#3
Possibly:
Linognathus vituli - blue cattle louse, Solenopotes capillatus - small blue cattle louse
due to 'blue' inside english name ?
#4
I believe that most, if not all, of the
Linognathus species are blue. They tend to be very host specific, although
africanus occurs (as different subspecies) on goats, sheep and gazelles.
L stenopsis is specific to goats.