Arthropods moving on large horizontal branches of old oaks (Quercus robur L.) in seven oak woodlands, SW Finland, were studied using a new trap type. The most abundant groups included Formicidae (Hym.), Oribatida (Acari), Thysanoptera, Nematocera (Dipt.), Collembola, Auchenorrhyncha (Hom.), Coleoptera, Araneae, Psocoptera and Hemiptera. The last three groups showed the least intersite variation in numbers of individuals. About 120 abundant, rare and other interesting species of Diplopoda (4 species mentioned), Chilopoda (2), Araneae (19), Opiliones (4), Pseudoscorpionida (1), Oribatida (9), Psocoptera (9), Blattodea (1), Neuroptera (1), Homoptera (10), Heteroptera (13), Coleoptera (25), Lepidoptera (14) and Formicidae (6) are listed, and the new trap is described.

The Cimicidae is a family of blood‐dependent ectoparasites in which dispersion capacity is greatly associated with host movements. Bats are the ancestral and most prevalent hosts for cimicids. Cimicids have a worldwide distribution matching that of their hosts, but the global classification is incomplete, especially for species outside the most common Cimicidae taxa. In this study, we place a little‐studied cimicid species, Bucimex chilensis , within a comprehensive molecular phylogeny of Cimicidae by sequencing the genomic regions of this and other closely related species. For this study, we collected B. chilensis females from Myotis chiloensis in Tierra del Fuego, 1,300 km further south than previously known southernmost distribution boundary. We also sequenced COI regions from Primicimex cavernis , a species which together with B. chilensis comprise the entire subfamily Primiciminae. Using Bayesian posterior probability and maximum‐likelihood approaches, we found that B. chilensis and P. cavernis clustered close to each other in the molecular analyses, receiving support from similar morphological features, agreeing with the morphology‐based taxonomic placement of the two species within the subfamily Primiciminae. We also describe a previously unrecognized morphological adaptation of the tarsal structure, which allows the austral bat ectoparasite, B. chilensis , to cling on to the pelage of its known host, the Chilean myotis ( Myotis chiloensis ). Through a morphological study and behavioral observation, we elucidate how this tarsal structure operates, and we hypothesize that by clinging in the host pelage, B. chilensis is able to disperse effectively to new areas despite low host density. This is a unique feature shared by P. cavernis , the only other species in Primiciminae.

Based on chromosomal, molecular and morphological analyses, two new Cacopsylla Ossiannilsson, 1970 species are described, C. lapponica S. Nokkala & Ch. Nokkala, sp. nov. and C. borealis S. Nokkala et Ch. Nokkala, sp. nov. (Hemiptera, Psylloidea). C. lapponica is a rare bisexual alpine species living on Vaccinium uliginosum Linnaeus, 1753 above tree line on northern hills, where it forms sympatric populations with C. myrtilli W. Wagner, 1947. So far, the species has been found in northern Finland, Utsjoki and Kilpisjärvi, and in northern Sweden, Abisko. The chromosome number in males is 2n = 12+X(0), characteristic of psyllids. The species is easily distinguished from C. myrtilli by its conspicuously smaller size mainly due to difference in wing size. Additional morphological differences are found in the length of antennae, female genital plates and male parameres. C. borealis, in turn, is a relatively common apomictic parthenogenetic species with 5n = 60 + XXXXX living on the same host plant, Ledum palustre Linnaeus, 1753, as C. ledi (Flor, 1861) and occasionally forming sympatric populations with it. No males have been recorded in C. borealis. Its distribution range reaches at least from northern Fennoscandia to Lake Baikal in the East. C. borealis can be distinguished from C. ledi by differences in the length and width of antennae, dark brown markings on the wing and female terminal structures. For molecular analysis, a 638 bp fragment of the mitochondrial COI gene was sequenced. C. lapponica differs from the cohabitating C. myrtilli by 20 fixed nucleotide substitutions (uncor rected p-distance 3.13 %), while C. borealis differs from C. ledi by 21 fixed nucleotide substitutions (uncorrected p-distance 3.29 %). Molecular phylogeny construction (ML and BI) reveals two highly divergent clades, one comprising two bisexual species, C. lapponica and C. fraudatrix Labina & Kuznetsova, 2012, and the other clade comprising the parthenogenetic species C. borealis, C. myrtilli, and C. ledi. Within this clade, C. borealis is more closely associated with C. myrtilli than with C. ledi.

We investigated changes in the reproductive output and the effect of female phenotype on reproductive parameters in a shield bug Elasmostethus interstinctus (L.) (Heteroptera: Acanthosomatidae) over the whole reproductive period. At the beginning and the middle of the reproductive period eggs were smaller than at the end of the period. Clutch mass and number of eggs per clutch decreased in laying sequence, first clutches being much larger than any of the later ones. Lifetime fecundity correlated positively with female size: large females produced more eggs and lived longer than small ones. Egg size did not vary with female size. Offspring survival until adulthood increased with egg weight. Individuals overwinter before reproduction, and because the nymphs from later‐laid eggs have the least time to gather resources before overwintering, it may be important for later‐laid eggs to be of high quality. Reproductive allocation varies during the reproductive period; females allocate resources relatively more to offspring number at the beginning of the reproductive period and more to offspring quality at the end of their life.

1. Community assembly is affected by four processes: dispersal, filtering effects (selection), ecological drift and evolution. The role of filtering relative to dispersal and drift should decline with patch size, hampering possibilities to predict which organisms will be observed within small‐sized patches. However, vegetation structure is known to have a marked impact on species assemblages, and plant quality may act as a biotic filter. This challenges the assumption of unpredictable species assemblages in small‐sized vegetation patches.2. Using 32 stands of five shrub species in south‐west Finland, this study investigated whether biotic filtering effects caused by patch‐forming plants are strong enough to overcome the mixing of mobile arthropod assemblages across small patches.3. Stochastic variation did not hide the signals of biotic filtering and dispersal in the small shrub patches. Habitat richness around the patches explained a three times larger share of variation in the species composition than did the identity of the patch‐forming plant, but it had less effect on the abundance of arthropods. A radius of 50–100 m around a patch explained the species composition best.4. Abundance patterns varied between the feeding guilds; the patch‐forming shrub influenced the abundances of detritivores and leaf‐feeding herbivores, whereas the abundances of flower‐visiting herbivores appeared to track the flowering phenology of the plants. Shrub identity had little effect on omnivores or predators. Predator abundances were correlated with the abundance of potential prey.5. The results of this study suggest that community composition within a vegetation patch may be predictable even if dispersal overrides local filtering effects, as suggested by the mass‐effects paradigm.