morphologically. The males and females of only two spec- ies of this family have been described so far, and even these matches might be conjectural. Among the 108 Myr- mecolacidae described, the ant hosts of only eight species of males are known (see tables 1 and 2 in electronic The discovery after 94 Appendix A, available on The Royal Society’s Publi- cations Web site). The rest of the species have been years of the elusive female described from free-living males that have been caught of a myrmecolacid in traps. Previous records of female myrmecolacids were mostly (Strepsiptera), and the of single specimens, except for two instances from Papua New Guinea: 15 specimens of Stichotrema jeyasothiae cryptic species of Kathirithamby (Kathirithamby et al. 2001) and large num- bers of female S. dallatorreanum Hofeneder, a parasite of Caenocholax fenyesi an oil palm pest (Solulu et al. 1998). Females parasitic in Hapithus agitator Uhler (Gryllidae) were originally ident- Pierce sensu lato ified as C. fenyesi (Cook et al. 1996). However, molecular analysis confirmed that this identification was incorrect 1* Jeyaraney Kathirithamby (Halbert et al. 2001). Kathirithamby & Hamilton (1992) 2 and J. Spencer Johnston discussed the intriguing phenomenon of the scarcity of 1Department of Zoology, University of Oxford, South Parks Road, female Myrmecolacidae. Oxford OX1 3PS, UK Male C. fenyesi, described by Pierce in 1909, is the type 2Department of Entomology, Texas A&M University, College Station, TX 77843-2475, USA species by monotypy and we here propose two nominotyp- * Author for correspondence ( [email protected]). ical subspecies of the Fenyesi group. Kifune (1979) stated that, except for records dating from 1935 of a dead male Recd 20.05.03; Accptd 08.07.03; Online 17.09.03 in a banana thrash boat from Panama and Argentina Due to its extreme sexual dimorphism and disparate (Bohart 1941), no distributional data are available. How- hosts, no female myrmecolacid has been matched to ever, males of morphologically identical C. fenyesi sensu its conspecific male to date. Here, for the first time lato have since been found in large numbers in traps from to our knowledge, a morphological description is the neotropics and southern USA (Kathirithamby 1992; given of the matched female and male myrmecola- Kathirithamby & Hughes 2002), and are parasitic in sev- cid, Caenocholax fenyesi waloffi ssp. nov. from eral species of ants throughout the neotropics and south- Veracruz, Mexico: the female parasitic in a cricket ern USA (see table 1 in electronic Appendix A). and the male parasitic in an ant. For examined seg- We present, to our knowledge, the first morphological ments of DNA, the male and female are identical. description of a female myrmecolacid, parasitic in a cricket Male C. fenyesi Pierce sensu lato was described 94 Macroanaxipha mecilenta (Saussure) and that was con- years ago from Veracruz. The male from Texas firmed by molecular characterization as a 100% match to USA, which, for the same DNA segments, shows a sexually dimorphic male parasitic in an ant Dolichoderus 15% divergence from the morphologically identical bispinosus Olivier (J. Kathirithamby, L. D. Ross, G. Moya- male from Veracruz, is given subspecies status, and Raygoza, D. P. Hughes and J. S. Johnston, unpublished is named Caenocholax fenyesi texensis ssp. nov. The data). It has hitherto been impossible to match males and discovery of the female finally enables many inter- females of Myrmecolacidae because of their heterotrophic esting studies to be pursued, such as speciation in heteronomous biology and their extreme sexual dimor- morphologically cryptic taxa, the sexes of which phism. Now, however, with the help of molecular tools, parasitize disparate hosts. Caenocholax fenyesi one such match has been established. sensu lato may also be evaluated for biocontrol of During the present study it was also found that the male the red imported fire ant, Solenopsis invicta Buren, C. fenyesi sensu lato from Texas parasitic in Solenopsis which is a pest in the USA and Australia. invicta Buren is 15% divergent from the morphologically Keywords: Strepsiptera; Myrmecolacidae; identical male from Mexico, parasitic in D. bispinosus Caenocholax fenyesi sensu lato; Mexico; Texas (J. Kathirithamby, L. D. Ross, G. Moya-Raygoza, D. P. Hughes and J. S. Johnston, unpublished data). Hence, C. 1. INTRODUCTION fenyesi sensu lato from Texas is given subspecies status. The discovery of a female myrmecolacid parasitic in an It is not clear whether these are (hitherto unrecognized) orthopteran comes 94 years after the free-living male reproductive isolated sibling species that parasitize dispar- Caenocholax fenyesi sensu lato was described from the same ate hosts, or if the