CHEMICAL ANALYSIS OF THE REPELLENT SECRETION AND GLAND, FAT BODY AND HAEMOLYMPH OF ADULT VARIEGATED GRASSHOPPER Zonocerus variegatus (L) (ORTHOPTERA: PYRGOMORPHIDAE)
NJE Vol. 41(2): 154-174, 2025
DOI.10.36108/NJE/5202/14.0221
Odubote O.S.1, Ademolu K.O.2, Afolabi T. A.3 and Idowu, A. B.4
Department of Pure and Applied Zoology, Federal University of Agriculture Abeokuta, Abeokuta, Nigeria1,2,4
Department of Chemistry, Federal University of Agriculture Abeokuta, Abeokuta, Nigeria3
Abstract
Chemical analysis of the repellent gland and secretion, fat body and haemolymph of adult variegated grasshopper Zonocerus variegatus (L) (Orthoptera: Pyrgomorphidae) reared on Manihot esculenta and those collected from the wild were analyzed using Gas Chromatography- Mass Spectrometry (GC-MS). The chemical compounds present in the repellent gland of the reared insects were twenty-two and were classified as esters, alkanes and alkenes while six compounds were present in those collected from the wild although with more varieties and were grouped into: heterocyclic aromatic hydrocarbon (pyrazine), amine, ether, ester and alcohol. Repellent secretion of Z. variegatus reared on M. esculenta had sixteen chemical compounds grouped into heterocyclic hydrocarbon, alkane, ester, alkene. However, that of the wild had five compounds classified as heterocyclic hydrocarbon and glycoside. Irrespective of the sources, pyrazine was present in the repellent secretion of Z. variegatus, though more abundant in the wild. Sixteen compounds were identified in the fat body of the reared insects and classified into alkanes, ester, alkene while those from the wild had thirteen compounds grouped into: alkane, alcohol, nitrobenzene and amine. The haemolymph of the reared insects had sixteen compounds classified as: alkane, alkene, acid and ester while that of the wild had seventeen compounds grouped as alkane, ester, nitrobenzene, aldehyde, heterocyclic hydrocarbon, acid, glycoside and alcohol. This study shows that the smell associated with Zonocerus variegatus is by the presence of pyrazine and esters containing sulphur present in the repellent gland and secretion.
Keywords: Zonocerus variegatus, Repellent gland, Repellent secretion, Pyrazine, Chemical compounds