Repellent Activity of Clove Essential Oil Volatiles and Development of Nanofiber-Based Dispensers against Pear Psyllids (Hemiptera: Psyllidae).

Pear psyllids are the main vectors of the pathogen 'Candidatus Phytoplasma pyri' causing pear decline. Based on earlier reports, we tested the behavioral activity of the major synthetic compounds of clove essential oil (eugenol, eugenyl acetate, and ß-caryophyllene) against Cacopsylla pyri and C. pyricola. Of six mixtures tested in olfactometer assays, a formulation consisting of three specific compounds (M6 mixture) demonstrated a repellent effect on both psyllid species. In addition, this formulation masked the odor of the host Pyrus communis cv. Williams Christ, disturbing the host finding ability of C. pyri. Electrospun fibers were produced with biocompatible polymers poly(ε-caprolactone), cellulose acetate, and solvents formic acid and acetic acid, loaded with the repellent mixture to test their efficacy as dispensers of repellents in laboratory and field. The fibers produced were repellent to C. pyri and effectively masked the odors of pear plants in olfactometer tests. In a pear orchard, we compared the captures of pear psyllids in green-colored attractive traps treated with nanofibers loaded with M6 mixture or unloaded nanofibers (blank). The result showed no differences in the captures of C. pyri between treatments. The release rates of volatiles from the fibers were evaluated weekly over 56 days. The fibers were able to entrap the major compound of the M6 mixture, eugenol, but the release rates were significantly reduced after 21 days. Our results suggest that biodegradable dispensers could be produced with electrospinning, but further improvements are necessary to use repellents as a management tool for pear psyllids in the field.

Lothar Jaenicke (1923-2015) zum Gedächtnis.

Among the post-war European biochemists, L. Jaenicke (1923-2015) stands out as a distinctive character with bright ideas and professional elegance, yet with personal modesty. His contributions to diverse fields such as C1 metabolic pathways, signal compounds (aquatic sex attractants) of brown algae and chemotaxis appear as distinctive features not covered by his peers. His rich scientific œuvre is documented in 291 journal articles, nine books, and a huge number of almost 570 book reviews, recensions, biographies and commentaries on the politics of science and the history of biochemistry. A quantitative approach is attempted here to make his diversified life's work more transparent through graphical analysis by the novel method of ergography. At a glance, his different strands of activities stand out clearly and speak for themselves, without the need for excessive verbal interpretation.

ELECTROSPUN MESOFIBERS, A NOVEL BIODEGRADABLE PHEROMONE DISPENSER TECHNOLOGY, ARE COMBINED WITH MECHANICAL DEPLOYMENT FOR EFFICIENT IPM OF LOBESIA BOTRANA IN VINEYARDS.

Behaviour modifying pheromones are well known agents for disrupting mating communication of pest insects. For optimal activity, they must be dispensed in time and space at a quantitatively measurable, predetermined release rate covering the flight period of the target species. Pheromones appeal to environmentally conscientious entomologists for their biodegradability, non-toxicity and ecological compatibility. In attempts of combining the virtues of pheromones, suitable slow release dispensers, and their mechanical deployment, an ecologically sensible, reasonably priced and patented procedure was developed and tested with the vineyard pest Lobesia botrana (Lep.: Tortricidae). It is characterized by (1) Electrospun mesofibers with diameters ranging from 0.6 to 3.5 micrometres, containing disruptants and dispensing it by slow release diffusion into the crop, (2) simultaneous application of the fully biodegradable combination of pheromone with Ecoflex polyester mesofiber, (3) combination of mechanical deployment by multi-purpose cultivators of the prefabricated pheromone dispensers with other simultaneous cultivation measures, and thus further reducing labour time and treatment costs. The dispensers are biodegradable within half a year without leaving any objectionable residues. In the standard eco-toxicology tests pheromone dispensers are harmless to non-target organisms. The disruptive effect of one treatment lasts for seven weeks which covers well one of several flight periods of L. botrana.

ERGOGRAPHY-RATIONAL METHOD FOR HANDLING AND EXTRACTING INFORMATION CONTAINED IN BIBLIOGRAPHIES OF PROLIFIC AUTHORS.

