Persistence and efficacy of spinosad on wheat,maize and barley grains against four major stored product pests

The insecticidal and residual effect of spinosad on wheat, maize and barley grain was evaluated in the laboratory against adults of Sitophilus oryzae (F.) (Coleoptera: Curculionidae), Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), Tribolium confusum (DuVal) (Coleoptera: Tenebrionidae), Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae) as well as against larvae of T. confusum. Spinosad was applied as a solution to 2 kg lots of each commodity at three concentrations, 0.1, 0.5 and 1 ppm, and the treated grain quantities were kept at 25 °C and 65% RH. Samples were taken from each concentration-commodity combination at the day of storage and every 30 d for 6 consecutive months (6 bioassays). The test species were exposed for 14 d to the samples and mortality and reproduction were assessed over this exposure interval. With the exception of T. confusum, 1 ppm of spinosad was highly effective against the remainder of the tested species and provided protection for a period of storage at least 4 months. Although in general, spinosad performance was not very much affected by the grain type, efficacy on maize was less stable over the 6-month period of storage and declined sooner compared to the other commodities. Spinosad almost suppressed progeny production of R. dominica during the storage period, but did not suppress progeny of the other species, since progeny were recorded even 30 d post application especially with the lowest of the tested concentrations. The results of this study indicated that spinosad may provide suitable protection for 6 months against S. oryzae or R. dominica, but is not suitable for long-term protection against T. confusum or C. ferrugineus.     

How do grassroot NGOs in rural Myanmar express their visions for the food system? Food security and food sovereignty as entangled narratives within NGO struggles and strategies

Recent research has promoted the idea that political struggles over food systems can be understood through the concepts of food security (the right to access food) and food sovereignty (the right to exercise control over food systems). These concepts emphasise different political priorities in the social relations of food: for the former, the promotion of decent work and the strengthening of the social safety net to enhance people's abilities to put food on their plates; for the latter, the defence of land, water and resource rights, to underpin capabilities for food own‐provisioning. The question we pose in this paper is how these priorities are articulated by grassroots non‐government organisations working at the frontline of global food poverty? Interviews with 22 representatives of food‐related non‐government organisations in Myanmar were used to elicit narratives about how they understood their challenges. The paper finds that narratives did not cohere exclusively to either the food security or food sovereignty concept, but blended ideas associated with the political priorities of both in complex and contradictory ways. These insights lend important firsthand evidence to the argument that supports a multi‐dimensional framing of the politics of food that is inclusive of the diverse struggles highlighted by food security and food sovereignty concepts.     

Experimental deepwater culture of the Sydney rock oyster (Crassostrea commercialis): V. Commercial raft trials

Four large rafts (6.4 × 4.3 m), each costing $ A 543 totally equipped and holding 600 kg of trayed layers of oysters, were sited in New South Wales estuaries during 1977 and 1978. Small, single oysters (spat at 25–29 g whole weight or seconds at 29–40 g) were grown to restaurant (plate) grade (40–67 g).Sixteen crops were harvested, usually after three months growout. None showed evidence of overspatting (attachment of young oysters to the crop). Growth rates (measured as oyster weight increases) ranged from 5 to 30% per month and averaged 19%. In four of the crops mortality was high (12, 22, 22 and 90%) due to parasites, predators or wave action. In the remaining 12 crops natural mortality averaged 6% total for the growout period. The average actual wholesale value of the crops was $ A 422 and this could be raised to an estimated wholesale value of $A 527 per crop by utilising pregrowout grading and harvest date selection. Several husbandry practices are recommended. (1) Grading oysters mechanically before growout to produce more uniform crops. (2) Covering top trays to prevent fish attacks and losses through waves. (3) Deciding optimum harvest date by inspection after three months growth.     

