Large, ball rolling dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) are competitively dominant and can strongly influence community succession in dung pads. Ball production by Scarabaeus sacer Linnaeus was recorded in the Kizilirmak Delta on the Black Sea coast of Turkey by using artificial dung pads from 125 g to 2,000 g. Utilisation of pads across the 16-fold range of pad sizes demonstrated behavioural variation that may reduce intraspecies competition. Ball production was highly concentrated, with 66 balls (61%) produced from 8 pads of the 3 largest pad sizes, which may be related to chemical attraction between males and females. Ball size increased with increasing pad size (P < 0.05) but the number of balls produced per 100 g of dung decreased with increasing pad size (P < 0.01). Pad size for maximum ball production and ball size were 1,371 g and 1,260 g, respectively. The highest and lowest percentage of dung used for ball production was 43% of 125 g pads and 13% of 2,000 g pads, respectively. Ball production and time of day were significantly related (P < 0.01); S. sacer was almost exclusively nocturnal, with 59% of all balls produced between 21.00 and 22.00. This optimum period for ball production early in the night may be a compromise between reduced risk of predation and the increased energy costs of ball production as the temperature falls., Gregory T. Sullivan, Sebahat K. Ozman-Sullivan, Jean-Pierre Lumaret, Myron P. Zalucki, Greg Baxter., and Obsahuje bibliografii
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
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
We investigated the predatory potential and food preference of different life stages of Coccinella septempunctata L. for a nutritious aphid (mustard aphid, Lipaphis erysimi) and toxic aphid (cabbage aphid, Brevicoryne brassicae). We provided all the life stages of C. septempunctata with either L. erysimi or B. brassicae and found that the second, third and fourth instar larvae and adult females of this predator consumed daily greater numbers of L. erysimi. However, the first instar larvae and adult males consumed similar numbers of both of these aphids. In choice condition, each larva, adult males and females were each provided separately with a mixed aphid diet in three proportions (i.e. low: high, equal: equal and high: low densities of L. erysimi: B. brassicae). We hypothesized that life stages of C. septempunctata will prefer L. erysimi regardless of its proportions. Laboratory experiments supported this hypothesis only at the adult level in terms of high values of β and C preference indices. However, it rejects this hypothesis at the larval level, as larvae preferred B. brassicae when provided with certain combinations and showed no preference in a few combinations. We infer that mixtures of nutritious and toxic aphids may enable this ladybird to overcome any probable nutritional deficiency and/or reduce the toxicity of a toxic diet, especially for the larvae. Results of the treatment in which a high proportion of B. brassicae were consumed along with fewer L. erysimi indicates that a mixed diet could be better for the development of immature stages of C. septempunctata., Mushtaq A. Guroo, Ahmad Pervez, Kuldeep Srivastava, Rakesh K. Gupta., and Obsahuje bibliografii
The potato tuberworm, Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae), is a major pest of potato, Solanum tuberosum L. (Solanales: Solanaceae), both in the field and storehouses. The rate of development and survival of P. operculella, reared on potato tubers cv. Spunta at eight constant temperatures (17.5, 20, 22.5, 25, 27.5, 30, 32.5 and 35°C), were studied in the laboratory. The duration of development of the immature stages was recorded. Adult longevity was also recorded under the same conditions. Developmental time decreased significantly with increase in temperature within the range 17.5-32.5°C. No development occurred at 35°C. Survival (%) from egg to adult was higher at temperatures within the range 17.5-27.5°C than at either 30 or 32.5°C. Linear and a non-linear (Logan I) models were fitted to our data in order to describe the developmental rate of the immature stages of P. operculella as a function of temperature and estimate the thermal constant (K) and critical temperatures (i.e., lower developmental threshold, optimum temperature for development, upper developmental threshold). Lower developmental threshold and optimum temperature for development ranged between 12.5-16.2 and 31.7-33.8°C, respectively. The estimated upper developmental threshold for total immature development was 35.0°C. Thermal constant for total development was 294.0 degree-days. Adult longevity was significantly shorter at high (30 and 32.5°C) than at low temperatures (17.5-27.5°C). Our results not only provide a broader insight into the thermal biology of P. operculella, but also can be used as an important tool in planning an effective pest control program both in the field and storehouses., Stefanos S. Andreadis, Christos G. Spanoudis, Georgia Zakka, Barbara Aslanidou, Sofia NoukariI, Matilda Savopoulou-Soultani., and Obsahuje bibliografii
The Asian long-horned beetle, Anoplophora glabripennis, is a serious destructive pest of forests throughout China as it attacks a wide range of host plants. The effect of host trees on the cold hardiness of A. glabripennis larvae could be the basis for predicting the performance of this forest pest on different common hosts.To evaluate the effect of different species of host plant on the cold hardiness of overwintering larvae of A. glabripennis, we measured the supercooling point (SCP), fresh mass, protein content and concentrations of low molecular weight substances in overwintering larvae collected from three different host species (i.e., Populus opera, Populus tomentosa and Salix matsudana). Mean SCPs and protein contents of larvae from these three hosts differed significantly. The SCPs and protein contents of the larvae collected from P. opera and P. tomentosa were significantly higher than those collected from S. matsudana. The concentrations of glycerol, glucose and trehalose in overwintering larvae collected from these host species also differed significantly, but there were no significant differences in the concentrations of sorbitol and inositol. The larvae that were collected from S. matsudana had the highest concentrations of glycerol and trehalose and those from P. opera the lowest contents of glycerol, whereas those from P. tomentosa had the lowest concentrations of trehalose but the highest concentrations of glucose. Because of the significant differences in the quantities of these biochemical substances in their bodies, the cold hardiness of overwintering larvae of A. glabripennis was significantly dependent on the tree they fed on. These effects on the cold hardiness of the overwintering larvae might affect the selection of a host tree and therefore the spread of this beetle. and Yuqian Feng, Reaxit Tursun, Zhichun Xu, Fang Ouyang, Shixiang Zong.
