' and some species of the family Acanthosomatidae.<ref>{{cite journal | last1 = Gollner-Scheiding | first1 = U | year = 2006 | title = Family Acanthosomatidae | journal = Catalogue of the Heteroptera of the Palaearctic Region | volume = 5 | pages = 166–181 }}</ref>

==Subspecies==
Subspecies within ''Elasmucha grisea'' include:<ref>[http://www.eu-nomen.eu/portal/taxon.php?GUID=urn:lsid:faunaeur.org:taxname:453898 EU-Nomen]</ref>
* ''Elasmucha grisea cypria'' Josifov, 1971
* ''Elasmucha grisea grisea'' (Linnaeus, 1758)

==Distribution==
''Elasmucha grisea'' is a rather common and widespread species present in most of [[Europe]].<ref name=Fauneur>[https://web.archive.org/web/20150202174500/http://www.faunaeur.org/full_results.php?id=453898 Fauna europaea]</ref>

==Description==
''Elasmucha grisea'' can reach a length of {{convert|6.5|-|8.8|mm}}. Males are smaller than females. These medium-sized shield bugs are usually brown-reddish, but there are also gray (hence the Latin species name ''grisea'') and green-brown specimens. The connexiva are black and white. The upper side is covered with several dark dots. The scutellum usually shows an evident black patch.<ref name=BB>[http://www.britishbugs.org.uk/heteroptera/Acanthosomatidae/elasmucha_grisea.html British Bugs]</ref> The ventral face is largely punctuated with black. The lateral corners of the pronotum are simply beveled. The front corners of the pronotum show a more pronounced tooth. Antennae are blackish in the male, dark brown in the female.<ref name=Cle>François Dusoulier, Claire Mouquet [http://www.gretia.org/phocadownload/cahiers_gretia/IA01/Invertebres_Armoricains_N1_7-13.pdf Clé de détermination des Acanthosomatidae Signoret, 1864 du Massif armoricain (Hemiptera, Heteroptera).]</ref>

This species, like other parent bugs, possesses [[Metathorax|metathoracic]] and abdominal glands, which discharge a foul smelling [[secretion]].<ref name="roth">Roth S, Adaschkiewitz, Fischer C (2006) Notes on the bionomics of ''Elasmucha grisea'' (LINNAEUS 1758) (Heteroptera, Acanthosomatidae) with special regard to joint brood guarding. zugleich Kataloge der OÖ, Landesmuseen Neue Serie 50:1153–1167</ref><ref name="hanelova">Hanelova J, Vilimova J (2013) Behaviour of the central European Acanthosomatidae (Hemiptera: Heteroptera: Pentatomoidea) during oviposition and parental care Acta Musei Moraviae, Scientiae biologicae 98:433-457</ref> This secretion is used to deter potential enemies and is sometimes released when the bug is disturbed.

==Life cycle==
Adults of ''E. grisea'' can be found all year around. In fact this species overwinters as an adult. Mating occurs in the spring and new adults can be found in August.<ref name=BB/> These shield bugs feed on various woody plants, preferably on birch (''[[Betula]]'' sp.), but also on alder (''[[Alnus]]'' sp.), beech ([[Fagus (plant)|''Fagus'']] sp.), holly (''[[Ilex]]'' sp.), spruce (''[[Picea]]'' sp.), etc.<ref name=Cle/> Like most shield bugs, ''E. grisea'' and other parent bugs suck plant [[sap]] and require [[symbiotic bacteria]] for their digestion.<ref name="fischer">Fischer C (2006) The biological context and evolution of Pendergrast’s organs of Acanthosomatidae (Heteroptera, Pentatomoidea) 50:1041-1054</ref> They obtain [[symbionts]] at an early age: the mother covers her eggs with bacteria so that the [[Nymph (biology)|nymphs]] ingest them as they feed on the egg case.<ref name="fischer"/> Both adults and nymphs readily feed on developing seeds, and breeding individuals can be observed on host plants with many young [[catkin]]s.<ref name="mappes1">{{cite journal | last1 = Mappes | first1 = J | last2 = Kaitala | first2 = A | year = 1995 | title = Host-plant selection and predation risk for offspring of the parent bug | journal = Ecology | volume = 76 | issue = 8| pages = 2668–2670 | doi=10.2307/2265839| jstor = 2265839 }}</ref> However, they seem to avoid trees with a high [[predation]] risk.

