250 ENTOMOLOGICAL NEWS MATERNAL CARE IN THE NEOTROPICAL CENTIPEDE OTOSTIGMUS SCABRICAUDA (CHILOPODA: SCOLOPENDROMORPHA) 1 G. Machado^ ABSTRACT: This paper provides the first field report of maternal care in a Neotropical centi- pede. Nine females of Otostigmus scabricauda were found taking care of eggs or first instar nymphs at Sao Sebastiao Island, southeastern Brazil. Brood-guarding females were found in the leaf litter or under fallen trunks. The mean clutch size was 29.1 15.7 and no egg was observed to be infected with fungi. The nymphs are non-pigmented and hatch with 21 segments. Egg- laying in O. scabricauda probably takes place in the beginning of the wet-warm season (Octo- ber), and the reproductive season lasts until February. Predation pressure in the leaf litter and the high risk of infection due to fungi may have favored the evolution of maternal care in many arthropods living on the soil, such as centipedes. Parental investment is defined as any behavior exhibited by a parent to- wards the progeny which increases its survival rate at the cost of the aptitude of the parent to invest in another progeny (Trivers, 1972). Among arthropods this may include investment by females in the choice of an appropriate site for oviposition, incubation, and egg-guarding, as well as the feeding of young by one or both parents (Clutton-Brock, 1991). There are about 2500 described species of centipedes (order Chilopoda) in both temperate and tropical regions (Cloudsley-Thompson, 1958; Lewis, 1981). Centipedes usually live in damp and dark places such as under stones, fallen leaves, logs, under barks, or in crevices. The reproductive biology of centi- pedes is poorly known, but at least some species present some degree of pa- rental care. Females in the suborders Scolopendromorpha and Geophilomorpha lay their eggs in clusters and guard the eggs from oviposition to hatching, then caring for the young until they disperse (Brunhuber, 1970). While the female guards her offspring she is very sensitive to disturbance and commonly abandons the egg-batch which may be attacked by fungi or predators. Thus, females and their brood cannot be transported to the labora- tory in order to observe their behavior and development (Brunhuber, 1970). Among the Scolopendromorpha, maternal care has been reported only for Scol- opendra cingulata (Heymonds, 1901 ; Klingel, 1960), S. dalmatica (Heymonds, 1901), 5. amazonica (Lewis, 1966), and Cormocephalus anceps anceps (Brunhuber, 1970), all from Asian and African regions. There is no record of maternal care in Neotropical centipedes. 1 Received June 4, 1999, Accepted October 23, 1999. 2 Museu de Hist6ria Natural, Institute de Biologia, CP 6109, Universidade Estadual de Campinas, 13083-970 Campinas SP, Brazil, fax 55 19 2893124 e-mail glaucom@unicamp.br ENT. NEWS 1 1 1(4): 250-254, September & October 2000 Vol. 1 1 1. No. 4. September & October, 2000 251 The genus Otostigmus (Scolopendridae: Otostigminae) has a global distri- bution, including the Americas, Africa, Oceania, India and Japan. Its repre- sentatives range from 4- 1 2 cm in length and their tegument is colorful (Bucherl, 1939a). Otostigmus scabricauda H. & Saus., 1870 is common in Brazil, espe- cially in the coastal forests. Observations on reproductive behavior from labo- ratory indicate that in this species females take care of their eggs and nymphs (Martins & Knysak, 1996). However this behavior has never been recorded in nature and this paper provides the first field account of maternal care for a Neotropical centipede. MATERIAL AND METHODS This study was conducted on Sao Sebastiao Island (2347' S; 4524' W), southeastern coast of Sao Paulo State, Southeast Brazil. Approximately 80% of the island is area covered by Atlantic Forest (IBGE, 1983). The climate is warm and wet with maximum rainfall in December (2000 mm) and minimum in August (80 mm). Collections of centipedes were made between 100 and 900 m altitude during March and February 1997, and from December 1997 to January 1998 (wet and warm season). Individuals of Otostigmus scabricauda were