MAIISG

Assessment Rationale:

Listed as Least Concern as the species is common in Madeira, the population seems to be stable and it has a broad tolerance of habitats. However, research should be conducted on the population size, trends and specific threats to the species.

Geographic Range:

Andrena (Suandrena) maderensis is endemic to the island of Madeira (Kratochwil and Scheuchl 2013, Kratochwil et al. 2014).

Population:

There is no information available on the population size and trend of the species. However, the species is widely distributed across Madeira and the population there is presumed to be quite large and stable overall.

Habitat and Ecology

Andrena maderensis is quite ubiquitous on the island of Madeira and it is thought to have a catholic choice of habitats, being present in dune areas, fallow lands and ruderal sites with suitable pollen sources. The range of altitudes extends from sea level up to 950 m asl. According to the differentiation into thermotypes and ombrotypes (Capelo et al. 2004), the localities where A. maderensis has been recorded correspond mainly to the temperature zones 1 and 2 (infra-Mediterranean), but also to frequency zones 3 and 4 (lower and upper thermo-Mediterranean). High abundances were reached in humidity class 1 (dry), 2 (lower subhumid), 3 (upper subhumid) and 4 (lower humid). The main vegetation zones are zone 1 (Mayteno umbellatae-Oleo maderensis sigmetum), zone 2 (Helichryso melaleuci-Sideroxylo marmulanae sigmetum), and zones 3 and 4 (Semele androgynae-Apollonio barbujanae sigmetum) (Kratochwil et al. 2014).

The nesting and pollen foraging biology is not known but the species is reported to visit Brassica, Rapistrum rugosum, Raphanus raphanistrum (Brassicaceae) (Fellendorf et al. 1999), Oxalis pes-caprae (Oxalidaceae) and Calendula species (Asteraceae) (Cockerell 1922). Andrena maderensis is one of the principal pollinators of cabbage plants on Madeira.

The flower visitation include records of 43 females on Brassicaceae (Sinapidendron angustifolium, Raphanus raphanistrum ssp. raphanistrum, Rapistrum rugosum, Brassica oleracea, Sinapis arvensis), five females on Asteraceae (Crepis vesicaria ssp. haenseleri, Sonchus oleraceus) and one female on Geraniaceae (Geranium maderense). The species is therefore assumed to be oligolectic on Brassicaceae (Kratochwil et al. 2014).

While, A. maderensis flies from March to June, the latest literature states that flight activity lasts from February to May. The highest abundances of males and females are in April (Kratochwil et al. 2014).

Major Threat(s):

Andrena maderensis is only known from a small area. However, the specific threats to this species remain unknown. Given its presumed catholic choice of habitat within the Madeira island group, the threats are likely to be minimal as the localities where the species is found represent a wide range of habitats.

Conservation Actions

The species is not listed on any National Red Lists or Red Data Books and is not the subject of any targeted conservation action. It is not known if it is found in any protected areas. Further research is required to establish the details of the population size and trends and specific threats to the species.