Effects of spatial variation on the chemical composition of the frontal gland of soldiers of \textit{Constrictotermes cyphergaster} in a semiarid region of Northeastern Brazil

The frontal gland of soldiers presents a great diversity of substances including alcohols, monoterpenes, diterpenes, sesquiterpenes, which constitute the defensive secretion. This study evaluated the composition of substances present in the frontal gland of soldiers of \textit{Constrictotermes cyphergaster} collected in 10 nests of two caatinga areas (FAL and SJC) in the state of Paraíba, Brazil. With a distance of 50 km between them, the areas showed noticeable differences in temperature (FAL: 25.28°C / SJC: 31.48°C) and air humidity (FAL: 66.6% / SJC: 36.6%). Hexanic extracts were produced from 20 heads of soldiers (five replicates per nest/area) and analyzed by gas chromatography coupled to quadrupole mass spectrometer. A total of 30 substances were identified for FAL populations (45.52% monoterpenes, 35.18% sesquiterpenes, 9.21% benzenoids) and 31 for SJC (53.68% monoterpenes, 27.28% sesquiterpenes, 9.11% benzenoids). The α-pinene was the main component identified for all samples (FAL: 28.86% / SJC-27.59%). The other major compounds differed according to the locality (FAL: γ-amorphene - 6.42%, β-caryophyllene - 4.23%, Limonenoe - 3.95% / SJC: β-pinene - 8.45%, Sylvestrene - 5.63%, Limonene - 4.91%). Despite the chemical similarity in qualitative terms, exclusive compounds were identified for populations of each area (FAL: Camphene - 2.25% / SJC: Limonen10-ol - 0.55%; (E)-γ- bisabolene – 0.78%). There was a significant difference between the chemical groups of each area (MANOVA: F1,8=17887.7; P