found during a study of litter invertebrate diversity. A leaf litter area of about 5800 m 2 corresponding to 92 plots of 64m 2 was sampled. All centipedes found were collected and later preserved in 70% ethanol. During the collec- tion I recorded the behavioral responses of the individuals to disturbance, such as attempts to escape, and the egg or nymph cannibalism. Voucher specimens are in the Museu de Zoologia da Universidade de Sao Paulo (MZUSP), Sao Paulo, Brazil. RESULTS AND DISCUSSION I found nine females of Otostigmus scabricauda with offspring: three of them cared for eggs and six cared for first instar nymphs. Female length ranged from 36.4 to 53.5 mm. Brood-guarding females were found in the leaf litter (n = 5) or under fallen trunks (n = 4). The female curls herself around the 'ggs or the young, laying on her side and enclosing the brood between her legs and the ventral surface of her body (Fig. 1). As recorded for other centipede species, the eggs and the young are thus safeguarded from contact with the soil (see Cornwell, 1934; Lawrence, 1947; Brunhuber, 1970). When disturbed during brooding, the females abandon their eggs or young (7 observations), or eat them (2 observations). Apparently, females caring for first instar nymphs aban- don their offspring more frequently than females caring for eggs (x 2 = 5.5; d.f. = 1 ; p > 0.05). After the mother deserts, the nymphs generally flee, or burrow themselves in the soil. The mean clutch size was 29.1 (S.D. = 15.7; range = 16 - 58; n = 9). The 252 ENTOMOLOGICAL NEWS Figure 1 : Female of Otostigmus scabricauda curled around her early-hatched nymphs as found under a fallen trunk in nature. eggs are oval, yellowish, and have a mean individual volume of 48.5 mm 3 (SD = 5.9 mm 3 ; range = 40.6 - 56.8 mm 3 ; n = 10) (Fig. 1). No egg was ob- served to be infected with fungi. The nymphs are non-pigmented and have a mean length of 1 1.6 mm (S.D. = 1.1 mm; range = 8.4 - 13.5 mm; n = 65) (Fig. la). The nymphs hatch with 21 segments, and as in other scolo-pendromorphs (see Cloudsley-Thompson, 1958) the development is epimorphic (the young display the complete number of segments upon hatching). The embryonic phase of Otostigmus scabricauda under laboratory conditions ranged from 45 to 60 days and the nymphs remain with the mother for 1 5 -20 days before dispersal (Martins & Knysak, 1996). If the incubation time in the field is similar to that described in the laboratory, egg-laying in O. scabricauda probably takes place in the beginning of the wet-warm season (October), and the reproductive sea- Vol. 1 1 1 , No. 4. September & October. 2000 253 son lasts until February. The same pattern seems to occur in other scolopendrid species that reproduce during the rainy season (see Lewis, 1966). Despite the large number of species of centipedes in the Neotropical re- gion (see Biicherl, 1 939b) the behavior and ecology of the group is still poorly known. The developmental stages of the Geophilomorpha (Palmen & Rantal, 1954) and Scolopendromorpha (Lawrence, 1947; Brunhuber, 1970) have al- ready been described and in these groups maternal care is crucial for the sur- vival of the eggs and young. The female grooms the eggs and juveniles; this apparently increases offspring survival, because without the mother the eggs and nymphs always die from fungal attack or unknown reasons (Brunhuber, 1970). In some cases a female can also move her egg batch to other microsites with better temperature and humidity conditions (see Brunhuber, 1 970). Among arthropods, parental care is commonly associated with physically harsh or bio- logically dangerous habitats (Clotton-Brock, 1991; Zeh & Smith, 1985). Pre- dation pressure in the leaf litter and the high risk of infection due to fungi may have favored the evolution of maternal care in many arthropods living on the soil, such as some beetles (Scott, 1990), earwigs (Wilson, 1971), crickets (West & Alexander, 1 963), harvestmen (Goodnight & Goodnight, 1976; Mora, 1990), spiders (Horel & Gundermann, 1992), and probably centipedes. ACKNOWLEDGMENTS I am most grateful