scieee Open visual document viewer

Morphological characterisation of three isolates of Heterorhabditis Poinar, 1976 from the "Irish group" (Nematoda: Rhabditida: Heterorhabditidae)and additional evidence supporting their recognition as a distinct species, H. downesi n. sp

Stock, Patricia,Griffin, Christine,Burnell, Ann

Abstract

The morphological variation of three representative isolates of the "Irish group" of Heterorhabditis was examined. First generation hermaphrodites were characterised by having a blunt and mucronate tail. Females (second generation) and third-stage infective juveniles were also distinguished by the morphology of the tail and the presence of a refractile projection in the tail tip. Males were characterised by the position of the excretory pore and by the value of ratio SW. These morphological features do not fit the description of currently recognised Heterorhabditis species, and provide additional evidence in support for the consideration of the Irish group as a new species. A description of this species, as H. downesi n. sp., is provided.

Full text

Sys ema ic Pa asi ology 51: 95–106, 2002. © 2002 Kluwe Academic Publishe s. P in ed in he Ne he lands. 95 Mo phological cha ac e isa ion o h ee isola es o He e o habdi is Poina , 1976 om he ‘I ish g oup’ (Nema oda: Rhabdi ida: He e o habdi idae) and addi ional e idence suppo ing hei ecogni ion as a dis inc species, H. downesi n. sp. S. Pa icia S ock1∗, Ch is ine T. G i in2&AnnM.Bu nell 2 1Depa men o Nema ology, Uni e si y o Cali o nia Da is. One Shields A e., Da is, CA 95616-8668, USA 2Ins i u e o Bioenginee ing and Ag oecology, Depa men o Biology, Na ional Uni e si y o I eland, Maynoo h, Co. Kilda e, I eland ∗P esen add ess: Depa men o Plan Pa hology, Uni e si y o A izona, 1140 E. Sou h Campus D i e, Tucson, AZ 85721-0036, USA Accep ed o publica ion 19 h Ma ch, 2001 Abs ac The mo phological a ia ion o h ee ep esen a i e isola es o he ‘I ish g oup’ o He e o habdi is was examined. Fi s gene a ion he maph odi es we e cha ac e ised by ha ing a blun and muc ona e ail. Females (second gene - a ion) and hi d-s age in ec i e ju eniles we e also dis inguished by he mo phology o he ail and he p esence o a e ac ile p ojec ion in he ail ip. Males we e cha ac e ised by he posi ion o he exc e o y po e and by he alue o a io SW. These mo phological ea u es do no i he desc ip ion o cu en ly ecognised He e o habdi is species, and p o ide addi ional e idence in suppo o he conside a ion o he I ish g oup as a new species. A desc ip ion o his species, as H. downesi n. sp., is p o ided. In oduc ion En omopa hogenic nema odes o he amily He - e o habdi idae Poina , 1976 a e obliga e and le hal pa asi es o insec s. The only ee-li ing s age is he hi d-s age in ec i e ju enile (IJ), which is symbio - ically associa ed wi h en e ic bac e ia o he genus Pho o habdus Boema e e al., 1993. The IJs pene a e in o he haemocoel o he hos ei he om he gu o by ab ading he in e segmen al memb anes o he in- sec by using a do sal oo h. Once in he haemocoel o he insec , he IJs elease he bac e ial cells, which mul iply and diges he hos issues, he eby p o id- ing sui able nu ien condi ions o nema ode g ow h and de elopmen . The insec hos dies apidly, usually wi hin 2 days o he ini ial pene