Extensive Field Observations Throw Light on the Evolution of Mimicry in Camponotus lateralis (Hymenoptera:...

The Mediterranean ant-ant association between Camponotus lateralis and Crematogaster scutellaris has fascinated naturalists for long, with a focus on documenting the attraction of Ca. lateralis workers to Cr. scutellaris trails. Little attention, in contrast, has been put on similar behaviors between other Camponotus and Crematogaster species. Moreover, neither the adaptive value of mimicry in Ca. lateralis, which mimics the color patterns of different Crematogaster species, nor its evolution is understood. Data and video records (https://figshare.com/s/b627084f6a7f60e6dc4c) of 2 one-month-long and several short field trips brought insights into this mimicry evolution: We recorded trail following, a behavior hitherto known from four Mediterranean species, from 10 Camponotini species. The percentage of Ca. lateralis workers to those of Crematogaster on trails was only 2.4%. Camponotus lateralis, Ca. ruber, and Colobopsis species were the only trail followers mimicking Crematogaster color patterns. Dealate gynes of Ca. lateralis and Ca. kiesenwetteri founded colonies next to Crematogaster trails. Of 211 Ca. lateralis colonies, 79% were associated with Crematogaster. Camponotus lateralis nests putatively associated with Crematogaster had 2.2 times more workers and a 2.2 times higher chance to produce sexuals. Camponotus lateralis major workers defended entrances against Crematogaster by blocking them with their heads, in a similar manner as Colobopsis. At 15 of 19 sites, lacertid lizards were present; some ingested ants but avoided Crematogaster. Several characteristics of Ca. lateralis concerning its behavior, morphology, colony structure, and nesting site selection are advantageous for the mimicry strategy. Of these, we identified those shared with related non-mimetic species as putative preadaptations. The manifestation of regional color morphs could be the only species-specific mimicry adaptation, while several common characteristics among Mediterranean Camponotini appear as preadaptations to trail following or to mimicry. Trail following facilitates access to food and protection; color mimics likely evolved from non-mimetic trail followers and enjoy reduced predation through Batesian mimicry.