to C. H. F. Vasconcelos, R. J. Sawaya, R. Nunes, L. A. Anjos and A. M. F. Pacheco for help in field work; to I. Knysak for identification of the centipede species; to R. J. Sawaya for photographs; to P. S. Oliveira, K. S. Brown Jr., A. V. L. Freitas, I. Sazima, and an anonymous reviewer for comments on the manuscript. LITERATURE CITED Brunhuber, B. S. 1970. Egg laying, maternal care and development of young in the scolopendromorph centipede, Cormocephalus anceps anceps Porat. Zool. J. Linn. Soc. 49: 225-234. Biicherl, W. 1939a. Os Quilopodos do Brasil. Mem. Inst. Butantan 13: 49-320. Biicherl, W. 1939b. Catalogo dos Quilopodos de zona neotropica. Mem. Inst. Butantan 15: 251-372. Clutton-Brock, T. H. 1991. The evolution of parental care, Princeton Univ. Press, Princeton, NJ. Cornwell, W. S. 1934. Notes on the egg-laying and nesting habits of certain species of North Carolina myriapods and various phases of their life history. J. Elisha Mitchell Sci. Soc. 149: 289-291. Cloudsley-Thompson, J. L. 1958. Spiders, Scorpions, Centipedes and Mites. Pergamon Press, Oxford, London. Goodnight, M. R. and C. J. Goodnight. 1976. Observations on the systematics, development and habits of Erginulus clavotibialis (Opiliones, Cosmetidae). Trans. Amer. Microsc. Soc. 95: 654-664. Heymonds, R. 1901. Entwicklungsgeschichte der Skolopender. Zoologica Stuttg. 13: heft 33. 254 ENTOMOLOGICAL NEWS Horel, A. and J. L. Gundermann. 1992. Egg sac guarding by the funnel-web spider Coelotes terrestris: function and development. Behav. Proc. 27: 85-94. IBGE 1983. Levantamento de Recursos Naturais, Folhas SF 23/24 Rio de Janeiro/Vit6ria. MinisteYio das Minas e Energia, Projeto Radambrasil. Secretaria Geral, Rio de Janeiro. Klingel, H. 1960. Vergleichende Verhaltungsbiologie der Chilopoden Scutigera coleoptrata L. ('Spinnenassel') und Scolopendra cinculata L. (Skolopender). Z. Tietpsychol. 17: 11-30. Lawrence, R. F. 1947. Some observations on the post-embryonic development of the Natal forest centipede Cormocephalus multispinus (Kraep.). Ann. Natal. Mus. 11: 139-156. Lewis, J. G. E. 1966. The taxonomy and biology of the centipede Scolopendra amazonica in the Sudan. J. Zool. 149: 188-203. Lewis, J. G. E. 1981. The biology of centipedes, Cambridge Univ. Press, Cambridge. Mora, G. 1990. Parental care in a neotropical harvestman, Zygopachylus albomarginis (Arach- nida: Gonyleptidae). Anim. Behav. 39: 582-593. Martins, R. and I. Knysak. 1996. Observances sobre cuidados com a prole em Otostigmus scabricauda (Scolopendridae) nascidos em cativeiro. Anais de Etologia, Uberlandia, MG, 14: 288. Palmen, E. and M. Rantala. 1954. On the life history and ecology of Pachymeriumferruginum Koch (Chilopoda: Geophilidae). Ann. Zool. Soc. 'Vanamo' 16: 1-44. Scott, M. P. 1990. Brood guarding and the evolution of male parental care in burying beetles. Behav. Ecol. Sociobiol. 26: 31-39. Trivers, R. L. 1972. Parental investment and sexual selection, pp. 136-179. In Sexual selec- tion and the descent of man, (Campbell, B. ed.), Chicago, Aldine. West, K. J. and R. D. Alexander. 1963. Sub-social behavior in a burrowing cricket Anurogryllus muticus (De Geer). Orthoptera: Gryllidae. Ohio J. Sci. 63: 19-24. Wilson, E. O. 1971. Insect societies. Harvard Univ. Press, Cambridge. Zeh, D. W. and R. L. Smith. 1985. Paternal investment by terrestrial arthropods. Am. Zool 25: 785-805. NOTICE DEFECTIVE MARCH/APRIL, 2000, VOL. Ill (2) ISSUE When one Society member & subscriber wrote to me that he had received a defective March/ April, 2000 issue, I checked and discovered that of the 128 copies I had on hand, 22, or 17%, were defective. In the majority of cases the problem was one of four pairs of blank pages opposite each other for a total of eight blank pages. In one case, four pages were in double. Each and every subscriber, both individual and institutional, should check his or her copy for any possible defect and, if one is found, please advise our business office in Philadelphia and request a replacement copy. Entomological News regrets any inconvenience this printing error may hav* caused. H. P. B.