Forficula auricularia (European earwig).

The European earwig, Forficula auricularia, is a polyphagous insect that is native to large parts of Europe and western Asia as far east as western Siberia. In the early twentieth century it was accidentally introduced into North America where it became widespread in a number of states/provinces of both the USA and Canada. It has also invaded Australia and New Zealand, and more recently Mexico, Chile and the Falkland Islands. Although economic damage to vegetable and flower gardens is generally minor, when high population densities occur it is a major pest in gardens and greenhouses, and a significant nuisance in households. Within and sometimes also outside its native range it is also regarded as a beneficial organism used or encouraged as a biological control agent to control other insect pests in orchards and gardens.

Alteration of gut microbiota with rifampicin does not impair maternal care in the European earwig

ABSTRACTThe microbes residing within the gut of an animal host often maximise their own fitness by modifying their host’s physiological, reproductive, and behavioural functions. Whereas recent studies suggest that they may also shape host sociality and therefore have critical effects on animal social evolution, the impact of the gut microbiota on maternal care remains unexplored. This is surprising, as this social behaviour is widespread among animals, often determines the fitness of both juveniles and parents, and is essential in the evolution of complex animal societies. Here, we address this gap in knowledge by testing whether life-long alterations of the gut microbiota with rifampicin - a broad-spectrum antibiotic - impair the expression of pre- and post-hatching maternal care in the European earwig, an insect exhibiting extensive forms of maternal care towards eggs and juveniles. Our results first confirm that rifampicin altered the mothers’ gut microbial communities and revealed that the composition of the gut microbiota differs before and after egg care. Contrary to our predictions, however, the rifampicin-induced alterations of the gut microbiota did not modify the expression of pre- or post-hatching care. Independent of maternal care, rifampicin increased the females’ feces production and resulted in lighter eggs and juveniles. By contrast, rifampicin altered none of the other 23 physiological, reproductive and longevity traits measured over the females’ lifetime. Overall, these findings reveal that altering the gut microbiota does not necessarily affect host sociality. More generally, our results emphasize that not all animals have evolved a co-dependence with their microbiota.

The first of five moults of Forficula auricularia L. (Dermaptera: Forficulidae)

Most studies about the European earwig Forficula auricularia L. (Dermaptera: Forficulidae) assume that four larval moults occur from hatching to adult. In this note, we use observational and quantitative approaches to reveal the presence of an additional intermediate moult occurring immediately after egg hatching. We then briefly discuss how this finding may open up new possibilities for follow-up studies to improve our general understanding of the taxonomy, biology, and evolution of this species.

Speciation patterns in the Forficula auricularia species complex: cryptic and not so cryptic taxa across the western Palaearctic region

Forficula auricularia (the European earwig) is possibly a complex of cryptic species. To test this hypothesis, we performed: (1) a phylogeographic study based on fragments of the mitochondrial COI and the nuclear ITS2 markers on a wide geographic sampling, (2) morphometric analyses of lineages present in Spain and (3) niche overlap analyses. We recovered five reciprocally monophyletic ancient phylogroups with unique historical patterns of distribution, climatic niches and diversification. External morphology was conserved and not correlated with speciation events, except in one case. Phylogenetic placement of the morphologically distinct taxon renders F. auricularia paraphyletic. Based on the congruence of the phylogenetic units defined by mtDNA and nuclear sequence data, we conclude that phylogroups have their own historical and future evolutionary trajectory and represent independent taxonomic units. Forficula auricularia is a complex of at least four species: the morphologically diagnosable Forficula aeolica González-Miguéns & García-París sp. nov., and the cryptic taxa: Forficula mediterranea González-Miguéns & García-París sp. nov., Forficula dentataFabricius, 1775stat. nov. and Forficula auriculariaLinnaeus, 1758s.s. We also provide new synonymy for F. dentata.

Arthropod Infestation Levels on Mandarins in California

Integrated pest management (IPM) guidelines for horticulture are typically established from years of experimental research and experience for a crop species. Ecoinformatics methods can help to quickly adapt these guidelines following major changes in growing practices. Citrus production in California is facing several major challenges, one of which is a shift away from sweet oranges [Citrus sinensis (L.) Osbeck Sapindales: Rutaceae] toward mandarins (including mostly cultivars of C. reticulata Blanco and C. clementina hort. ex Tanaka). In the absence of IPM guidelines for mandarins, growers are relying on pest information developed from oranges. We mined a database of management records from commercial growers and consultants to determine densities for four arthropod pests: cottony cushion scale (Icerya purchasi Maskell Hemiptera: Monophlebidae), citricola scale (Coccus pseudomagnoliarum Kuwana Hemiptera: Coccidae), European earwig (Forficula auricularia Linnaeus Dermaptera: Forficulidae), citrus red mite (Panonychus citri McGregor Acari: Tetranychidae), and a natural enemy, predatory mites in the genus Euseius (Congdon Acarina: Phytoseiidae). Densities of cottony cushion scale were approximately 10–40 times higher in the two most commonly grown mandarin species than in sweet oranges, suggesting this pest is reaching outbreak levels more often on mandarins. Densities of the other pests and predatory mites did not differ significantly across citrus species. This is a first step toward establishing IPM guidelines for mandarins for these pests; more research is needed to determine how arthropod densities relate to crop performance in mandarins.