Bironella gracilis Theobald, 1905.
Subfamily Anophelinae. The genus includes eight species divided between three subgenera: Bironella (2 species), Brugella (3) and Neobironella (3). Genus abbreviation – Bi.
The adults and immature stages of Bironella are similar to those of Anopheles. Bironella are delicate insects that vary from light to dark brown in overall coloration. They are easily distinguished from Anopheles by wing venation and larval thoracic chaetotaxy. Wing vein M1+2 and vein M3+4 are conspicuously wavy; cell R2 may be complete and nearly as long as vein R2+3, complete but distinctly shorter than vein R2+3 (about 0.20–25 its length) or incomplete with vein R3 absent basally. Larval thoracic seta 1-M and seta 3-T are both palmate and seta 4-P is closer to 1–3-P than to 5–7-P. In Anopheles, veins M1+2 and M3+4 are both straight, cell R2 is complete and approximately as long as vein R2+3; only larval thoracic seta 3-T is palmate and 4-P is closer to 5–7-P than to 1–3-P. See Anophelinae.
The phylogenetic relationships of Bironella are uncertain. It may be the sister group of genus Anopheles (Harbach & Kitching, 1998; Besansky & Fahey, 1997; Foley et al., 1998; Krzywinski et al., 2001a, 2001b; Foster et al., 2017) or a species group of subgenus Anopheles (Sallum et al., 2000, 2002; Harbach & Kitching, 2005, 2016). The single species of Bironella (Bi. hollandi) included in the study of Foster et al. based on analyses of mitochondrial protein coding genes was recovered as the sister of a clade parenthetically expressed as Nyssorhynchus + (Cellia + Anopheles).The evolutionary relationships of the subgenera and species of Bironella have not been investigated.
The immature stages of Bironella are usually found in undisturbed areas, most frequently in dense shade in swamp margins and the margins of slow-moving streams. They also inhabit rock pools in and along margins of streams, backwaters of streams, seepages, river banks and temporary pools. The adults are seldom collected or seen in nature, but some have been captured in Malaise traps set up in virgin forest. The females of Bi. gracilis have been reported to bite humans, and have been induced to bite in the laboratory, but Bironella do not habitually attack people.
Species of Bironella are not known to transmit any pathogens of human diseases.
Bironella occur in the Australasian Region, principally in the Papuan Subregion.