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

__
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