Abstract. 1. For the first time, long-term changes in total aerial insect biomass have been estimated for a wide area of Southern Britain.2. Various indices of biomass were created for standardised samples from four of the Rothamsted Insect Survey 12.2 m tall suction traps for the 30 years from 1973 to 2002.3. There was a significant decline in total biomass at Hereford but not at three other sites: Rothamsted, Starcross and Wye.4. For the Hereford samples, many insects were identified at least to order level, some to family or species level. These samples were then used to investigate the taxa involved in the decline in biomass at Hereford.5. The Hereford samples were dominated by large Diptera, particularly Dilophus febrilis, which showed a significant decline in abundance.6. Changes in agricultural practice that could have contributed to the observed declines are discussed, as are potential implications for farmland birds, with suggestions for further work to investigate both cause and effect.

Genetic diversity is the determinant for pest species' success and vector competence. Understanding the ecological and evolutionary processes that determine the genetic diversity is fundamental to help identify the spatial scale at which pest populations are best managed. In the present study, we present the first comprehensive analysis of the genetic diversity and evolution of Rhopalosiphum padi, a major pest of cereals and a main vector of the barley yellow dwarf virus (BYDV), in England. We have used a genotyping-by-sequencing approach to study whether (a) there is any underlying population genetic structure at a national and regional scale in this pest that can disperse long distances; (b) the populations evolve as a response to environmental change and selective pressures; and (c) the populations comprise anholocyclic lineages. Individual R. padi were collected using the Rothamsted Insect Survey's suction-trap network at several sites across England between 2004 and 2016 as part of the RIS long-term nationwide surveillance. Results identified two genetic clusters in England that mostly corresponded to a North-South division, although gene flow is ongoing between the two subpopulations. These genetic clusters do not correspond to different life cycle types, and cyclical parthenogenesis is predominant in England.

This chapter describes several methods for management and control of Oestridae flies, including those used for biological, mechanical, environmental, chemical, genetic (i.e., sterile insect technique), and immunological control.

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17Genetic diversity is determinant for pest species' success and vector competence. Understanding the 18 ecological and evolutionary processes that determine the genetic diversity is fundamental to help 19 identify the spatial scale at which pest populations are best managed. In the present study, we 20 present the first comprehensive analysis of the genetic diversity and evolution of Rhopalosiphum 21 padi, a major pest of cereals and a main vector of the barley yellow dwarf virus (BYDV), in Great 22Britain. We have used a genotype by sequencing approach to study whether i) there is any 23 underlying population genetic structure in this long distant disperser pest at a national and regional 24 scale; ii) the populations evolve as a response to environmental change and selective pressures, and; 25 iii) the populations comprise anholocyclic lineages. Individual R. padi were collected using the 26Rothamsted Insect Survey's suction-trap network at several sites across England between 2004 and 27 2016 as part of the RIS long-term nationwide surveillance. Results identified two genetic clusters in 28Great Britain that mostly paralleled a North -South division, although gene flow is ongoing between 29 the two subpopulations. These different groups do not correspond to sexual and asexual types, 30 sexual reproduction being predominant in Great Britain, and could correspond to ecotypes. Results 31 also show that there is migration with gene flow across Great Britain, although there is a reduction 32 between the northern and southern sites with the Southwestern population being the most 33 genetically differentiated. There is no evidence for isolation-by-distance and other factors like 34 primary host distribution could influence the migration patterns. Finally, results also show no 35 evidence for the evolution of the R. padi population, and it is demographically stable despite the 36 ongoing environmental change. These results are discussed in view of their relevance to pest 37 management and the transmission of BYDV. 38