of a human-infesting European trombiculid mite Kepkatrombicula desaleri
(Acari: Trombiculidae) with data on its mouthparts and stylostome
and A.A. Stekolnikov
of Acarology, 37(Suppl. 1): 176-193 (2011).
S U M M A R Y
morphology of trombiculid larvae Kepkatrombicula desaleri
(Methlagl, 1928) collected on chamois in Alps with special
consideration of the mouth apparatus was studied by scanning electron
microscopy (SEM). Standard morphological description of this species
using optical microscopy is also given, with the discussion on its
taxonomy. Neotype of K. desaleri is designated.
Feeding tube or stylostome formed by larvae in the host skin was
examined using histological methods. Larvae of this species possess an
unusual organization of the apical portions of the hypostome forming a
soft sucker disk. The latter being applied to the stratum corneum of
the host epidermis provides an additional pumping effect for
engorgement of food through the long stylostome that may extend deep
into the dermis at different angles to the surface of the epidermis.
Stylostome corresponds to the mesenchymal type of stylostome. Skin
reaction is strong and is expressed in the intensive infiltration of
the inflammatory foci with leukocytes and erythrocytes. Besides fluid
components of the inflammatory focus and cellular debris, larvae also
may uptake the whole erythrocytes. Edema, scab formation, as well as
the epidermal hyperplasia and hyperkeratosis are not characterized for
feeding of larvae of this species. Stylostome organization and the
character of the skin inflammatory reaction suggest that big animals
like chamois and probably humans are not natural hosts for larvae of
this species that may serve as vector of Rickettsiae and causes
trombidiosis in man.