Ergography is a novel technique invented in 2003 by the first author in his attempts to understand, analyze, and quantify at one glance the work of creative scientists without reading through lengthy, usually boring laudations of invited speakers. Traditional enumeration of accomplishments is helpful but less than satisfactory. Simple descriptive texts often do not satisfactorily answer the question of how, when and why certain observations and theories were established and how they influenced the development and advance of scientific fields at large. Five influential entomologists, R.L. Metcalf, H. Schmutterer, P. Karlson, T. Eisner and E.O. Wilson, as well as two biochemists, A. Butenandt and F. Lynen, a few of them still alive, were selected as targets to gain some experience with the new technique superficially resembling chromatograms or spectra. Pretty soon, it became clear that the "when" is easy to answer and follows from simple time diagrams. More difficult is the analysis of the "how" and "why" and "under whose influence" certain subject areas were pursued. Even more difficult to analyze is the impact, if any, certain papers had on subsequent authors and to what extent the "memes" influence contemporary or future authors within and outside established research schools of thought. Ergographic analysis is an ongoing project that learns its rules by trying and doing. It links the forefront of research to the task of the science historian who is looking back over considerable distances. Ergographists try to speed up this process by the tools of analyzing working patterns and hopefully finding similarities and signs of influences in other schools of thought. In the virtual absence of suitable critical electronic software with semantic resolution power, ergography is still a matter of personal enterprise, curiosity, intuition, and willingness to follow with a prepared mind the paths investigated before by ingenious talent and make them more transparent.

Cultural diabrotica containment strategy in Switzerland: until now a convincing success story.

Ever since 2000 Switzerland belongs to the 22 European countries where the quarantine pest Diabrotica virgifera virgifera LeConte, Western corn rootworm (WCR), has been detected. It is reported to be the most important maizepest worldwide with an economic damage reaching 1.5 billion US$. In Switzerland it is constantly present in the southern part of the Alps while only few beetles are sporadically found in the northern part. Observations from 2000 up to 2012 support the hypothesis that the populations in the southern part of the Alps are generated by yearly migrations from principal foci situated in neighbouring Italian areas of Lombardy. Neither the tight correlation between travel distance and time of first arrival at various points from South to North, nor the steady decline of population along the route can be explained otherwise. Control measures enacted by Swiss authorities were principally based on a tightly enforced crop rotation scheme without chemical inputs as usually practiced in parts of the European Union. The effectiveness of crop rotation has been tested in a 5 year field trial comparing a continuous maize cropping system with a croprotation system and a maximum of one year of maizewithin a two year period (1:1). Population density was measured using synthetic pheromone baited traps and observations of root damage. Results showed that no economically relevant population built up during this period in the crop rotation treatment, whereas in the statistical evaluation of continuous maizecropping root damages could be detected after 4 years. One to one (1:1) year crop rotations are a common practice since 2001 in Southern Switzerland and are well accepted by farmers. Consequently, not a gram of pesticide has been employed against WCR in Switzerland up to now. The low level population density also helped to avoid the introduction of WCR populations into Cantons north of the Alps and thus prevented further spreading towards the state territories of northern neighbours.

Pheromone dispensers, including organic polymer fibers, described in the crop protection literature: comparison of their innovation potential.

