Cydnidae: Difference between revisions

{{Short description|Family of true bug}}

{{Automatic taxobox

| fossil_range = {{fossilrange|Aptian|Present}}<ref>{{cite journal |author1=Jerzy A. Lis |author2=Barbara Lis |author3=Ernst Heiss |year=2018 |title=''Chilamnestocoris mixtus'' gen. et spec. nov., the first burrower bug (Hemiptera: Pentatomoidea: Cydnidae) in Upper Cretaceous Burmese amber |journal=Cretaceous Research |volume=91 |pages=257–262 |doi=10.1016/j.cretres.2018.06.017 |url=http://osf.io/e5qsu/ }}</ref>

| image_caption = ''Cydnus aterrimus''<br /> Type genus for the family

| taxon = Cydnidae

| authority = [[Gustaf Johan Billberg|Billberg]], 1820

| subdivision_ranks = Subfamilies

'''Cydnidae''' are a family of [[Pentatomoidea|pentatomoid]] bugs, known by [[common name]]s including '''burrowing bugs''' or '''burrower bugs'''.<ref>{{cite web |url=http://stri.discoverlife.org/mp/20q?search=Cydnidae&guide=Groups_Insecta |title=Cydnidae |publisher=[[Discover Life]] |access-date=2007-03-09}}</ref> As the common name would suggest, many members of the group live a subterranean lifestyle, burrowing into soil using their head and forelegs, only emerging to mate and then laying their eggsinsoil. Other members of the group are not burrowers, and live above the soil layer, often in close association with plants. Several species are knownasagricultural pests.<ref name="Acanthamnestus" />

== Description ==

Burrowing bugs range from 2 to 20&nbsp;mm in length.<ref name=":0">{{Cite web |title=Family Cydnidae - Burrowing Bugs |url=https://bugguide.net/node/view/6980 |access-date=2023-01-05 |website=bugguide.net}}</ref> They are dark, ovoid in shape and highly sclerotised. The head is generally subquadrate to semicircular in shape, and has a pair of 5-segmented [[Antenna (biology)|antennae]]. The coxae of the legs have [[seta]]l combs, while the apices of the mid and hind coxae are fringed with rigid setae. The tibiae of the legs (also often the head and pronotum) have spines. The tarsi of the legs are 3-segmented and often reduced.<ref name=":1">{{Cite web |title=Australian Faunal Directory |url=https://biodiversity.org.au/afd/taxa/CYDNIDAE |access-date=2023-01-05 |website=biodiversity.org.au |language=en}}</ref>

Similar to other pentatomoids, Cydnidae have [[gland]]s in the thorax (adults) or the lateral part of the abdomen (nymphs) that secrete a foul-smelling mix of chemicals for [[Anti-predator adaptation|defense against predators]].<ref name=":2">{{Cite journal |last=Malhotra |first=Amit K. |last2=Lis |first2=Jerzy A. |last3=Ramam |first3=M. |date=2015-02-01 |title=Cydnidae (Burrowing Bug) Pigmentation: A Novel Arthropod Dermatosis |url=http://archderm.jamanetwork.com/article.aspx?doi=10.1001/jamadermatol.2014.2715 |journal=JAMA Dermatology |language=en |volume=151 |issue=2 |pages=232 |doi=10.1001/jamadermatol.2014.2715 |issn=2168-6068}}</ref>

== Ecology ==

Cydnidae in subfamilies Cydninae and Cephalocteinae live mostly in soil and feed on roots of plants. Those in subfamilies Parastrachinae, Sehirinae and Thyreocorinae instead live on aboveground parts of plants. Adults are attracted to light and sometimes in large numbers.<ref name=":1" />

Cydnidae feed on sap from [[phloem]], unlike other heteropterans.<ref name=":0" />

== Importance ==

As of 2003, there were 27 cydnid species reported as crop pests and six that feed on [[peanut]]. Of the peanut-feeding species, ''Pangaeus bilineatus'' is the most abundant and the only one associated with feeding injury to peanut kernels.<ref>{{Cite journal |last=Chapin |first=Jay W. |last2=Thomas |first2=James S. |date=2003-08-01 |title=Burrower Bugs (Heteroptera: Cydnidae) in Peanut: Seasonal Species Abundance, Tillage Effects, Grade Reduction Effects, Insecticide Efficacy, and Management |url=http://dx.doi.org/10.1093/jee/96.4.1142 |journal=Journal of Economic Entomology |volume=96 |issue=4 |pages=1142–1152 |doi=10.1093/jee/96.4.1142 |issn=1938-291X}}</ref>

Another pest is ''Fromundus pygmaeus'', which attacks [[rice]] seedlings, [[sugarcane]], fallen seeds of [[Poaceae|grasses]] and roots of [[Glycine (plant)|soybean]] and [[clover]].<ref name=":3">{{Cite journal |last=Shehta, Manar |last2=Sawaby, Rabab F. |last3=Gad-Allah, Sohair |last4=Okely, Mohammed |date=2022-09-15 |title=Fromundus pygmaeus (Dallas, 1851), the first species of the genus Fromundus Distant, 1901 (Hemiptera: Heteroptera: Cydnidae) recorded in Egypt |url=https://zenodo.org/record/7058518 |language=en |doi=10.5281/ZENODO.7058518}}</ref>