Der Streuwald

Ohne Zusammenfassung     

The effect of arable field margin composition on invertebrate biodiversity

A replicated field experiment designed to compare five types of field margin in terms of their invertebrate biodiversity was established in North Yorkshire, UK. Four replicate margins on arable land each contained five treatment plots 72 m long by 6 m wide. The treatments were: (1) cropped to the edge; (2) sown ‘tussocky’ grass mix; (3) sown ‘grass and wildflower’ mix; (4) Split margin (3 m ‘tussocky’ grass adjacent to hedge and 3 m ‘grass and wildflower’ next to crop); and (5) natural regeneration. Invertebrates were sampled by pitfall trapping, sweep netting, and butterfly and bumblebee transects, and identified to species level. The use of different flower species by foraging bumblebees was also examined.Despite all treatments containing a flush of annual weeds early in the establishment year, the five margin types were distinct in their vegetation composition by their first mid-summer. Where statistically significant results were obtained for invertebrates, avoidance of the ‘cropped’ treatment was by far the commonest observed response. This tendency could be clearly demonstrated amongst the carabids, spiders, butterflies, bumblebees, millipedes and harvestmen, with margins often containing double or more the number of invertebrates of similar areas cropped to the edge. Having avoided the crop, preferences for other margin types were mixed, but there was a marked tendency by many nectar and/or pollen-feeding, flying insects towards greater abundance on those margins containing sown ‘wildflowers’ (e.g. butterflies Meadow Brown and Ringlet, Bumblebees, Pollen Beetle Meligethes sp.) or flowers either sown or unsown (Soldier Beetle Rhagonycha fulva). There was a less strong tendency for predatory species occurring in the vegetation canopy and depending on small, especially flying insects for food, to also prefer the flowery treatments (e.g. total spiders caught by sweeping, seven-spot ladybird). Harvestmen in autumn reject natural regeneration in favour of any sown treatment. Only one species, the carabid Nebria brevicollis, was trapped in higher numbers in the cropped treatment than on any sown margin, and then only in autumn. Of the six common bumblebee species, the two longest-tongued species showed different patterns of flower visitation from the remaining four.These results clearly demonstrate that sown field margins can rapidly produce substantial biodiversity benefits on arable land, with the resulting fauna influenced by the type of field margin created.     

Australindolones,New Aminopyrimidine Substituted Indolone Alkaloids from an Antarctic Tunicate Synoicum sp.

Five new alkaloids have been isolated from the lipophilic extract of the Antarctic tunicate Synoicum sp. Deep-sea specimens of Synoicum sp. were collected during a 2011 cruise of the R/V Nathanial B. Palmer to the southern Scotia Arc, Antarctica. Crude extracts from the invertebrates obtained during the cruise were screened in a zebrafish-based phenotypic assay. The Synoicum sp. extract induced embryonic dysmorphology characterized by axis truncation, leading to the isolation of aminopyrimidine substituted indolone (1–4) and indole (5–12) alkaloids. While the primary bioactivity tracked with previously reported meridianins A–G (5–11), further investigation resulted in the isolation and characterization of australindolones A–D (1–4) and the previously unreported meridianin H (12).     

Waste excretion characteristics of Manila clams (Tapes philippinarum) under different temperature conditions

Water recirculating systems have been used in the shellfish industry for depuration and wet-storage. Knowledge of shellfish excretion characteristics is critical to recirculating system design. In this study, the excretion rate of total ammonia nitrogen (TAN), total Kjeldahl nitrogen (TKN), and 5-day biochemical oxygen demand (BOD₅) from Manila clams (Tapes philippinarum) were investigated under both laboratory and commercial conditions. The laboratory tests were conducted under temperatures ranging from 3 to 30°C. The experimental results showed that temperature was a key factor in determining the excretion rate of all the above parameters. The relationship between TAN excretion rate (R_TAN) and temperature (T) can be represented by an exponential function (R_TAN=0.57×1.25^T). For the temperature range between 3 and 20°C, the daily mean excretion rates of TAN, TKN and BOD₅ ranged between 1.5–46.1, 4.8–131.0 and 57.4–219.4 mg per kilogram of the clams (wet weight with shell on), respectively. There were linear correlations between TAN, TKN and BOD₅ production rates. The data presented in this paper can be used to estimate waste generation from a given shellfish processing operation and to size the waste treatment components for a recirculating depuration (or wet-storage) system.     

Wandlungen

Ohne Zusammenfassung