Prevalence of ectoparasite infestation in neonate Yarrow's spiny lizards, Sceloporus jarrovii (Phrynosomatidae), from Arizona

Great Basin Naturalist 54(2), ©1994, pp. 189-190 PREVALENCE OF ECTOPARASITE INFESTATION IN NEONATE YARROW'S SPINY LIZARDS, SCELOPORUS JARROVII (PHRYNOSOMATIDAE), FROM ARIZONA Stephen R. Goldberg^ and Charles R. Bursey^ Key words: chigger, Eutrombicula lipovskyana, mite, Geckobiella texana, Sceloporus jarrovii, Phrynosomatidae, neonate, prevalence, intensity. While it is well known that ectoparasites infest lizards (Frank 1981), we know of no reports concerning how quickly newborn (neonate) lizards are infested under natural conditions. Ectoparasites have been shown to cause a diffuse inflammatoiy response in the skin of infected lizards from natural popula-tions (Goldberg and Bursey 1991, Goldberg and Holshuh 1992). The purpose of this inves-tigation is to report the age at which ectopara-site (chigger and mite) infestation first occurs in neonate Yarrow's spiny lizards {Sceloporus jarrovii). This lizard is well suited for deter-mining age at which infestation first occurs since it is a live-bearing lizard in which partu-rition occurs within a short period of time near the end of June each year (Goldberg 1971). This contrasts with egg-laying lizards that may contain eggs for several months (Goldberg 1973), with hatchlings emerging over an extended period. Goldberg and Bursey (1992) reported on prevalence of the nematode Spaidigodon giganticus in neonate S. jarrovii. Methods Thirty-six neonate S. jarrovii were collect-ed by hand or hand-held noose 28-30 June 1991 at Kitt Peak (31°95'N, lir59'W, eleva-tion 1889 m) in the Baboquivari Mountains, 85 km SW of Tucson, Pima County, Arizona. Lizards were measured to the nearest mm snout-vent length (SVL), and ectoparasites were counted at time of capture. Sizes of these wild-caught specimens were compared to 223 S. jarrovii neonates born of 37 female captive lizards in 1967-69 (Goldberg 1970). Specimens were deposited in the herpetology collection of the Los Angeles County Natural History Museum (LACM) (139070-139105). Results and Discussion Lizards in the 1991 sample averaged 30.1 ± 2.0 mm SVL, range 26-36 mm. Eighteen of the 36 (50%) neonate S. jarrovii were infested by ectoparasites (Table 1). Seventeen (47%) were infested by chiggers {Eutrombicula lipovskijana), with a mean intensity of 6.5 ± 6.9 and a range of 1-26 chiggers per lizard. Three (8%) lizards were infested by larval Geckobiella texana, with a mean intensity of 3.0 ± 2.6 and a range of 1-6 mites per lizard. Adult G. texana were not present. Two infect-ed lizards had concurrent infections (£. lipovskijana and G. texana). The sample of 19 male and 17 female lizards contained 11 infested males (58%) and 7 infested females (41%). There was no statistical difference in rate of ectoparasite infestation between males and females (chi square = 1.0, 1 df, P > .05). Likewise, there was no statistical difference in intensity of infestation between male and female lizards (Kruskal-Wallis statistic = 0.46, 1 df, P > .05; E. lipovskijana and G. texana combined). Mean intensities were 5.7 ± 6.3 for infested males and 8.14 ± 9.20 for infested females. Eutrombicula lipovskijana was found most frequently within skin folds on both ventrolat-eral surfaces of the neck (the mite pockets of Arnold 1986), but they were occasionally encountered in other areas of the body. Geck-obiella texana was taken from the hind legs only. Representative specimens were deposited 'Department of Biology, Whittier College, Whittier, California 90608. ^Department of Biology, Pennsylvania State University', Shenango Valley Campus, 147 Shenango Avenue, Sharon, Pennsylvania 16146. 189

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Prevalence of ectoparasite infestation in neonate Yarrow's spiny lizards, Sceloporus jarrovii (Phrynosomatidae), from Arizona

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