Plant volatiles can synergize the response to moth pheromone. Synthetic pheromone analogs, in turn, have the opposite effect in reducing pheromone attractiveness. To determine how these two types of stimuli interact and influence male moth behaviour, we performed wind tunnel experiments on the grapevine moth, Lobesia botrana. We noticed that a blend of host plant volatiles [(E)-β-caryophyllene, 1-hexanol, (Z)-3-hexenyl acetate and 1-octen-3-ol in a 100:20:10:5 ratio] significantly increased the response of males to an optimized blend of sex pheromone [(7E,9Z)-dodeca-7,9-dienyl acetate (E7,Z9-12:Ac), (7E,9Z)- dodeca-7,9-dienol (E7,Z9-12:OH) and (Z)-9-dodecenyl acetate (Z9-12:Ac)] in a 100:10:2 ratio. However, the response of males to the natural attractant was significantly reduced by two analogs [(9E,11Z)-tetradeca-9,11-dien-2-one (MK 2) and [(9E,11Z)-1,1,1-trifluoro-tetradeca-9,11-dien-2-one (TFMK 3)], of the major component of the sex pheromone of the insect (E7,Z9-12:Ac). When both stimuli were tested on males at pheromone:analog:plant volatile blend 1:100:1000 ratio, the plant blend offset the inhibitory effect induced by TFMK 3 but not that of MK 2. Our results show for the first time that under laboratory conditions plant volatiles can prevent inhibition by a pheromone analog., Albert Sans, Miguel Morán, Magí Riba, Ángel Guerrero, Jaume Roig, César Gemeno., and Obsahuje bibliografii
Pollination of Sedirea japonica (Orchidaceae) by Bombus diversus diversus (Hymenoptera: Apidae), Kenji Suetsugu, KOji Tanaka., and Obsahuje seznam literatury
Lygus lineolaris (Palisot de Beauvois, 1818) (tarnished plant bug) is a serious pest of cotton (Gossypium hirsutum L.) in the Delta region as compared to cotton in the Hills region of the state of Mississippi in USA. The reason for this is unclear but it was hypothesized that the plant cell wall degrading polygalacturonase enzyme system in the salivary glands of L. lineolaris from the Delta could be better adapted for cotton, which is grown more predominantly in the Delta region than in the Hills region. Expression analysis of three primary polygalacturonase genes (LlPG1, LlPG2 and LlPG3) was conducted in laboratory reared and field collected populations of L. lineolaris. Assay of polygalacturonase enzyme activity was also conducted to compare wild collected populations. Initial laboratory and field data revealed gene expression differences in sex, age, region, and host plant which guided the direction of our subsequent study during 2013 and 2014. Based on the results of this study, we propose that the three genes studied may not be reflective of the entire polygalacturonase enzyme system and may not be solely responsible for the observed adaptation of L. lineolaris to cotton in the Delta region than in the Hills region. Analyses also revealed that the expression of the three targeted polygalacturonase genes was affected by the host plant from which the insects were collected and that adults had higher polygalacturonase expression than nymphs. Taken together, our results provide strong evidence for developmental stage specific and host plant based change in expression of PG genes in the salivary glands of L. lineolaris. This, however, was not reflected in total polygalacturonase enzyme activity which was not significantly different between regions, hosts, sex, or developmental stage., Daniel Fleming, Natraj Krishnan, Fred Musser., and Obsahuje bibliografii
A number of aphid species have been shown to produce winged dispersal morphs in the presence of natural enemies. Previous studies tested specialized aphid predators such as ladybirds or lacewing larvae. We confronted colonies of pea aphids with the polyphagous rove beetles, Drusilla canaliculata and Tachyporus hypnorum. For both predators we found that the percentage of winged morphs increased in predator-attacked pea aphid colonies compared to a control. The behaviour of the two rove beetles species was noticeably different. D. canaliculata mostly foraged on the ground and rarely on the plant, while T. hypnorum was almost exclusively observed on the plants, causing a higher number of aphids to drop to the ground, which resulted in a stronger increase in winged morph production. Our results clearly show that not only monophagous aphid predators but also more polyphagous insect predators, which include aphids in their diet, can induce aphids to produce winged morphs., Adalbert Balog, Mohsen Mehrparvar, Wolfgang W. Weisser., and Obsahuje seznam literatury
Polyploidie je důležitým evolučním mechanismem přispívajícím k biodiverzitě současných ryb a také významným nástrojem v akvakultuře. Tento článek podává přehled o mechanismech vzniku polyploidie a o kauzálním vztahu mezi hybridizačními událostmi a zvýšením stupně ploidie. Uvádí rovněž příklady využití specifických vlastností polyploidů v akvakultuře., Polyploidy is an important evolutionary mechanism contributing to the biodiversity of extant fishes, and it also represents a notable tool in aquaculture. This paper reviews the mechanisms by means of which polyploidy arises and the causal relationship between hybridisation events and elevation of the ploidy level. Utilization of specific traits of polyploids in aquaculture is also discussed., Martin Flajšhans, Petr Ráb., and Obsahuje seznam literatury
The ladybird beetle, Cheilomenes sexmaculata (Fabricius), has been extending its distribution in and around urban areas at higher latitudes in Japan over the past 100 years. Between 2003 and 2011, we investigated the seasonal occurrence, aphid prey and population dynamics of this species in an urban park in Osaka City, central Japan. We found that C. sexmaculata completes three generations a year in Osaka. Overwintered adults emerge in March or April and produce two (or rarely one) generations by summer. Second-generation adults aestivate and subsequently produce another generation in autumn. This species feeds on five species of aphids that infest planted shrubs and alien weeds throughout the vegetative season. We analyzed the association between accumulated temperature and when overwintered adults first emerged. In addition, we determined the association between their time of emergence, peak abundance and last occurrence, and meteorological conditions. There was no association between the sum of effective temperatures and termination of adult overwintering. There was, however, an association between first occurrence and peak abundance, and climatic conditions, such as warm temperatures or low humidity. This species maintained a stable population in an urban park by becoming quiescent when climatic conditions were unfavourable or prey was scarce. We discussed these findings in relation to urban environmental factors, such as climate, food conditions and vegetation., Yasuko Kawakami, Kazuo Yamazaki, Kazunori Ohashi., and Obsahuje bibliografii
We conducted a comparative population genetic analysis of levels of genetic variation and its geographical structuring in three closely related species of grasshopper that co-occur in the Mediterranean Basin: Calliptamus italicus, C. barbarus and C. wattenwylianus. In the western part of their distributions 5 populations of C. italicus, 13 of C. barbarus and 10 of C. wattenwylianus were sampled. Bootstrap re-sampling of populations and microsatellite loci within each species indicated a lower level of genetic diversity and higher level of genetic differentiation in C. barbarus, which is less of an outbreak pest species than either of the other Calliptamus species studied. This may be due to lower effective sizes of non-outbreak populations and/or lower gene flow among them., Elodie Blanchet ... [et al.]., and Obsahuje seznam literatury
High host specificity and dependence on the host plants are common attributes of herbivorous insects. Their usage in ecosystem studies and landscape assessment is shown by examples from a group of Central European weevils and leaf beetles. Biodiversity can be assessed from the degree of completeness of present herbivore feeding guilds. Wingless species with narrow habitat requirements can be used as good bioindicators of relic natural habitats. and Pavel Špryňar, Jaromír Strejček.