Some cydnids are medically important. The aforementioned ''F.'' ''pygmaeus'' facultatively [[Hematophagy|sucks blood]] from humans,<ref name=":3" /> while ''Chilocoris assmuthi'' can cause brown [[lesion]]s on skin (usually on the feet) with its defensive secretions.<ref name=":2" />

==Subfamilies and taxonomy==

''BioLib'' includes the following subfamilies:

*Amnestinae {{small|Hart, 1919}}

** †''[[Acanthamnestus]]'' {{small|Du, Yao & [[Michael S. Engel|Engel]], 2022}} [[Burmese Amber]], Myanmar, mid Cretaceous (latest [[Albian]]-earliest [[Cenomanian]])<ref name=Acanthamnestus>{{cite journal |last1=Du |first1=S. |last2=Gu |first2=L. |last3=Engel |first3=M. S. |last4=Ren |first4=D. |last5=Yao |first5=Y. |year=2022 |title=Morphological Phylogeny of New Cretaceous Fossils Elucidates the Early History of Soil Dwelling Among Bugs |journal=Frontiers in Ecology and Evolution |volume=10 |pages=Article 908044 |doi=10.3389/fevo.2022.908044 |doi-access=free }}</ref>

** ''[[Amnestus]]'' {{small|Dallas, 1851}}

** †''[[Chilamnestocoris]]'' {{small|Lis ''et al.'', 2018}} Burmese Amber, Myanmar

** †''[[Cilicydnus]]'' {{small|Yao ''et al.'', 2007}} [[Yixian Formation]], China, Early Cretaceous ([[Aptian]])

** ''[[Lattinestus]]'' {{small|Eger, 2008}}

** †''[[Latiscutella]]'' {{small|Pinto & de Ornellas, 1974}} [[Crato Formation]], [[Codo Formation]], Brazil, Aptian

** †''[[Orienicydnus]]'' {{small|Yao ''et al.'', 2007}} Yixian Formation, China

** †''[[Pricecoris]]'' {{small|Pinto & de Ornellas, 1974}} Codo Formation, Brazil

** †''[[Punctacorona]]'' {{small|Wang ''et al.'', 2019}} Burmese Amber, Myanmar

* Cephalocteninae {{small|Mulsant & Rey, 1866}}

** Cephaloctenini {{small|Mulsant & Rey, 1866}}

*** ''[[Cephalocteus]]'' {{small|Dufour, 1834}}

*** ''[[Heissocteus]]'' {{small|Lis, 2006}}

** Scaptocorini {{small|Froeschner, 1960}}

*** ''[[Afroropus]]'' {{small|Lis, 1999}}

*** ''[[Atarsocoris]]'' {{small|Becker, 1967}}

*** ''[[Pseudostibaropus]]'' {{small|Lis, 1991}}

*** ''[[Scaptocoris]]'' {{small|Perty, 1833}}

*** ''[[Schiodtella]]'' {{small|Signoret, 1882}}

*** ''[[Stibaropus]]'' {{small|Dallas, 1851}}

* †[[Clavicorinae]] {{small|Popov, 1986}}

** †''[[Clavicoris]]'' {{small|Popov, 1986}} [[Gurvan-Eren Formation]], Mongolia, Aptian

** †''[[Cretacoris]]'' {{small|Popov, 1986}} [[Daya Formation]], Russia, Early Cretaceous, [[Gurvan-Eren Formation]], Mongolia

* [[Cydninae]] {{small|Billberg, 1820}}

* [[Garsauriinae]] {{small|Froeschner, 1960}}

** ''[[Garsauria]]'' {{small|Walker, 1868}}

** ''[[Garsauriella]]'' {{small|Linnavuori, 1993}}

* [[Sehirinae]] {{small|Amyot & Audinet-Serville, 1843}}

** †''[[Eocenocydnus]]'' {{small|Popov, 2019}} [[Bembridge Marls]], United Kingdom, [[Eocene]] ([[Priabonian]])

In some older classifications, Cydnidae ''sensu lato'' includes the subfamily Thyreocorinae (now a separate family, [[Thyreocoridae]]), which are known commonly as "negro bugs" or "ebony bugs", and/or the families [[Thaumastellidae]] and [[Parastrachiidae]].<ref>{{Cite journal|author=Dolling, W. R.|year=1981|title=A rationalized classification of the burrower bugs (Cydnidae)|journal=Systematic Entomology |volume=6 |issue=1 |pages=61&ndash;76 |doi=10.1111/j.1365-3113.1981.tb00016.x |s2cid=84097067}}</ref><ref>{{Cite journal|author1=Yao, Yunzhi |author2=Ren, Dong |author3=Rider, David A. |author4=Cai, Wanzhi |year=2012|title=Phylogeny of the Infraorder Pentatomomorpha Based on Fossil and Extant Morphology, with Description of a New Fossil Family from China|journal=PLOS ONE|volume=7|issue=5|pages=e37289|doi=10.1371/journal.pone.0037289 |pmid=22655038 |pmc=3360028|doi-access=free }}</ref>

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