Subgenus Grabhamia Theobald, 1903

Type species: 

Psorophora jamaicensis (Theobald, 1901); original combination: Culex jamaicensis.

Classification: 

Subfamily Culicinae, genus Psorophora. Subgenus Grabhamia includes16 species. Subgenus abbreviation – Gra.

Characteristics: 

Species of subgenus Grabhamia are characterised and distinguished from species of subgenera Janthinosoma and Psorophora by the following combinations of characters. Characters that diagnose Grabhamia in the phylogenetic analyses of Reinert et al. (2009), based on features observed in Ps. columbiae and Ps. jamaicensis, are indicated by an asterisk (*).

ADULTS – Small to medium-sized mosquitoes; *interocular space with 6 or more setae; proboscis of females with *ring or ventral patch of pale scales; areas between acrostichal and dorsocentral setae and between supraalar and prescutellar setae with scales; wing with mixture of dark and pale scales, *alula without marginal scales; hindfemur with narrow subapical pale band (*femora of all legs with complex subapical pale band), tibiae with speckling or spots of pale scales, at least tarsomeres 1 and 2 of all legs with basal pale markings (*hindtarsomere 1 with one or more median pale bands). MALE GENITALIA – Claspette without foliform setae, *columnar stem ≤ 0.85 length of aedeagus; aedeagus conical or cylindrical, without lateral spine. LARVAE – Head and lateral palatal brushes normal, antenna short, distinctly shorter than head capsule, no more than 0.8 as long; siphon strongly inflated, pecten usually with fewer than 20 spines. PUPAE – Trumpet relatively short; seta 10-CT and seta 5-II usually with more than 5 branches, 5-II inserted anterior to seta 3-II; caudolateral angle of abdominal tergum IV without spines; paddles without contrasting pigmentation near external buttress and apex. See genus Psorophora.

Phylogenetic relationships: 

Subgenus Grabhamia was recovered as the sister of subgenera Janthinosoma + Psorophora in the preferred phylogeny of Reinert et al. (2009) based on extensive morphological data for the genera and subgenera of Aedini. The monophyly of Grabhamia was strongly supported in the phylogenetic study of Liria & Navarro (2014) based on 66 morphological characters from the adult, larval and pupal stages analysed under equal weighting. However, relationships within the subgenus were poorly resolved in their strict consensus tree of 11 most parsimonious trees. Grabhamia was recovered with rather weak support as the sister of subgenus Psorophora in the maximum likelihood phylogeny of Soghigian et al. (2017) based on seven molecular markers, and the pair was strongly supported as the sister to subgenus Janthinosoma.

Bionomics and disease relations: 

The immature stages of species of subgenus Grabhamia are found primarily in open, sunlit groundwater habitats. Females of several species readily feed on humans.

Venezuelan equine encephalitis virus is transmitted by Ps. confinnis. Cache Valley, Tensaw and Venezuelan Equine encephalitis and West Nile viruses have also been isolated from this species. Females of Ps. cingulata have tested positive for Cache Valley virus.

Distribution: 

Subgenus Grabhamia is widespread in the New World, from approximately 51º N in southern Canada to northern Argentina and Uruguay in South America (there are currently no records from Chile).

Principal references: 

Lane, 1953 (Neotropical Region, bionomics, keys, taxonomy, distributions); Forattini, 1965 (Neotropical Region); Cova-García et al., 1966 (Venezuela); Belkin et al., 1970 (Jamaica, keys, taxonomy, bionomics, distributions); Wood et al., 1979 (Canada, keys, taxonomy, biology, distribution); Darsie & Ward, 1981, 2005 (North America, keys); Clark-Gil & Darsie, 1983 (Guatemala, keys); Darsie, 1985 (Argentina, keys); Reinert, 2000 (female genitalia); Reinert et al., 2004, 2006, 2008, 2009 (morphology, phylogeny); Liria & Navarro, 2014 (morphology, phylogenetic relationships); Soghigian et al., 2017 (phylogenetic relationships).

Species: 

cingulata (Fabricius, 1805)
columbiae (Dyar & Knab, 1906)
confinnis (Lynch Arribálzaga, 1891)
dimidiata Cerqueira, 1943
discolor (Coquillett, 1903)
funiculus Dyar, 1920
infinis (Dyar & Knab, 1906)
insularius (Dyar & Knab, 1906)
jamaicensis (Theobald, 1901)
leucocnemis Martini, 1931
paulli Paterson & Shannon, 1927
pygmaea (Theobald, 1903)
santamarinai Broche, 2000
signipennis (Coquillett, 1904)
toltecum (Dyar & Knab, 1906)
varinervis Edwards, 1922

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