Adaptation of Defensive Strategies by the Pea Aphid Mediates Predation Risk from the Predatory Lady Beetle

Within a species, individual animals adopt various defensive strategies to resist natural enemies, but the defensive strategies that are adopted in response to variations in predation risk are poorly understood. Here, we assessed consecutive foraging processes on cohorts of two biotypes (green and red) of the pea aphid, Acyrthosiphon pisum, by the predatory lady beetle Propylea japonica, to investigate the adaptive mechanism underlying the defensive strategy. We observed the behavioral responses of individuals (continue feeding or escape, i.e., walk away or drop off from initial feeding site), simultaneously quantified the amount of alarm pheromone, (E)-β-farnesene (EβF) released from cohorts using gas chromatography-mass spectrometry (GC-MS), and recorded the foraging times of predators in intervals. The results indicated that: (1) the anti-predator responses differed markedly between biotypes and among the stages of the consecutive foraging processes. (2) Few green cohorts tended to release EβF during the first foraging; those that did released only a low dose that did not increase the number of escapes. However, the amount of EβF rose rapidly following the second foraging process, which caused an intense escape response. In contrast, more red cohorts released greater amounts of EβF, which caused more individuals to escape from their innate feeding sites during the first foraging. During the second foraging, more red individuals tended to escape without releasing EβF in greater quantities. (3) The foraging time was effectively shortened in each biotype cohort that adopted diverse defensive strategies. This study of the defensive strategies of the pea aphid may contribute to understanding the intraspecific differences in aphid defense mechanisms.     

Environmental cognition in the vernacular landscape: assessing the aesthetic quality of Al-Alkhalaf village,Southwestern Saudi Arabia

Changes in socio-cultural patterns, economic activities, and the technologies for agricultural productions and climate controls are bringing new patterns of visual qualities to the age-old vernacular landscape of Saudi Arabia's Asir region. Unfortunately, the lack of reference between old and new is threatening to destroy the overall environmental quality that is one of the region's greatest economic and cultural assets. Through detailed examination of Al-Alkhalaf vernacular landscape in Asir, one of the largest villages, this paper defines the major components of the landscape and assesses the basis for their aesthetic qualities and values. Throughout the traditional era, a sense of beauty was imparted to this vernacular landscape through an unconscious balancing of natural systems and human needs. Such result owed much to the management efforts of a homogenous group of villagers expressing consensus about their place in the world. Today, in the more complicated context of modern Saudi Arabia, a new appreciation for landscape traditions arises and vernacular invites pertinent commentaries. A more conscious effort is needed to achieve the same old sense of regional and aesthetic values. The paper suggests that such an effort should begin by employing concepts like aesthetic values, aesthetic qualities and visual qualities when searching for new expressions of the relationship between people and nature.     

Does geographical origin affect lateralization and male mating success in Rhyzopertha dominica beetles?

The lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), is an important pest of stored grains globally. In this study, the impact of geographical origin on male mating success and lateralization in three strains of R. dominica (i.e., a Greek strain, a Romanian strain and a Turkish strain) was investigated. Concerning the Greek strain, even though most males showed a left-biased approach, males performing right-biased copulation attempts achieved the highest proportion of successful copulations. Males of the Romanian and Turkish strains exhibited right-biased approaches and copulation attempts, resulting in higher mating success over the males that approached and performed copulation attempts from the left or backside of females. Copula was significantly longer than mate recognition and precopula phases. Furthermore, copula duration was significantly longer in the Turkish strain over the Romanian strain, while copula duration differences between Greek and Romanian individuals, as well as between Greek and Turkish individuals, were not significant. Unsuccessful sexual interactions were characterized by a longer precopula in Greek and Romanian strains, but not in the Turkish strain. Our results add basic knowledge to the mating behaviour of R. dominica, with emphasis on impact of the geographical origin and laterality on male mating success, which may be helpful for optimizing mass-rearing techniques of stored-product pests needed for large-scale laboratory or semi-field experiments, as well as to contribute to the development of behaviour-based control tools.     

