Purpose of Review Climate change affects populations of forest insect pests in a number of ways. We reviewed the most recent literature (2013–2017) on this subject including previous reviews on the topic. We provide a comprehensive discussion of the subject, with special attention to insect range expansion, insect abundance, impacts on forest ecosystems, and effects on forest insect communities. We considered forest insects according to their major guilds and biomes. Recent Findings Effects of climate change on forest insects are demonstrated for a number of species and guilds, although generalizations of results available so far are difficult because of species-specific responses to climate change. In addition, disentangling direct and indirect effects of climate change is complex due to the large number of variables affected. Modeling based on climate projections is useful when combined with mechanistic explanations. Summary Expansion of either the true range or the outbreak range is observed in several model species/groups of major insect guilds in boreal and temperate biomes. Mechanistic explanations are provided for a few species and are mainly based on increase in winter temperatures. In relation to insect abundance, climate change can either promote outbreaks or disrupt trophic interactions and decrease the severity of outbreaks. There is good evidence that some recent outbreaks of bark beetles and defoliating insects are influenced by climate change and are having a large impact on ecosystems as well as on communities of forest insects.

Background: Knowledge of animal mitochondrial genomes is very important to understand their molecular evolution as well as for phylogenetic and population genetic studies. The Lepidoptera encompasses more than 160,000 described species and is one of the largest insect orders. To date only nine lepidopteran mitochondrial DNAs have been fully and two others partly sequenced. Furthermore the taxon sampling is very scant. Thus advance of lepidopteran mitogenomics deeply requires new genomes derived from a broad taxon sampling. In present work we describe the mitochondrial genome of the moth Ochrogaster lunifer. Results: The mitochondrial genome of O. lunifer is a circular molecule 15593 bp long. It includes the entire set of 37 genes usually present in animal mitochondrial genomes. It contains also 7 intergenic spacers. The gene order of the newly sequenced genome is that typical for Lepidoptera and differs from the insect ancestral type for the placement of trnM. The 77.84% A+T content of its α strand is the lowest among known lepidopteran genomes. The mitochondrial genome of O. lunifer exhibits one of the most marked C-skew among available insect Pterygota genomes. The protein-coding genes have typical mitochondrial start codons except for cox1 that present an unusual CGA. The O. lunifer genome exhibits the less biased synonymous codon usage among lepidopterans. Comparative genomics analysis study identified atp6, cox1, cox2 as cox3, cob, nad1, nad2, nad4, and nad5 as potential markers for population genetics/phylogenetics studies. A peculiar feature of O. lunifer mitochondrial genome it that the intergenic spacers are mostly made by repetitive sequences. Conclusion: The mitochondrial genome of O. lunifer is the first representative of superfamily Noctuoidea that account for about 40% of all described Lepidoptera. New genome shares many features with other known lepidopteran genomes. It differs however for its low A+T content and marked C-skew. Compared to other lepidopteran genomes it is less biased in synonymous codon usage. Comparative evolutionary analysis of lepidopteran mitochondrial genomes allowed the identification of previously neglected coding genes as potential phylogenetic markers. Presence of repetitive elements in intergenic spacers of O. lunifer genome supports the role of DNA slippage as possible mechanism to produce spacers during replication.

The ecological phenomenon of arthropods with defensive hairs is widespread. These urticating hairs can be divided into three categories: true setae, which are detachable hairs in Lepidoptera and in New World tarantula spiders; modified setae, which are stiff hairs in lepidopteran larvae; and spines, which are complex and secretion-filled structures in lepidopteran larvae. This review focuses on the true setae because their high density on a large number of common arthropod species has great implications for human and animal health. Morphology and function, interactions with human tissues, epidemiology, and medical impact, including inflammation and allergy in relation to true setae, are addressed. Because data from epidemiological and other clinical studies are ambiguous with regard to frequencies of setae-caused allergic reactions, other mechanisms for setae-mediated disease are suggested. Finally, we briefly discuss current evidence for the adaptive and ecological significance of true setae.