Population levels of Phthiraptera on greylag goose, Anser anser (L.).

OBJECTIVE The present study was performed to record the mean monthly prevalence, intensity of infestation, sample mean abundance and frequency distribution pattern of one phthirapteran species infesting of A. anseris. METHODS Ten birds were examined every month. Infested birds were deloused. The bird was placed in a polythene bag containing a wool of cotton soaked in chloroform (head protruded out to allow breathing). After 10 minutes, the bird's feathers were ruffled on a white plastic sheet placed below. The head was examined separately. The louse load was transferred to 70% alcohol and separated stage wise and sex wise. RESULTS A total of 339 specimens of A. anseris were recovered from 66 infested hosts. Male-female ratio was 1: 1.8. Prevalence of Anaticola anseris was 55% (n=120). The sample mean abundance was 2.38 lice/bird. Variance to mean ratio exceeded unity (10.70). The index of discrepancy (D) was 0.75 and the value of exponent of negative binomial (k) remained 0.334.The observed and expected frequencies did not differ significantly (χ2= 13.33, df= 15, p=0.05). CONCLUSION The prevalence of A. anseris on Indian greylag goose was high but its intensity remained quite low. The distribution pattern of A. anseris conformed the negative binomial model.The temperature, photoperiod and heat index exhibited significant positive correlations with the prevalence of A. anseris.