a ion o he nema- odes. The nema odes esume de elopmen , moul o he J4 s age and each adul hood wi hin h ee days (in H. bac e iopho a Poina , 1976) when cul u ed in i o in la ae o he g ea e wax mo h Galle ia mellonella a 23 ◦C (Wang & Bedding, 1996). Nema ode ep o- duc ion con inues o a leas wo gene a ions un il he nu ien s a us o he cada e de e io a es, whe eupon adul de elopmen is supp essed and IJs accumula e and eme ge in o he soil whe e hey may su i e o se e al mon hs in he absence o a sui able hos . He e o habdi ids a e e ec i e biological con ol agen s o se e al insec pes s (Be y e al., 1997; Ge - i sen e al., 1998; Shields e al., 1999; Long e al., 2000; Mannion e al., 2000). Thus, in e es in s udying hese nema odes has inc eased d ama ically in ecen yea s, no only o add ess aspec s ela ed o biological con ol, bu also ega ding basic esea ch a eas such as ecology, biodi e si y, e olu ion, biochemis y, sym- biosis and molecula gene ics ( e iew by Bu nell & S ock, 2000). The He e o habdi idae cu en ly comp ise one genus, He e o habdi is Poina , 1976, wi h nine ecog- nised species, H. bac e iopho a Poina , 1976 ( ype- species); H. megidis Poina , Jackson & Klein, 1987; H. zealandica Poina , 1990; H. indicus Poina , Ka unaka & Da id, 1992; H. a gen inensis S ock, 96 1993; H. hawaiiensis Ga dne , S ock & Kaya, 1994; H. b e icaudis Liu, 1994; H. ma ela us Liu & Be y, 1996 and H. poina i Kakulia & Mikaia, 1997. How- e e , he axonomic s a us o some o hese species is cu en ly being e iewed (S ock e al., unpublished). Su eys o he e o habdi ids, which ha e been conduc ed in many pa s o he wo ld, indica e ha hese nema odes ha e a global dis ibu ion (Hominick e al., 1996; G i in e al., 1999; S ock e al., 1999). S udies conduc ed in Eu ope indica e ha h ee He e o habdi is ypes a e p esen in his con inen , H. bac e iopho a, he no h-wes Eu opean (NWE) (conside ed o be H. megidis) and he ‘I ish g oup’ (Smi s e al., 1991; G i in e al., 1994). H. bac- e iopho a isola es ha e been eco e ed in Spain, sou he n F ance, I aly, cen al Ge many, Hunga y and Molda ia, sugges ing his species is dominan in sou he n and cen al Eu ope (Smi s e al., 1991; De Douce & Gaba a, 1994; G enie e al., 1996; G i in e al., 1999). NWE ype isola es ha e been epo ed om he Ne he lands, Poland, he sou h o England, Belgium, no he n Ge many, Denma k and Es onia, (Smi s e al., 1991; Hominick e al., 1995; Midu u i e al., 1996; G i in e al., 1999). I ish ype isola es we e o iginally eco e ed in I eland (G i in e al., 1991, 1994), bu we e subsequen ly epo ed in B i ain (G i in e al., 1994; Hominick e al., 1995), Hun- ga y and Denma k (G i in e al., 1999). Addi ionally, anewHe e o habdi is species, H. poina i, has been epo ed om Geo gia (Kakulia & Mikaia, 1997). Molecula e idence (RFLP p o iles and IEF p o- ein elec ophenog ams) s ongly indica es he I ish ype isola es ep esen a sepa a e species (Smi s e al., 1991; Joyce e al., 1994a, b). Mo eo e , c oss- hyb idisa ion es s ha e demons a ed ha he I ish ype isola es a e ep oduc i ely isola ed om o he He e o habdi is species (Dix e al., 1994; G i in e al., 1994; Joyce e al., 1994b). Likewise, a molecula phy- logene ic s udy, based on ITS-1 DNA sequence da a, by Adams e al. (1998) indica ed he I ish ype o He e o habdi