Cydnidae

Billberg, 1820

burrowing bugs, burrower bugs

Genus Guides

Amnestus(burrowing bugs)
Cydninae(burrower bugs)
Scaptocoris(burrowing bugs)
Sehirus(burrower bugs)

is a of pentatomoid true bugs commonly known as burrowing or burrower bugs. Many are , burrowing into soil using their and forelegs, emerging primarily to mate and lay . Other members live above ground, often associated with plants. The family includes agricultural pests and exhibits diverse preferences across .

Pangaeus bilineatus by (c) Justin Williams, some rights reserved (CC BY), uploaded by Justin Williams. Used under a CC-BY license.

Cydnidae by (c) christine123, some rights reserved (CC BY), uploaded by christine123. Used under a CC-BY license.

Cydnidae by (c) Martin Cooper, some rights reserved (CC BY). Used under a CC-BY license.

Pronunciation

How to pronounce Cydnidae: /ˈsɪdnɪdiː/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from other pentatomoid by the combination of: coxal setal combs, rigid setae at apices, and often reduced 3-segmented . Cydninae and Cephalocteinae are with digging-adapted forelegs; Parastrachinae, Sehirinae, and Thyreocorinae (when included) are non-burrowing and plant-associated. Similar to Thyreocoridae (negro bugs) but separated by pretarsal and genitalic structures; historically confused but now generally treated as distinct family.

Images

Habitat

Primarily terrestrial. Members of Cydninae and Cephalocteinae inhabit soil, often burrowing deeply; found in agricultural fields, grasslands, and riparian areas with suitable substrate. Non-burrowing subfamilies (Parastrachinae, Sehirinae) occupy aboveground plant . Rarely recorded from caves; only ten across three subfamilies documented globally from cave environments.

Distribution

Worldwide distribution. Fossil record from Late Mesozoic of China (Yixian Formation, Aptian). Western Hemisphere fauna catalogued with ongoing taxonomic updates. Palearctic cave records reported from Tajikistan. Extant occur across all major biogeographic regions.

Diet

Phloem sap feeders. Cydninae and Cephalocteinae feed on plant roots; non-burrowing subfamilies feed on aboveground plant parts. Unlike other heteropterans, feed specifically on sap from phloem tissue.

Life Cycle

laid in soil for burrowing . Nymphal stages develop in soil ( species) or on plants (non-burrowing species). Five nymphal instars typical of pentatomoids. Maternal care has been documented in some species (e.g., Sehirus cinctus).

Behavior

Burrowing excavate soil using and forelegs, spending most of underground and emerging primarily for mating. attracted to light, sometimes in large . Defensive secretions produced from thoracic glands (adults) or lateral abdominal glands (nymphs) containing foul-smelling chemical mixtures. Some species facultatively blood-feed from humans.

Ecological Role

Root-feeding may influence plant structure and soil processes through herbivory and burrowing activity. Agricultural pests affect crop yields directly through feeding damage. Prey for soil-dwelling and aboveground ; chemical defenses provide protection.

Human Relevance

Agricultural pests: 27 reported as crop pests as of 2003, including six species feeding on peanut. Pangaeus bilineatus causes feeding injury to peanut kernels; Fromundus pygmaeus attacks rice seedlings, sugarcane, grass seeds, and roots of soybean and clover. Medical relevance: F. pygmaeus facultatively sucks human blood; Chilocoris assmuthi causes brown skin (typically on feet) from defensive secretions. Some species suppressed or favored by cover crop selection in agricultural management.

Similar Taxa

ThyreocoridaeFormerly included in sensu lato as Thyreocorinae; separated based on pretarsal structure, genitalia, and ecological differences. Known as 'negro bugs' or 'ebony bugs'.
PentatomidaeRelated pentatomoid ; distinguished by coxal setal combs, rigid coxal setae, reduced , and adaptations in many .
CyrtocoridaeSmall Neotropical pentatomoid possibly related to ; distinguished by expanded scutellum with broad-based spine, flattened expansions, and mediodistal tibial .

More Details

Subfamily classification

BioLib recognizes: Amnestinae, Cephalocteninae, Cydninae, Garsauriinae, Sehirinae. Extinct †Clavicorinae and fossil documented from Cretaceous amber and deposits in Myanmar, China, Brazil, and Mongolia. Thyreocorinae now generally excluded as separate Thyreocoridae.

Defensive chemistry

Thoracic glands in and lateral abdominal glands in nymphs secrete defensive compounds; specific chemistry varies but generally foul-smelling mixtures effective against .

Fossil record

First fossil described from Late Mesozoic of China (2007); additional fossil from Burmese amber (mid-Cretaceous), Brazilian Crato and Codo formations (Aptian), and Russian Daya Formation.