Details of this species in Madeira Is. Status: Alien
Invasiveness: Invasive
Occurrence: Established
Source: Wetterer et al. 2006 Arrival Date:
Introduction: Species Notes for this Location:
Pheidole megacephala has been recognized as senior synonym of Oecophthora pusilla Heer, from Madeira (Bolton, 1995 in Wetterer, 2007).P. Megacephala is not widespread or abundant in Madeira. A number of reports from the nineteenth century claimed that enormous outbreaks of P. megacephala and Linepithema humile occurred in the 1850s and 1890s respectively. Wetterer et al. (2006) report that “Researchers have long assumed that these invaders spread across all of Madeira and exterminated most or all native ants, despite no research actually documenting such impact”. A recent comprehensive study of the ant fauna of Madeira suggests these outbreaks were restricted to the lowlands, which only makes up a fraction of Madeira’s land area. If the “plague” of P. megacephala described by Heer (1852 in Wetterer et al., 2006) is correct it would only represent 5% of the area of the island. Thus these invasive ants would only have impacted native ants in a small portion of Maderia. Indeed 2002 surveys revealed that native ants dominated most of Madeira; P. megacephala and L. Humile were restricted to ˜ 0.3% and ˜ 6% of Madeira’s land area respectively. Wetterer et al. (2006) conclude that “even after 150 or more years of residence, P. megacephala and L. humile have come to occupy only a small part of Madeira, and appear to have had little impact.” Management Notes for this Location:
Location Notes:
"The subtropical Atlantic archipelago of Madeira, off the coast of North Africa, was originally settled by the Portuguese
in the early 1400s, and is now an autonomous region of Portugal.
Only the two largest islands, Madeira (737 km 2 ) and Porto Santo (41 km 2 ), are currently inhabited. In addition, there are more than 50 smaller, uninhabited islands (17 km 2 total), including
two island clusters to the south, the Desertas and Selvagens. At
32.6°N, Funchal, Madeira is at approximately the same latitude
as Hamilton, Bermuda (32.3°N)" (Wetterer et al. 2006). Impacts:
Competition: P. megacephala may compete with native ants. However the impact of this exotic ant on native ant fauna is thought to be minimal. Last Modified: 30/03/2010 12:55:48 p.m.
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