A rationalized classification of the Burrower Bugs (Cydnidae)

Abstract

Cydnidae are defined as those Pentatomoidea with setal combs at the apices of the coxae and a strigil on the ventral surface of the metathoracic wing. Eight subfamilies are recognized: Thaumastellinae, Amnestinae, Cydninae, Scaptocorinae, Sehirinae, Garsauriinae, Thyreocorinae (including only Thyreocoris, Carrabas and Strombosoma) and Corimelaeninae. Eumetopia is included in Corimelaeninae. Dismegistus is excluded from Cydnidae.

Nymphal and adult cephalic chaetotaxy of the Cydnidae (Hemiptera: Heteroptera), and its adaptive, taxonomic and phylogenetic significance

“…26). The pairs III-IV-V are normally developed and obvious, although setae are usually torn out and thus may appear to be absent (therefore Froeschner, 1960, andDolling, 1981 recorded Garsauriinae as lacking cephalic setae). Setae III-VI in N5 of Garsauria laosana are pre sent in the same position as in N5 of all Cydninae (Fig.…”

“…The presence of cephalic primary setae, as well as two easily recognized types of secondary setae (hair-like and peg-like) in both nymphal and adult stages of Cydnidae, is unique to the Pentatomoidea; setae of similar stoutness and position are unknown in other shieldbugs (Dolling, 1981;Linnavuori, 1993;Lis, unpublished data). It is most probably connected with their mode of life -they live deep in the soil, under stones or in litter.…”

“…like primary setae is regarded by many authors (e. g., China, 1955;Cobben, 1978) as characteristic of all ground-living bugs; furthermore, among Pentatomomorpha this type of cephalic setae is known only in the Rhyparochromidae, which are also ground-dwelling bugs (Cobben, 1978;Schuh, 1975;Dolling, 1981;Henry, 1997). 2.…”

“…Dif ferent types of setae (often stout, sometimes even peg-like or spine-like) are present on the margins of the head, tho rax, abdomen and always on the legs, particularly on the tibiae. Their function is still poorly understood, but are usually presumed to be tactile setae (mechanoreceptors) developed as an adaptation for burrowing (Froeschner, 1960;Dolling, 1981;Linnavuori, 1993). Signoret (1881) was the first to use characters related to the types, number and distribution of setae (mainly cephalic) for the classification of Cydnidae; he was fol lowed by Froeschner (1960), Dolling (1981), Linnavuori (1993) and Lis (1994).…”

“…Their function is still poorly understood, but are usually presumed to be tactile setae (mechanoreceptors) developed as an adaptation for burrowing (Froeschner, 1960;Dolling, 1981;Linnavuori, 1993). Signoret (1881) was the first to use characters related to the types, number and distribution of setae (mainly cephalic) for the classification of Cydnidae; he was fol lowed by Froeschner (1960), Dolling (1981), Linnavuori (1993) and Lis (1994). Moreover, certain characters con nected with cephalic chaetotaxy were regarded as of generic importance within the Cydnidae (Froeschner, 1960;Linnavuori, 1993;Lis, 1994).…”