TWO NEW MEXICAN SPECIES OF MICROGASTRURA (COLLEMBOLA: HYPOGASTRURIDAE) ASSOCIATED WITH MUSHROOMS

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1 Folia Entomol. Mex. 98:59-65 (1996) TWO NEW MEXICAN SPECIES OF MICROGASTRURA (COLLEMBOLA: HYPOGASTRURIDAE) ASSOCIATED WITH MUSHROOMS M. MAGDALENA VAZQUEZ* AND JOSÉ G. PALACIOS-VARGAS** *División de Ciencias e Ingenierías, Universidad de Quintana Roo, MEXICO. **Lab. Ecología y Sistemática de Microartrópodos, Depto. de Biología, Fac. de Ciencias, UNAM México, D.F., MEXICO. ABSTRACT. Two new species of Microgastrura Stach, 1922 are described and illustrated. One is from a humid jungle in Los Tuxtlas, Veracruz and the other is from an inundated jungle in Sian ka'an, Quintana Roo. A key for all the known species of the genus is included. KEY WORDS: Microgastrura, new species. RESUMEN. Se describen e ilustran dos nuevas especies de Microgastrura Stach, Una procede de la selva húmeda de Los Tuxtlas, Veracruz y la otra de una selva inundable en Sian Ka'an, Quintana Roo. Se incluye una clave para la identificación de todas las especies conocidas del género. PALABRAS CLAVE: Microgastrura, especies nuevas. The genus Microgastrura includes seven described species to date. They are M. duodecimoculata, Stach, 1922; M. cantabrica, Simon Benito & Pozo Martínez, 1984; M. selgae, Simon Benito & Pozo Martínez, 1984; M. massoudi, Deharveng & Najt, 1988; M. sensiliata, Jordana, 1981; M.jamaicensis, Massoud & Bellinger, 1963; and M. minutissima, Milis, This is an unusual genus among Hypogastruridae, because of the reduction and modification of mouth parts. Due to this, it was first placed in the family Neanuridae and later in the Hypogastruridae. Only one other genus of the family lacks apical teeth on the mandible (Stenogastrura Christiansen & Bellinger, ) and that genus, unlike Microgastrura, has a simple postantennal organ and clavate body setae. In this paper we describe two new Mexican species, one from mushrooms of the Biological Station, Los Tuxtlas, Veracruz, and another one from soil and mushrooms on bark of trees, from the Biosphere Reserve of Sian Ka'an, Quintana Roo. Both were associated with fungi.

2 Vázquez & Palacios-Vargas: New Microgastrura in mushrooms MICROGASTRURA Stach, 1922 It is characterized as follows: Mandible reduced without apical teeth and rudimentary molar plate. Ant.IV with 7-10 sensilla, with one or two subapical bulbs, and with "file setae" ventrally. Postantennal organ with 4 centraly jointed lobes; 6+6 eyes; tibiotarsi without capitate tenent hairs; unguiculus with lamella and sometimes with filament. Dens with subapical bulb and muero with externallamella. Without anal spines. Unguis with inner teeth. Tenaculum with 4+4 teeth and no setae on corpus. Ventral tube with 4+4 or 3+3 setae. Dens with seven setae, sorne of them spiniform. Muero distinctly separate from dens. No anal spines. Microgastrura nanacatlica sp. nov. (Figs. 1-7) Maximum body length: 400 p.m. Body with short setae (7-12..m), and longer sensilla ( m). Distribution and relative length of setae as in Fig. l. Color dark blue in alcohol. Ratio head: antenna = 1:1.5. Ant. 1 with 6 dorsal setae, Ant. 11 with 10 setae. Sense organ of Ant. 111 with two microsensilla and two guard sensilla. Ant. IV with five ( or 6) thin dorsal sensilla and three thick dorso-external sensilla and one microsensillum (Fig. 2). Apical bulb simple. Ventral file with ten modified setae (Fig. 3). 6+6 eyes and postantenal organ with 4 vesicles forming a star with four long arms. With three ocular setae. Mandible thin and elongate (Fig. 4). Maxilla with four different apical teeth (Fig. 5). Labial chaetotaxy illustrated in Fig. 6. Leg chaetotaxy (1-III: coxae 5, 7, 7; trochanter 4,4,4; femora 12, 12, 10; tibiotarsi 19,19,18. Tenent hairs lacking. Unguis thin, with one median apical ventral tooth. Unguiculus lamellar with a fine and long filament (Fig. 7). Ratio tibiotarsus: unguis = 1:1.1. Ventral tube with 4+4 setae. Tenaculum with 4+4 teeth. Manubrium dorsally with four pairs of setae. Dens with seven setae, the three distal spiniform. A bladder ventrally, on distal part of dens. Muero thin, with small lamella. Total dorsal chaetotaxy as in Fig. l. Th. 11 with a lateral microsensilla. Etymology. The name comes from the Nahuatllanguage "nanacatl" (mushrooms) and oicus (Greek= house), meaning the biotope of this species. TYPE MATERIAL: Holotype female and one paratype adult and 8 paratypes juveniles are deposited at the Laboratorio de Ecología y Sistemática de Microartrópodos, Facultad de Ciencias, UNAM. 60

3 Folia Entorno!. Mex. 98 (1996) Figs. 1-8, Microgastrura nanacatlica sp. nov. 1, dorsal chaetotaxy; 2, Ant. IV dorsal view; 3, Ant. IV ventral view; 4, mandibule; 5, maxilla; 6, labial chaetotaxy; 7, tibiotarsus I; 8, mucrodens. 61

