M. Larrere et al., JUVENILE-HORMONE BIOSYNTHESIS AND DIAPAUSE TERMINATION IN BOMBUS-TERRESTRIS, INVERTEBRATE REPRODUCTION & DEVELOPMENT, 23(1), 1993, pp. 7-14
Corpora allata from female Bombus terrestris, incubated in a medium co
ntaining L-[methyl-H-3]methionine, released three radiolabelled produc
ts, one of which was identified as JH-III by RPLC analysis. Two others
did not correspond to any JH analogues or JH-related compounds, and t
hey remain unidentified. Exogenous farnesol stimulated JH-III biosynth
esis and suppressed the synthesis of the two unidentified products. Co
rpora allata activity was monitored throughout and after adult diapaus
e. Rates of JH-III biosynthesis were low during prediapause and diapau
se. Corpora allata reactivation occurred several days after emergence
from soil and thus seemed not to be involved in diapause termination p
rocesses. Experimental diapause breakdown revealed two phases in imagi
nal Bombus diapause: diapause development and post-diapause quiescence
. Carbon dioxide narcosis associated with 20-degrees-C, 13L/11D condit
ions provided rapid and reliable diapause termination in both diapause
phases. The mode of CO2 narcosis action is not mediated by corpora al
lata reactivation and remains to be elucidated.