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Resource partitioning among sympatric species is crucial for assembling ecological communities, such as caterpillar–ant assemblages in tropical forests. Myrmecophilous caterpillars use behavioral and chemical strategies to coexist with ants, avoiding attacks. While these strategies are well‐understood in single pair of interacting species, such as those involving myrmecophiles and ants, their role in complex multitrophic interactions that include several species of plants, herbivores and ants remains unclear. We aimed to identify the role of cuticular hydrocarbons and specialized morphological structures that caterpillars use to interact with ants (called ant organs) in the recognition process between two riodinid caterpillar species and their respective ant–plant systems. We hypothesized that caterpillars’ cuticular profiles would be conspicuous, possessing cues of rewards to ants, allowing specific ants to recognize and not attack them on plants. We performed experiments exposing caterpillars to ants to assess the role of larval ant organs and the specificity of caterpillar–ant interactions on plants. We analyzed cuticular hydrocarbons of caterpillars, ant workers and plants using gas chromatography/mass spectrometry. Our experiments showed that larval ant organs were activated according to each treatment and caterpillars were consistently accepted by their associated ants when transferred to host plants occupied by the same ant species. However, caterpillars transferred to plants with a non‐associated ant species that do not tend them were often killed. This highlights the specificity of these interactions. Caterpillar cuticular hydrocarbon profiles, while present in far lower amounts than those of ant workers and plants, were distinctive, suggesting a strategy of chemical conspicuousness that helps caterpillars to be recognized by ants and prevents attacks in specific ant–plant systems. Our results indicate that ants recognize conspicuous cuticular hydrocarbons, while caterpillars convey multimodal signals from ant organs during interactions, which are essential for caterpillar survival in these specific interactions. [ABSTRACT FROM AUTHOR]

In myrmecophilous organisms, which live in symbiosis with ants, cuticular hydrocarbons (CHCs) play a pivotal role in interspecific communication and defense against chemical-oriented predators. Although these interactions form complex information webs, little is known about the influence of biotic environmental factors on the CHC profiles of myrmecophiles. Here, we analyzed the effect of different host plants and tending ants on the larval CHC profile of Synargis calyce (Lepidoptera: Riodinidae), a polyphagous species with facultative myrmecophily. Groups of caterpillars were fed individually with three host plant species (without tending ants), and with two tending ant species. Through gas chromatography analysis, we compared the cuticular profiles of treatments and found a high similarity between plants and caterpillars (65–82%), but a low similarity between caterpillars and their tending ants (30 − 25%). Cluster analysis showed that caterpillars, ants, and plants form distinct groups, indicating that S. calyce caterpillars have their own chemical profile. These results are similar to those observed for Lycaenidae caterpillars indicating that there is functional convergence in the chemical strategies used by myrmecophilous caterpillar species with similar ecology. Also, the results suggest that the cuticular compounds of S. calyce are primarily influenced by their host plants rather than their tending ants. Thus, we propose that these caterpillars present a trade-off between camouflage and directly informing their presence to ants, maintaining their unique chemical profile, though slightly affected by biotic environmental factors. [ABSTRACT FROM AUTHOR]

Ants patrol foliage and exert a strong selective pressure on herbivorous insects, being their primary predators. As ants are chemically oriented, some organisms that interact with them (myrmecophiles) use chemical strategies mediated by their cuticular hydrocarbons (CHCs) to deal with ants. Thus, a better understanding of the ecology and evolution of the mutualistic interactions between myrmecophiles and ants depends on the accurate recognition of these chemical strategies. Few studies have examined whether treehoppers may use an additional strategy called chemical camouflage to reduce ant aggression, and none considered highly polyphagous pest insects. We analyzed whether the chemical similarity of the CHC profiles of three host plants from three plant families (Fabaceae, Malvaceae, and Moraceae) and the facultative myrmecophilous honeydew-producing treehopper Aetalion reticulatum (Hemiptera: Aetalionidae), a pest of citrus plants, may play a role as a proximate mechanism serving as a protection against ant attacks on plants. We found a high similarity (>80%) between the CHCs of the treehoppers and two of their host plants. The treehoppers acquire CHCs through their diet, and the chemical similarity varies according to host plant. Chemical camouflage on host plants plays a role in the interaction of treehoppers with their ant mutualistic partners. [ABSTRACT FROM AUTHOR]

Our research aimed to compare the chemical cues of treehoppers and host plants in two rare cases of herbivorous myrmecophilous butterflies laying eggs on treehoppers. Our hypothesis that the cuticular hydrocarbon (CHC) profiles of the treehoppers would resemble those of their host plants was confirmed. [ABSTRACT FROM AUTHOR]

Ants exert strong selective pressure on herbivorous insects, although some caterpillars can live in symbiosis with them using chemical defensive strategies.We investigated the adaptive resemblance of cuticular hydrocarbons (CHCs) in multitrophic systems involving a guild of facultative myrmecophilous caterpillar species (Lepidoptera: Lycaenidae), tending ants (Hymenoptera: Formicidae), and host plants from three families. We hypothesised that the CHCs of the caterpillars would resemble those of their host plants (chemical camouflage).We analysed CHCs using gas chromatography/mass spectrometry. Morisita's similarity index (SI) was used to compare CHC profiles of caterpillar species with different types of ant associations (commensal or mutualistic), ants, and host plants.We found strong convergence between caterpillars' CHCs and plants, especially for commensal species that do not provide secretion rewards for ants. Moreover, we found unexpected chemical convergence among mutualistic (trophobiotic) caterpillar species that offer caloric reward secretions to ants.These results show that the studied caterpillars acquire CHCs through their diet and that they vary according to host plant species and type of ant association (commensalism or mutualism). This 'chemical camouflage' of myrmecophilous caterpillars may have arisen as a defensive strategy allowing coexistence with ants on plants, whereas 'chemical conspicuousness' may have evolved in the context of honest signalling between mutualistic partners.We suggest the existence of chemical mimicry among myrmecophilous species, especially between mutualistic caterpillars. Cuticular chemical mixtures can play a key adaptive role in decreasing ant attacks and increasing caterpillar survival in multimodal sensory systems. [ABSTRACT FROM AUTHOR]