Orsillinae

Stål, 1872

seed bugs

Genus Guides

3

Orsillinae is a of seed bugs (Lygaeidae) comprising at least 110 described in four tribes: Lepionysiini, Metrargini, Nysiini, and Orsillini. Members harbor obligate bacterial in specialized bacteriocytes, transmitted transovarially to offspring. Several species are economically significant, including pests of cypress and agricultural false chinch bugs.

Belonochilus numenius by (c) Even Dankowicz, some rights reserved (CC BY), uploaded by Even Dankowicz. Used under a CC-BY license.Neortholomus scolopax by (c) christine123, some rights reserved (CC BY), uploaded by christine123. Used under a CC-BY license.Nysius raphanus by (c) Don Loarie, some rights reserved (CC BY), uploaded by Don Loarie. Used under a CC-BY license.

Pronunciation

How to pronounce Orsillinae: /ɔrˈsɪlɪniː/

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Images

Habitat

Associated with herbaceous vegetation and seed-bearing plants; some specifically linked to Cupressaceae (cypress). Nysius ericae and Nithecus jacobaeae collected from grasses and forbs including Potentilla argentea, Festuca pratensis, Rumex acetosella, Oenothera biennis, Senecio jacobaea, and Hieracium pilosella.

Distribution

Global distribution spanning Mediterranean Basin (native range of Orsillus depressus), northeastern Europe (expanded range), Australia (Lepionysiini), Neotropics and Pacific islands (Metrargini), and Argentina (New World/Southern Hemisphere records including central-southern provinces).

Diet

Seed feeding predominant; Orsillus depressus feeds on seeds of Cupressaceae, mainly cypress. Phloem sap feeding inferred in some based on presence of nutrient-supplementing bacterial .

Host Associations

  • Cupressaceae - seed feedingprimary for Orsillus depressus
  • cypress - seed feedingmain of Orsillus depressus
  • Potentilla argentea - associationcollected with Nysius ericae
  • Festuca pratensis - associationcollected with Nysius ericae
  • Rumex acetosella - associationcollected with Nysius ericae
  • Oenothera biennis - associationcollected with Nysius ericae
  • Senecio jacobaea - associationcollected with Nithecus jacobaeae
  • Hieracium pilosella - associationcollected with Nithecus jacobaeae

Ecological Role

Obligate mutualism with prokaryotic housed in paired bacteriomes; symbionts synthesize to compensate for nutritional deficiencies in phloem sap or seed diets. ensures vertical inheritance of symbionts through female germ line.

Human Relevance

Orsillus depressus is an pest of cypress with expanding range in Europe and recent establishment in Argentina. Nysius (false chinch bugs) are agricultural pests.

Similar Taxa

  • Lygaeinaealso seed-feeding Lygaeidae, distinguished by tribal and generic composition; Orsillinae defined by four tribes (Lepionysiini, Metrargini, Nysiini, Orsillini) with distinct geographic distributions
  • other Lygaeidae subfamiliesOrsillinae distinguished by characteristic bacteriome structure with paired bacteriomes containing large elongated bacteria, and transovarial transmission mechanism

Sources and further reading