Countries of Occurrence:
Portugal - Azores
Facilitators / Compilers/s:
Phloeosinus gillerforsi is an endemic species present in Pico, S. Jorge, Terceira and S. Miguel islands (Azores, Portugal). It has a large extent of occurrence (EOO = ca 10,100 km²) and small area of occupancy (AOO = 40 km²). The species is common and only known from four fragmented subpopulations in 8 locations. Most of the area of occurrence is protected and is well preserved. In the past, the species has probably strongly declined due to changes in habitat size and quality. One of the most important ongoing threat to this species is the fragmentation of the host plant (the endemic tree Juniperus brevifolia) habitat. Based on Ferreira et al. (2016) the habitat will further decline as a consequence of climate change (increasing number of droughts). Therefore, we suggest as future measures of conservation: (1) regular monitoring of the species; and (2) control of cuts of the endemic tree Juniperus brevifolia. Based upon the small area of occupancy it is assessed as Endangered.
Phloeosinus gillerforsi is an endemic species present in Pico, S. Jorge, Terceira and S. Miguel islands (Azores, Portugal) (Borges et al. 2010), known from Natural Forest Reserves of Mistério da Prainha (Pico); Pico Pinheiro (S. Jorge); Biscoito da Ferraria and Caldeira Sta. Bárbara e Mistérios Negros (Terceira); Atalhada and Pico da Vara (S. Miguel). The extent of occurrence (EOO) is ca 10,100 km² and the maximum estimated area of occupancy (AOO) is 40 km².
P. gillerforsi is a widespread and particularly abundant species in native forests (very common in the host tree Juniperus brevifolia). The species is currently abundant but a declining in the abundance of some subpopulations is inferred from the fragmentation and declining in the abundance of the host species Juniperus brevifolia. This species is assessed here as severely fragmented as at least 50% of its population can be found in subpopulations that are 1) smaller than would be required to support a viable population, and 2) separated from other habitat patches by a large distance. In fact, the species occurs in fragments that are isolated in a matrix of pastures.
The species occurs in native forests dominated by the main host Azorean endemic tree Juniperus brevifolia in Pico, S. Jorge, Terceira and S. Miguel islands (Azores), with an altitudinal range between 0 and 1200 m. Adults and larvae are herbivores and feed on plant tissues. Based on seasonal data from SLAM traps obtained in several islands between 2012 and 2016 (Borges et al. 2017), the adults are active all year, being most abundant in spring and autumn.
In the past, the species has probably strongly declined due to changes in habitat size and quality (Triantis et al. 2010, Terzopoulou et al. 2015). One of the most important ongoing threat to this species is the fragmentation of the host plant habitat due to invasive plants (e.g. Hedychium gardnerianum; Hydrangea macrophylla, Pittosporum undulatum, Clethra arborea) and Cryptomeria japonica pulp plantation management. Based on Ferreira et al.(2016) the habitat will further decline as a consequence of climate change (increasing number of droughts).
The species is not protected by regional law. Its habitat is in regionally protected areas (Natural Parks of Pico, S. Jorge, Terceira, Pico and S. Miguel). Further spread of invasive plants needs to be stopped in order to avoid any future declines of the host plant species. Degraded habitats should be restored and a strategy needs to be developed to address the future threat by climate change. A habitat management plan is needed and 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 small fragments with the host plant Juniperus brevifolia. and obtain information on population size, distribution and trends. It is also necessary a monitoring plan for the invertebrate community in the habitat in order to contribute to perform a species potential recovery plan in some areas. Monitoring every ten years using the BALA protocol will inform about habitat quality (see e.g. Gaspar et al.2011).