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Qiryat Shemona, Israel

Martinez J.-J.I.,Galilee College | Martinez J.-J.I.,Galilee Research Institute Ltd. | Raz R.,Galilee College | Mgocheki N.,Bindura University of Science Education | Alvarez R.,University of Leon
Arthropod-Plant Interactions

The presence of epiphytic foliose lichen amplifies the heterogeneity of habitat by creating shelters for insects living on tree bark. It thus should enhance species number and spatial niche segregation among these canopy insects. We studied this hypothesis in a field experiment using four aphid species that induce galls on Pistacia atlantica trees covered with Xanthoria parietina lichen. In autumn 2008, 3 months after aphid fundatrices were oviposited, we marked six branches on each of 29 trees. Two served as a control, whereas the other four were isolated with insect glue; two of them were scraped with sandpaper to remove epiphytic foliose lichens. We therefore obtained three treatments comprising control branches, isolated branches with lichen, and isolated branches without lichen. In summer 2009, we counted all the galls developing on five new annual shoots on each of 174 branches. We observed more cecidogenic aphid species on all the branches with lichens than without, but each species at different proportions. The different frequencies of utilization of the lichen did not lead to habitat partitioning between species. In conclusion, although habitat heterogeneity itself was associated with species richness and population abundance, it did not induce spatial niche segregation. Considering that many economically important insect species, pests and natural enemies, oviposit or spend some portion of their lives in bark cracks, it is possible that some can use lichens too for protection or/and oviposition sites. As a consequence, lichens may affect management of agrosystems and their impacts should be investigated more deeply in such contexts. © 2013 Springer Science+Business Media Dordrecht. Source

Alvarez R.,University of Leon | Molist P.,University of Vigo | Gonzalez-Sierra S.,National Research Center sobre la Evolucion Humana | Itzhak Martinez J.J.,Tel-Hai Academic College | And 2 more authors.

Morphological differentiation of gall tissues induced on plants may play a role to characterize the real taxonomic position of the gall inducer. We verified this hypothesis with galls induced by Rectinasus buxtoni on Pistacia palaestina. There is controversy about the taxonomic localization of genus Rectinasus: in one classification it is situated with the genera Forda and Paracletus while in another it is linked to the genera Geoica and Baizongia. Histological examination of the walls of the galls reveals the presence of two opposed vascular bundles and an inner surface of the gall with cavities. These features place Rectinasus in the same group as Geoica and Baizongia, and not with Paracletus and Forda, whose galls have a different histological structure, as generally admitted. Copyright © 2014 Magnolia Press. Source

Frank A.,Galilee Research Institute Ltd. | Frank A.,Galilee College | Cohen H.,Galilee Research Institute Ltd. | Cohen H.,Technion - Israel Institute of Technology | And 4 more authors.
Amino Acids

Methionine is a nutritionally essential sulfur-containing amino acid found at low levels in plant tissues. Yet, the factors that regulate its synthesis and accumulation in seeds are not fully known. Recent genetic studies demonstrate that Arabidopsis seeds are able to synthesize methionine de novo through the aspartate family pathway similarly to vegetative tissues; however, additional biochemical studies suggest that the S-methylmethionine (SMM) cycle also plays a major role in methionine synthesis in seeds. To better understand the contribution of these two pathways to methionine synthesis, we have sampled various vegetative and reproductive tissues during the Arabidopsis life cycle and determined the contents of soluble and protein-incorporated methionine, SMM, as well as the expression levels of the key genes involved in these two pathways. Our results strengthen the hypothesis that SMM that is produced in the rosette leaves from methionine contributes to methionine accumulation in seeds. However, the SMM cycle may have additional functions in plant tissues since its key genes were expressed in all of the examined tissues, although at different rates. The accumulation patterns of soluble and protein-incorporated methionine during the Arabidopsis life cycle were found to be similar to most of the other amino acids, especially to those belonging to the branched-chain and aromatic amino acids that are produced in chloroplasts together with methionine. This indicates that similar factors regulate the levels of amino acids during development. © 2014 Springer-Verlag Wien. Source

Martinez J.J.I.,Tel-Hai Academic College | Martinez J.J.I.,Galilee Research Institute Ltd. | Amar Z.,Tel-Hai Academic College
Journal of Insect Conservation

Small holy woods protected for centuries for cultural purposes may have conservation value for small animals, despite their tiny sizes. To verify this hypothesis we used transects to quantified ants in a small sacred forest in a hot Mediterranean region, and the impact of cattle presence in part of it. We hypothesized that it should be mainly inhabited by species having a northern temperate distribution. We detected ants belonging to 39 species including 15 new species for the region. As expected, the majority of them had Palearctic distribution, while others were endemic to the Levant. All of them were known to live in regions with temperate climate. The presence of cattle did not statistically impact on either the number of species or on their biodiversity indices: the average number of ant species per transect was 21 ± 4.6 (SD) in the presence of cows and 23 ± 4.8 in their absence. As hypothesized, the main impact of cattle was on community composition: in the presence of cattle more species were specialists for, or tolerant to, disturbed habitats, resulting in a relatively low Jaccard coefficient of similarity between the two parts of the forest (Sj = 0.56). In conclusion, this small sacred forest, protected for centuries, facilitates the conservation of a great number of shade-loving ant species in a hot region by providing suitable habitats, but the presence of livestock reduces the conservation value of the forest by promoting ant species tolerant to disturbed habitats. © 2014 Springer International Publishing Switzerland. Source

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