The cattle lice of Great Britain Part I. Biology, with special reference to Haematopinus eurysternus

Abstract

1. The geographical distribution of cattle lice in Britain is recorded in detail. Bovicola bovis is the commonest and most widely distributed species in Britain.2. The incubation period for the eggs was found to be: Haematopinus eurysternus, 9–19 days (av. 12); Bovicola bovis, 7–10 days (av. 8); Linognathus vitula, 10–13 days; Solenopotes capillatus, 10–13 days. With eggs of H. eurysternus it was found that the higher the minimum air temperature the shorter was the incubation period.3. In H. eurysternus the average length of the instars was: 1st, 4 days; 2nd, 4 days; 3rd, 4 days; pre-oviposition period, 3–4 days. The average time for the complete life cycle, egg to egg, was 28 days.4. The maximum longevity of H. eurysternus on the host was: males, 10 days; females, 16 days. No males or females of H. eurysternus survived a starvation period of 72 hr. at 20° C. and R.H. 70 or 0–10° C. and R.H. 70–85; but some nymphs survived this period at 20° C. and R.H. 70, but none survived 96 hr. starvation.5. The maximum number of eggs recorded for one female was 24; and eggs were laid at the rate of 1–4 a day.6. The threshold of development of the eggs of H. eurysternus appears to be about 27·5° C.