Fig 1 - uploaded by Martin H Villet
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Worker laying a recruiting trail. On the left of the ant is a segment of a millipede, the food source of this species.
Source publication
Although workers of Plectroctena mandibularis laid trails with their stings while foraging, the trails appeared to be for individual orientation, because they never recruited nestmates to prey. However, both workers and queens laid trails when recruiting nestmates of either caste to new nest sites. During trail-laying, fluted hairs on the posterior...
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... would approach a potential recruit and tug at its mandibles and forelegs for a second or so, and then turn around and set off with its gaster curled downwards. The tugged ant would usually follow. While leading recruits, the leading ant curled the tip of its abdomen ventrally and the surface of tergite VII was apparently dragged across the ground (Fig. 1) as though laying a trail. Recruited ants followed close behind the leading ant, but not in contact with it. As they moved along the trail, they held their antennae to the ground and seemed to tap the ground with their forelegs in a more exaggerated way than was observed in other situations. As many as five or six ants were seen to ...
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... abdomen is in its normal resting position, contact between the duct openings in the intersegmental membrane and the openings of the lamellae transfer pheromone from the pygidial gland into the cavities within the cuticle of the pygidium (Fig. 4b). The crevices thus act as a reservoir. When the abdomen is inverted during recruitment trail-laying (Fig. 1), gravity could cause the pheromone to leak from the exposed reservoir onto the four fluted hairs (Fig. 4b), which transfer it to the ground as they are dragged ...
Citations
... Qualitatively, we found that several tandem running ants followed the same path, suggesting trail laying behavior, although marking of the trail was not observed (Video S1). Similar trail laying through hind gut fluids or pygidial gland secretions has been reported in other ponerine species using tandem running [73][74][75][76]. ...
In the Yucatan Peninsula, the ponerine ant Neoponera villosa nests almost exclusively in tank bromeliads, Aechmea bracteata. In this study, we aimed to determine the factors influencing nest site selection during nest relocation which is regularly promoted by hurricanes in this area. Using ants with and without previous experience of Ae. bracteata, we tested their preference for refuges consisting of Ae. bracteata leaves over two other bromeliads, Ae. bromeliifolia and Ananas comosus. We further evaluated bromeliad-associated traits that could influence nest site selection (form and size). Workers with and without previous contact with Ae. bracteata significantly preferred this species over others, suggesting the existence of an innate attraction to this bromeliad. However, preference was not influenced by previous contact with Ae. bracteata. Workers easily discriminated between shelters of Ae. bracteata and A. comosus, but not those of the closely related Ae. bromeliifolia. In marked contrast, ants discriminated between similar sized Ae. bracteata and Ae. bromeliifolia plants, suggesting that chemical cues and plant structure play an important role. Size was also significant as they selected the largest plant when provided two dissimilar Ae. bracteata plants. Nest site selection by N. villosa workers seems to depend on innate preferences but familiarization with plant stimuli is not excluded.
... While dolichoderine ants like L.humile include many invasive species, comparatively few ponerines are invasive [93]. Furthermore, native non-hypogaeic ponerine species are generally eliminated by invasive ants [35,94], due in part to their relatively small colonies [95,96], generally solitary foraging behavior979899, and characteristic subdominant or subordinate behavior [100]. Subordinate behavior in particular can facilitate coexistence between invasive and native ant species, and this could explain, in part, habitat overlap between P. chinensis and L. humile [101,102]. ...
Identifying mechanisms governing the establishment and spread of invasive species is a fundamental challenge in invasion biology. Because species invasions are frequently observed only after the species presents an environmental threat, research identifying the contributing agents to dispersal and subsequent spread are confined to retrograde observations. Here, we use a combination of seasonal surveys and experimental approaches to test the relative importance of behavioral and abiotic factors in determining the local co-occurrence of two invasive ant species, the established Argentine ant (Linepithema humile Mayr) and the newly invasive Asian needle ant (Pachycondyla chinensis Emery). We show that the broader climatic envelope of P. chinensis enables it to establish earlier in the year than L. humile. We also demonstrate that increased P. chinensis propagule pressure during periods of L. humile scarcity contributes to successful P. chinensis early season establishment. Furthermore, we show that, although L. humile is the numerically superior and behaviorally dominant species at baits, P. chinensis is currently displacing L. humile across the invaded landscape. By identifying the features promoting the displacement of one invasive ant by another we can better understand both early determinants in the invasion process and factors limiting colony expansion and survival.