The Tisza River Basin is an important area as it is a green corridor in which there are highly endangered habitats and a high level of biodiversity. The patterns in the species richness of invertebrates and the environmental conditions affecting these patterns are poorly studied in the grassy habitats in the lower reaches of the Tisza River Basin. The present study focuses on the effects of flooding, habitat and landscape features on the species richness of orthopterans at 24 grassland sites in two different landscapes. The relations between the explanatory variables and the pattern of diversity of orthopterans with different life-history traits were studied, using ordination and Generalized Linear Mixed Models. Although the influential factors for the different trait groups differed, we suggest that landscape features are the most important in shaping orthopteran assemblages, whereas habitat characteristics and flooding have comparatively little effect. Habitat characteristics affected only the non-xerophilous and Ensifera species and only the species richness of non-xerophilous orthopterans in flooded and non-flooded sites differed. We emphasize that even in countries where there are still considerable areas of high value natural grasslands, such as Hungary, non-protected meadows, linear grassy habitats (dikes, ditch banks, road verges, etc.) need more attention and should be given higher priority in the conservation of invertebrates., Attila Torma, Miklós Bozsó., and Obsahuje bibliografii
The maize weevil, Sitophilus zeamais (Motschulsky), is a major pest of stored grain kernels. Irradiation is an established technique for controlling insects in stored grain and is a major stress factor affecting these insects. Since heat shock protein (hsp) genes respond to this stress, we proposed that hsps may be associated with irradiated stress tolerance in S. zeamais. The responses of the maize weevil to exposure to ultraviolet-C (UV-C) and microwave irradiation were assessed at four developmental stages: egg, larva, pupa and adult. The results revealed that exposure to UV-C (254 nm, < 8 h) did not affect the survival of the maize weevils; however, Szhsp70, Szhsc70 and Szhsp90 mRNA levels significantly increased during the first 1 h of UV-C exposure. The median lethal time (LT50) of exposure to microwave irradiation indicated that the adult stage was more tolerant of microwave irradiation than the other developmental stages. Microwave irradiation enhanced the expression of the three hsps, but the intensity of up-regulation differed among the three genes, with Szhsp70 the most highly up-regulated. Our experiments revealed that UV-C and microwave irradiation influenced the expression profile of hsp genes in S. zeamais. At the tissue level, the gene responses to UV-C and microwave irradiation varied greatly in different tissues., Jatuporn Tungjitwitayakul, Nujira Tatun, Boongeua Vajarasathira, Sho Sakurai., and Obsahuje bibliografii
Traps baited with plant volatiles and/or bark beetle pheromones have been used to survey for exotic and potentially invasive bark and wood-boring beetles in North America since the mid-1990s. Recent discoveries of sex and aggregation pheromones in the Cerambycidae offer means of improving detection rates of longhorn beetles, but little is known of their effects on detection of bark and ambrosia beetles in the subfamily Scolytinae. Our objectives were to determine the efficacy of host volatile trap lures for survey and detection of Scolytinae species and whether that efficacy was affected by the addition of longhorn beetle pheromones. More than 12,000 specimens and 36 species of Scolytinae were collected in two field trapping bioassays conducted in the Russian Far East in 2009 and 2010. The lure combination of spruce blend (a blend of racemic α-pinene, (-) β-pinene, (+)-3-carene, (+)-limonene, and α-terpinolene) and ethanol significantly increased detection rates and mean catches of Hylastes brunneus Erichson, Hylastes obscurus Chapuis, Ips typographus (L.), and Dryocoetes striatus Eggers compared with unbaited traps. The addition of the longhorn beetle pheromones, E-fuscumol, or E-fuscumol acetate, to traps baited with spruce blend and ethanol, slightly reduced mean catches of D. striatus but otherwise did not affect catch of any Scolytine species. Baiting traps with ethanol significantly increased mean catches of Anisandrus apicalis (Blandford), Anisandrus dispar (Fabr.), Anisandrus maiche (Kurenzov), Xyleborinus attenuatus (Blandford), Xyleborinus saxesenii (Ratzeburg), Xylosandrus germanus (Blandford), Scolytoplatypus tycon Blandford, and Trypodendron lineatum (Olivier). By themselves, the longhorn beetle pheromones, racemic hydroxyhexan-2-one and racemic hydroxyoctan-2-one, were not attractive to any Scolytine species. However, when added to ethanol-baited traps, hydroxyhexan-2-one lures significantly increased mean catch of S. tycon, hydroxyoctan-2-one lures significantly reduced mean catches of A. maiche and X. attenuatus, and lures of either hydroxyketone significantly reduced mean catch of T. lineatum. The lure treatments that detected the greatest number of species per sampling effort were spruce blend plus ethanol in 2009 (16 Scolytinae species and 13 species of Cerambycidae combined in an eight-trap sample) and hydroxyhexan-2-one plus ethanol in 2010 (20 Scolytinae species and 7 species of Cerambycidae combined in an eight-trap sample). Species accumulation curves did not reach an asymptote for any lure treatment, indicating that many species would go undetected in samples of 8-9 traps per site., Jon D. Sweeney, Peter Silk, Vasily Grebennikov, Michail Mandelshtam., and Obsahuje bibliografii