RNA interference (RNAi) technology uses dsRNAs to silence specific targeted genes by downregulating their expression. It has become a potent tool for functional and regulatory studies of insect genes and has potential to be applied for insect control. Though it has been challenging to generate effective RNAi in lepidopteran insects, in the current study this technology was applied to develop specific RNAi-based molecular tools that could be used to negatively impact the invasive lepidopteran forest pest, gypsy moth (GM). GM midgut-specific genes were selected for dsRNA design from larval transcriptome profiles. Two methods were used to produce specific dsRNAs, bacterial expression and in vitro synthesis, which were then fed per os to GM larvae. Depletion of uncharacterized gene targets known as locus 365 and locus 28365, or their stacked combination, depleted target transcripts in a sequence specific manner and resulted in 60% reduction in body mass. Treated GM females that were able to moult to the adult stage displayed an approximately two-fold reduction in egg masses. These have potential to be developed as molecular biopesticides for GM., Saikat Kumar B. Ghosh, Dawn E. Gundersen-Rindal., and Obsahuje bibliografii
The expansion of urban areas is one of the most significant anthropogenic impacts on the natural landscape. Due to their sensitivity to stressors in both aquatic and terrestrial habitats, dragonflies and damselflies (the Odonata) may provide insights into the effects of urbanisation on biodiversity. However, while knowledge about the impacts of urbanisation on odonates is growing, there has not been a comprehensive review of this body of literature until now. This is the first systematic literature review conducted to evaluate both the quantity and topics of research conducted on odonates in urban ecosystems. From this research, 79 peer-reviewed papers were identified, the vast majority (89.87%) of which related to studies of changing patterns of biodiversity in urban odonate communities. From the papers regarding biodiversity changes, 31 were performed in an urban-rural gradient and 21 of these reported lower diversity towards built up city cores. Twelve of the cases of biodiversity loss were directly related to the concentrations of pollutants in the water. Other studies found higher concentrations of pollutants in odonates from built-up catchments and suggested that odonates such as Aeshna juncea and Platycnemis pennipes may be candidate indicators for particular contaminants. We conclude by identifying current research needs, which include the need for more studies regarding behavioural ecology and life-history traits in response to urbanisation, and a need to investigate the mechanisms behind diversity trends beyond pollution., Giovanna Villalobos-Jiménez, Alison M. Dunn, Christopher Hassall., and Obsahuje bibliografii
Twenty years ago, Przewalski’s horse (last spotted in the wild in 1969) returned to Mongolia and China. In the mid-1980’s, number of horses in zoological gardens reached 500 and ideas of their reintroduction started to take shape. After a failure of the first plan, private foundations took up the initiative, helped to build acclimatization stations and arranged the air trans - port. Not only the acclimatization but also a behavioural adaptation of the horses proved to be crucial. Despite the definite success, the wild populations remain small, they are exposed to winters with extreme amounts of snow, and will face a risk of inbreeding in the future. and Evžen Kůs.
