Understanding the life history characteristics of bird lice: Amblycera vs. Ischnocera

Permanent ectoparasites, adapted to living on their hosts, face limited
survival abilities and food availability off the host body. We
investigated the variance in survivability and the diet type preferences
between bird lice from two different groups – Amblycera and Ischnocera.
While phylogenetic or morphological data can easily separate these groups,
the difference in their life history characteristics is poorly understood.
We observed that ischnoceran lice showed significantly longer survival
than amblyceran lice (p<0.05) off the host body and experimental
supplementing with host feathers further increased the survival time of
ischnoceran lice. To examine the preference and possible effects of the
diet, we evaluated the presence of feathers, blood, or both in 4587
chewing lice (1418 amblyceran, and 3169 ischnoceran lice). Blood was found
in 36% of amblyceran lice from 14 genera, and no blood was found in
ischnoceran lice, pointing to different feeding habits between these two
groups. Haematophagy is recorded here for the first time for the
genera Ardeiphilus, Gruimenopon, Kurodaia, Machaerilaemus, and
Meromenopon. Furthermore, we evaluated hypopharynx reduction as a
potential predisposition for blood-feeding in bird lice. Amblyceran lice
may be more sensitive to changes in microhabitat conditions than
ischnoceran lice and in some cases, many species of Amblycera may also
require an additional dietary source beyond bird feathers for their
survival.