Correlation of juvenile hormone titer changes with reproductive tract development in the posteclosion Monarch butterfly


The posteclosion growth of the reproductive tracts of male and female Monarch (Danaus plexippus) butterflies was quantified over a 30‐day period of storage in summer conditions. Concomitantly, the Galleria bioassay was used to quantify hemolymph juvenile hormone (JH) titers in both sexes. The data demonstrated rapid posteclosion growth, lasting for about one week, of the female ovaries and colleterial glands and the male accessory glands, tubular glands, and ejaculatory ducts. This rapid growth was not directly related to increased animal weight, but it was associated with high JH titers. The highest titers observed were found in females on the third day after eclosion. Subsequently, most of the above organs exhibited a reduced growth rate that appeared to depend upon increased body weight. Butterflies examined during this latter stage (from about 8‐30 days posteclosion) exhibited significant reductions of hemolymph JH. JH injections into both sexes showed that most organs known to be JH‐sensitive retained hormone sensitivity during the period of reduced growth. The growth of female receptacle glands and bursa copulatrix and the male testes and seminal vesicle‐vas deferens complex was not directly comparable to those organs discussed above. Copyright © 1981 Wiley‐Liss, Inc., A Wiley Company

Publication Title

Journal of Experimental Zoology