3.1.4.1. Marking SHB larvae

Coloured food is a good method to mark SHB larvae.

  1. Dissolve 1 g of the dye (Sudan Blue 670, Sudan M Red, Rhodamine B; S. Spiewok, unpublished data) in 9 g olive oil to obtain a stock solution.
  2. Stir 3 g stock solution into 57 g honey.
  3. Mix the honey with 90 g powdered pollen to obtain dye-concentrations of 2,000 ppm.
  4. Fill 10 g of the coloured food into small containers with lids ventilated with tiny holes that allow airflow but prevent escape of SHB larvae.
  5. Place 10 young larvae (see section 3.1.2.1.) into each container and incubate for 8 days at 30°C till they reach the wandering stage.
  6. Wandering larvae fed with Sudan Blue 670 will show green coloration. Sudan M Red results in reddish and Rhodamine B in violet coloured larvae.

Note: Feeding SHB larvae with food colours showed no decent results in the adults after metamorphosis (S. Spiewok, unpublished data).