NINHYDRIN-POSITIVE SUBSTANCE ANALYSIS OF LARVAL HEMOLYMPH OF THE EASTERN HEMLOCK LOOPER, LAMBDINA FISCELLARIA FISCELLARIA (LEPIDOPTERA: GEOMETRIDAE) AND GROWTH OF ENTOMOPHTHORA EGRESSA PROTOPLASTS

Abstract

AbstractA ninhydrin-positive substance analysis of fourth instar larval hemolymph of the eastern hemlock looper, Lambdina fiscellaria fiscellaria (Guenée), was conducted. Two separate larval populations were reared on a defined diet during the early stages and later on fresh, young balsam fir foliage. The results indicated the presence of at least 38 compounds. L-glutamine and(or) L-asparagine, L-histidine, and L-lysine occurred at high concentrations (> 5000 nM/ml). Ammonia, L-arginine, L-threonine, L-serine, L-glutamic acid, glycine, L-alanine, L-valine, L-isoleucine, L-leucine, L-tyrosine, and L-phenylalanine occurred at intermediate levels (1000–5000 nM/ml). The current report of the presence of L-1-methylhistidine and L-3-methylhistidine is the second report of any methylated derivative of histidine in insect hemolymph. The results of the analytical study were used to modify the composition of Grace’s insect tissue culture medium which had previously been found to support growth of protoplasts of the looper pathogen Entomophthora egressa MacLeod and Tyrrell. Fungal growth indicated a shorter generation time (4.7 h) on the medium modified to more closely approximate the looper hemolymph as compared with the generation time (6.2 h) on Grace’s medium.