Monkwood ponds and back swimmers Notonecta October 2011
Will Watson
On the 16th October 2011 I looked in the ponds within Monkwood with James Hitchcock, Conservation Officer at Worcestershire Wildlife Trust. I found all four native species of backswimmer; Notonecta glauca (Fig. 1.), Notonecta maculata (Fig. 2.), Notonecta viridis (Fig. 3.) and Notonecta obliqua (Fig. 4.). N. viridis was found in the round pond, N. obliqua was found in the large pond. The latter species has always been associated with ponds with low pH (acid ponds). However, I am sure the Monkwood ponds would be classed as eutrophic, but I think I heard somewhere the species is spreading. It turns up in the Wyre Forest and has always been present on the ponds on the Old Red Sandstone but localised. This is only the second time I have found all four species together; the other site was in Herefordshire.
Images
Fig. 1. Common Backswimme Notonecta glauca. ©Will Watson
Fig. 2. Spotted Backswimmers Notonecta maculata. ©Will Watson
Fig. 3. Small Backswimmer Notonecta viridis on Horned Pondweed. ©Will Watson
Fig. 4. Black Backswimmer Notonecta obliqua. ©Will Watson
Fig. 5. Monkwood pond. ©Roger Plant
Fig. 6. Monkwood pond. ©Roger Plant
Fig. 7. Monkwood round pond. ©Roger Plant
