Functional responses at each developmental stage of predators and intraspecific competition associated with direct interactions among them provide insights into developing biological control strategies for pests. The functional responses of Harmonia axyridis (Pallas) at each developmental stage of Melanaphis sacchari (Zehntner) and intraspecific competition among predators were evaluated under laboratory conditions. The results showed that all stages of H. axyridis displayed a type II functional response to M. sacchari. Based on Holling's disc equation, the instantaneous searching rates were highest (a) and handling time was shortest (Th) of fourth instar larvae (a = 0.8818; Th = 3.9 min) and female adults (a = 0.9881; Th = 3.0 min) at larval and adult stages, respectively. The coefficients of mutual interference (m) assessed by the intraspecific competition equation were higher for fourth instar larvae (m = 0.4764) and female adults (m = 0.4183). The present study indicates that fourth instar and female adult were more effective stages of H. axyridis in the context of biological control but suitable predator densities need to be considered before natural enemy release., Pengxiang Wu, Jing Zhang, Muhammad Haseeb, Shuo Yan, Lambert Kanga, Runzhi Zhang., and Obsahuje bibliografii
In the last two decades a huge amount of research has focused on the invasive harlequin ladybird, Harmonia axyridis, particularly on potential or actual deleterious effects that have arisen after it has colonised new regions. A focus of this work has been real or anticipated declines in native ladybird abundance since the introduction of H. axyridis, for which it is deemed responsible. Scientists have generally painted a very bleak picture of the effects of H. axyridis on native species: in this paper I argue that the picture painted is often too bleak. I use the case of the 2-spot ladybird, Adalia bipunctata, the species most often invoked as threatened by H. axyridis, to illustrate my point. While there is little question that H. axyridis has led to a decline in A. bipunctata populations in Europe, it seems likely that prior to the invasive ladybird's arrival A. bipunctata occurred in artificially high numbers in the urban environments in which it was typically studied. Pollution in towns and cities led to enhanced numbers of prey aphids on plants there which initially favoured A. bipunctata, and later H. axyridis. Thus one species, A. bipunctata, that has benefitted from an association with humans has been replaced by another, H. axyridis, just as brown rats replaced black rats in Europe and North America. Viewed with a longer perspective, A. bipunctata has more likely declined back to pre-industrial levels: the artificially high level from which it has declined recently was not a 'natural' one, and thus its decline from this level does not imply that it is now threatened or endangered. More broadly, we need a wider perspective, encompassing other ladybirds, longer timeframes and better comparisons with other (non-ladybird) invasive species to more clearly assess whether H. axyridis really poses as much of a threat as is often proposed., John J. Sloggett., and Obsahuje bibliografii
We deployed branch traps in an ash (Fraxinus) plantation to investigate how Agrilus planipennis behavior is associated with Fraxinus pennsylvanica condition and dispersal patterns. Data were collected from traps with or without the presence of beetle visual decoys, and from a yearly survey of exit holes. The traps were placed on trees that were either clearly declining, with most foliage arising from epicormic sprouting, or on apparently healthy trees, with little evidence of damage or decline. We calculated correlations of exit holes among neighboring tree rings and also between exit holes and male trap captures. The damaged trees the traps were hung upon had more cumulative exit holes observed than the corresponding healthy trees. However, there was otherwise no evidence that the experiment was biased by differences in exit hole patterns of the surrounding trees. Male captures were greater on decoy-baited traps than controls and this decoy effect was most clearly apparent late in the season when traps were placed on healthy trees. There were also patterns of correlations between male captures and exit hole numbers that may be indicative of short-range mate finding-and dispersal behaviors. Female captures were sparser, but were positively affected by decoys on healthy and declining trees early in the season. Thus, the results suggest that the placement of such traps on healthier trees will maximize detection, and the branch traps also show promise for further use in dispersal studies., Michael J. Domingue, Jennifer Berkebile, Kim Steiner, Loyal P. Hall, Kevin R. Cloonan, David Lance, Thomas C. Baker., and Obsahuje bibliografii
The European stag beetle, Lucanus cervus, is recognised as a flagship species for biodiversity conservation. Although the species is widely distributed across Europe declines have led to it being granted protected or endangered status in a number of countries and regarded as "near threatened" by the IUCN. The integration of genetic approaches into conservation efforts is urgently needed but has been impeded to date by the lack of appropriate genetic markers. To provide such a resource the development of the first microsatellite loci for stag beetle is described. Loci were identified using two methods (i) enriched library cloning (ELC) and (ii) Restriction enzyme Associated DNA sequencing (RAD-Seq). Inefficient microsatellite detection using the ELC method suggests that RAD-Seq, or other Next Generation Sequencing based methods, may ultimately be more cost effective for obtaining informative suites of markers for this and other coleopteran species. 18 loci were characterised by genotyping 42 UK specimens collected as prey leftover/roadkill. All loci produced unambiguous genotypes and were polymorphic. Though preliminary, estimates of genetic variability suggest UK populations may be genetically depauperate. The microsatellite loci represent a suite of genetic markers that can be applied to non-invasive population monitoring and numerous other areas of Lucanus conservation and evolutionary research., Niall J. McKeown, Deborah J. Harvey, Amy J. E. Healey, Ilze Skujina, Karen Cox, Alan C. Gange, Paul W. Shaw., and Obsahuje bibliografii
