Cylindrocites browni, George Poinar, Jr., 2016

George Poinar, Jr., 2016, Beetles with Orchid Pollinaria in Dominican and Mexican Amber, American Entomologist 62 (3), pp. 172-177 : 173

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.

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.

Figures

Fig. 1. Dominican amber cryptorhynchid weevil with attached pollinarium (arrow) of Cylindrocites browni gen. n., sp. n. Floral remains in background. Scale = 3.0 mm.

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.

Fig. 7. Outlines of pollinaria of Cylindrocites browni gen. n., sp. n. (A) and Annulites mexicana gen. n., sp. n. (B). Arrows show viscidia.