Integumental grafting and immunorecognition in insects

In preliminary experiments, integumental grafting was conducted on a range of insect species in order to elucidate levels of insect immunorecognition. Subsequently, however, only Blaberus craniifer and Extatosoma tiaratum were utilised for detailed study because of their high survival rates and longevity. In both host species, most autografts and allografts rapidly healed and were accepted while xenografts usually became melanized and were rejected. A significant correlation was obtained between the mean rejection times, which ranged from 8.0 +/- 1.8 days to 28.2 +/- 6.6 days, and the phylogenetic relatedness of the xenograft donors to the host species. A preliminary histological investigation revealed the accumulation of blood cells below the grafts, a process that was much more marked with xenografts than with autografts.