is (isola e K122) was a dis inc species. In spi e o his cumula i e e idence, he axonomic s a us o he I ish g oup o He e o habdi is has no ye been implici ly se led. No s udies ha e been ca ied ou o desc ibe he mo phological a iabili y (i any) among hese isola es and hei di e ences o known He e o habdi is species. In his s udy we examined he mo phological a i- a ion o h ee ep esen a i e isola es o he I ish ype o He e o habdi is, p o iding addi ional e idence in suppo o hei conside a ion as a dis inc species. A desc ip ion o his new species is he ein p esen ed. Ma e ials and me hods Th ee isola es ep esen ing he I ish ype o He - e o habdi is we e selec ed o his s udy. One o hese isola es, K122, was he i s isola e eco e ed in his g oup; he e o e, i will be conside ed as he ype iso- la e. This isola e was eco e ed om g asslands in Wex o d, I eland (G i in e al., 1991, 1994). The e- maining isola es s udied a e om con inen al Eu ope. Isola e EU94 was collec ed om an open coni e ous o es wi h g ound oak, oses and g ass in Ho nbaek, Denma k (G i in e al., 1999), and isola e EU349 was collec ed om a oadside e ge wi h ees in Kesckeme , Hunga y (G i in e al., 1999). All isola es we e p opaga ed in i o wi h las in- s a la ae o Galle ia mellonella a 22 ±3◦C. Insec cada e s we e dissec ed on days 3-5 o eco e i s gene a ion he maph odi es and on days 7-9 o eco e second gene a ion adul s, ollowing Kaya & S ock (1997). Thi d-s age in ec i e ju eniles we e ha es ed du ing he i s 2 days a e ini ial eme gence (app ox- ima ely days 13-18) om he cada e , as sugges ed by Nguyen & Sma (1996). Fo each o he s udied isola es, 20 specimens om each s age ( i s -gene a ion he maph odi es, second- gene a ion males, second-gene a ion emales and hi d-s age in ec i e ju eniles) we e andomly col- lec ed om 10 G. mellonella cada e s (Hominick e al., 1997). Nema odes we e examined li e o hea - killed in 60 ◦C Ringe ’s solu ion. Nema odes we e ixed in ie hanolamine o malin (TAF) (Cou ney e al., 1955) and p ocessed o anhyd ous glyce ine o moun ing (Seinho s , 1959). Specimens we e moun ed on glass slides suppo ed wi h glass ods o a oid hei la ening. Obse a ions we e made om li e and moun ed specimens using a Nikon Eclipse E600 mi- c oscope equipped wi h di e en ial in e e ence con- as op ics. Specimen measu emen s we e made using Scion Image so wa e (F ede ick, Ma yland, USA) ha was calib a ed using a s age mic ome e . Selec- ion o mo phome ic cha ac e s was done acco ding o S ock & Kaya (1996) and S ock (1997). Illus a ions we e p epa ed om digi ised came a lucida images. The ollowing abb e ia ions ha e been used in he ex o ables: L = o al body leng h; ABW =anal o cloacal body wid h; EP =exc e o y po e posi ion; ES =oesophagus leng h; GS =GuL/SpL; GuL =gu- 97 be naculum leng h; MBW =maximum body wid h; ML =muc o leng h; NR =ne e- ing posi ion; a io a=L/MBW; a io b =L/ES; a io c =L/TL; a io d=EP/ES; a io e =EP/TL; SpL =spicule leng h (measu ed along he cu a u e in a line along he cen- e o he spicule); S L =s oma leng h; S W =s oma wid h; SW =SpL/ABW; TL = ail leng h (measu ed wi hou conside ing he ex a cu icula shea h o he second s age ju enile); TRL = es is e lexion leng h; V= ul a posi ion om an e io end exp essed as pe cen age o L. He e o habdi is