Revision of Subgenus Nyssorhynchus Blanchard, 1902 from Wed, 2015-01-28 17:28

Type species: 

Anopheles argyritarsis Robineau-Desvoidy, 1827.

Classification: 

Subfamily Anophelinae, genus Anopheles. Subgenus Nyssorhynchus includes 39 formally recognised species and a growing number of unnamed members of sibling species complexes that are divided between three Sections, the two largest of which are further subdivided into Series and Groups (see Anopheles Classification, subgenus Nyssorhynchus) believed to represent phylogenetically related assemblages based principally on morphological similarity (Harbach, 2004).

Characteristics: 

Subgenus Nyssorhynchus is most closely related to subgenus Kerteszia. The two subgenera are very similar in overall morphology, but the following features easily distinguish the adults, larvae ana pupae of Nyssorhynchus. The scutum of adults lacks dark longitudinal lines  and has scales on the acrostichal and dorsocentral areas in addition to a few scales in patches on the lateral and/or anterior areas. The scutellum numerous scattered white, yellow or silver scales along the posterior border. The wings differ in having crossveins sc-r and r1-rs closer together (distance about 0.30 or less the length of the sector dark spot on the costa and radius-one), no spot of dark scales where the humeral crossvein intersects the radius, the subcosta terminates at the proximal end or the middle of the subcostal pale spot, vein R4+5 is narrowly pale-scaled apically with a corresponding isolated apical pale fringe spot, vein CuA is mostly pale-scaled or equally pale- and dark-scaled without a basal dark spot and the anal vein has three pale-scaled areas setting off two dark areas between the basal and an apical pale spot (a greater amount of dark scaling occurs in species of the Myzorhynchella Section). The gonocoxite, claspette and aedeagus of the male genitalia exhibit a number of distinctions. The gonocoxite has a subapical seta, two subequal accessory setae are inserted before mid-length (about 0.4 from base), the internal seta is as long but much weaker then the accessory setae, and the parabasal seta is shorter than the internal seta (about 0.6 its length). The ventral lobes of the claspette are fused to form a single structure, the dorsal lobes each bear a single group of two or three specialised setae, and the aedeagus is broad and not noticeably tapered (at least in the basal 0.8). Larvae exhibit differential and diagnostic features, which include, but are not limited to, seta 1-A branched and inserted dorsomesally, seta 2-C inserted anterior to seta 3-C, seta 4-C inserted posteromesal to seta 3-C, hypostomal suture well developed (but not reaching the posterior tentorial pit), presence of a sclerotised tubercle at the bases of setae 1,2-P, short seta 4-M (not more than half as long as seta 6-M), strongly plumose setae 8-M,T and 6,7-I,II, palmate or fanlike seta 3-T, multiply branched seta 2-I-IV, presence of seta 14-III, seta 2-IV inserted mesad to seta 4-IV, well developed seta 1-S (with multiple branches) and eight pairs of seta 4-X. Salient features of Nyssorhynchus pupae include a trumpet with a long pinna (more than half as long as the trumpet) and a meatal cleft, seta 9-I more than half the length of seta 6-I, well developed setae 1-I-VII and 5-V-VII (nearly as long or longer than the segment), seta 14-III present, seta 2 on segments IV and V inserted mesad of seta 3, seta 3-VI inserted mesad to or in line with seta 1-VI, seta 10-VI absent, and seta 1-Pa slender, similar to seta 2-Pa or sinuous and apically hooked. See genus Anopheles.

Phylogenetic relationships: 

Phylogenetic studies of anopheline mosquitoes based on both morphological and molecular data support for the monophyly of subgenus Nyssorhynchus and its sister relationship with subgenus Kerteszia (Krzywinski et al., 2001, 2001; Sallum et al., 2000, 2002; Collucci & Sallum, 2003; Harbach & Kitching, 2005). The analysis of morphological data by Harbach & Kitching (2005) indicated subgenus Cellia (Old World) is sister to Nyssorhynchus + Kerteszia. It is noteworthy, however, that a molecular phylogeny of 18 species constructed from aligned protein sequences of 1,085 single-copy orthologs indicates that the Nyssorhynchus lineage diverged prior to the lineages that gave rise to subgenera Anopheles and Cellia (Neafsey et al., 2015). Phylogenetic relationships among species of subgenus Nyssorhynchus based on nuclear and mitochondrial gene sequences were elucidated by Bourke et al. (2010). Similarly, relationships among five of the six species belonging to the Myzorhynchella Section of subgenus Nyssorhynchus were investigated by Bourke et al. (2011) based on the ITS2 region of rDNA and the nuclear white gene.

