An incredibly rare and mysterious bug. It is currently only found at six ponds in the country.
The Pondweed Leafhopper Erotettix (=Macrosteles) cyane is a very rare little bug, just 5mm in length (image from species dossier), which is currently only found in six ponds in South East England. It is exclusively found in ponds on its only food plant, Broad-leaved Pondweed. This diminutive invertebrate has a characteristic bright blue dusty coating which easily rubs off to reveal a dark blue undercoat. It is worth remembering that several other leafhopper species live in the vegetation around ponds – these can be disturbed as you approach the pond and may fall into the water or onto pondweed leaves close to the pond margin. If these individuals are not blue in colour and or they head back to shore, they are unlikely to be Pondweed Leafhopper.
Adults and juveniles feed on the floating leaves of Broad-leaved Pondweed, Potamogeton natans. This host plant is relatively widespread but the Pondweed Leafhopper has apparently always been rare. There are still a lot of unanswered questions about the habitat requirements of the Pondweed Leafhopper. The sites occupied include long established ponds, newly created ponds and a former brick works.
The Pondweed Leafhopper has been recorded from both clay ponds and clay-lined chalk ponds, which suggests that it has a preference for circumneutral to mildly acidic ponds. Broad-leaved Pondweed seems able to withstand some fluctuation in water levels but is generally found in more permanent ponds.
Very little is known about the life cycle of Pondweed Leafhopper. Nothing is known about how the species disperses naturally and no one has studied how it survives the winter or where it lays its eggs.
Distribution and threats
Pondweed Leafhopper is very vulnerable to extinction. If conditions at any one of the ponds where it is currently found became unsuitable a large proportion of the population would be lost. Without fully understanding this species’ ecology it is difficult to say for certain what are the principle threats are. However this species is likely to be affected by the main issues impacting most freshwater life: pollution, changes in land management and loss of grazing. All the places it has been found so far are amongst the very highest quality unpolluted, rich ponds.