Scanning Electron Microscopy of the Eggs of Aedes scapularis from Southern South America

DOS SANTOS MALLET, J.R.; MULLER, G.A.; GLEISER, R.M.; ALENCAR, J.; MARQUES W.A.; SARMENTO J.S.; MARCONDES C.B.

JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION

AMER MOSQUITO CONTROL ASSOC

Año: 2010 vol. 26 p. 205 - 209

8756-971X

The eggs of Aedes scapularis analyzed by scanning electron microscopy are black and elliptical in outline, measuring approximately 620.4 ± 16.74 µm long and 163.7 ± 16.90 µm (n = 10) wide, with an egg index (length/width ratio) of 3.79. The anterior extremity tapered abruptly from a width of 51.6 µm, while such tapering was more gradual at the posterior extremity, from a width of 61.4 µm. The ventral surface of the chorionic coating presented cells with a tubular aspect containing tubercles in rows at a density of 5 to 9 per cell with 2 different sizes, the largest measuring 7.23 ± 0.98 µm in a longitudinal diameter and the smallest 4.15 ± 0.53 µm (n = 30). In the dorsal region, the external chorionic reticulum had a porous appearance, and its thickness ranged from 2.5 to 4.1 µm. Isolated tubercles presented wide variation per cell. In the central region of some chorionic cells were tubercles of greater diameter, characterized as central tubercles of 8.45 ± 0.67 µm, and around them 3 to 5 smaller tubercles measuring 2.57 ± 0.26 µm. The micropylar apparatus presented a collar with a very evident molding and edges with defined margins for the transition area and a thickness of around 11.1 µm. The micropyle disc margins were raised, measuring around 17.8 µm in diameter and 229 µm in circumference. The micropyle orifice was very evident, with a diameter of 1.41 µm.