A taxonomic study of the thrips (Thysanoptera) of the Maltese Islands

Abstract

The thrips (Thysanoptera) of the Maltese Islands have so far been very little studied, with the few existing works focusing on species of agricultural importance. The current study has investigated the biodiversity of thrips species of the Maltese Islands, discriminated between these species by means of a simple illustrated identification key and investigated their feeding habits and geographical distribution. Thrips were collected from 252 indigenous and 146 cultivated plant species and subsequently mounted individually on glass slides to be identified. Literature describing 691 species from the Palaearctic region was consulted to help select which plants to sample for thrips. Online and printed identification keys were used to identify the species. Specimen photos were then sent to world thrips experts to confirm identification. One of these experts, Dr Arturo Goldarazena, inspected the collection of thrips amassed during the current study to help identify species of the genera Haplothrips, Karnyothrips and Odontothrips. In all, 53 species were identified to species level. One species under the genus Karnyothrips is a possible new record to science. Following literature, 48 of the locally recorded species are phytophagous, with six of these being facultative predators, while three species mycophagous and two being obligate predators. Chorological data for the species in the Maltese Islands revealed that 23 species are of cosmopolitan or subcosmopolitan distribution, while 25 species are found across Europe and the Mediterranean region. Nine are alien species, very likely introduced with imported crops and cultivars, since they were not recorded on indigenous plants. These species could affect the local agricultural scenario, even though locally they were found in numbers too small for these thrips to be considered pests. The current study recommends further investigation of the agricultural impact of thrips species in the Maltese Islands, as well of thrips which may be introduced with locally imported plant material. Further research on the species that could not be identified to species level, as well as on the possible new species of Karnyothrips are also recommended.