downesi n. sp. Type-hos : Unknown. Nema odes eco e ed by soil bai ing echnique (Bedding & Akhu s , 1975). Type-locali y: G assland a Cu acloe, Co. Wex o d, I eland. This ype-locali y co esponds o he sampling si e whe e isola e K122 ( he ype-isola e) was eco - e ed (see G i in e al., 1994). Type-specimens: Holo ype, second gene a ion male (UCDNC 3816), allo ype second-gene a ion e- male (UCDNC 3817), 15 pa a ype he maph odi es (UCDNC 3818-3820), 15 males (UCDNC 3821- 3823), 15 hi d-s age in ec i e ju enile (UCDNC 3824-3826) deposi ed a he Uni e si y o Cali o nia Da is Nema ode Collec ion. Addi ional pa a ype ma- e ial (5 he maph odi es, 4 second-gene a ion males, 4 second-gene a ion emales and 5 hi d-s age in ec i e ju eniles deposi ed a CABI Bioscience Nema ode Collec ion, UK Cen e (Egham), UK. E ymology: This species is named o P o esso Ma - in J. Downes, a colleague and ac i e collabo a o in he isola ion o he I ish ype o He e o habdi is. Desc ip ion (Figu es 1-3) The ollowing desc ip ion is based on he examina ion o mo phological and mo phome ic ea u es o 3 He - e o habdi is isola es conside ed in his s udy. Adul s. Head unca ed o sligh ly ounded (Fig- u e 1A,F). Six dis inc p o uding poin ed lips su - ounding o al ape u e. Each lip bea s one labial papilla. Amphidial ape u es inconspicuous, po e-like. S oma sho , wide. Cheilos om sho wi h e ac ile habdions; gymnos om and s egos om educed (Fig- u e 2A). Oesophagus habdi oid. Co pus cylind ical; me aco pus no di e en ia ed. Is hmus sho . Basal bulb py i o m wi h educed al e. Ne e- ing loca ed in middle o is hmus. Exc e o y po e loca ed a le el o basal bulb (Figu e 1A). He maph odi e ( i s gene a ion). Wi h o o es is. Vul a loca ed nea middle o body. Vul al lips p o- uding, wi h an e io lip la ge han pos e io lip (Figu es 1B, 2B). Pos anal swelling well de eloped (Figu es 1C, 2C). Tail e minus blun and muc ona e (Figu es 1C, 2C). Female (second gene a ion). Amphidelphic. Vul a si - ua ed nea middle o body. Vul al lips sligh ly p o ud- ing (Figu es 1D, 2D). Tail conoid, na owing owa ds end in o e ac ile spike-like s uc u e (Figu es 1E, 2E). Pos anal swelling sligh ly de eloped (Figu e 1E). Male (second gene a ion). Mono chic. Tes is an e i- o ly e lexed. Spicules pai ed, symme ical, s aigh o a cua e, wi h poin ed ips (Figu es 1G, 2F,H). Manub ium (head) squa e, well se o om lamina. Calamus dis inc . Lamina wi h one in e nal ib. Velum absen . Gube naculum hin, abou hal size o spicules. Bu sa open, pelode an, a ended by complemen o 9 pai s o bu sal ays (papillae). A angemen o papillae isas ollows:12()33(Figu e1G).Pai s4and7 ben do sally. Pai 8 does no each im o bu sa (Fig- u e 2G). Thi d-s age in ec i e ju enile (IJ). Enshea hed in cu i- cle o second-s age ju enile (J2) (Figu e 3A). Cu icle o J2 wi h longi udinal idges h oughou mos o body leng h and essella e pa e n in mos an e io pa o body (seen wi h DIC ligh mic oscopy). Body slende , g adually ape ing pos e io ly. IJ wi h p ominen cu- icula do sal oo h (seen wi h DIC ligh mic oscopy) (Figu e 3B,C). Amphidial opening small, po e-like. Ne e- ing loca ed in middle o is hmus. Exc e o y po e loca ed pos e o o basal bulb (Figu e 1H). La - e al ield wi h 2 idges (as seen wi h DIC mic oscopy and con i med by c oss-sec ions) (Figu e 3D). Tail sho , conoid, ape ing o small spike-like ip (Fig- u es 1I-K, 3E-G). Mo phology o ail ip a iable, wi h mos cha ac e is ic shape (80% o examined IJs om 3 s udied isola es) shown in Figu es 1I,J, 3E,F. Dimensions Holo ype male (isola e K122): L =877 µm; MBW = 33 µm; S L =7µm; S W =4.5 µm; ES =100 µm; NR =62.5 µm; EP =90 µm; TL =32 µm; ABW =23 µm; TRL =131 µm; SpL =42 µm; GuL = 19 µm; GS =0.45; SW =1.8. 