New species of gall midge (Diptera: Cecidomyiidae) damaging flower buds of ornamental Alstroemeria plants

Alstroemeria (Liliales: Alstroemeriaceae) is a plant genus native to South America with many interspecific hybrids cultivated as ornamentals worldwide. Several yellow larvae of an undescribed gall midge (Diptera: Cecidomyiidae) were found feeding inside flower buds of Alstroemeria plants grown in production greenhouses in South Australia in 2013; Queensland, Australia, in 2015 and the Netherlands in 2016. Infested buds became malformed, did not produce flowers and turned necrotic later. In Queensland and the Netherlands, the necrotised buds became additionally infected by a saprophytic fungus Cladosporium sp. With up to 80% of flower buds infested, the new gall midge decreased the value of plants aimed for the cut flower market and reduced seed of reproduction plants. The new species, named Contarinia jongi Kolesik sp. nov., is described, and a segment of its Cytochrome Oxidase unit I mitochondrial gene is sequenced. This is the first gall midge known to feed on a host plant from the family Alstroemeriaceae. Previously, Alstroemeria cut flowers imported from Australia and New Zealand to Japan were found to contain viable larvae of the new species, demonstrating that the new species can spread with the flower trade. It is possible that Contarinia jongi is native to South America, the homeland of its host plant.