sexes exhibit distinct (disparate) host area in Mexico (Pierce 1909), and is a major breakthrough preferences in the absence of any barriers to gene flow in the study of Strepsiptera. The family Myrmecolacidae between races. exhibits an extreme form of heterotrophic heteronomy (Kathirithamby 1991), where males develop in ants, and the females in grasshoppers, crickets and mantids (a) Myrmecolacidae Saunders (Ogloblin 1939; Kathirithamby 1989; Kathirithamby & Myrmecolacides Saunders (1872). Hamilton 1992). This feature, together with the fact that Myrmecolacidae Pierce (1908). the sexes exhibit extreme dimorphism in Strepsiptera, Strichotrematoidae Hofeneder (1910). means that it is impossible to match females and males Stichotrematidae Hofeneder (1910). Proc. R. Soc. Lond. B (Suppl.) 271, S5–S8 (2004) S5 2003 The Royal Society DOI 10.1098/rsbl.2003.0078 S6 J. Kathirithamby and J. S. Johnston Discovery of an elusive female myrmecolacid (b) Caenocholax Pierce Hughes et al. 2003) from Veracruz, Mexico (J. Kathiri- Caenocholax Pierce (1909). thamby, L. D. Ross, G. Moya-Raygoza, D. P. Hughes and Type species: male, Caenocholax fenyesi Pierce, Co´rdoba, J. S. Johnston, unpublished data) (figure 1d). Veracruz, Mexico USNM type 10081, originally part of Distribution: tropical species—neotropical. the Fenyes collection at the California Academy of Sciences, San Francisco. (v) DNA analysis Aedeagus: shield-shaped with a pair of lateral spines and The female parasitic in the cricket M. macilenta is 100% a ventral projection. identical to the male parasitic in the ant D. bispinosus (J. Host: unknown. Kathirithamby, L. D. Ross, G. Moya-Raygoza, D. P. Hughes and J. S. Johnston, unpublished data). (c) Caenocholax fenyesi Pierce sensu lato Caenocholax fenyesi Pierce (1909, 1911, 1918); Bohart (vi) Collection of taxa (1941); Kifune & Brailovsky (1987, 1988, 1997); Estacio´n de Biologı´a Tropical ‘Los Tuxtlas’, Instituto de Kathirithamby & Johnston (1992); Maes & Kathirithamby Biologı´a UNAM, 30 km Carretera Catemaco, Montepio (1993); Kathirithamby & Peck (1994); Kathirithamby & Apdo, San Andre´s, Tuxtla, Veracruz, Mexico, (18°35Ј N Hughes (2002). 95° 5Ј W), between 20 and 24 June 2002. (d) Synonymy Caenocholax brasiliensis Oliveira & Kogan (1959), Teso´n& (vii) Etymology de Remes Lenicov (1979) (sym. nov.) is synonymized with C. fenyesi waloffi ssp. nov. is named after the late Nadia C. fenyesi sensu lato based on the unique structure of the Waloff. aedeagus and the ninth abdominal segment. (viii) Voucher specimens Two neotenic female endoparasitic in Macroanaxipha mac- 2. DESCRIPTION ilenta (Saussure) (Orthoptera), Mexico: Estacio´n de Biol- (a) Caenocholax fenyesi waloffi ssp. nov ogı´a Tropical ‘Los Tuxtlas’, Instituto de Biologı´a UNAM, (i) Female 30 km Carretera Catemaco, Montepio Apdo, San Andre´s, The extruded cephalothorax lies flat on the host abdomen Tuxtla, Veracruz, Mexico, (18°35ЈN, 95°5ЈW), June 2002 (figure 1a–c), light brown with rounded anterior region; (G. Moya-Raygoza) (Coleccio´n Nacional de Insectos, brood canal opening broad. The cephalothorax always Instituto de Biologia, Universidad Nacional Auto´noma de extrudes through the abdominal pleurites of the host and Mexico, Mexico City, in alcohol). is cryptic (figure 1a). Numerous spines on inner surface Two neotenic female endoparasitic in M. macilenta, Mex- of mandibles (figure 1c). ico: same data as above (Oxford University Museum of Genital apertures/invaginations in the apron: one on each Natural History, Oxford, UK, in alcohol). of the second and third abdominal segments. Two male pupa endoparasitic in Dolichoderus bispinosus Cephalothorax length of 0.55 mm; width of 0.43 mm. Olivier (Formicidae), Mexico: same data as above, June Brood canal opening length of 0.18 mm; width of 2002 (D. P. Hughes) (Coleccio´n Nacional de Insectos, 0.33 mm. Instituto de Biologia, Universidad Nacional Auto´noma de Total length of female of 1.91 mm. Mexico, Mexico City, in alcohol). First-instar larva: total length of 0.89 mm. Two male pupa endoparasitic in D. bispinosus, Mexico: same data as above (University Museum of Natural His- (ii) Host tory, Oxford, UK, in alcohol). Macroanaxipha macilenta (Saussure) (Orthoptera: Grylli- dae: Trigonidiinae) (figure 1a) is most abundant during the evening after 18.00. (b) Caenocholax fenyesi texensis ssp. nov Distribution: neotropical. (i) Male The morphologically identical males from Texas, USA, collected from Bee Creek and Lick Creek, are 16.5% and (iii) Male 14.3% divergent, respectively, based upon D2 and V2 Morphologically identical males have been described from nuclear gene alignments from male C. fenyesi waloffi ssp. Texas (Kathirithamby & Johnston 1992), the Bahamas nov. from Veracruz (J. Kathirithamby, L. D. Ross, G.