Pheidole megacephala Fabricius, 1793

P. megacephala can also have a negative impact by displacing beneficial ants. Oecophylla longinoda protects coconut trees from the coconut bug Pseudotheraptus wayi in Tanzania and infestation by P. megacephala can reduce the abundance of Oecophylla (Vanderplank, 1960; Oswald, 1991). Cabi, acesso em 03/05/2021

Concerning the decline of the Laysan Duck (Anas laysanensis Rothschild), Reynolds et al. (2005) wrote “alien insects, including bigheaded ants (Pheidole megacephala) are suspected of reducing the duck's food abundance.” (Wetterer, 2007)

Perkins (1913:xli) wrote of P. megacephala, “It may be said that no native Hawaiian Coleoptera insect can resist this predator, and it is practically useless to attempt to collect where it is well established.” Zimmerman (1970:34) wrote that in Hawai‘i, “the endemic insect faunas of the lowlands of all the islands mostly have been exterminated throughout the range of the voracious introduced predatory ant Pheidole megacephala.” Loss of invertebrate species that serve key functions in the natural community (e.g., important prey species, pollinators, seed dispersers, scavengers, decomposers) may have cascading effects leading to severe disruptions of natural nutrient cycling and the subsequent loss of additional native plant and animal species (Howarth 1985). Pheidole megacephala is extremely aggressive toward other ant species. Colonies of P. megacephala are strongly territorial and exclude other dominant territorial ants, such as Anoplolepis gracilipes (F. Smith) and Linepithema humile (Mayr) (Fluker and Beardsley 1970). When live ants are collected in an aspirator, P. megacephala workers will quickly cut to pieces other ants in the collection vial (pers. obs.). Pheidole megacephala often dominates over extensive areas (e.g., much of the Hawaiian lowlands). In many parts of Tonga, I (Wetterer 2002) found P. megacephala under almost every rock and log and virtually no other ants. Pheidole megacephala may also negatively impact vertebrates in the Pacific, both directly and indirectly. In Hawai‘i, C. Daehler (pers. comm.) observed (and filmed) hundreds of P. megacephala workers attacking 3-week-old hatchlings of an exotic bird, the Japanese White-eye (Zosterops japonicus). Banko and Banko (1976:31) concluded that in Hawai‘i, P. megacephala “played an indirect though paramount role in the reduction and extinction of all insectivorous birds. Pheidole was particularly effective in displacing an exceptionally wide variety of insects, even causing species extinctions in the Coleoptera and Lepidoptera, the two orders of insects which are most important as food to a majority of insectivorous birds of the Hawaiian Islands.” (Wetterer, 2007)