Fine structure of the egg of Trichoprosopon digitatum (Diptera: Culicidae) and its relationship to egg raft formation.
Eggs of Trichoprosopon digitatum (Rondani) occur in rafts; the anterior poles are submerged, and the posterior two-thirds float above the water surface. Each egg is approximately 1,060 microns long and 270 microns wide. The hydrophilic end is more curved dorsally than ventrally and is covered with flattened, anteriorly pointed, scalelike tubercles except for a small area around the micropyle. The hydrophobic portion is clad in a layer of closely arrayed, small, round tubercles among which are positioned much larger, flattened, anteriorly directed tubercles with deeply fissured surfaces. At three positions equidistant around the periphery of the egg, narrow, tongue-shaped extensions (the embrasures) from the anterior hydrophilic region project posteriorly into the hydrophobic region. Along these embrasures, progressing posteriorly, the tubercles change in form from flattened and bladelike to finely tapered, then, at the extension's posterior two-thirds, to long filaments with well-developed terminal hooks. Eggs in rafts are maintained in polygonal rosettes by the interlocking of these filaments and hooks and the surface tension of menisci between contiguous embrasures.
Linley
J R
JR
Florida Medical Entomology Laboratory, IFAS University of Florida, Vero Beach 32962.
Lounibos
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LP
Linley
P A
PA
D000818:Animals; D009033:Culicidae / Q000648:ultrastructure*; D005260:Female; D008855:Microscopy, Electron, Scanning; D010063:Ovum / Q000648:ultrastructure