Juvenile hormones (JHs) are a group of acyclic sesquiterpenoids that regulate many aspects of insect physiology. JHs being secreted by a pair of endocrine glands behind the brain called the corpora allata, regulates the development, reproduction, diapause, and polyphenisms. It refers to a group of hormones, which ensure growth of the larva, while preventing metamorphosis. Because of their rigid exoskeleton, insects grow in their development by successively shedding their exoskeleton (a process known as molting).

The effect of this hormone in any organism particularly in insects, depends upon three main factors

1. Hormone titre

2. Interaction between hormone and cellular receptors and

3. Regulation of hormone or hormone-receptor-complex transcriptional pathway.

So, for dealing any particular factors, viz., hormone titre you must follow its position within that organism. In the juvenile phase of insects, this hormone can be synthesized by isolating corpora allata, where it available in abundance, but its concentration gets restricted in the adult hemolymph.

for identifying the Juvenile Hormone titre in chemically treated insects, best way would be the collection of hemolymph where it gets accumulated and distributed throughout because of significant positive correlation between rates of hormone synthesis and concentration in the hemolymph.

Following collection, Hemolymph samples (5–10 µl) should be diluted in 2 ml methanol containing 0.5 pmol ethyl ester homologues of JH I and JH III as internal standards and probing them for the measurement by combined gas chromatography-selected ion monitoring mass spectrometry (GC-MS-SIM).

Have a good Luck!!!!

RT

Thank you Aarti for your valuable suggestion