The mallow flea beetle, Podagrica fuscicornis (Linnaeus) (Chrysomelidae) - feeding on Hoheria and Sidalcea (Malvaceae), new host records

摘要

On 30 June 2015 an extensive infestation of adult Podagrica fuscicornis (Linnaeus) was noted on plants of Hoheria sexstylosa 'Stardust' (Malvaceae) in a garden in the village of Wisley, Surrey (TQ0659). Extensive 'shot-hole' damage typical of the adults of this species was also evident on the plant. The authors believe this is the first time that P. fuscicornis has been found feeding on Hoheria. The larvae of P. fuscicornis feed on the roots of host plants (Cox, 2007). It was not possible to examine the roots of the host and it was therefore not possible to determine if the beetle can complete its lifecycle on this plant. Adults of this species are known to feed on several plants within the Malvaceae including several Malva species, notably musk mallow M. moschata and common mallow M. sylvestris, hollyhock Alcea rosea, marsh-mallow Althaea officinalis and tree mallows, Lavatera spp. (Cox, 2007). This nationally scarce (Hubble, 2014) beetle is regularly reported to the Royal Horticultural Society (RHS) Gardening Advice service; since 2000 ten reports have been received on Lavatera, three on Malva and one on Alcea. Dobson (2001) also noted damage from adults of this beetle on cultivated A. rosea and Lavatera. Examination of the RHS records also indicate two reports where samples were received of P. fuscicornis adults feeding on prairie mallows Sidalcea (Malvaceae), from Folkestone, East Kent (TR1340, 29 June 2007) and Midhurst, West Sussex (SU8821, 3 August 2007). Sidalcea also appears to be an undocumented host. It is therefore possible that P. fuscicornis is able to feed on a wider range of the Malvaceae than has been listed previously. Specimens collected from the Hoheria in Wisley Village have been incorporated into the RHS insect reference collection.