... In the social insects, the intracolony communication mediated by semiochemicals plays an important role in organizing collective activities, such as defense, reproduction, foraging, and nest relocation [2,3]. The trail pheromones of ants, in particular, are known to play a critical role in foraging and nest relocation processes, by efficiently leading colony members to prospective food sources or nesting sites [4][5][6][7]. ...
The Argentine ant (Linepithema humile) is recognized as one of the world's most damaging invasive species. One reason for the ecological dominance of introduced Argentine ant populations is their ability to dominate food and habitat resources through the rapid mobilization and recruitment of thousands of workers. More than 30 years ago, studies showed that (Z)-9-hexadecenal strongly attracted Argentine ant workers in a multi-choice olfactometer, suggesting that (Z)-9-hexadecenal might be the trail pheromone, or a component of a trail pheromone mixture. Since then, numerous studies have considered (Z)-9-hexadecenal as the key component of the Argentine ant trails. Here, we report the first chemical analyses of the trails laid by living Argentine ants and find that (Z)-9-hexadecenal is not present in a detectible quantity. Instead, two iridoids, dolichodial and iridomyrmecin, appear to be the primary chemical constituents of the trails. Laboratory choice tests confirmed that Argentine ants were attracted to artificial trails comprised of these two chemicals significantly more often than control trails. Although (Z)-9-hexadecenal was not detected in natural trails, supplementation of artificial dolichodial+iridomyrmecin trails with an extremely low concentraion of (Z)-9-hexadecenal did increase the efficacy of the trail-following behavior. In stark contrast with previous dogma, our study suggests that dolichodial and iridomyrmecin are major components of the Argentine ant trail pheromone. (Z)-9-hexadecenal may act in an additive manner with these iridoids, but it does not occur in detectable quantities in Argentine ant recruitment trails.
The tribal and generic classification of the diverse ant subfamily Ponerinae (Hymenoptera: Formicidae) is revised to re-flect recent molecular phylogenetic information and a reappraisal of ponerine morphological diversity. The monogeneric tribe Thaumatomyrmecini (Thaumatomyrmex) is newly synonymized under Ponerini (syn. nov.), and the diverse genus Pachycondyla is fragmented into 19 genera, largely along the lines of its junior synonyms: Bothroponera, Brachyponera (gen. rev.), Ectomomyrmex (gen. rev.), Euponera (gen. rev.), Hagensia (gen. rev.), Megaponera (gen. rev.), Mesoponera (gen. rev.), Neoponera (gen. rev.), Ophthalmopone (gen. rev.), Pachycondyla, Paltothyreus (gen. rev.), Pseudoneopon-era (gen. rev.), Pseudoponera (gen. rev.), and 6 new genera: Austroponera (gen. nov.), Buniapone (gen. nov.), Fishero-pone (gen. nov.), Mayaponera (gen. nov.), Parvaponera (gen. nov.) and Rasopone (gen. nov.). Some junior synonyms of Pachycondyla are transferred to junior synonym status under other genera: Wadeura as a junior synonym of Cryptopone (syn. nov.), and both Termitopone and Syntermitopone as junior synonyms of Neoponera (syn. nov.). A new genus, Iro-ponera (gen. nov.), based on the new species Iroponera odax (sp. nov.), is described from Australia. Molecular and mor-phological justifications for these taxonomic changes are given alongside discussions of phylogenetic relationships. Keys to the world genera of Ponerinae are provided, and morphological diagnoses and species lists are given for each genus. Finally, the available information on ponerine ecology and behavior is reviewed and synthesized.
Outdoor residual sprays are among the most common methods for targeting pestiferous ants in urban pest management programs. If impervious surfaces such as concrete are treated with these insecticides, the active ingredients can be washed from the surface by rain or irrigation. As a result, residual sprays with fipronil and pyrethroids are found in urban waterways and aquatic sediments. Given the amount of insecticides applied to urban settings for ant control and their possible impact on urban waterways, the development of alternative strategies is critical to decrease the overall amounts of insecticides applied, while still achieving effective control of target ant species. Herein we report a "pheromone-assisted technique" as an economically viable approach to maximize the efficacy of conventional sprays targeting the Argentine ant. By applying insecticide sprays supplemented with an attractive pheromone compound, (Z)-9-hexadecenal, Argentine ants were diverted from nearby trails and nest entrances and subsequently exposed to insecticide residues. Laboratory experiments with fipronil and bifenthrin sprays indicated that the overall kill of the insecticides on Argentine ant colonies was significantly improved (57-142% increase) by incorporating (Z)-9-hexadecenal in the insecticide sprays. This technique, once it is successfully implemented in practical pest management programs, has the potential of providing maximum control efficacy with reduced amount of insecticides applied in the environment.
