Redescription of Anopheles (Anopheles) shannoni Davis; a member of the Arribalzagia series from the Amazon Basin (Diptera: Culicidae)

11 Pages·1997·4.8 MB·

by  R C Wilkerson

PROC. ENTOMOL. SOC. WASH.
99(3), 1997, pp. 461-471
REDESCRIPTION OF ANOPHELES (ANOPHELES) SHANNONI DAVIS;
A MEMBER OF THE ARRIBALZAGIA SERIES FROM THE
AMAZON BASIN (DIPTERA: CULICIDAE)
Richard C. Wilkerson, Maria Anice M. Sallum, and Oswaldo Paulo Forattini
(RCW) Department of Entomology, Walter Reed Army Institute of Research % Mu-
seum Support Center, Smithsonian Institution, Washington, D.C. 20560, U.S.A.; (MAMS,
OPF) Departamento de Epidemiologia, Faculdade de Saiide Publica, NUPTEM, Univer-
sidade de Sao Paulo, Av. Dr Amaldo, 715, CEP 01246-904, Sao Paulo, S.P, Brazil.
—
Abstract. Anopheles (Anopheles) shannoni Davis is redescribed and illustrated in the
adult female, male genitalia, and larval and pupal stages. This species is distributed
throughout the Amazon Basin of South America. The larvae are found in shaded forest
pools, and the adults appear to be zoophilic and prefer to bite outdoors. This species is a
member of the Neotropical Arribalzagia Series.
Key Words: Diptera, Culicidae, Arribalzagia, Anopheles shannoni, redescription, Ama-
zon Basin
Anopheles {Anopheles) shannoniDavis is Anopheles {Anopheles) shannoni Davis
a member of the Arribalzagia Series (Reid
Davis 1931: 345 (female* [wing, hind-
and Knight 1961). Wilkerson and Peyton
leg]). State ofPara, Brazil. Holotype female
(1990) implied that the approximately 23 (National Museum of Natural History,
species in this Neotropical group are mono-
Washington, DC).
phyletic based on shared wing spot char- —
acters. Except for An. vestitipennis Dyar broFwenmatloeda(rFkigb.row1n)., grIanytiesghubmrenotwn ppaolle-
and Knab (Belkin et al. 1970), An. male- linose. Head: Interocular space with 6-9 {n
factor Dyar and Knab, An. pimctimacula
Dyar and Knab (Wilkerson 1990) and An. = 10 for this and following measurements
and counts except where indicated) long,
calderoni Wilkerson (Wilkerson 1991),
white setae and row of small, narrow, ap-
these species are not adequately described.
pressed pale yellow scales; vertex, occiput
This redescription is part of an incremental
and upper portion of postgena with numer-
effort to characterize the species in the
group. In the following redescription Har- ous erect, truncate scales; a patch ofgrayish
bach and Knight (1980, 1982) were used white to pale yellow scales on dorsal area
for morphological terminology and num- ofvertex, nearly concolorous with scales on
bering of larval and pupal setae and, Wilk- median area ofanteriorpromontory, a patch
erson and Peyton (1990) for wing spot no- ofdark scales laterally on head concolorous
menclature. Generic and subgeneric abbre- with scales on lateral area ofanterior prom-
viations follow Reinert (1975). An asterisk ontory and upper antepronotum; head with
in a taxonomic citation indicates illustration 15-23 long, black ocular setae; postgena
of a given developmental stage. The spe- with long black setae ventrally. Clypeus
cific feature(s) illustrated follows in brack- bare. Pedicel of antenna with 4-10 small,
ets. dorsolateral, narrow to broad, grayish white
462 PROCEEDINGS OFTHE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Fig. 1. Anopheles shannoni. Adult female habitus.
VOLUME 99, NUMBER 3 463
spatulate scales; flagellomere 1 with nu- sokatepistemum with 3-6 setae, rarely with
merous narrow to broad, dark spatulate 1 narrow scale; lower mesokatepistemum
scales. Scales of maxillary palpus slender with 2-5 setae, 7-9 scales; upper mesepi-
and spatulate, mostly dark brown with in- meron with 6-14 setae, 0-4 scales. Legs as
termixed dark brown setae; scales on pal- figured, scales dark brown and white or
pomeres 2-4 erect; pale yellow scales pres- pale yellow, scales and setae at apices of
ent on the bases of palpomeres 3, 4 and 5; fore- and hindtibiae yellow. Distribution of
mm
length of maxillary palpus 1.99-2.61 scales on coxae and trochanters as figured.
