basisternum

basisternum

[¦bās·ə¦stər·nəm]
(invertebrate zoology)
In insects, the anterior one of the two sternal skeletal plates.
References in periodicals archive ?
Basisternum ([stns.ub.2]) about 250-275 [micro]m wide and 170-175 [micro]m long; with a narrow, complete median ridge (mdr); marginal ridges well developed; furca (f) with arms extending anteriorly to about halfway to marginal ridge (mr).
Thorax: Black in ground color with dark gray pruinosity; scutum with 5 distinct black vittae, the inner vitta reaching scutoscutellar suture; 2 rows of hair-like prst acr (the second pair stronger), only 1 pair of post acr developed, these situated in front of scutellum, dc 2+3, ial 0+2, with 1 pair of outer posthumeral setae; pra about 1.5 times longer than posterior notopleural seta; scutellum without spots, ventral margins with some long pale setae apically; anterior anepisternal setae absent; notopleuron, basisternum of prosternum, anepimeron, meron and katepimeron bare; both anterior and posterior spiracles small and fuscous; katepisternal seta 1+3.
Thorax: Black with sap green luster, scutum indistinctly with 3 black vittae, prst acr hair-like, in 2 rows (sometimes the first pair distinct), only 1 pair of post act developed, located in front of scutellum, dc 2+3, ial 0+2, posthumeral seta l+0; pra longer than anterior notopleural seta, about 2.0 times longer than posterior notopleural seta; scutellum without spots, lower surface with some pale setae distally, without anterior anepisternal seta, notopleuron, basisternum, anepimeron, meron and katepimeron bare; both anterior spiracle and posterior spiracles small and grey-brown; katepisternal seta 1+2(3).
Morphology and evolution of the insect thorax) the prosternum in Chauliognathus consists of a short basisternum which is continuous with the furcasternum bearing simple, paired furcae.