BASIS OF THE PREDOMINANCE OF MALE-FEMALE ASSOCIATION IN THE DOUBLE COCOONS OF SILKWORM, BOMBYX MORI L.
K. SASHINDRAN NAIR *
CENTRAL SERICULTURAL RESEARCH AND TRAINING INSTITUTE, SRIRAMPURA, MYSORE -570008, INDIA.
JULA S. NADIR *
CENTRAL SERICULTURAL RESEARCH AND TRAINING INSTITUTE, SRIRAMPURA, MYSORE -570008, INDIA.
KANIKA TRIVEDY *
CENTRAL SERICULTURAL RESEARCH AND TRAINING INSTITUTE, SRIRAMPURA, MYSORE -570008, INDIA.
S.B. MAGADIUM *
CENTRAL SERICULTURAL RESEARCH AND TRAINING INSTITUTE, SRIRAMPURA, MYSORE -570008, INDIA.
*Author to whom correspondence should be addressed.
Abstract
Double cocoons of silkworm Bombyx mori (NB4D2 x KA and PM X NB4D2) were collected and the pupal sex
association was examined. Male-female pupal association occurred more frequently than male-male and femalefemale
in double cocoons formed in normal populations of silkworm larvae. The percentage occurrence of male-male,
male-female and female-female association was 26.8, 51.2 and 22.0 respectively in NB4D2 XKA and 27.2, 50.0 and
22.8 respectively in PMX NB4D2. The overall participation of male larvae in double cocoon formation was found more
than that of females. When male and female larvae were made to spin separately, the double cocoons formed had
either male-male association or female-female association depending on the treatment. This study, for the first time
proves that the predominance of male-female sex association in the double cocoons is not due to any affinity
between the opposite sexes but only due to the random encounter of male and female larvae during spinning