Bionomics and disease relations: 

The immature stages of Nyssorhynchus species occur in a variety of sunlit or partially shaded habitats, including ponds, lakes, swamps, stream and river margins, canals, ditches, flood land, ground pools, borrow pits, spring water, wheel ruts and animal tracks. The immature stages of An.  aquasalis mainly occur in brackish water habitats such as in mangrove swamps and coastal ground pools, and those of An. albimanus, in addition to ground pools and stream margins, have also been found in crab holes, tree holes and artificial containers. Females of most Nyssorhynchus species feed at dusk or during the night. They feed a variety of large mammals and infrequently on birds. Some species readily attach humans.

Anopheles albimanus, An. aquasalis, An. argyritarsis, An. darlingi, An. nuneztovari and An. oswaldoi s.l. are vectors of malarial protozoa. Anopheles albitarsis and An. aquasalis also transmit arboviruses, and some species also transmit Wuchereria bancrofti.

Distribution: 

Species of subgenus Nyssorhynchus are restricted to the Neotropical Region, except for An. albimanus, which extends into the Nearctic Region (northern Mexico and along the Rio Grande River in Texas, USA).

Principal references: 

Lane, 1953; Cova-Garcia, 1961 (Venezuela); Forattini, 1962; Faran, 1980 (Albimanus Section); Faran & Linthicum, 1981 (Amazonia); Clark-Gil & Darsie, 1983 (Guatemala); Linthicum, 1988 (Argyritarsis Section); Wilkerson & Strickman, 1990 (keys, Central America and Mexico); Peyton et al., 1992 (taxonomy); Bourke et al., 2011 (Myzorhynchella Section, phylogeny).

Species: 

albertoi Unti, 1941
albimanus Wiedemann, 1820
albitarsis Lynch Arribálzaga, 1878
anomalophyllus Komp, 1936
antunesi Galvão & Franco do Amaral, 1938
aquasalis Curry, 1932
argyritarsis Robineau-Desvoidy, 1827
arthuri Unti, 1941
atacamensis González & Sallum, 2010
benarrochi Gabaldon, Cova-Garcia & Lopez, 1941
braziliensis (Chagas, 1907)
darlingi Root, 1926
deaneorum Rosa-Freitas, 1989
dunhami Causey, 1945
evansae (Brèthes, 1926)
galvaoi Causey, Deane & Deane, 1943
goeldii Rozeboom & Gabaldon, 1941
guarani Shannon, 1928
halophylus Silva do Nascimento & Lourenço-de-Oliveira, 2002
ininii Senevet & Abonnenc, 1938
janconnae Wilkerson & Sallum, 2009
konderi Galvão & Damasceno,1942
lanei Galvão & Franco do Amaral, 1938
lutzii Cruz, 1901
marajoara Galvão & Damasceno, 1942
nigritarsis (Chagas, 1907)
nuneztovari Gabaldon, 1940
oryzalimnetes Wilkerson & Motoki, 2009
oswaldoi (Peryassú, 1922)
parvus (Chagas, 1907)
pictipennis (Philippi, 1865)
pristinus Nagaki & Sallum, 2010 
rangeli Gabaldon, Cova-Garcia & Lopez, 1940
rondoni (Neiva & Pinto, 1922)
sanctielii Senevet & Abonnenc, 1938
sawyeri Causey, Deane, Deane & Sampaio, 1943
strodei Root, 1926 triannulatus (Neiva & Pinto, 1922)
trinkae Faran, 1979

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith