Behavioral characters of the mature silkworm, Bombyx mori, and mode of inheritance

• Published in: Bulletin of the National Institute of Sericultural and Entomological Science (Japan) no. 20
• Main Authors: Ninagi, O. (National Inst. of Sericultural and Entomological Science, Tsukuba, Ibaraki (Japan)), Mikuni, T, Maruyama, M, Nagayasu, K
• Format: Journal Article
• Language: Japanese
• Published: 01.01.1998
• Subjects: BEHAVIOUR; BOMBYX MORI; CAPULLOS; COCON; COCOONS; COMPORTAMIENTO; COMPORTEMENT; COMPORTEMENT ALIMENTAIRE; FEEDING HABITS; GENETIC VARIATION; HABITOS ALIMENTARIOS; HEREDABILIDAD; HERITABILITE; HERITABILITY; LARVAE; LARVAS; LARVE; VARIACION GENETICA; VARIATION GENETIQUE
• ISSN: 0915-2652

Behavior of the mature larvae of the silkworm, Bombyx mori, is closely related to the efficiency of the mounting work for cocooning. Geotaxis dispersal and phototaxis were investigated in order to save labor for the mounting work. Then, in some strains which showed special behavioral characteristics, the mode of inheritance was studied by crossbreeding experiments. 1) Geotaxis of the mature larvae was essentially negative, because larvae moving downward were hardly recognized in every stain. The level of geotaxis in each strain and race ranged from active to extremely weak. Consequently, the difference among strains were detected. In the crossbreeding experiments, it was concluded that the inheritance of geotaxis depended on polygenes and was controlled by some major genes which were non-allelic abased on the gene dosage effect in the BF1 generation, though active behavior in negative geotaxis was a dominant character in the F1 hybrids. 2) Dispersal of the mature larvae also varied, ranging from strains which dispersed actively to strains which scarcely moved. The difference was distinctive. 3) Phototaxis of the mature larvae was classified into three types by the direction of the movement: type 1 stains in which mature larvae always moved toward the light, type 2 strains in which larvae moved toward the light at a low illuminance and moved to the opposite site from the light at a high illuminance, and type 3 strains in which mature larvae always moved toward darker areas. Besides, some strains showed either a strong reaction to light, a weak reaction or an intermediate reaction. Phototaxis was also characterized by polygenic inheritance and was controlled by some major genes as geotaxis, though positive phototaxis was a dominant character in the F1 hybrids