Quali-quantitative variations in \textit{Constrictotermes cyphergaster} instars (Termitidae, Nasutitermitinae) in dryland Caatinga vegetation in northeastern Brazil

\textit{Constrictotermes cyphergaster} is a termite species that constructs arboreal nests and is very abundant in Caatinga vegetation. We investigated the quali-quantitative temporal variations in \textit{C. cyphergaster} instars in nests collected in the municipality of São João do Cariri, Paraíba State, Brazil. Five nests were collected every 60 days between October/2011 and August/2012, totaling 30 nests. To estimate nest populations, five subsamples of 5 ml were removed from each colony and all of the instars counted. The nests had mean volumes of 72.6 ± 22.5 L. Their total estimated populations varied from 23,021 to 128,113 individuals/nest. The apterous population varied from 22,958 to 127,178 individuals/nest, and the nymphal population varied from 0 a 5,109 individuals/nest. There were significant differences in the populations of workers (F=5.26, p<0.05), soldiers (F=5.69, p<0.05), pre-soldiers (F=6.26, p<0.05), larvae 2 (F=4.29, p<0.05), nymphs 5 (F=5.17, p<0.05), and alates (F=3.84, p<0.05) during the different months of the year. Workers, pre-soldiers, and larvae 2 were most abundant in February, and soldiers in April. In relation to the presence of nymphal instars: N1 were present in April and June; N2 and N3 were absent in October and December; N5 were present in December and February; and alates were observed only in February. The fourth nymphal instar were observed throughout the year. As February was the month with the greatest rainfall, our results should reflect a high energetic investment in terminal nymph instar differentiation before swarming; with subsequent greater differentiation of apterous lineage and initial nymphal instars.