Rethinking the early medieval settlement of woodlands: evidence from the western Sussex Weald

The assumptions underlying the interpretation of the early medieval settlement of woodland are challenged through a detailed study of the Weald in western Sussex. The patterns of usage of woodland in England were very varied, and each area needs to be looked at individually. Systems of woodland exploitation did not simply develop from extensive to intensive, but may have taken a number of different forms during the early medieval period. In one area of the Weald, near to Horsham, the woodland appears to have been systematically divided up between different estates. This implies that woodland settlement may not always have developed organically, but this type of landscape could have been planned. It is argued that the historical complexity of woodland landscapes has not been recognised because the evidence has been aggregated. Instead, each strand of evidence needs to be evaluated separately.

Widespread dispersal of the microsporidian Nosema ceranae, an emergent pathogen of the western honey bee, Apis mellifera

The economically most important honey bee species, Apis mellifera, was formerly considered to be parasitized by one microsporidian, Nosema apis. Recently, [Higes, M., Martin, R., Meana, A., 2006. Nosema ceranae, a new microsporidian parasite in honeybees in Europe, J. Invertebr. Pathol. 92, 93-95] and [Huang, W.-F., Jiang, J.-H., Chen, Y.-W., Wang, C.-H., 2007. A Nosema ceranae isolate from the honeybee Apis mellifera. Apidologie 38, 30-37] used 16S (SSU) rRNA gene sequences to demonstrate the presence of Nosema ceranae in A. mellifera from Spain and Taiwan, respectively. We developed a rapid method to differentiate between N. apis and N. ceranae based on PCR-RFLPs of partial SSU rRNA. The reliability of the method was confirmed by sequencing 29 isolates from across the world (N = 9 isolates gave N. apis RFLPs and sequences, N = 20 isolates gave N. ceranae RFLPs and sequences; 100%, correct classification). We then employed the method to analyze N = 115 isolates from across the world. Our data, combined with N = 36 additional published sequences demonstrate that (i) N. ceranae most likely jumped host to A. mellifera, probably within the last decade, (ii) that host colonies and individuals may be co-infected by both microsporidia species, and that (iii) N. ceranae is now a parasite of A. mellifera across most of the world. The rapid, long-distance dispersal of N. ceranae is likely due to transport of infected honey bees by commercial or hobbyist beekeepers. We discuss the implications of this emergent pathogen for worldwide beekeeping. (c) 2007 Elsevier Inc. All rights reserved.