Lipidomics Reveals Mitochondrial Membrane Remodeling Associated with Acute Thermoregulation in a Rodent with a Wide Thermoneutral Zone

Mongolian gerbils (Meriones unguiculatus) have high physiological flexibility in response to acute temperature changes, and have the widest thermoneutral zone (TNZ, 26.5–38.9 °C) reported among small mammals. At the upper critical temperature (T _uc, 38.9 °C), body temperatures of gerbils were significantly increased (39–41 °C) while metabolic rates were maintained at the basal level. In contrast, below the lower critical temperature (T _lc, 26.5 °C), metabolism was elevated and body temperature stable. Rapid changes in mitochondrial membrane lipidome were hypothesized to play an important role during acute thermoregulation of gerbils. Taking advantage of a recent lipidomic technique, we examined changes in the membrane phospholipids environment and free fatty acids (FFA) production in mitochondria between 38 and 27 °C (in the TNZ), and between 27 and 16 °C (below the TNZ). At 38 °C, acute heat stress elicited distinct remodeling in mitochondrial membrane lipidome which related to a potential decrease in mitochondrial respiration and membrane fluidity compared to 27 °C. At 16 °C, a sharply decreased unsaturation index and increased chain lengths were detected in mitochondrial FFA production both in muscle and brown adipose tissue. Our results suggest that mitochondrial membrane lipid remodeling may stabilize membrane function and activity of respiration related membrane protein to maintain a stable metabolic rate at T _uc, and improve heat production by decomposing less fluid fatty acid conjugates of membrane lipids under acute cold exposure. These data therefore imply an important role of membrane remodeling during acute thermoregulation in a non-hibernating endotherm.     

Coupled cluster algorithms for networks of shared memory parallel processors

As the popularity of using SMP systems as the building blocks for high performance supercomputers increases, so too increases the need for applications that can utilize the multiple levels of parallelism available in clusters of SMPs. This paper presents a dual-layer distributed algorithm, using both shared-memory and distributed-memory techniques to parallelize a very important algorithm (often called the “gold standard”) used in computational chemistry, the single and double excitation coupled cluster method with perturbative triples, i.e. CCSD(T). The algorithm is presented within the framework of the GAMESS [M.W. Schmidt, K.K. Baldridge, J.A. Boatz, S.T. Elbert, M.S. Gordon, J.J. Jensen, S. Koseki, N. Matsunaga, K.A. Nguyen, S. Su, T.L. Windus, M. Dupuis, J.A. Montgomery, General atomic and molecular electronic structure system, J. Comput. Chem. 14 (1993) 1347–1363]. (General Atomic and Molecular Electronic Structure System) program suite and the Distributed Data Interface [M.W. Schmidt, G.D. Fletcher, B.M. Bode, M.S. Gordon, The distributed data interface in GAMESS, Comput. Phys. Comm. 128 (2000) 190]. (DDI), however, the essential features of the algorithm (data distribution, load-balancing and communication overhead) can be applied to more general computational problems. Timing and performance data for our dual-level algorithm is presented on several large-scale clusters of SMPs.     

Comparing push and pull measures for PV and wind in Europe

Successful technological innovation frameworks are based on synergistic packages of technology-push and demand-pull measures. As the massive deployment of premature renewable energy technologies risks becoming very expensive, the debate on the optimal trajectory of renewable technologies should explicitly consider the balance between deployment incentives and R&D efforts.This paper explores this balance regarding wind and PV technology support in Europe. Based on rather conservative estimates, we calculate future deployment costs and compare these figures to the current public investments in PV and wind R&D. We find that, today, for each Euro spent on R&D to develop future technologies, 35 to 41 Euros are spent on the deployment of existing technologies. Furthermore, private PV and wind technology companies tend to underinvest in R&D for various reasons. In an alternative scenario, we assess the optimal R&D efforts for the PV and wind sectors based on a 7% R&D-to-sales benchmark that is typical for engineering sectors. If public R&D efforts would increase according to this benchmark, and hence compensate for the private underinvestments in R&D, pull/push ratios between 6 and 8 could be achieved. This leads us to conclude that the current balance between deployment and R&D is far from optimal.     

An algorithm for insertion of idle time in the single-machine scheduling problem with convex cost functions

This paper addresses the problem of optimally inserting idle time into a single-machine schedule when the sequence is fixed and the cost of each job is a convex function of its completion time. We propose a pseudo-polynomial time algorithm to find a solution within some tolerance of optimality in the solution space, i.e., each completion time will belong to a small time interval z within which the optimal solution lies. Letting H be the planning horizon and |J| the number of jobs, the proposed algorithm is superior to the current best algorithm in terms of time-complexity when |J|<H/z.     

