• Through their geographical distribution, the distinct populations live in a wide range of conditions, from strictly urban habitats - streets with heavy traffic to semi-urban sites, mildly degraded habitats or seemingly undisturbed localities. A common feature to all such places is the presence of trees, on whose aphid populations the ants depend.

  • Some of those populations have attained pest status, affecting man or other biological components. Those populations can properly be qualified as invasive (=an agent of change, threatening native biological diversity). Other populations are still merely established and seem to have a more limited expansion as they have yet to be reported as pernicious; this may correspond to the lag phase found in many invaders. Perhaps this is only due to lack of knowledge or, alternatively, climate has, indeed, a limiting effect on the dispersal or expansion processes.

  • From its description, it is known that in the areas occupied by this species, other surface-foraging ant species have vanished or have very reduced populations. Spatial and temporal foraging of native ants and their richness on trees is strongly diminished when L. neglectus is present (Paris & Espadaler, 2012). Other arthropod groups  also seem to be affected in positive (=enhanced presence; aphids), negative (=lesser density; lepidoptera larvae) or neutral ways.


  • Not all populations seem to be invasive. In some of these, ants do not invade buildings or houses, and opt to nest outside, in public gardens, at the base of trees or in the cracks in cemented areas or sidewalks. 

  • In certain populations (Seva, Taradell, and Matadepera in Spain, or Paris, in France, ants enter buildings and occupy diverse components of the construction. Killing ants by insecticide spray may produce impressive results. They seem to be attracted to electrical fields, causing failure and damage by shorting or by occupying electrical plugs, connexion boxes or electro-mechanical devices, such as automatic blinds.

Page authors: Xavier Espadaler  (Xavier.Espadaler@uab.es) and Víctor Bernal (v.bernal@creaf.uab.es).