Increased initial task difficulty drives social foragers to develop sub-optimal conformity instead of adaptive diversity.

The extent to which animal societies exhibit social conformity as opposed to behavioural diversity is commonly attributed to adaptive learning strategies. Less attention is given to the possibility that the relative difficulty of learning a task socially as opposed to individually can be critical for social learning dynamics. Here we show that by raising initial task difficulty, house sparrows previously shown to exhibit adaptive social diversity become predominantly conformists. The task we used required opening feeding well covers (easier to learn socially) and to choose the covers with the rewarding cues (easy to learn individually). We replicated a previous study where sparrows exhibited adaptive diversity, but did not pre-train the naive sparrows to open covers, making the task initially more difficult. In sharp contrast to the previous study results, most sparrows continued to conform to the demonstrated cue even after experiencing greater success with the alternative rewarding cue for which competition was less intense. Thus, our study shows that a task's cognitive demands, such as the initial dependency on social demonstration, can change the entire learning dynamics, causing social animals to exhibit sub-optimal social conformity rather than adaptive diversity under otherwise identical conditions.

First report of aphaenopsoid trechines (Coleoptera: Carabidae: Trechini) from Serbia, with descriptions of new taxa.

The trechine ground beetle taxa, Velesaphaenops gen. n., Velesaphaenops tarensis sp. n., and Acheroniotes lethensis sp. n., are described and diagnosed. The new taxa differ clearly from their closest relatives in a number of external characters and the shape of the genitalia. They probably belong to phyletic lineages of Pliocene age (the age of the palaeokarst of Kamena Gora and Mt. Tara). The new taxa are endemic to western and southwestern Serbia. Keys to the aphaenopsoid trechine genera in Serbia and to species of the genus Acheroniotes Lohaj Lakota, 2010 are appended.

Seven new taxa of Leptodirini (Coleoptera: Leiodidae: Cholevinae) from the Balkan Peninsula.

Seven new troglobitic leiodid beetle taxa (six new species and one new subspecies) from several caves and pits in the Balkan Peninsula (Bosnia and Herzegovina and Serbia) are described and diagnosed. Three new species belong to the genus Adelopidius Apfelbeck, 1907, two-to the genus Pholeuonopsis Apfelbeck, 1901, one-to the genus Leonhardia Reitter, 1901, while a new subspecies belongs to the genus Apholeuonus Reitter, 1889. All important morphological characteristics of the new taxa have been mentioned and imaged, including the aspects of the male and female genitalia. The new leiodid taxa are properly distinguished from their relatives and are endemics of the Dinaric mountain chain. A key to Adelopidius taxa is added.

Molecular Diversity of Compounds from Pygidial Gland Secretions of Cave-Dwelling Ground Beetles: The First Evidence.

Three adult cave-dwelling ground beetle species were induced to discharge secretions of their pygidial glands into vials. Dichloromethane extraction was used to obtain the secretions. In total, 42 compounds were identified by GC/MS analysis. Pheggomisetes ninae contained 32 glandular compounds, Laemostenus (Pristonychus) punctatus 13, whereas Duvalius (Paraduvalius) milutini had nine compounds. Caproic, oleic, palmitic, and stearic acids were present in the samples of all analyzed species. Undecane was predominant in the extract of L. punctatus. Palmitic acid was the major component in the secretion of D. milutini. Finally, the most abundant compounds in P. ninae secretion were heptacosene and nonacosadienes. Herein, we present the first data on the identification of pygidial gland secretion components in both troglophilous and troglobite cave-dwelling ground beetles. Some compounds are reported for the first time in the secretions of ground beetles and other higher or lower taxa. The adaptation to underground life has not led to a reduction or changes in the chemical defense mechanism in the analyzed troglophilous and troglobitic Platyninae and Trechinae taxa.