Quest Journals Journal of Research in Agriculture and Animal Science Volume 7 ~ Issue 3 (2020) pp: 32-37 ISSN(Online) : 2321-9459 www.questjournals.org Corresponding Author: Ashok Kumar 32 | Page Research Paper Population Composition of Three Phthirapteran Ectoparasites Infesting Sheep Ashok Kumar and Adesh Kumar Parasitology Laboratory, Department of Zoology, Pt. P.D.B. Himalayan Government P.G. College, Kotdwara, Uttarakhand-246149, India ABSTRACT: Information regarding the population composition of phthirapteran ectoparasites affecting birds and mammals has always attracted the parasitic entomologists. Population of Phthiraptera remains confined to the body of host and is highly variable, ranging from absence to many thousands per host. Heavy and very heavy Population have affected the productivity and vitality of the host. So Study of population must be considered for the development of an effective method for monitoring pest and establishing economic threshold on which the pest management should be based. In the present study, the population structure of three phthirapteran (viz. Bovicola ovis; Schrank, 1781, Linognathus ovillus, Newman; 1907 and Linognathus pedalis, Osborn, 1896) on sheep has been recorded by examining the four sheep hide. In case of B. ovis the male-female ratio was 1:1.5, adult-nymph ratio was 1:1.94 and the ratio between three instars of nymph was 1.12:1.95:1. The ratio between the male-female of L. ovillus was 1:4.1, the adult nymph ratio was 1:2.66 and the ratio between first, second and third nymph instars were 1:1.08:1.15. In case of L. pedalis the male female ratio was 1:2.94, the adult nymph ratio was 1:2.9 and ratio between three instars of nymph was 1:1.04:1.28. The female population was outnumbered in all the cases. The number of male and female follow similar pattern throughout population and were found to exhibit a high degree of correlation. However, study of population these parasite give clue for the need of eradication programme required at any places (India). Furthermore, there is no need of eradication measures because population levels of these parasites have not as much high to cause significant loss. KEYWORDS- Phthiraptera, Mallophaga, Anoplura, Population composition, Bovicola ovis, Linognathus ovillus, Linognathus pedalis Received 16 November, 2020; Accepted 02 December, 2020 © The author(s) 2020. Published with open access at www.questjournals.org I. INTRODUCTION Population of Phthiraptera remains confined to the body of host and is highly variable, ranging from absence to many thousands per host. From mammals, maximum numbers of lice recorded is 19,000 Damalinia jellisoni from Dall’s sheep (Kim, 1977) and 20,000 Trichodectis canis from injured dog (Hopkins, 1949). The size and composition of ectoparasite population are also highly variable, both spatially and temporally. Information regarding the population levels and composition of phthirapteran ectoparasites affecting birds and mammals has always attracted the parasitic entomologists. Only few workers like Hopkins (1949), Rawat et al. (1991), Kumar et al. (1993) and Kumar et al. (1996) have provided information on the population of Phthiraptera on domestic mammals. However, few other aspects of population of Phthiraptera on domestic mammals have been studied from time to time (by direct observation of live hosts) by certain workers. For instance, seasonal variations in the population of Phthiraptera (on domestic mammals) have been recorded on cattle by Matthysse (1946), Craufurd-Benson (1941), Jensen and Roberts (1966), Lewis et al. (1967) and Rawat and Saxena (1990); on sheep by Scott (1952), Murray (1963a, b, c, d, and 68) and Murray and Gordon (1969); on horses by Pafadt (1971); on pigs by Melnikova (1960) and Rawat et al. (1991); on dogs by Amin and Madbouly (1973) and Goel et al. (1990); on buffaloes by Blagovestchensky and Serdukove (1935), Chauduri and Kumar (1961) and Rawat et al. (1992); on deer by Samuel and Trainer (1971). The above said workers casually discussed about the impact of different factors (i.e. climate, host age, sex, health, nutrition, behaviour, hair density, nature of hair coat etc.) on population levels of Phthiraptera on mammals. Few other workers like