Evidence for trail-pheromone precursor in termiteReticulitermes speratus (Kolbe) (Rhinotermitidae: Isoptera)

Area of Science:

• Chemical Ecology
• Insect Behavior
• Organic Chemistry

Background:

• Termites utilize chemical signals for navigation and social communication.
• Trail pheromones are crucial for termites to find food and return to their nests.
• The exact precursor and storage form of termite trail pheromones are not fully understood.

Purpose of the Study:

• To investigate the presence and nature of trail-pheromone precursors in Reticulitermes speratus.
• To identify the chemical structure of the active trail-following compound and its precursor.

Main Methods:

• Whole body termite extracts were fractionated using silica gel column chromatography.
• Fractions were subjected to alkaline hydrolysis and subsequent bioassays for trail-following activity.
• Chemical analysis, including structural elucidation, was performed on the active compounds.

Main Results:

• Hexane extracts yielded fractions rich in fatty acid esters.
• Trail-following activity was significantly enhanced (approx. 20-fold) after alkaline hydrolysis.
• The hydrolyzed product's chemical structure was identified as (Z,Z,E)-3,6,8-dodecatrien-1-ol, the native termite trail pheromone.

Conclusions:

• Reticulitermes speratus stores trail-pheromone precursors in an esterified form.
• Alkaline hydrolysis releases the active trail pheromone, (Z,Z,E)-3,6,8-dodecatrien-1-ol.
• This finding elucidates the storage mechanism and chemical nature of termite trail pheromone precursors.