A: Minimum spanning network for the 43 cloned sequences of the SSU rDNA region studied, and the published sequence of G. caledia (L31799). Each link between haplotypes indicates one mutation, including indel events. The colors indicate the species or subspecies of the host. This network was inferred using POPART [25]. B: Distribution of the 22 polymorphic positions in SSU rDNA locus regions V1-V8 (1638-bp), between type 1 (presumably G. garnhami) (n = 20) and type 2 (presumably G. acridiorum) (n = 23) sequences, amplified from gregarines parasitizing respectively S. gregaria and L. migratoria. The corresponding positions are also given for G. caledia (L31799, 1210 bp) parasitizing Caledia captiva. Eleven additional positions, otherwise conserved between G. garnhami and G. acridiorum sequences, are modified in G. caledia sequence: site 1059, G deletion; sites 1161-1164: GAGC substituted by AG-G; site 1181: G substituted for C; site 1187: G substituted for A; sites 1231 and 1240: T substituted for C; site 1493: T insertion; site 1584: G substituted for A.