Tenebrio molitor(Coleoptera): effect of metacestodes ofHymenolepis diminuta(Cestoda) on haemolymph amino acids

Abstract

SummaryHaemolymph free amino acids (HFAAs) in adultTenebrio molitorvaried in concentration with beetle age. Between 9 and 30 days post-emergence the concentration range was 34–94 mMwith a peak occurring in 15-day-old insects. Much of this age-related variation was due to changes in the concentration of a single amino acid, proline. An analysis of concentrations of individual HFAAs in 15-day-old beetles, following infection with metacestodes ofHymenolepis diminuta, revealed that changes in female insects are more marked than those occurring in males. In the former, changes occurred in the concentration of 9 amino acids (isoleucine, leucine, arginine, serine, threonine, tyrosine, phenylalanine, proline and alanine/citrulline) whereas in the latter only 4 amino acids were affected (threonine, glycine, histidine and arginine). It is suggested thatH. diminutamay interact with the endocrine system of its beetle host.