GC-MS Investigation of Volatiles from Honeybee Worker Larvae and Larval Food at Different Instars

(E)-β-ocimene was the only found volatile chemical emitted by whole, live worker larvae of Apis mellifera L. by sampling in the vapor phase. While in addition to (E)-β-ocimene, there is evidence for the existence of other volatiles; but the changes of their composition and contents remain unknown during larval development, as are their differences from larvae to larval food. This is the main purpose of the study. We investigated volatile components of worker larvae and larval food using solid phase dynamic extraction (SPDE) coupled with gas chromatography-mass spectrometry (GC-MS). Nine compounds were identified with certainty and six tentatively, consisting of terpenoids, aldehydes, hydrocarbons, ester and ketone. The contents of volatiles of the second-instar worker larvae differ greatly from larvae of other stages mainly attributable to terpenoids, which made the second-instar worker larvae had significantly higher amounts of overall volatiles. Larval food contained significantly higher amounts of aldehydes and hydrocarbons than the corresponding larvae from the fourth to fifth-instar. We discovered volatiles in worker larvae and their food which were never reported before; we also mastered the change of these volatiles’ contents during larval development.