(mean 2.27 mm); ratio oflength ofpalpom- Extent and number of pale spots on femora
eres 2-5 to total length ofpalpus, 2 = 0.26- and tibiae variable. Bases and apices of
0.35 (mean 0.31), 3 = 0.32-0.37 (mean femora pale; mid- and hindfemora with
0.35), 4 = 0.17-0.22 (mean 0.20), 5 = ventral pale stripes, stripe on hindfemurdis-
0.12-0.17 (mean 0.15); ratio of palpomere tinct and with well demarcated borders;
4 to 5, 1.10-1.65 (mean 1.35); palpus 1.01- fore- and midtibiae with ventral longitudi-
1.25 (mean 1.12) forefemur length. Probos- nal stripe of yellow scales, anterior, poste-
cis with dark brown setae and decumbent rior and dorsal surfaces with yellow spots,
dark brown scales, base with longer erect hindtibia with an anteriorlongitudinal stripe
scales and setae; proboscis length 2.21-2.81 of yellow scales and an indistinct stripe of
mm (mean 2.50 mm), proboscis 1.03-1.16 pale yellow scales on posterior surface, ba-
(mean 1.10) palpus length. Thorax: Integ- sal portion with spots of yellow scales;
ument brown to dark brown, silvery polli- foretarsomere 1 with a ventral stripe ofpale
nose. Scutum with 3 prominent dark brown scales, apex of foretarsomeres 1-5 with
spots, 2 at the ends ofand slightly posterior pale spots, more evident on anterior sur-
to prescutal sutures and another in prescu- face, 5 sometimes totally pale, midtarso-
tellar area continuing onto scutellum, some- mere 1 with indistinct pale stripe on ventral
times 2 smaller spots at the ends of lateral surface, apex of tarsomeres 1-5 with pale
portions of prescutellar area. Scutal setae spots, these more evident anteriorly, ante-
numerous, pale yellow with golden reflec- rior surface of hindtarsomere 1 with an in-
tions; scutum mottled with small dark distinct longitudinal stripe of pale scales
brown spots mostly corresponding to setal and with a few spots of pale scales at base,
insertions in acrostichal and dorsocentral hindtarsomere 2 with intermixed pale
areas; median anterior promontory with scales, hindtarsomeres 1-5 with pale rings
mm
patch of long, narrow falcate white to pale at apices. Forefemur length 1.76-2.28
yellow scales; scutal fossa without scales (mean 2.03 mm), ratio of forefemur length
except anterior scutal fossa with patch of to proboscis length 1.16-1.29 (mean 1.23).
broad, spatulate dark brown erect scales, Wing (Table 1). Length (measured from hu-
mm
sometimes with a few intermixed pale meral crossvein) 3.47-4.52 (mean 3.93
scales; supraalar area with spatulate, elon- mm). Dark scales brown to black, pale
gate, narrow falcate, pale yellow scales. scales nearly white. Basal pale spot usually
Scutellum with 11-23 shorter and 14-20 present; prehumeral pale spot absent; sub-
long, pale yellow setae. Antepronotum with costa basad ofhumeral crossvein with patch
20-43 yellowish to dark brown setae and of dark scales ventrally, sometimes also
10-20 upper, dark spatulate scales. Pleural with a few white scales; humeral crossvein
vestiture as follows, with all scales white or dark-scaled dorsally and ventrally; acces-
pale yellowish white and spatulate: upper sory sector dark spot present; often 2 pre-
proepistemum with 3-6 setae, rarely with 1 and 2 postsubcostal pale spots and 1 pre-
narrow scale; prespiracular area with 6-13 and 1 postsubcostal dark spot, less often a
setae, a single scale sometimes present; presubcostal and/or a postsubcostal pale
prealar area with 10-24 setae; upper me- spot and/or a postsubcostal dark spot ab-
'
464 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Table L Anopheles shannoni: descriptive statistics
forratios ofcostal wing spot lengths to length ofwing
measured from the humeral crossvein (/; = 10 wings
from 10 individual females).
WingSpot
VOLUME NUMBER
99, 3 465
Fig. 2. Anopheles shummni. Pupa and male genitalia. GC—gonostylarclaw, Gs—gonostylus, Gc—goncox-
ite, CI—claspette, IX-Te—tergum IX, Ac—aedeagus, T—trumpet.
466 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Table 2. Pupal setal branching forAnopheles shannoni: range, mode ( ). Mostarebased on countsoftwenty
setae. In the case of equal modes, the highest is given. A range shown without a mode indicates that it was
indefinite. Seta 8-II was found in only one specimen.
VOLUME 99, NUMBER 3 467
Fig. 3. Anopheles shannoni. Larva.
468 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Table 3. Larval setal branching for Anopheles shcmnoni: range, mode (). Most based on counts of twenty
setae. In the case ofequal modes, the highest is given. A range shown without a mode indicates that the mode
was indefinite.
Seta
VOLUME 99, NUMBER 3 469
Table 3. Extended.
