INSECUTOR INSCITI^ MENSTRUUS 61 



EGGS AND OVIPOSITION IN CERTAIN SPECIES 

 OF MANSONIA 



(Dipt era; Culicid<s) 



By HARRISON G. DYAR and FREDERICK KNAB 



The writers, in 1910, briefly reviewed what was then known 

 concerning the developmental stages in the genus Mansonia.^ 

 Somewhat fuller data appear in a later work f however, as far 

 as the eggs are concerned, no new data have been made avail- 

 able within the last eight years. The eggs of but three Ameri- 

 can species, fasciolatus Arrib., arribalzagce Theob., and per- 

 turbans Walk., have been made known, the first two by Goeldi,' 

 the last by several North American writers.* In these forms 

 the eggs do not differ greatly in shape, arrangement, and man- 

 ner of disposal from eggs of typical Culex. They are sub- 

 cylindrical, slightly tapered toward one end and rounded at 

 both extremities. They are placed upright, in contact along 

 their sides and with the broader end downward, thus condi- 

 tioning the convex lower surface of the egg-boat. These egg- 

 boats float upon the surface of the water, one end usually rest- 

 ing against an aquatic plant. 



There is some difference in the arrangement of the eggs 

 in the three species. In Mafisonia perturbafis they form the 

 usual roughly elliptical boat-shaped mass. In M. fasciolatus 

 and M. arribalsagce the eggs, while placed upright and in con- 

 tact as in M. perturbans, are arranged in a long double row 

 consisting of about 120 eggs in all ; this long band is gently 

 convex on its lower surface, in consequence of the slight up- 

 ward taper of the eggs. 



The eggs of Mansonia titillans, the type of the genus, have 



•The genus Mansonia. Entom. News, xxi, 1910, 2.59-264. 



'Howard, Dyar and Knab. The Mosquitoes of North and Central America 

 and the West Indies, iii, 1915, p. 50.3 et seq. 



'Os Mosquitos no Para. Boll. Mus. Paraense, 1902, p. 27, and Mem. Mus. 

 Goeldi, iv, 1905, p. 106, pi. G. 



*Dyar and Currie. Proc. Ent. Soc. Wash., vi, 1904, 218-219. Smith, John 

 B.. Entom. News, xix, 1908, 22. 



