Carbon and Nitrogen Mineralization of Lead Treated Soils in the Eastern Mediterranean Region,Turkey

The aim of this study was to determine the first effect of lead on microbial activity in soil. The study was carried out in the soil samples from four different radish (Raphanus sativus L. var. radicula, Brassicaceae) fields along the highway in a district (Kadirli, Osmaniye) of the Eastern Mediterranean Region, Turkey. After the calculation of Pb contents, the Pb amounts of the soil samples were brought up to 50 and 100 mg Pb kg^?1 by treatment with Pb(NO ₃ ) ₂ , and the samples for the carbon and the nitrogen mineralization were incubated under controlled conditions (28°C, constant moist). The carbon mineralization was determined by a CO ₂ respiration method for 30 days. The nitrogen mineralization was observed in vitro for 6 weeks. The untreated group was statistically different from the 50 and 100 mg Pb kg^?1 treatments in the aspect of the C(CO ₂ ) outlet during mineralization (P ≤ 0.05), but difference between the 50 and 100 mg Pb kg^?1 treatments was not significant. NH ₄ -N and NO ₃ -N contents of each soil were shown differences between across treatments. Based on these results, it is possible to conclude that the addition of 50 and 100 mg Pb kg^?1 provided a toxic effect threshold for the microbial activity into 30 days.     

Incidence of mycoflora and mycotoxins in some edible fruits and seeds of forest origin

Twelve fungi namelyAlternaria alternata, Aspergillus flavus, A niger, A ochraceus, Actinomucor repens, Capnodoium spp., Curvularia lunata, Fusarium pallidoroseum, F solani, F verticillioides, Penicillium citrinum and Rhizopus stolonifer were recorded from samples ofAegle marmelos, Aesculus indica, Buchanania lanzan andPinus gerardiana. In case ofPrunus amygdalus only Rstolonifer was recorded. A significant variation in pattern of mycoflora incidence was observed in terms of source and season. Fungal infestation in most of the substrates was found to be highest during monsoon. Aflatoxins were the most common mycotoxins elaborated by different isolates ofA flavus obtained fromA marmelos, B lanzan andP gerardiana. The amount of aflatoxins produced by the toxigenic isolates ofA flavus was in the range of traces to 0.9–26.0 μg/ml inA marmelos, 0.8–17.5 μg/ml inP gerardiana and 0.65–13.2 μg/ml inB lanzan. The percentage toxigenicity was comparatively lower in the isolates of other mycotoxigenic fungi. Aflatoxins were detected almost in all the samples analyzed for mycotoxin contamination. However, traces of zearalenone were detected inA marmelos. The concentration of aflatoxin B₁ was in the range of 0.13–0.75 μg/g inA marmelos, 0.09–0.60 μg/g inP gerardiana and 0.01–0.20 ug/g inB lanzan. Mycotoxins were not detected inAesculus indica andPrunus amygdalus.     

Western corn rootworm larval movement in SmartStax seed blend scenarios

Insect resistance management (IRM) can extend the lifetime of management options, but depends on extensive knowledge of the biology of the pest species involved for an optimal plan. Recently, the Environmental Protection Agency (EPA) registered seed blends refuge for two of the transgenic Bacillus thuringiensis (Bt) corn products targeting the western corn rootworm, Diabrotica virgifera virgifera LeConte. Larval movement between Bt and isoline plants can be detrimental to resistance management for high dose Bt products because the larger larvae can be more tolerant of the Bt toxins. We assessed movement of western corn rootworm larvae among four spatial arrangements of SmartStax corn (expressing both the Cry34/35Ab1 and Cry3Bb1 proteins) and isoline plants by infesting specific plants with wild type western corn rootworm eggs. Significantly fewer western corn rootworm larvae, on average, were recovered from infested SmartStax plants than infested isoline plants, and the SmartStax plants were significantly less damaged than corresponding isoline plants. However, when two infested isoline plants surrounded a SmartStax plant, a significant number of larvae moved onto the SmartStax plant late in the season. These larvae caused significant damage both years and produced significantly more beetles than any other plant configuration in the study (including isoline plants) in the first year of the study. This plant configuration would occur rarely in a 5% seed blend refuge and may produce beetles of a susceptible genotype because much of their initial larval development was on isoline plants. Results are discussed in terms of their potential effects on resistance management.     

Wind-powered wheel locomotion, initiated by leaping somersaults, in larvae of the southeastern beach tiger beetle (Cicindela dorsalis media)

Rapid movement is challenging for elongate, soft-bodied animals with short or no legs. Leaping is known for only a few animals with this "worm-like" morphology. Wheel locomotion, in which the animal's entire body rolls forward along a central axis, has been reported for only a handful of animals worldwide. Here we present the first documented case of wind-powered wheel locomotion, in larvae of the coastal tiger beetle Cicindela dorsalis media. When removed from their shallow burrows, larvae easily can be induced to enter a behavioral sequence that starts with leaping; while airborne, larvae loop their body into a rotating wheel and usually either "hit the ground rolling" or leap again. The direction larvae wheel is closely related to the direction in which winds are blowing; thus, all our larvae wheeled up-slope, as winds at our study site consistently blew from sea to land. Stronger winds increased both the proportion of larvae wheeling, and the distance traveled, exceeding 60 m in some cases. In addition, the proportion of larvae that wheel and the distance traveled by wheeling larvae are significantly greater on smooth sandy beaches than on beach surfaces made rough and irregular by pedestrian, equestrian, and vehicular traffic. Like other coastal species of tiger beetles, C. dorsalis media has suffered major declines in recent years that are clearly correlated with increased human impacts. The present study suggests that the negative effects of beach traffic may be indirect, preventing larvae from escaping from predators using wheel locomotion by disrupting the flat, hard surface necessary for efficient wheeling.     

Gall mite Fragariocoptes setiger (Eriophyoidea) changes leaf developmental program and regulates gene expression in the leaf tissues of Fragaria viridis (Rosaceae)

The interaction of plants with certain types of parasites leads to the formation of galls, organised structures that create the habitat of the parasite, caused by an abnormal proliferation of host plant's cells under the influence of growth regulators, secreted by the parasite, or by the plant itself under the influence of the parasite. Arthropods, mites in particular, are the largest group of gall‐inducing phytoparasites, but the mechanisms of their interaction with plants remain virtually unexplored. The interaction of the gall‐inducing eriophyoid mite Fragariocoptes setiger with Fragaria viridis plants was used as a model gall–mite system where data were obtained on the changes in the histological structure of F. viridis leaf blades under the influence of the mites as well as F. viridis gene expression during gall formation. For histological purposes, gall formation was split into four stages with each corresponding to the age of the gall as well as to specific changes that occur during that period. A dramatic change of adaxial–abaxial polarity of the lamina throughout the four stages was observed. Moreover, qRT‐PCR analysis of F. viridis gene expression in the developing gall revealed changes in the expression levels of certain meristem‐specific genes, as well as the genes that determine adaxial–abaxial polarity and signalling of phytohormones.