the material studied herein is deposited in the entomological collection of oswaldo 
 cruz institute ( ceioc ) , oswaldo cruz foundation , rio de janeiro , brazil . the type 
 specimens of t. b. macromelasoma and t. melanica 
 have been lost ; therefore , these specimens were identified based on the literature 
 and on comparisons with previously determined material deposited in the ceioc , 
 including the holotypes of t. juazeirensis ( costa & felix 2007 ) and t. brasiliensis 
 ( gonalves et al . 1993 ) . the redescription of t. b. macromelasoma is based on two specimens 
 from its type locality ( municipality of petrolina , pe ) , as well as 15 males and 15 
 females from an f1 colony reared from insects collected in this locality . the manner of description and morphological terminology mainly follow the style of 
 lent and wygodzinsky ( 1979 ) . t. b. macromelasoma galvo , 1956 , revalidated fig . 1 
 
 t. b. macromelasoma 
 galvo ( 1956 ) t. brasiliensis 
 lent and wygodzinsky ( 1979 ) 
 length : males 19.4 - 24.3 mm , females 21.5 - 25.5 mm ; width of pronotum 
 ( posterior lobe ) : males 3.9 - 5.4 mm , females 4.4 - 5.3 mm ; width of abdomen : males 
 6.0 - 7.6 mm , females 6.6 - 9.1 mm . tablemeasurements ( in mm ) of triatoma brasiliensis macromelasoma based on 
 15 males and 15 females from a f1 colony reared from insects collected 
 in the type locality ( municipality of petrolina , state of pernambuco , 
 brazil)gender malefemalevariables  minmaxxs 
 sd  minmaxxs 
 sdtotal length19.424.321.171.5731.25421.525.523.040.9370.968length of head3.74.74.190.0010.0274.14.84.400.0000.018width of head1.92.42.090.0000.0122.02.32.130.0000.008synthlipsis1.01.21.070.0000.0071.11.31.150.0000.007width of eyes0.50.60.500.0000.0030.50.60.510.0000.003length of 1st antennal 
 segment0.71.00.820.0000.0070.81.00.930.0000.007length of 2nd antennal 
 segment3.44.03.700.0000.0213.44.33.780.0010.023length of 3rd antennal 
 segment2.32.82.520.0000.0142.42.92.610.0000.017length of 4th antennal 
 segment1.82.11.950.0000.0132.02.42.140.0000.011length of 1st rostral 
 segment0.91.10.980.0000.0061.01.11.040.0000.005length of 2nd rostral 
 segment2.12.42.240.0000.0102.22.52.280.0000.009length of 3rd rostral 
 segment1.01.21.150.0000.0061.11.41.200.0000.006length of pronotum2.83.93.160.0010.0303.13.93.340.0000.022anterior width of 
 pronotum2.43.12.660.0000.0202.63.22.830.0000.016posterior width of 
 pronotum3.95.44.390.0010.0374.45.34.690.0010.027width of abdomen6.07.66.690.0030.0526.69.17.440.0040.062max ; maxima ; min : minimum ; sd : standard deviation ; s   : 
 variance ; x : average . max ; maxima ; min : minimum ; sd : standard deviation ; s   : 
 variance ; x : average . figs 1 - 5:the five members of the triatoma brasiliensis species complex , dorsal 
 habitus . 1 : triatoma brasiliensis macromelasoma , male ; 2 : triatoma 
 brasiliensis brasiliensis , female ; 3 : triatoma juazeirensis , male ; 4 : 
 triatoma melanica , male ; 5 : triatoma sherlocki , female . bars = 5 
 mm . twice as long as wide across the eyes ( males 
 1:0.35 - 0.42 ; females 1:0.35 - 0.41 ) and distinctly longer than the pronotum ( males 
 1:0.70 - 0.86 ; females 1:0.72 - 0.89 ) . genae tapering distally , but with apex narrowly rounded , not pointed , slightly 
 projecting beyond the level of the apex of clypeus . eyes , in lateral view , approaching , but not attaining the level of the under surface 
 and remote from the level of the upper surface of the head . ratio width of eye to 
 synthlipsis 1:2.00 - 2.30 ( males ) and 1:1.91 - 2.67 ( females ) . first antennal segment 
 attaining the level of the apex of clypeus ; second segment subcylindrical , beset 
 with declivous setae shorter than diameter of the segment . ratio of antennal 
 segments 1:4.0 - 5.3:2.4 - 3.8:2.0 - 2.8 ( males ) and 1:3.4 - 4.5:2.4 - 3.2:2.0 - 2.8 ( females ) . rostrum thick , as dark as the head capsule , with medium - sized hairs on the first and 
 on the underside of the second segment , with long and very numerous hairs on the 
 upper surface of the second and on the entire third segment ; hairs especially dense 
 dorsally at the junction of the second and third segments . first rostral segment 
 extending to the level of the apex of antenniferous tubercles , second one to the 
 level of the apex of the middle of the eyes . ratio of rostral segments 
 1:1.9 - 2.7:1.1 - 1.4 ( males ) and 1:2.1 - 2.3:1.1 - 1.3 ( females ) . posterior lobe with submedian carinae evanescent 
 on posterior fourth ; 1 + 1 narrow brownish - yellow stripes on carinae broadening 