Biosynthesis of Unusual Moth Pheromone Components Involves Two Different Pathways in the Navel Orangeworm, <Emphasis Type="Italic">Amyelois transitella</Emphasis>

The sex pheromone of the navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), consists of two different types of components, one type including (11Z,13Z)-11,13-hexadecadienal (11Z,13Z-16:Ald) with a terminal functional group containing oxygen, similar to the majority of moth pheromones reported, and another type including the unusual long-chain pentaenes, (3Z,6Z,9Z,12Z,15Z)-3,6,9,12,15-tricosapentaene (3Z,6Z,9Z,12Z,15Z-23:H) and (3Z,6Z,9Z,12Z,15Z)- 3,6,9,12,15-pentacosapentaene (3Z,6Z,9Z,12Z,15Z-25:H). After decapitation of females, the titer of 11Z,13Z-16:Ald in the pheromone gland decreased significantly, whereas the titer of the pentaenes remained unchanged. Injection of a pheromone biosynthesis activating peptide (PBAN) into the abdomens of decapitated females restored the titer of 11Z,13Z-16:Ald and even increased it above that in intact females, whereas the titer of the pentaenes in the pheromone gland was not affected by PBAN injection. In addition to common fatty acids, two likely precursors of 11Z,13Z-16:Ald, i.e., (Z)-11-hexadecenoic and (11Z,13Z)-11,13-hexadecadienoic acid, as well as traces of (Z)-6-hexadecenoic acid, were found in gland extracts. In addition, pheromone gland lipids contained (5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-icosapentaenoic acid, which also was found in extracts of the rest of the abdomen. Deuterium-labeled fatty acids, (16,16,16-D₃)-hexadecanoic acid and (Z)-[13,13,14,14,15,15,16,16,16-D₉]-11-hexadecenoic acid, were incorporated into 11Z,13Z-16:Ald after topical application to the sex pheromone gland coupled with abdominal injection of PBAN. Deuterium label was incorporated into the C₂₃ and C₂₅ pentaenes after injection of (9Z,12Z,15Z)- [17,17,18,18,18-D₅]-9,12,15-octadecatrienoic acid into 1–2 d old female pupae. These labeling results, in conjunction with the composition of fatty acid intermediates found in pheromone gland extracts, support different pathways leading to the two pheromone components. 11Z,13Z-16:Ald is probably produced in the pheromone gland by Δ11 desaturation of palmitic acid to 11Z-16:Acid followed by a second desaturation to form 11Z,13Z-16:Acid and subsequent reduction and oxidation. The production of 3Z,6Z,9Z,12Z,15Z-23:H and 3Z,6Z,9Z,12Z,15Z-25:H may take place outside the pheromone gland, and appears to start from linolenic acid, which is elongated and desaturated to form (5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-icosapentaenoic acid, followed by two or three further elongation steps and finally reductive decarboxylation.     

SEX PHEROMONE COMPONENTS OF THE SANDTHORN CARPENTERWORM, <Emphasis Type="Italic">Holcocerus hippophaecolus</Emphasis>

Extracts of female sex pheromone gland of the carpenterworm moth, Holcocerus hippophaecolus Hua, a pest of sandthorn, Hippophae rhamnoides L. were found to contain (E)-3-tetradecenyl acetate (E3-14:Ac), (Z)-3-tetradecenyl acetate (Z3-14:Ac), (Z)-7-tetradecenyl acetate (Z7-14:Ac), the corresponding alcohols, E3-14:OH, Z3-14:OH, Z7-14:OH, and (E)-9-tetradecenyl acetate (E9-14:Ac). Electroantennographic (EAG) analysis of these chemicals and their analogs demonstrated that Z7-14:Ac elicited the largest male EAG response, followed by E3-14:Ac. In field trials, traps baited with either Z7-14:Ac or E3-14:Ac alone caught no male moths, whereas a combination of these two components in a 1:1 ratio caught more males than control traps. Addition of Z7-14:OH and Z3-14:OH or the alcohols plus E9-14:Ac did not enhance trap catches. We conclude that the sex pheromone of H. hippophaecolusis composed of Z7-14:Ac and E3-14:Ac. Optimal ratios and doses of these two components, and the possible role of other minor components, remain to be determined.     

春尺蠖性信息素类似物的合成及活性成分筛选

[目的]确定春尺蠖性信息素的有效成分及结构,为进一步的田间诱引试验提供方向并为利用春尺蠖性信息素进行害虫无公害防治奠定基础。[方法]已初步鉴定春尺蠖性信息素的有效成分为单烯十四碳烯醇乙酸酯,但双键位置和顺反构型都不确定,通过合成双键在不同位置的十四碳烯乙酸酯,用GC-EAD筛选活性成分。[结果]根据GC-EAD测试结果,化合物Z4-14∶OAc和Z6-14∶OAc能引起春尺蠖雄蛾触角电位的明显变化。[结论]Z4-14∶OAc和Z6-14∶OAc是春尺蠖雌蛾性信息素的有效活性成分。