==Parental care==
[[File:Elasmucha grisea 20050608 916 part.jpg|thumb|250px|left|''Elasmucha grisea'' with eggs]]
The common name of "parent bug" comes from the relatively rare insect behaviour of prolonged caring for eggs and juveniles, exhibited by females of this species. Predators, such as bugs, beetles, earwigs and ants, can eliminate all the offspring of the parent bug if there is no maternal care. The repertoire of female [[defensive behaviour]]s includes wing fanning, body jerking, tilting towards the enemy and, finally, releasing of 'nasty' odours from the scent glands,<ref name="mappes1"/><ref>Jordan KHC (1958) Die Biologie von ''Elasmucha grisea'' L. (Heteroptera: Acanthosomatidae). Beitr Entomol 8:385-397</ref><ref>Melber A, Hölsher L, Schmidt GH (1980) Further studies on the social behaviour and the ecological significance in ''Elasmucha grisea'' L. (Hem.-Het.: Acanthostomatidae) Zool Anz Jena 205:27-38</ref>

After oviposition, the parent bug female stands over the egg batch and shields it throughout egg development. Predation appears to limit the clutch size in ''E. grisea''. Experiments have shown that large females lay larger egg clutches than small females. However, when the clutch size was manipulated, small females protecting large clutches lost significantly more eggs than large females guarding small clutches or females in the control groups (guarding clutches of optimal size).<ref>{{cite journal | last1 = Mappes | first1 = J | last2 = Kaitala | first2 = A | year = 1994 | title = Experiments with ''Elasmucha grisea'' L. (Heteroptera: Acanthosomatidae). Does a female parent bug lay as many eggs as she can defend? | journal = Behav Ecol | volume = 5 | issue = 3| pages = 314–317 | doi=10.1093/beheco/5.3.314}}</ref>

After hatching, larvae of the parent bug remain in a tight aggregation, feeding on their empty egg shells.<ref name="hanelova"/> When any larva tries to abandon the aggregation, the female tilts her body, stretches her antennae to reach the larva and pushes the larva back to the aggregation.<ref name="roth"/> During the second and third [[instar]] they move, for food, towards catkins then back to the leaf with the female in close attendance.<ref name="hanelova"/> The female keeps a lookout for the larvae constantly and manages them with touches of her antennae. Finally, larvae form smaller groups and disperse at the end of the third instar, at which point the female leaves them.

[[File: Eggs of Ectophasia crassipennis.JPG|thumb|200px|right|''E. grisea'' with the white eggs of ''[[Subclytia rotundiventris]]'' on pronotum]]
It has been noted that, in ''E. grisea'', [[moulting]]s during the early instar stages can be asynchronous.<ref name="roth"/> While some larvae are still at the first instar stage, others have already moulted to the stage of second instar larvae and abandon the brood leaf for food. Under such circumstances, the female is no longer able to provide effective protection for all her larvae. The offspring of different females make contact with each other and form mixed groups. There is no kin-recognition in this species. Both single and joint guarding females provide parental care for their own larvae or other females' offspring. Larvae are likely to benefit from 'kindergartens', when their mothers disappear or die.<ref name="roth"/> Moreover, joint-guarding females defend the egg clutches much more successfully than single females.<ref>{{cite journal | last1 = Mappes | first1 = J | last2 = Kaitala | first2 = A | last3 = Alato | first3 = RV | year = 1995 | title = Joint brood guarding in parent bugs – an experiment on defence against predation | journal = Behav Ecol Sociobiol | volume = 36 | issue = 5| pages = 343–347 | doi=10.1007/bf00167795}}</ref>