Here we describe 16 novel microsatellite loci in the genome of the dragonhead sap beetle Thymogethes norvegicus, which were identified using a next-generation sequencing approach. In 40 dragonhead sap beetles from a population in southern Norway, we found 2-4 alleles per locus. Expected heterozygosity ranged from 0.18-0.65. Three of the loci showed significant deviation from Hardy-Weinberg equilibrium. After correcting for multiple tests, one pairwise locus combination displayed significant linkage disequilibrium. These novel microsatellite loci will be useful for future population structure, genetic diversity and conservation genetic studies of the dragonhead sap beetle., Oddmund Kleven, Anders Endrestøl., and Obsahuje bibliografii
Velká část hmyzu má v temperátní či mediterrání oblasti jednoletý vývojový cyklus, který je dán výraznou sezonní proměnlivostí tohoto prostředí. Mezi druhy s jednoletým cyklem patří i chrobáci rodu Lethrus, kam patří i na Moravě vymizelý chrobák révový (L. apterus). Při pokusech o chov těchto chrobáků bylo zjištěno, že část jedinců pocházejících z volné přírody upustila v pokusných podmínkách od aktivní fáze života a zahrabala se na dno chovných boxů, kde přežila více jak rok a půl od jejich odchycení v terénu. Po jejich násilném probuzení, začali někteří brouci aktivovat a přijímat potravu. Zda se jedná o náhodné pozorování nebo o strategii, při které se brouci rozhodují, zda v danou sezonu aktivovat či nebo „přeležet“ do následujícího roku zůstává nejasné a je předmětem dalších výzkumů., The genus Lethus (Geotrupidae) is believed to be a typical representative of a beetle with one-year life cycle. The adults mate and dig maternal chambers between the end of March and May. The larvae develop inside these chambers and pupate within a few months of eclosion. The inactive imago remains inside the burrow until spring. In our breeding experiments several wild caught beetles abandoned the active phase of life, burrowed themselves, and were inactive for more than a year and half. Some beetles resumed foraging and remained active for another three months after they were dug out., and Petr Šípek, Dana Drožová, Petr Janšta, David Král.
The influence of female mating status on ovarian development of the ladybird, Propylea dissecta (Mulsant) (Coleoptera: Coccinellidae), was investigated under laboratory conditions. We assessed the extent to which ovariole development was affected by mating and for that we initially created a base line by observing age specific ovariole development. Results show that the number of follicles in each ovariole increased with the age of both virgin and mated females up to the age of 3 days, thereafter, no increase in number of follicles was recorded. Ovariole width also increased with age in both virgin and mated females up to 4 days, thereafter, no increase in ovariole width was recorded. The ovariole width of mated females was significantly greater than that of virgin females. Egg maturation and the egg load started to increase at the age of 8 days in virgin females. Thereafter, it increased with increase in female age. While in mated females, immature eggs were recorded in their ovarioles from the age of 1 to 2 days. In mated females, however, the increase in the number of mature eggs per ovariole and egg load started when they were 3 days old. Egg load continuously increased with increasing female age., Mhd Shahid, Arshi Siddiqui, Omkar, Geetanjali Mishra., and Obsahuje bibliografii
The Asian ladybird Harmonia axyridis is an invasive insect in Europe and the Americas and is a great threat to the environment in invaded areas. The situation is exacerbated by the fact that non native species are resistant to many groups of parasites that attack native insects. However, very little is known about the complex microbial community associated with this insect. This study based on sequencing 16S rRNA genes in extracted metagenomic DNA is the first research on the bacterial flora associated with H. axyridis. Lady beetles were collected during hibernation from wind turbines in Poland. A mean ± SD of 114 ± 35 species of bacteria were identified. The dominant phyla of bacteria recorded associated with H. axyridis were Actinobacteria, Proteobacteria, Firmicutes and Bacteroidetes. Representatives of these phyla are common in the environment, e.g. in the soil, and are often identified as the dominant bacteria associated with arthropods. We also identified animal pathogenic bacteria, such as Burkholderia, Rhodococcus, Chlamydiae and Anaplasmataceae spp. (Neorickettsia helminthoeca and Ehrlichia ovina). We also identified Wolbachia pipientis in a single beetle. This bacterium is a causative agent of reproductive alterations in arthropods. These results support the enemy release hypothesis in the case of this ladybird invasion. Pathogenic bacteria were recorded in only a few samples. Moreover, male-killing bacteria such as Spiroplasma spp., Wolbachia spp. and Rickettsia spp. were only recorded in single insects so they cannot be responsible for the observed alterations in the sex-ratio of the ladybird population studied., Krzysztof Dudek, Kinga Humińska, Jacek Wojciechowicz, Piotr Tryjanowski., and Obsahuje bibliografii