 posteriorly , not attaining pronotal apex . scutellum : black , posterior process with small yellow or brownish - yellow point on 
 apex . posterior process as long as the main body of the scutellum , subcylindrical , but 
 slightly compressed laterally ; apex slightly elevated , rounded . hemelytra : extending to variable levels from the base to the apex 
 of the seventh urotergite . corium light yellow , with dark areas of variable 
 extension , mainly in veins cu , m - cu and r+m , attaining sc . membrane fumose , yellowish - brown , as light as light - coloured areas of corium . veins 
 of membrane black ; lumen of cells with a more or less extensive , irregularly shaped 
 sooty spot extending over the central portion , mainly extending to the cu and pcu 
 veins . legs : dark , with light markings on the trochantera ; incomplete 
 brownish - yellow ring on the apical half of the femora and the subapical portion of 
 the tibiae . fore and mid 
 femora salient below subapically or with one or two weak denticles . males with 
 spongy fossulae on tibiae of fore and mid legs ; absent in females . abdomen : slightly flattened below in both sexes , delicately striate 
 transversally , sparsely setose . connexival segments presenting a black spot on 
 anterior region , posterior edge rounded , followed by a larger light yellow spot ; 
 wide black spot enclosing intersegmental sutures . male genitalia : as described by lent and jurberg ( 1978 ) { according to costa et al . ( 1997a ) , individual variations in the male genitalia of 
 t. brasiliensis and the other members of the complex are not 
 correlated with their different and stable chromatic forms . therefore , the genital 
 structures are not useful for distinguishing t. b. 
 macromelasoma.}. 
 material examined - t. b. macromelasoma - pe : two 
 males , petrolina , ceioc ; 15 males , 15 females , f1 colony reared from insects from 
 petrolina , ceioc . t. b. brasiliensis - rn : one female ( holotype ) , 
 caic , ceioc ; state of cear : five males , five females , jaguaru - ana , ceioc . t. juazeirensis - ba : one female ( holotype ) , three males 
 ( paratypes ) , two females ( paratypes ) , juazeiro , ceioc ; seven males , 12 females , 
 juazeiro , ceioc . t. melanica - mg : three males , three females , 
 espinosa , ceioc . t. sherlocki - ba : one male , one female , gentio do 
 ouro , ceioc . brachypterous specimens , hemelytra not extending posteriorly beyond the 
 posterior margin of urotergite vi ; legs unusually long ; ground colour dark 
 brown to black , connexivum and femora with orange to red marks 
 ....................................... t. sherlocki ( fig . macropterous specimens , hemelytra extending posteriorly at least as far 
 as urotergite vii ; legs normally long ; ground colour brown , hemelytra and 
 connexivum with brownish - yellow marks 
 ............................................ 2 2a . pronotum and scutellum dark brown to black , rarely with few inconspicuous 
 brownish - yellow marks ; femora entirely dark brown to black , without 
 brownish - yellow rings .......................... t. 
 juazeirensis ( fig . pronotum with 1 + 1 elongate or subtriangular broad areas or narrow 
 stripes , brownish - yellow ; scutellum with apex of posterior process 
 brownish - yellow ; femora with complete or incomplete brownish - yellow rings 
 ....................................................................................... 
 3 3a . pronotum with 1 + 1 narrow brownish - yellow stripes ; membrane of hemelytra 
 with lumen of cells partially darkened ......... t. b. 
 macromelasoma ( fig . 1 ) 
 ( pe )   3b . pronotum with 1 + 1 broad , elongated brownish - yellow areas ; membrane of 
 hemelytra with lumen of cells entirely or not darkened pronotum with 1 + 1 brownish - yellow areas extending from posterior portion 
 of anterior lobe to posterior lobe ; femora with broad brownish - yellow rings ; 
 membrane of hemelytra with lumen of cells not darkened ; males with spongy 
 fossulae on fore and mid tibiae .......................... t. b. 
 brasiliensis ( fig . 2 ) 
 ( northeast region of brazil , state of gois and federal district )   4b . pronotum with 1 + 1 brownish - yellow areas only on posterior lobe ; femora 
 with narrow brownish - yellow rings ; membrane of hemelytra with lumen of cells 
 entirely darkened ; males with spongy fossulae only on fore tibiae 
 ........................... t. melanica ( fig . triatoma b. brasiliensis and t. b. macromelasoma 
 are the most closely related forms among all members of the t. 
