While honey bees appear to have maintained each of the known insect immune-related pathways, they appear to do so with a reduced number of paralogous members. When comparing a set of 17 gene families and functional groups implicated in immune responsiveness (Christophides et al ., 2002) , honey bees have substantially lower paralogue counts than either Drosophila or Anopheles (Table 1 ). The 71 genes placed into these groups for honey bees are in sharp contrast to the 196 and 209 found in Drosophila or Anopheles , respectively. Bees have the lowest gene counts for 12 of the 17 families and are tied for the lowest count two more times. Drosophila and Anopheles were lowest for only one family each (defensins and dorsal, respectively). In contrast, Drosophila and Anopheles show the highest paralogue counts for this triad seven and eight times, respectively, versus once in bees (for the Toll-pathway candidate cactus, with three copies). These rankings are significantly different under an ordinal contingency-table analysis ( P < 1.0 × 10 -4 ), and reflect differences for genes involved with pathogen recognition and signalling, as well as effectors.