[...] Though extremely rare nowadays north of the Humber, it seems that a small north eastern population still survives. In Durham, Robson reported its presence along the lower Tees at Hartlepool, Darlington and Stockton as being quite a regular occurrence, and even as far north as Bishop Auckland and Durham City. Since then, there had been no sign of it until comparatively recently when a single specimen was taken in the Middleton-in-Teesdale trap in September 1974. There has been a recent shortage of workers in the south of the county, but even so it looks as if there has been some reduction in the abundance of the species.