The Phthiracarus species of C. L. Koch
Author
Kamill, B. W.
text
Bulletin of the British Museum of Natural History (Zoology series)
1981
41
263
274
http://unknown
journal article
ORI5390
[Genus
Hoplophora C. L. Koch
]
Koch (1841) described a number of species of
Hoplophora
from Regensburg, Germany, of which nine are currently classified in
Phthiracarus
:
crinita
,
ferruginea
,
globosa
,
laevigata
,
lentula
,
longula
,
lucida
,
straminea
and
testudinea
(Parry, 1979). Apart from the last mentioned species, which appears from Koch's original figure to have a greater affinity with the
Euphthiracaroidea
(but see Jacot, 1936), all are undoubtedly members of the genus
Phthiracarus
. These species are, however, extremely difficult to reidentify since Koch's very brief descriptions are based almost entirely on body shape and colour, two characters now known to be uniform in many species of this genus. Only
globosa
and
laevigata
can be characterized by body shape alone: in comparison with the other
Phthiracarus
species collected at Regensburg,
H. globosa
was said to be very 'globular' while the illustration of
H. laevigata
shows the notogaster to be 'angled' anteriorly.
Several redescriptions of Koch's species have been published, including those of Jacot (1936), Feider and Suciu (1957) and van der Hammen (1963). Jacot collected at more than 20 localities in the Regensburg area, recognizing six of Koch's species (
laevigata
,
testudinea
,
crinita
,
lentula
,
straminea
and
ferruginea
) and one new
Phthiracarus
species,
P. boresetosus
. Localities were chosen based not only on Koch's habitat descriptions but on
Fuernrohr's
detailed lists of the Regensburg flora published in 1839. Jacot treated the redescriptions in eonsiderable detail, identifying each species on the basis of body shape and size, and setal form and length. However, he neglected to includc details of the leg chaetotaxy which are now regarded as being essential for the Separation of
Phthiracarus
species. Although Jacot's interpretations of
crinitus
and
lentulus
correspond with those of the present study, his specimens have not been considered for neotype designation, since all are entire, uncleared and mounted together with one or more other species in Canada Balsam. In this condition, Jacot's material would not easily withstand dismounting, dissection and remounting. Further collecting at Regensburg by van der Hammen in 1959 and 1961 resulted in his description of
P. laevigatus
and the designation of a neotype. A number of other species were tentatively identified by van der Hammen (pers. comm.) as representing Koch's seven other species - this material has been examined as part of the present study. Material collected by the late Dr Max Sellnick at Regensburg, and made available to the author through the courtesy of Dr Gisela Rack, Hamburg, has also been examined in an attempt to determine the identities of Koch's
Phthiracarus
species. Unfortunately, it has not been possible to borrow any of the specimens studied by Feider and Suciu.
[....]
Survey
Of the eight
Phthiracarus
species described by C. L. Koch, six are capable of being reidentified with reasonable certainty. The two remaining species (
lucida
and
straminea
) cannot in the author's opinion be separated by any morphological characters mentioned in the original descriptions, although
lucida
was collected from a 'swampy' meadow, while
straminea
was recorded from moss in woods. However,
Phthiracarus
species are not generally considered to be habitat specific and it seems likely therefore, that Koch was in fact concerned with only one species, different specimens of which exhibited minor differences in colour.