Sennius nappi Ribeiro­Costa & Reynaud

Caron, Edilson, Ribeiro-Costa, Cibele S. & Linzmeier, Adelita M., 2004, The egg morphology of some species of Sennius Bridwell (Coleoptera: Chrysomelidae: Bruchinae) based on scanning electron micrographs, Zootaxa 556, pp. 1-10 : 5

Sennius nappi Ribeiro­Costa & Reynaud

Eggs laid singly, ovoid, 0.74 mm in length and 0.39 mm in width (n=10) ( Fig. 8 ), covered by an ornamented membranous flange composed of small triangles ( Figs. 9, 10 ). Membranous flange surrounding egg larger, smooth at one end, elongate, truncate and tubular at other end, respiratory tube 0.23 mm in length (n=10), with a small aperture ( Fig. 8 ). The size of egg and flange together are 1.07 mm in length and 0.55 mm in width (n=10).

Due to its ovoid form, the egg of S. nappi is more similar to the egg of S. bondari when compared to the other Sennius that have elongated eggs.

An ornamented membrane is found in other bruchine species as already quoted in this work. Nevertheless, the type of the ornamentation, composed of small triangles, is described for the first time.

The flange of the membrane that surrounds the egg of S. nappi is irregular, similar to those found in some other species of Bruchinae ( Johnson & Kingsolver 1975; Johnson 1978; Pfaffenberger 1979, 1981, 1986; Terán & L’Argentier 1979; Wightman & Southgate 1982; Pfaffenberger et al. 1984; L’Argentier 1990; Ribeiro­Costa 1998; Johnson et al. 2001; Ribeiro­Costa & Costa 2002).

The tube with a small aperture occurs in some species of Callosobruchus . This structure is used as a route between the exterior and interior of the egg for exchange of respiratory gases and water loss or uptake (Wightman & Southgate 1982; Credland 1992; Daniel & Smith 1994). The morphology of this tube is used for species identification as in the case of Callosobruchus (Wightman & Southgate 1982) , or for identification of strains ( Daniel & Smith 1994).

Figures

FIGURES 8 – 10. Scanning electron micrographs of Sennius nappi Ribeiro­Costa & Reynaud egg: (8) general view; (9) membrane covering the egg; (10) small triangles that compose the membrane.