A new genus and species of Hemiptera: Heteroptera: Enicocephalomorpha: Aenictopecheidae: Aenictopecheinae, Ulugurocoris grebennikovi gen. et sp. n., based on micropterous females from Tanzania, Uluguru Mts, Budunki, is described and differentiated. The males are probably macropterous. Some general aspects of morphology of U. grebennikovi are discussed in a broader context, such as presence of cephalic trichobothria (suggested to be a groundplan character of Heteroptera), presence of “gular sulci” (suggested to have an ecdysial function), lack of cephalic neck (symplesiomorphy with other Hemiptera), presence of posterior lobe of pronotum associated with the epimeroid (a new term for so called “proepimeral lobe”), and presence of notopleural sulcus on the propleuron. Diagnostic characters of the Aenictopecheinae are summarized and distribution of their seven genera is reviewed. Ulugurocoris grebennikovi is the first representative of the basal family Aenictopecheidae in the Afrotropical Region. The type locality is situated in the Eastern Arc Mountains (Tanzania), a recently identified hotspot of Afrotropical diversity characterized by a high degree of endemism caused by high rates of speciation combined with low rates of extinction. A brief characterization of the area is provided., Pavel Štys, Petr Baňař., and Obsahuje seznam literatury
Velia currens (Fabricius, 1794) and V. gridellii Tamanini, 1947 are two South European species of Veliidae, whose ecology and behaviour are poorly known. The aims of this study were to investigate their life histories, quantify occurrence of wing polymorphism and gather information on their degree of co-occurrence. Nine different populations were regularly surveyed from April to November 2010. Furthermore, a dataset containing information on the occurrence of the two species and the presence of winged morphs at 294 sites was compiled from museum collections, private collections and published literature. No evidence for multivoltinism was detected in either species. However, oviposition and and/or hatching were protracted in time so that early-instar nymphs and adults co-occurred up to midsummer. Although their distributional ranges completely overlap at a large spatial scale, the two species co-occurred only rarely at the same sites and the degree of co-occurrence was lower than expected by chance. Winged specimens were rarely recorded. At least in V. gridellii, the numbers of winged individuals were inversely related to the altitudes of the sites. During the summer, when some of the streams surveyed dried up, several specimens were found in an apparent state of lethargy, under stones. It is hypothesized that the ability to aestivate, coupled with the ability to walk from one site to another may reduce the advantage associated with producing winged forms and account for the low rate of occurrence of macropterism in these species., Fabio Cianferoni and Giacomo Santini., and Obsahuje seznam literatury
Ant-aphid mutualism is considered to be a beneficial association for the individuals concerned. The population and fitness of aphids affected by ant attendance and the outcome of this relationship affects the host plant of the aphid. The main hypothesis of the current study is that ant tending decreases aphid developmental time and/or increases reproduction per capita, which seriously reduces host plant fitness. The effect of attendance by the ant Tapinoma erraticum (Latreille, 1798) (Hymenoptera: Formicidae) on population growth and duration of different developmental stages of Aphis gossypii Glover (Hemiptera: Aphididae) were determined along with the consequences for the fitness of the host plant of the aphid, Vicia faba L., in greenhouse conditions. The initial aphid density was manipulated in order to study aphid performance due to density-dependent changes in ant attendance. The population growth rate of ant attended aphids was more than that of unattended aphids. However, the ratio of 1st-2nd nymphs to adults in aphid populations attended by ants was lower. The yields of bean plants on which the aphids were attended by ants were significantly greater than those of unattended plants. This study indicates that ants not only increase aphid fitness in terms of their population growth rate, but also benefit the host plant., Afsane Hosseini, Mojtaba Hosseini, Noboru Katayama, Mohsen Mehrparvar., and Obsahuje bibliografii
Results of studies on prey suitability for generalist predators are important for efficient mass rearing and implementing Integrated Pest Management Programmes (IPM). The green lacewing, Chrysoperla sinica (Tjeder), is a polyphagous natural enemy attacking several pests on various crops in China. We investigated the effect of feeding it different species of prey on its pre-imaginal development, survival, adult longevity and fecundity under laboratory conditions. The prey species tested were nymphs of Aphis glycines Matsumura, cotton aphid Aphis gossypii Glover, peach aphid Myzus persicae Sulzer, corn aphid Rhopalosiphum maidis Fitch and cowpea aphid Aphis craccivora Koch, and eggs of the rice grain moth, Corcyra cephalonica Stainin. None of these species of prey affected the pre-imaginal survival or percentage survival of the eggs of the predator. However, eggs of C. cephalonica and nymphs of M. persicae and A. glycines were the best of the prey species tested, in that when fed on these species the pre-imaginal developmental period of C. sinica was shorter and its adult longevity, fecundity and percentage survival greater than when fed the other species of prey. In contrast, when fed nymphs of A. craccivora the pre-imaginal development period was longer, adult longevity shorter and fecundity lower. These findings could be helpful in defining more optimum conditions for the mass rearing of C. sinica for use in integrated pest management (IPM) programmes for various crops., Niaz Hussain Khuhro ... [et al.]., and Obsahuje seznam literatury