98 Figu e 1. He e o habdi is downesi n. sp. A. An e io end o he maph odi e; B. Vul a o he maph odi e; C. Tail o he maph odi e in la e al iew; D. Vul a o emale; E. Tail o emale in la e al iew; F. Male; en i e wo m; G. Male ail in la e al iew; H. An e io end o hi d-s age in ec i e ju enile; I-K. Tail o hi d-s age in ec i e ju enile. Scale-ba s:A,D-F,50µm; B,C,G,H, 25 µm; I-K, 18 µm 99 Figu e 2. Adul s ages o He e o habdi is downesi n. sp. A. An e io egion o i s gene a ion he maph odi e showing s oma egion; B. Tail o i s gene a ion he maph odi e showing muc o (a ow); C. Vul al lips o second gene a ion emale; D. Tail o male in la e al iew; E. Tail o male in en al iew showing a angemen o bu sal ays; F. Spicule. Scale:1cm=A, 8 µm; B, 2 µm; C, 8 µm; D-F, 1 µm. 100 Figu e 3. Thi d-s age in ec i e ju enile o He e o habdi is downesi n. sp. A-C. An e io end showing cu icula oo h (a ows); D. Cu icle showing la e al ield pa e n (l ); E-F. Tail showing mos ypical shape o he ‘spike-like’ ip (a ows). G. A ypical ail ip. Scale-ba s: A-C,E-G, 15 µm; D, 10 µm. 101 Table 1. Mo phome ic cha ac e s (in µm) o adul s o He e o habdi is downesi n. sp. Means and s anda d de ia ion a e gi en in pa en heses. Pa a ypes K122 EU94 EU349 H(1)M(2)F(3)H(1)M(2)F(3)H(1)M(2)F(3) (n =19) (n =19) (n =20) (n =20) (n =20) (n =20) (n =20) (n =20) (n =20) L 3,050-5,051 669-876 1,231-2,728 3,180-5,019 830-1,042 1,200-2,800 3,100-5,025 837-1,066 1,157-2,700 (4,362 ±266) (800 ±76) (1,747 ±387) (4,795 ±121) (936 ±79) (1,810 ±394) (4,510 ±298) (946 ±68) (1,837 ±464) MBW 183-291 33-40 74-131 185-284 37-55 74-129 195-255 33-46 73-119 (254 ±84) (36 ±3) (102 ±11) (231 ±29) (46 ±7) (104 ±13) (225 ±33) (39 ±4) (109 ±16) STL 11-15 6.5-8 8-13 12.5-15.5 6.5-9.7 8-13 11-14 6-10 8-13 (13.5±0.6) (7.5±0.5) (10 ±2) (13 ±1.5) (8 ±1) (10 ±1.5) (12.5±1.5) (8 ±1.3) (10 ±1) STW 7-10 3-4.5 3.5-9 9-11 3-5 3.5-9 7-9.5 3-5 3.5-9 (8.5±1.4) (4.2±0.5) (8.5±2) (8 ±1.5) (3.8±0.6) (6 ±1.5) (8.5±1) (4 ±1) (6 ±2) NR 172-230 62-78 117-151 169-208 82-103 121-151 165-225 63-75 117-149 (200 ±19) (70 ±7) (131 ±11) (187 ±10) (94 ±8) (130 ±9) 195 ±23 (69 ±3) (126 ±8) EP 200-254 86-91 99-126 197-271 66-78 98-135 198-275 73-92 98-124 (235 ±19) (89 ±2) (112 ±7) (236 ±17) (72 ±4.5) (112 ±10) (241 ±25) (84 ±5) (109 ±8) ES 230-244 97-106 111-155 218-244 75-94 113-153 225-251 90-107 113-150 (240 ±11) (101 ±3) (131 ±13) (230 ±13) (87 ±6) (130 ±10) (247 ±9) (96 ±4) (119 ±9) TRL – 108-181 – – 107-125 – – 103-179 – (150 ±22) (113 ±10) (146 ±26) TL 60-70 29-34 70-122 55-75 31-39 70-115 61-72 28-42 71-122 (65 ±3) (32 ±2) (89 ±18) (70 ±5) (33 ±3) (85 ±12) (68 ±7) (36 ±3) (86 ±15) ML 1.5-2.5 – 1.5-6 1.5-2.5 – 1.5-5 1.5-2 – 1.7-6.5 (2 ±0.2) (3 ±1.5) (2 ±0.2) (3 ±1) (1.8±0.3) (3 ±1.5) ABW 57-65 21-28 25-38 55-68 20-27 27-37 57-70 21-27 24-37 (62 ±2) (24 ±2) (33 ±3.5) (59 ±4) (24 ±2) (33 ±3) (65 ±5) (23 ±2) (32 ±4) V 50-55 – 47-60 51-55 – 47-56 51-55 – 47-55 (52 ±0.5) (51 ±4) (53 ±1) (52 ±3) (52 ±1) (51 ±3) SpL – 41-47 – – 40-51 – – 41-53 – (43 ±2) (44 ±4) (48 ±3) GuL – 17-19.5 – – 15-20 – – 13-23 – (18 ±1) (17 ±2) (18 ±3) GS – 0.36-0.47 – – 0.35-0.42 – – 0.28-0.45 (0.43 ±0.04) (0.39 ±0.02) (0.37 ±0.05) SW – 1.7-2.2 – – 1.7-2.3 – – 1.6-2.4 (1.8±0.2) (1.8±0.2) (2.1±0.2) (1)He maph odi e ( i s gene a ion). (2)Male (second gene a ion). (3)Female (second gene a ion). 