 brasiliensis complex . this was determined from an isoenzymatic analysis 
 with nine loci conducted to calculate the values of nei 's genetic distance ( nei 1987 , costa 
 et al . 1997b ) and the sequences of the mtdna cytochrome 
 b gene and by applying phylogeographic approaches among 136 
 specimens representing 16 populations ( monteiro et 
 al . the latter analysis revealed the existence of three discrete 
 lineages : brasiliensis+macromelasoma , 
 juazeiro ( t. juazeirensis ) and 
 melanica . these clades are separated from each other by more 
 than nine mutational steps , which is the 95% confidence interval for the statistical 
 parsimony process . despite this close relationship , the phylogenetic an - alyses showed that t. b. 
 brasiliensis and t. b. macromelasoma have significant 
 genetic differentiation , indicating their status as subspecies ( monteiro et al . ( 2009 ) used geometric morphometric 
 techniques to compare the shape of the wings of the t. brasiliensis 
 complex members . these authors proposed that t. b. macromelasoma 
 could have originated by homoploid hybrid speciation ( greig et al . 2006 , mallet 2007 ) via ancient contact between the 
 neighbouring species t. brasiliensis and t. 
 juazeirensis and the hybridisation of the putative parental forms most 
 likely occurred in the area of pe . furthermore , the geometric morphometric analysis 
 showed that t. b. macromelasoma is closely related to t. b. 
 brasiliensis and is distinct from all other members of the t. 
 brasiliensis complex ( costa et al . the mahalanobis distances were calculated for all members of the 
 complex based on the shape ( conformation ) of the wings and these were convergent 
 with the values of the matrices of genetic distances obtained either by isoenzyme 
 analyses or mtdna sequences ( costa et al . in addition , despite all morphological , biological , genetic and 
 ecological differences recorded among the members of the complex , they are all able 
 to produce viable hybrids under laboratory conditions ( costa et al . however , no evidence of natural crosses was observed between 
 the members of the complex , except for t. b. brasiliensis and 
 t. b. macromelasoma . these multidisciplinary analyses revealed that t. b. macromelasoma 
 has ( i ) a stable , homogeneous and differentiated colour pattern that is easily 
 distinguished from those of the other members of the complex ( costa et al . 1997a , 2009 ) , ( ii ) a distinct egg shape and 
 exochorion ornamentation ( costa et al . 1997a ) 
 and ( iii ) a distinct geographic distribution , as it is found only in areas of pe 
 ( costa et al . , 
 the revalidation of t. b. macromelasoma as a subspecies agrees with 
 the results of several independent taxonomic analyses , showing the closest 
 relationship between this taxon and t. b. brasiliensis when 
 compared to the other members of the complex . morphologically , t. b. macromelasoma can be distinguished from all 
 members of the t. brasiliensis species complex by the following 
 combination of features : ( i ) pronotum with 1 + 1 narrow brownish - yellow stripes on the 
 submedian carinae , not attaining its apex , ( ii ) hemelytra with darkened membrane 
 cells on the central portion and ( iii ) legs with an incomplete brownish - yellow ring 
 on the apical half of the femora . the yellow marks on the pronotum are the more 
 consistent feature that differentiates the members of the complex ( lent & wygodzinsky 1979 , costa 1997 ) . as expected , the females of 
 t. b. macromelasoma tend to be slightly larger than the males , 
 a pattern commonly observed in triatomines ( lent 
 & wygodzinsky 1979 ) and , more specifically , in other members of the 
 t. brasiliensis complex ( costa 
 et al . a definition of the taxonomic status of the t. brasili - ensis complex 
 members is important for epidemiological studies and control measures ( costa & felix 2007 ) and correct 
 morphological identification is equally important . thus , the present key , which 
 includes all members of the complex , can be considered a fundamental tool for the 
 identification of specimens , especially in fieldwork .
triatoma brasiliensis macromelasoma is revalidated based on the 
 results of previous multidisciplinary studies on the triatoma 
 brasiliensis complex , consisting of crossing experiments and 
 morphological , biological , ecological and molecular analyses . 
 these taxonomic 
 tools showed the closest relationship between t. b. 
 macromelasoma and triatoma brasiliensis 
 brasiliensis . 
 t. b. macromelasoma is redescribed 
 based on specimens collected in the type locality and specimens from a f1 
 colony . 
 the complex now comprises t. b. brasiliensis , 
 t. b. macromelasoma , triatoma melanica , 
 triatoma juazeirensis and triatoma 
 sherlocki . 
 an identification key for all members of the complex is 
 presented . 
 this detailed comparative study of the morphological features of 
 t. b. macromelasoma and the remaining members of the 
 complex corroborates results from multidisciplinary analyses , suggesting that 
 the subspecific status is applicable . 
 this subspecies can be distinguished by 
 the following combination of features : a pronotum with 1 + 1 narrow 
 brownish - yellow stripes on the submedian carinae , not attaining its apex , 
 hemelytra with membrane cells darkened on the central portion and legs with an 
 incomplete brownish - yellow ring on the apical half of the femora . because the 
 t. brasiliensis complex is of distinct epidemiological 
 importance throughout its geographic distribution , a precise identification of 
 its five members is important for monitoring and controlling actions against 
 chagas disease transmission .