4 Vázquez & Palacios-Vargas: New Microgastrura in mushrooms TYPE LOCALITY: MEXICO: Veracruz. Estación de Biología tropical "Los Tuxtlas". ex Polyporus sp., 24-VII-1988, J. Palacios col. Discussion. M. nanacatlica sp. nov. differs from other species of the genus in having only three spiniform setae on dens, and because an elongate mandible, the ventral file of antennal segment IV with 10 modified sensilla, anda long unguiculus filament. The North American species Microgastrura minutissima, has a short filament, the lamellate unguiculus, and a very different maxillae. Microgastrura sojiae sp. nov. (Figs. 9-17) Maximum body length: 454.tm. Body setae long and thin (15-22.tm), and longer sensilla (25-30.tm). Distribution and relative length of setae in Fig. 9. Color pale blue in alcohol. Ratio head: antenna = 1:1.5. Ant. I with six dorsal setae, Ant.II with 10 setae. Sense organ of Ant. III with two sensilla and two guard sensilla. Ant. IV with five (or 6) thin dorsal sensilla and 3 dorso-lateral thick sensilla and one microsensillum. Apical bulb simple. Ventral file with 8-10 modified setae (Figs. 10, 11 and 12). Labial chaetotaxy as in figure eyes and postantenal organ star shaped with 4lobes. Head with three ocular setae. Mandible thick (Fig. 13). Maxilla quadrangular with four subequal apical teeth (Fig. 14). Leg chaetotaxy (I-III): coxae 5,7,7; trochanter 4,4,4; femora 12,12,10; tibiotarsi 19,19,18 (Fig. 16). Without tenent hairs. Unguis thin, with one apical median ventral tooth. Unguiculus lamellate with fine filament. Ratio tibiotarsus: unguis = 1:0.7. Ventral tube with 4+4 setae. Tenaculum with 4+4 teeth. Manubrium with four pairs of setae. Mucrodens with seven setae; four are setiform and three spiniform. Muero with a well developed lamella (Fig. 17). Total body chaetotaxy as in Fig. 9. Prothorax with 2+2 dorsal setae and lateral seta. Th. II with one microsensilla. Etymology. Species dedicated to Sofía Velázquez, daughter of the senior author. TYPE MATERIAL: Holotype female and five paratype females deposited at senior author's institution. Five paratypes deposited at Laboratorio de Ecología y Sistemática de Microartrópodos. TYPE LOCALITY: MEXICO: Quintana Roo: Sian Ka'an Biological Reserve. Inundated jungle. ex mushrooms from trees. 6-IX-1995, J.L. Carvajal Col. 10-I-1995, M. Vázquez col. 62

5 Folia Entomol. Mex. 98 (1996) ~..... } r~ {y /, 15 L " Figs. 9-17, Microgastrura sofiae sp. nov. 9, dorsal chaetotaxy; 10, Ant. III dorsal view; 11, sensorial organ of Ant. III; 12, Ant. III ventral view; 13, mandibule; 14, maxilla; 15, labial chaetotaxy; 16, tibiotarsus I; 17, mucrodens. 63

6 Vázquez & Palacios-Vargas: New Microgastrura in mushrooms Discussion. M. sofiae sp. nov. is the only species of the genus with long dorsal sensilla (up to 30 JLm) and long setae (up to 20 JLm). lt also has 8-1 O modified ventral setae on Ant. IV, as M. nanacatlica sp. nov., but the head of the maxilla is quadrangular and the teeth are subequal. The mandible is very thick. The filament of the empodium in M. sofiae sp. nov. is shorter and and the empodium has no lamellae. Key for the identification of the species of Microgastrura l. With about 40 modified setae on the "ventral file" of Ant. IV M. jamaicensis 1' With fewer than 30 modified setae on the "ventral file" of Ant. IV With about 20 trumpet shaped setae, on the "ventral file" of Ant. IV M. massoudi 2' With less than 20 trumpet shaped setae, on Ant. IV Unguiculus without filament... M. cantabrica 3' Unguiculus with filament Abdominal segment V with sensory seta p ' Abdominal segment V with sensory seta p Body setae short, about 10 um ' Body setae long, about 20 um M. sofiae 6. Unguiculus with long filament (3 um) M. minutisima 6' Unguiculus with small filament (2 um) Unguiculus less than 1/5 the length of the ungues M. sensiliata 7' Unguiculus 113 the length of the unguis M. nanacatlica 8. Unguiculus knife shaped.. M. duodecimoculata 8' Unguiculus trapezoidal M. selgae ACKNOWLEDGEMENTS This project was made thanks to the support of CONABIO (Comisión Nacional para el Estudio y Conservación de la Biodiversidad). Dr. Peter F. Bellinger (University of California, Northridge, California) and Dr. Kenneth A. Christiansen (Grinnell College, Iowa) reviewed the manuscript and gave important suggestions. 64

7 Folia Entorno!. Mex. 98 (1996) LITERA TURE CITED CHRISTIANSEN, K.A. & P.F. BELLINGER, The Co/lembola of North America north of Rio Grande, a ta.xonomic analysis. Grinnell College, Iowa, 1322 pp. DEHARVENG, L. & J. NAJT, Collemboles Poduromorpha de Nouvelle-Caledonie. I. Hypogastruridae. In: S. Tillier (ed.), Zoología Neocaledonica, VoL I. Mem. Mus. natn. Hist. nat., (A), 142: JORDANA, R Contribución al conocimiento de los colémbolos de Navarra. Estudio faunístico del macizo de Quinto ReaL V Géneros Schaefferia, Willemia, Triachante/la, Xenylla y Microgastrura. Pub/. Biol. Univ. Nav. Serie Zool. 6:3-32. S!MON BENITO, J.C. & J. Pozo MARTÍNEZ, Contribución al conocimiento del Género Microgastrura Stach, 1922 (Collembola). Nouv. Rev. Ent. (N.S) 1(3): Recibido: 29 abril Aceptado: 10 julio