Countries of Occurrence:
Portugal - Azores
Facilitators / Compilers/s:
Chirothrips azoricus is endemic to Sao Miguel (Azores, Portugal). It has a very small Extent of Occurrence (EOO = 8 km²) and Area of Occupancy (AOO = 8 km²). There is a continuing decline in the EOO, AOO, extent and quality of habitat as well as the number of mature individuals as a result of the invasions of non-native plants; and, based on this threat, the species occurs only at one location. Therefore, the species is assessed as Critically Endangered (CR). We suggest as future conservation measures: (1) regular monitoring of the species; and (2) control of invasive species, namely Hedychium gardnerianum and Clethra arborea.
Chirothrips azoricus is a single-island endemic thrips species restricted to S. Miguel island (Azores, Portugal) (Borges et al. 2010), known from the Natural Forest Reserve of Pico da Vara (Tronqueira). The Extent of Occurrence (EOO) is 8 km² and the maximum estimated Area of Occupancy (AOO) is 8 km².
The species is rare and only known from a single subpopulation. A continuing decline in the number of mature individuals is inferred from the ongoing habitat degradation due to invasions of alien plants (Hedychium gardnerianum, Clethra arborea).
Current Population Trend: Decreasing
The ecology and traits of this species are unknown, but the larvae of known species of the genus Chirothrips develop only within the florets of Poaceae (Minaei and Mound 2010). This species occurs in the hyper-humid Azorean native forests, surrounded by plantations of exotic trees (Cryptomeria japonica) and under threat from invasive plant species.
In the past, the species has probably strongly declined due to changes in habitat size and quality. The most important ongoing threat to this species is the spread of invasive plants (Hedychium gardnerianum and Clethra arborea), which are changing the habitat structure and promoting the spread of other plants. Based on Ferreira et al. (2016) the habitat will decline as a consequence of climate change (increasing number of droughts and habitat shifting and alteration).
The species is not protected by regional law, but its habitat is in a regionally protected area (S. Miguel Natural Park). The Sao Miguel Natural Park administration is currently starting control measures of the invasive plants. A LIFE PRIOLO project started with a restoration of degraded habitats increasing the area of pristine forest. A habitat management plan is needed, though, and one is anticipated to be developed during the coming years. Further research is needed into its ecology and life history in order to find extant specimens in additional natural forest areas of the S. Miguel island and to obtain information on population size, distribution and trends. It is also necessary to develop an area-based management plan and a monitoring plan for the invertebrate community in this habitat in aid in the production of a potential species recovery plan. Monitoring every ten years using the BALA protocol will inform about habitat quality (see e.g. Gaspar et al. 2011).