Beetles with Orchid Pollinaria in Dominican and Mexican Amber
Author
George Poinar, Jr.
text
American Entomologist
2016
62
3
172
177
journal article
10.1093/ae/tmw055
42c2df7b-ac89-4f7a-a95f-6470ac40a533
269236
Cylindrocites browni
gen. n.,
sp. n.
(
Figs. 1-3
,
7
A)
Etymology
: Generic name from the Latin “cylinder” = cylindrical. Specific epithet named for amber collector Alex E. Brown.
Type
:
Holotype
in the Poinar amber collection maintained at Oregon State University (Cat. No. Sy-1-191).
Type
locality
: Amber mine in Altimira facies of the El Mamey Formation in the Cordillera Septentrional of
the Dominican
Republic (DD 71’23 by 19’ 34).
Diagnosis
: Pollinarium elongate, cylindrical with pollinia closely appressed; caudicles inconspicuous, viscidia terminal, round.
Description
: Pollinarium elongate, cylindrical, 2.0 mm in length, composed of two tightly appressed pollinia, each
1.8 mm
long,
0.3 mm
wide; exposed surface of outer pollinium with a distinctive pattern of dark bars and spots; caudicles inconspicuous; viscidium spherical,
0.3 mm
in diameter; pollen tetrads spherical, 18 µm–24 µm in diameter.
Remarks
: The long, cylindrical pollinia of
Cylindrocites browni
gen. n.
,
sp. n.
resemble those of the genera
Dichromanthus
Garay
,
Cyclopogon
C. Presl
and
Schiedeella
Schltr.
of the orchid Subtribe
Spiranthinae
that are found today in
Mexico
, the West Indies, and Central America. In these orchids, caudicles and stipes are absent and dimensions of the pollinia range from
1.3 mm
to
9.8 mm
in length and
0.4 mm
–
0.8 mm
in width (
Damon and Nieto 2012
), which compares with those of
Cylindrocites browni
n. gen.
,
n. sp.
Fig. 3. Lateral view of pollinarium of
Cylindrocites browni
gen. n.
, sp. n. attached to weevil. V
=
viscidium. Top arrow shows mucoid connection between viscidium and weevil. Bar
=
0.4 mm. Insert shows pollen tetrads (arrow) inside pollinium. Scale
= 60 µm.
The pattern of dark bars and spots on the exposed surface of the outer pollinium is curious, as the coloration can hardly be due to darker pollen tetrads in those areas. It possibly represents the remains of the thecal wall or some other covering (elastoviscin?) on the pollinium. The weevil (length = 4.0 mm) is a member of the
Cryptorhynchini
Schoenherr (
Coleoptera
:
Curculionidae
), a group known as the “hidden snout weevils” because in repose, the beak is partly concealed against the thorax and between the front coxae. The larvae breed in stems or wood and the adults are known to visit flowers (
Blatchley and Leng 1916
).
Cryptorhynchinae
were quite diverse in
the Dominican
amber forest (Poinar and
Legalov 2013
).
The pollinia are attached to the anterior portion of the pronotum of the weevil by a mucus-like sticky deposit (viscidium) (
Fig. 3
). The wee- vil is resting on one of two petals (length=
14 mm
, great- est width =
8 mm
) (
Fig. 1
). The petals are joined mid- way; however, the ends of both are missing, so the actual dimensions, degree of fusion, and whether they are from the orchid cannot be determined.