Drama in the orchid nursery!
There is a yellow beetle with black legs of the Chrysomelidae family which is sometimes seen feeding on orchid flowers. It tends to prefer Trichoglottis (Staurochilus) dawsonianus and Dendrobium orchids. We kill them mechanically, which is difficult since they fly quickly and drop immediately if alarmed. Always approach them from underneath. Lately we have received help from the weaver ants (Oecophylla smaragdina):
To control the demon you need to know its name. One suggestion is Aulacophora indica, but that one is all orange and feeds on cucumbers, while this species is yellow with black legs. Aulacophora belongs to the subfamily Galerucinae, while this beetle reminds more of the notorious scarlet lily beetle Lilioceris lilii of the Criocerinae subfamily. In Australia the black and yellow Dendrobium beetle (Stethopachys formosa) is a pest in orchid nurseries, and it seems like a close relative of our species. Lema pectoralis has been reported from orchid nurseries in Thailand, but that species is all yellow, this beetle is more elegant with its black stockings and antennae. If anyone has a suggestion for its species name, please let me know!
Update May 7, 2012: Since the ant attack we have been free from this beetle pest – without a drop of chemicals! The ants are now permanent and respected residents of the orchid nursery. In Indonesia the red weaver ants symbolize freedom fighters due to their bravery and solidarity.
Text & Photo: Eric Danell