070 PROTOZOOLOGY 



(Pasteur, 1870; Stempell, 1909; Kudo, 1916; Hutchinson, 1920; 

 Jameson, 1922), Nosema-disease of honey bees (Zander, 1911; 

 White, 1919; Farrar, 1947), microsporidiosis of mosquitoes (Kudo, 

 1921-1930), etc. Taxonomy (Leger and Hesse, 1922; Kudo, 1924b; 

 Jfrovec, 1936; Weiser, 1947); the polar filament (Kudo, 1913, 1918, 

 1924b; Morgenthaler, 1922; Ohshima, 1927, 1937). 

 The Microsperidia are subdivided into two suborders: 



Spore with a single polar filament Suborder 1 Monocnidea (p. 070) 



Spore with 2 polar filaments Suborder 2 Dicnidea (p. 078) 



Suborder 1 Monocnidea Leger and Hesse 



Spore oval, ovoid, or pyriform, if subcylindrical length less than 4 times 



breadth Family 1 Nosematidae 



Spore spherical or subspherical Family 2 Coccosporidae (p. 070) 



Spore tubular or cylindrical, width less than 1/5 length, straight or curved 

 Family 3 Mrazekiidae (p. 070) 



Family 1 Nosematidae Labbe 



The majority of Microsporidia belong to this family. 



Genus Nosema Nageli. Each sporont develops into a single spore. 

 Numerous species. 



N. bombycis N. (Fig. 289, a, b). In all tissues of embryo, larva, 

 pupa and adult of Bombyx mori; spores 3-4/z by 1.5-2/z, polar fila- 

 ment 57-72/z long when extruded; advanced infection is character- 

 ized by numerous minute brownish-black spots scattered over the 

 body surface, which gave rise to such names as pebrine disease 

 (France), Fleckenkrankbeit (Germany), Biriushi-Bio (Japan), Cota 

 (India), etc. (Fig. 289, b) to the disease; heavily infected larvae can- 

 not spin cocoon and perish; the organisms invade, and develop in, 

 ova so that newly hatched larvae are already infected with this mi- 

 crosporidian. Viable spores introduced per os bring about infections 

 in Arctia caja (Stempell, 1909), Margarnia pyloalis, Chilo simplex 

 (Ohshima, 1935), and Hyphantria cunea (Kudo and DeCoursey, 

 1940). Morphology and Development (Stempell, 1909; Kudo, 1924b). 



N. bryozoides (Korotneff) (Fig. 289, c, d). In the germ cells and 

 cavity of the bryozoans, Plumatella fungosa and P. repens; spores 

 7-10/x by 5-6 M (Braem, 1911; Schroder, 1914). 



N. apis Zander (Fig. 289, e-g). In the mid-gut of honey bees; spores 

 4-6^ by 2-4 n; the extruded filament shows often 2 sections of differ- 

 ent undulations (Fig. 289, g) (Kudo, 1921a). The infection is con- 

 fined to the digestive system, but the ovary of an infected queen bee 

 undergoes various degrees of degeneration depending on the extent 

 of the gut infection (Fyg, 1945; Farrar, 1947; Hassanein, 1951), 