Abdominal Segments
VII VIII
2-5 (4)
470 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
peryassui and An. mattogrossensis have Fig. 2. J. B. Lima was responsible for the
neither. In many other respects An. shan- collection and rearing of specimens from
noni is quite similar to An. minor but An. Ilha de Marajo, Para, Brazil, that provided
shannoni has wide wing scales, the apical the stimulus for this work. E. L. Peyton fur-
halfofthe cercus is strongly constrictedand nished a critical review of an early version
there is no speckling on hindtarsomere 1. of the manuscript. Partially supported by
Anopheles minor has narrow wing scales, a Grant no. 95/7157-2 from the Fundacao de
rounded cercus and speckling on hindtar- Amparo a Pesquisa do Estado de Sao Paulo
somere 1. (FAPESP), Brazil
The male genitalia of An. shannoni has
the ninth tergal lobes short and triangular Literature Cited
while they are short to long but rounded in
Belkin, J. N., S. J. Heinemann, and W. A. Page. 1970.
the other three species. Anopheles shannoni Mosquito studies (Diptera, Culicidae). XXI. The
has 5-8 large subequal aedeagal leaflets Culicidae ofJamaica. Contributions ofthe Amer-
with one edge usually thinner and nearly ican Entomological Institute 6(1): 1-458.
transparent, and with small apical denticles. Causey, O. R., L. M. Deane, and M. P Deane. 1944.
An illustrated key to the eggs ofthirty species of
Anopheles minor and An. mattogrossensis
Brazilian anophelines, with several new descrip-
both have one pair of leaflets (An. minor tions. American Journal ofHygiene 39(1): 1-7.
also has several very small pairs) and An. Causey, O. R., L. M. Deane, and M. P. Deane. 1946.
peryassui has 4-5 pairs of uniformly scler- Studies on Brazilian anophelines from the north-
otized leaflets without denticles. Ofthe four east andAmazonregions. II. An illustratedkeyby
male genitalic characteristics forthe identification
species only An. shannoni has a single pri-
of thirty-four species of Anophelini from the
mary seta on the ventral lobe of the clas- northeast and Amazon regions of Brazil, with a
pette. note on dissection technique. AmericanJournalof
In the larval stage An. shannoni can be Hygiene Monographic Series 18: 21-31.
distinguished from other An. (Anopheles) Cerqueira, N. L. 1943. ListadosmosquitosdaBolivia
(Diptera, Culicidae). Memorias do Instituto Os-
by the following combination ofcharacters:
waldo Cruz 39: 15-36.
seta 2-A lanceolate with a fine apical fringe Correa, R. R. 1950. Alguns mformes sohreAnopheles
on one margin; seta 3-C with 18-24 (sic.) (Arribalzagia) intermedins (Chagas, 1908),
branches; seta 1-P short with 2-5 branches; (Diptera,Culicidae). Arquivosde HigieneeSaude
setae 9-12-P single; seta 6-IV,V 2-3 Publica 24(39-42): 79-89.
Davis, N. C. 1931. A new anopheline mosquito from
branched and; the pecten plate with alter- Para, Brazil. American Journal of Hygiene 8:
nating short and long teeth. 345-348.
In the pupal stage. An. shannoni can be Deane, L. M., O. R. Causey, and M. P. Deane. 1946a.
easily recognized by setae 1-III-VII and Studies on Brazilian anophelines from the north-
5-IV-VII which have bases surrounded by east and Amazon regions. I. An illustrated key by
adult female characteristics for the identification
spinelike projections. Also, the trumpet has
ofthirty-five species ofAnophelini, with noteson
a slender, fingerlike tragus, the secondary the malariavectors(Diptera,Culicidae).American
cleft is absent and the paddle is strongly Journal ofHygiene Monographic Series 18: 1-20.
pigmented on the basolateral half. Deane, M. P., O. R. Causey, and L. M. Deane. 1946b.
The egg is unusual in having numerous Studies on Brazilian anophelines from the north-
frills (Causey et al. 1944, Lounibos et al. in ebaystlaarnvdalAcmhaarzaoctnerriesgtiiocsns.forIIIt.heAnidielnltuisftircaatteidonkeoyf
press), similar to An. peryassui Dyar and thirty-two species ofAnophelini with descriptions
Knab (Causey et al. 1944, Linley and Loun- oftwo larvae. AmericanJournalofHygieneMon-
ibos 1994). ographic Series 18: 35-50.
Deane, L. M., O. R. Causey, and M. P Deane. 1948.
Acknowledgments Notas sobre a distribuigao e a biologia dos ano-
felinos das regioes nordestina e amazonica do
We thank T. R. Litwak for Figs. 1 and 3 Brasil. RevistadoServigoEspecial deSaudePub-
and E. Roberts for the pupal drawings on lica 1(4): 828-965.