102 Allo ype second-gene a ion emale (isola e K122): L =1,500 µm; MBW =102 µm; S L =9µm; S W = 4µm; ES =128 µm; NR =110 µm; EP =131 µm; TL =76 µm; ML =4µm; ABW =29 µm; AE-V = 712 µm; V =47.5. Pa a ypes (he maph odi es, males and emales, and hi d-s age in ec i e ju enile): See Tables 1 and 2. Diagnosis and ela ionships He e o habdi is downesi n. sp. can be sepa a ed om o he species in he genus by a combina ion o mo - phological and mo phome ic ai s o all li e s ages (Tables 3, 4). He maph odi es o H. downesi n. sp. can be dis inguished om all cu en ly ecognised He - e o habdi is species by ha ing a blun and muc ona e ail. Males o he new species can be sepa a ed om o he He e o habdi is species by ha ing he na owes body wid h. Addi ionally, males o his species a e cha ac e ised by he posi ion o he exc e o y po e, which is mo e an e io ly loca ed han o he desc ibed He e o habdi is species. The spicules o H. downesi n. sp. esemble hose o H. ma ela us and H. megidis in ha ing a squa e-shaped manub ium (head), which is well se o om he lamina by a hin calamus (neck), bu can be sepa a ed om hese species by he alue o a io SW (mean: 1.8) (Table 3). The ail o he emales (second gene a ion) o H. downesi n. sp. esembles ha o H. ma ela us. Howe e , emales o he new species can be dis in- guished by he p esence o a conspicuous e ac ile muc ona ed p ocess. The body leng h o hi d-s age in- ec i e ju eniles o H. downesi n. sp. (mean: 637 µm) is p ac ically indis inguishable om H. a gen inensis (657 µm) and H. ma ela us (640 µm). The a e age ail leng h o H. downesi n. sp. (68 µm ) is simila o ha o H. ma ela us (65 µm). H. b e icaudis is also cha ac e ised by ha ing a sho ail (75.5 µm). Howe e , compa isons be ween he new species and H. b e icaudis a e di icul because he o iginal de- sc ip ion does no p o ide de ails o how he ail leng h o he hi d-s age in ec i e ju eniles was measu ed (i.e. conside ing o no he ex a cu icula shea h om he second-s age ju enile). Bu he in ec i e ju eniles o he new species can be dis inguished om hese and he es o he ecognised He e o habdi is species by he mo phology o he ail (which is poin ed and ape s o a sho spike-like ip) and/o he alue o he a io c (Table 4). Table 2. Mo phome ic cha ac e s (in µm) o hi d-s age in- ec i e ju eniles o He e o habdi is downesi n. sp. Means and s anda d de ia ion a e gi en in pa en heses. Pa a ypes K122 EU94 EU349 (n =20) (n =20) (n =20) L 588-692 521-691 520-741 (637 ±32) (607 ±51) (597 ±54) MBW 15-22 14-25 15-24 (18 ±2) (19 ±4) (20 ±3) NR 96-105 74-115 82-108 (101 ±3) (92 ±9) (92 ±6) EP 96-128 88-123 97-123 (115 ±8) (107 ±9) (106 ±9) ES 126-141 121-136 115-143 (135 ±4) (128 ±4) (127 ±8) TL 62-74 54-78 51-83 (68 ±4) (65 ±9) (64 ±10) ABW 9-14 9-14 10-15 (12 ±1) (12 ±1) (12 ±2) Ra io a 29-42 26-38 25-37 (35 ±4) (33 ±4) (31 ±3) Ra io b 4.4-5.3 4.3-5.2 4.3-5.2 (4.7±0.3) (4.7±0.3) (4.7±0.3) Ra io c 8.5-10.5 8-11 7.6-11 (9.5±0.5) (9 ±1) (9.5±1) Ra io d 0.76-0.98 0.66-0.97 0.8-0.90 (0.85 ±0.05) (0.84 ±0.1) (0.85 ±0.04) Ra io e 1.6-1.8 1.2-2.1 1.3-2.2 (1.7±0.1) (1.7±0.3) (1.7±0.2) Discussion He e o habdi is species ha e essen ially been de- limi ed on he basis o Linnaean species concep s. Mo phological and mo phome ic cha ac e s o adul s ages (speci ically second gene a ion males) and hi d-s age in ec i e ju eniles, ha e been used o diagnos ic pu poses and o assess hei iden i y as mo - phospecies (Poina , 1976; Poina 1990; S ock, 1993; Liu & Be y, 1996; S ock e al, 1996; S ock & Kaya, 1996). Howe e , because o he pauci y o mo pholog- ical ai s in he He e o habdi idae, o he app oaches ha e been applied o hei delimi a ion and diagnosis a he species le el. Fo ins ance, di e en molecula me hods, such as s a ch gel elec opho esis, es ic- ion enzyme analyses (RFLPs), isoelec ic ocussing (IEF), andom ampli ied polymo phic DNA (RAPD) ma ke s and sequence da a, ha e been success ully used o iden i y and in e phylogene ic ela ionships 103 Table 3. Compa ison o mo phome ic cha ac e s (in µm) o males o He e o habdi is species. Means and s anda d de ia ion a e gi en in pa en heses. Species L MBW AE-ES AE-NR AE-EP TL ABW SpL GuL SW GS H. bac e iopho a∗620-940 38-64 95-130 68-83 106-136 26-43 23-34 31-41 14-21 1.20-1.34 0.45-0.51 (831 ±75) (51 ±9) (125 ±14) (76 ±10) (125 ±16) (36 ±3.5) (28 ±2.5) (36 ±2) (18 ±2) (1.28 ±0.01) (0.48 ±0.1) H. a gen inensis∗1,000-2,000 42-70 103-121 75-88 145-172 28-49 28-36 35-49 20-25 1.75-1.95 0.38-0.51 (1,445 ±55) (56 ±11) (115 ±9) (79 ±8) (160 ±15) (40 ±4) (23 ±3) (45 ±3) (22 ±1.5) (1.80 ±0.02) (0.48 ±0.1) H. indicus∗573-800 35-47 93-109 69-84 110-138 24-33 19-24 34-48 18-23 1.7-1.9 0.43-0.48 (702 ±33) (42 ±2.5) (100 ±4) (78 ±6) (124 ±10) (28 ±3) (21 ±3) (42 ±4) (20 ±2) (1.8±0.10) (0.47 ±0.2) H. hawaiiensis∗864-1130 50-83 100-150 67-112 71-146 26-40 21-34 41-49 18-26 1.44-1.95 0.44-0.53 (998 ±33) (64 ±12) (119 ±9) (86 ±8) (130 ±17) (34 ±11) (26 ±5) (45 ±3) (21 ±2) (1.73 ±0.05) (0.46 ±0.2) H. ma ela us∗800-1,010 49-97 114-139 83-114 102-130 36-49 24-30 42-52 17-24 1.73-1.78 0.4-0.46 (910 ±35) (68 ±23) (125 ±11) (101 ±9) (115 ±10) (39 ±8) (27 ±2) (48 ±4) (22 ±2) (1.75 ±0.01) (0.42 ±0.1) H. megidis∗780-1,001 46-65 116-140 75-110 128-147 32-48 25-37 39-49 16-24 1.35-1.45 0.45-0.5 (892 ±45) (53 ±14) (131 ±9) (95 ±11) (136 ±8) (45 ±7) (33 ±4) (42 ±3) 19 (1.4±0.01) (0.47 ±0.1) H. zealandica∗958-1,693 46-53 157-197 79-110 132-148 30-46 26-36 36-47 16-24 1.3-1.4 0.44-0.51 (1209 ±186) (48 ±3) (175 ±9) (98 ±9) (135 ±8) (40 ±3) (30 ±2) (42 ±2.5) (19 ±2) (1.35 ±0.2) (0.45 ±0.01) H. b e icaudis∗∗ 840-950 40-48 104-112 80-88 92-100 no no 44-48 18-22 no no (900) (43) (108) (82) (95) a ailable a ailable (47) (19 ±2) a ailable a ailable H. poina i∗∗∗ 970-1,100 43-70 150-170 no no no no 43-55 24-32 no no a ailable a ailable a ailable a ailable a ailable a ailable H. downesi n. sp. (K122) 669-876 33-40 97-106 62-78 86-91 29-34 21-28 41-47 17-19.5 1.7-2.2 0.36-0.47 (800 ±76) (36 ±3) (101 ±3) (70 ±7) (89 ±2) (32 ±2) (24 ±2) (43 ±2) (18 ±1) (1.8±0.2) (0.43 ±0.04) ∗A e Hominick e al. (1997). ∗∗A e Liu (1993). ∗∗∗ A e Kakulia & Mikaia (1997).