Tanysphyrus lemnae (Paykull, 1792)

duckweed weevil

on Lemna, etc.

Spirodela polyrhiza, Belgium, prov. Antwerp, Laakdal,de Roost, 5.ix.2021 © Carina Van Steenwinkel: occupied mijn

larva, about to swim to a new leaf

mine

In duckweed the female eats a hole in the upper side, deposits an egg, and covers it with frass. The larva completely eats the content of the thallus, then moves, swimming if necessary, to other thalli that also ware mined out. Frass in thick lumps. Pupation in the soil or among water plants washed ashore.

The mine in Calla is a fan of strongly branched corridors, radiating from the leaf base. This very different aspect has originally been described as T. callae.

host plants

Araceae, oligophagous

Calla palustris; Lemna minor; Spirodela polyrhiza.

BENELUX

BE recorded (Curculionidae.be, 2010).

NE recorded (Vorst, 2010a).

LUX not recorded (Fauna Europaea, 2009).

distribution within Europe

From Fennoscandia to the Pyrenees, Sardinia and Italy, and from Britain to Poland; also Bulgaria (Fauna Europaea, 2009); introduced in North America.

synonyms

Tanysphyrus callae Voss, 1943.

references

Ahr (1966a), Dieckmann (1983a), Hering (1957a), Pešić (2000a), Rheinheimer & Hassler (2010a), Sønderup (1949a), Urban (1922b, 1926a), Vorst (2010a), Yunakov, Nazarenko, Filimonov & Volovnik (2018a), Zoerner (1969a).