  In this note we generalize the convolution formula for the Tutte polynomial
of Kook-Reiner-Stanton and Etienne-Las Vergnas to a more general setting that
includes both arithmetic matroids and delta-matroids. As corollaries, we obtain
new proofs of two positivity results for pseudo-arithmetic matroids and a
combinatorial interpretation of the arithmetic Tutte polynomial at infinitely
many points in terms of arithmetic flows and colorings. We also exhibit
connections with a decomposition of Dahmen-Micchelli spaces and lattice point
counting in zonotopes.