The [[Tachinidae|tachinid]] fly, ''[[Subclytia rotundiventris]]'', is a specialist [[endoparasite]] of the parent bug females.<ref name="mappes2">{{cite journal | last1 = Mappes | first1 = J | year = 2010 | title = Parasites and female ability to defend offspring in the parent bug ''Elsamucha grisea'' L | doi = 10.1111/j.1439-0310.1994.tb01030.x | journal = Ethology | volume = 97 | issue = 1–2| pages = 76–80 }}</ref> The parasite inserts a single egg through the upper [[prothorax]] of an ''E. grisea'' female and, after hatching, the larva feeds on its host. At the beginning the parasite feeds only on the non-vital parts of the bug, but finally it kills it and [[pupa]]tes outside the host. The larva ‘permits’ the parent bug to continue caring for the juveniles until their third stage. In experiments, the wing-fanning (regarded as the most effective defensive behaviour of the parent bug) did not differ significantly between parasited and non-parasited females until the nymphs were at the second instar stage. However, with older nymphs, females were much less effective in their defensive behaviour and often died before the end of maternal care. Considering that the older nymphs are more mobile and may escape from predators, some offspring of the parasited females of the parent bug probably survive and may also be potential hosts for the new generation of the parasite.<ref name="mappes2"/>

==Gallery==
<gallery widths="240" heights="180">
File:Elasmucha grisea (Parent bug), Arnhem, the Netherlands - 3.jpg|''Elasmucha grisea'' with eggs
File:Elasmucha grisea f3.jpg|A female is guarding her nest.
File:Elasmucha grisea (Parent bug), Arnhem, the Netherlands.jpg|Aggregation of nymphs
File:Elasmucha grisea nymph.jpg|Young nymph
</gallery>

==See also==
* [[List of shield bug species of Great Britain]]

==References==
{{Reflist}}

==External links==
*{{Cite web|title=Elasmucha grisea L. |publisher=Nature spot |url=http://www.naturespot.org.uk/species/parent-bug}}
*{{Cite journal|title=Experiments with Elasmucha grisea L. |journal=Behavioral Ecology |volume=5 |issue=3 |pages=314–317 |publisher=by Johanna Mappes and Arja Kaitala |doi=10.1093/beheco/5.3.314 |date=October 1994 |last1=Kaitala |first1=Arja |last2=Mappes |first2=Johanna }}
*{{Cite web|title=Distribution and Taxonomy  |url=https://data.nbn.org.uk/Taxa/NHMSYS0020309200}}
*{{Cite journal|title= Ovary structure in a presocial insect, Elasmucha grisea (Heteroptera, Acanthosomatidae)|author= A.Ogorzałek, A.Trochimczuk  | pmid=19682601 | doi=10.1016/j.asd.2009.08.001 |volume=38 |issue= 6 |journal=Arthropod Struct Dev |pages=509–19 |year=2009}}
*{{cite journal | last1 = Mappes | first1 = J | year = 2010 | title = Parasites and female ability to defend offspring in the parent bug ''Elsamucha grisea'' L | doi = 10.1111/j.1439-0310.1994.tb01030.x | journal = Ethology | volume = 97 | issue = 1–2| pages = 76–80 }}
*{{cite journal | last1 = Maschwitz | first1 = Ch. Gutmann | year = 1979 | title = Trail and alarm pheromones in Elasmucha grisea (Heteroptera: Acanthosomidæ) | journal = Insectes Sociaux | volume = 26 | issue = 2| pages = 101–111 | doi=10.1007/bf02223504}}
* {{Commons inline|Elasmucha grisea}}
* {{Wikispecies inline|Elasmucha grisea}}

{{Taxonbar|from=Q778700}}

[[Category:Acanthosomatidae]]
[[Category:Hemiptera of Europe]]
[[Category:Bugs described in 1758]]
[[Category:Taxa named by Carl Linnaeus]]