High Divergence of Cuticular Hydrocarbons and Hybridization Success in Two Allopatric Seven-Spot Ladybugs.

The seven-spotted ladybug is a widespread species in the Palearctic, and also acclimated in the Nearctic. It has been classified into different species on the basis of certain morphological characteristics, the geographical origin, and the genitalia structure of both sexes. The morphotypes of North Africa and the Canary Islands are separated, under the name of Coccinella algerica Kovář, 1977, from the rest of the Palearctic and Nearctic populations of Coccinella septempunctata Linnaeus, 1758.

Effect of the land area elevation on the collective choice in ants.

Collective decisions regarding food source exploitation in social insects are influenced by a range of parameters, from source quality to individual preference and social information sharing. Those regarding the elevation of the physical trail towards a food source have been neglected. In this work, we investigated the effect of ascending and descending paths from the nest to a food source on collective choice in two ant species Lasius niger and Myrmica rubra.

Dispersal strategies in the highly polygynous ant Crematogaster (Orthocrema) pygmaea Forel (Formicidae: Myrmicinae).

In ants, dispersal strategies and morphology of female sexuals are generally linked to the mode of colony founding. In species using long-range dispersal tactics, queen/worker dimorphism is generally high and young queens are able to initiate new colonies by themselves, using their metabolic reserves. By contrast, in species using short-range dispersal strategies, queen/worker dimorphism is generally low and, due to their limited metabolic reserves, queens have lost the capacity to raise their brood alone and to found their colony independently.

Social Structure and Genetic Distance Mediate Nestmate Recognition and Aggressiveness in the Facultative Polygynous Ant Pheidole pallidula.

In social insects, the evolutionary stability of cooperation depends on the privileged relationships between individuals of the social group, which is facilitated by the recognition of relatives. Nestmate recognition is based on genetically determined cues and/or environmentally derived chemical components present on the cuticle of individuals. Here, we studied nestmate recognition in the ant Pheidole pallidula, a species where both single-queen (monogyne) and multiple-queen (polygyne) colonies co-occur in the same population.

The differential response of workers and queens of the ant Lasius niger to an environment marked by workers: ants dislike the unknown.

It is well known that ants can use cuticular hydrocarbons (CHCs) as a specific recognition cue. Most previous studies addressed the perception of CHCs occurring on the cuticle. However, the presence of CHCs in the environment (e.

Queens defense by workers in the highly polygynous ant Crematogaster pygmaea (Hymenoptera: Myrmicinae).

Some aspects of the biology of Crematogaster pygmaea, a highly polydomous and polygynous ant, are more commonly found in monogynous species. One such characteristic is the high attractiveness of its queens. In this study, this attractiveness was assessed under varying experimental conditions to investigate the factors responsible for its expression and variation, and to identify the nature of queen attractiveness.

Genetics, behaviour and chemical recognition of the invading ant Pheidole megacephala.

Introduced species often become ecologically dominant, displacing native species and posing a serious threat to ecosystem function and global biodiversity. Ants are among the most widespread and damaging alien species; introductions are often accompanied by population-level behavioural and genetic changes contributing to their success. We investigated the genetic structure, chemical profile and nestmate recognition in introduced populations of the invasive big-headed ant, Pheidole megacephala, in Australia.

Ovarian activity correlates with extreme changes in cuticular hydrocarbon profile in the highly polygynous ant, Linepithema humile.

In social insects, cuticular hydrocarbons of adults may vary with ovarian activity. Such variations are suggested to function in the regulation of reproduction within colonies. The modification of the CH profile with ovarian activity is usually interpreted as a signal of fertility causing workers to refrain from reproducing in the presence of the queen.