Pheromone dispensers, although known in a variety of different designs, are one of the few remaining technical bottlenecks along the way to a sustainable pheromone based strategy in integrated pest management (IPM). Mating disruption with synthetic pheromones is a viable pest management approach. Suitable pheromone dispensers for these mating disruption schemes, however, are lagging behind the general availability of pheromones. Specifically, there is a need for matching the properties of the synthetic pheromones, the release rates suitable for certain insect species, and the environmental requirements of specific crop management. The "ideal" dispenser should release pheromones at a constant but pre-adjustable rate, should be mechanically applicable, completely biodegradable and thus save the costs for recovering spent dispensers. These should be made from renewable, cheap organic material, be economically inexpensive, and be toxicologically and eco-toxicologically inert to provide satisfactory solutions for the needs of practicing growers. In favourable cases, they will be economically competitive with conventional pesticide treatments and by far superior in terms of environmental and eco-toxicological suitability. In the course of the last 40 years, mating disruption, a non-toxicological approach, provided proof for its potential in dozens of pest insects of various orders and families. Applications for IPM in many countries of the industrialized and developing world have been reported. While some dispensers have reached wide circulation, only few of the key performing parameters fit the above requirements ideally and must be approximated with some sacrifice in performance. A fair comparison of the innovation potential of currently available pheromone dispensers is attempted. The authors advance here the use of innovative electrospun organic fibers with dimensions in the "meso" (high nano- to low micrometer) region. Due to their unique multitude of adjustable parameters, they hold considerable promise for future pest control against a variety of pest insects. In combination with well known synthetic sex pheromones, they can be used for communication disruption studies. One example, the pheromone of the European grape vine moth Lobesia botrana (Lepidoptera: Tortricidae), in combination with Ecoflex fibers, has been thoroughly tested in vineyards of Freiburg, Southwest Germany, with promising results. Seven weeks of communication disruption have been achieved, long enough to cover any one of several flights of this multivoltine grape pest. Disruption effects of around 95% have been achieved which are statistically indistinguishable from positive controls tested simultaneously with Isonet LE fibers, while an untreated negative control is significantly different. Ecoflex is a cheap organic co-polyester and completely biodegradable within half a year. Thus, an extra recovery step as with some other dispensers is unnecessary. This co-polyester is also of proven non-toxicity. The extension of the seven week disruption period towards half a year (the entire duration of all 3 Lobesia flights combined) is desirable and is under additional investigation in the near future. The discovery of suitable mesofibers is protected by European and US patents. The pheromone literature appearing between 1959 and today contains more than 25,000 references. This wealth of information is immediately applicable to pest management. It has major impacts on chemical ecology and IPM. In this paper, an attempt is made to compare the systems described in the literature and to derive some predictions about their prospective innovation potential. Special emphasis is given to the new development of organic biodegradable microfibers. To this end, a new electronic searching algorithm is introduced for reviewing the entries to be found in 4 specific databases. Its prominent features will be described. Surprisingly we found no previous entries in the literature linking pheromones with biodegradable organic polymer fibers whose diameters are in the dimension range of low micrometers and in the upper nanometer scale. In conclusion, the microfiber-pheromone combination must be considered as a novel approach whose virtues should be further explored for IPM in the near future.

Lobesia botrana IPM: electrospun polyester microfibers serve as biodegradable sex pheromone dispensers.

Modern insect pest management is faced with an increasingly sophisticated set of requirements. Control agent/dispenser combinations must be at the same time safe, nontoxic, inexpensive, reproducibly efficacious, environmentally compatible, biodegradable, and sustainable, and should be based on renewable resources. The methods employed preferably should be suitable for the growing and tightly controlled organic growing sector as well. All this calls for a level of sophistication and reproducibility previously unknown. Only very few systems can offer this kind of performance, but fortunately can be found in the area of suitable pheromone/dispenser combinations. This report is an attempt to adapt electrospun Ecoflex polyester micro fibers of the Greiner-Wendorff type to the very specific needs of the grape growing industry. Specifically required are "semi-intelligent" dispenser materials. On a weight basis, the electrospun product should achieve as high a proportion as possible of "retainable" sex pheromone (E,Z)-7,9-dodecadienyl acetate of Lobesia botrana (Lep.: Tortricidae) and should release it as uniformly as possible into the surrounding airspace. Using the Doye bioassay, some progress indeed has recently been achieved with electrospun Ecoflex microfibers of 0.5-3.5 microm diameter. They were employed as dispensers for programmed sex pheromone release with an effective mating disruption duration of up to seven weeks. With one microfiber/pheromone treatment, this covers one entire flight period of the trivoltine L. botrana. Mechanical application of this microfiber/pheromone preparation (with the option of automation) is possible. Disruption effects are comparable with those of commercially available dispensers of the Isonet type. Exposed under vineyard conditions, Ecoflex polyester fibers are a spider silk like material which is biodegradable within half a year. Thus, after releasing its pheromone load, it does not need removal, which saves one cultivation step. The fibers are under rigorous quantitative pretesting by analytical lab methods such as scanning EM, CLSA, timed weight loss curves in isothermal wind tunnels, and by thermogravimetry. Grapes produced under protection with these pheromone-charged biodegradable and mechanically deployable Ecoflex microfibers are completely free of pesticide residues.

Containment of the western corn rootworm Diabrotica v.virgifera: continued successful management 2008 in southern Switzerland by monitoring and crop rotation.

Diabrotica virgifera virgifera LeConte (Col.: Chrysomelidae), known as western corn rootworm (WCR) and endemic in North America, invaded Europe about two decades ago. Various unsuccessful attempts have been made to eradicate it from the Old World. Management with a variety of strategies is the option now remaining. WCR management in Southern Switzerland by a unique containment approach has been practiced successfully since 2003 using biotechnical means. Without any chemical pesticides or GMO input, the Swiss government mandated adherence to strict crop rotation. In addition to the economic benefits of this relatively simple approach, the environment was saved a considerable burden of pesticide applications. Other countries are invited to follow this example of sustainable pest management.

Monitoring western corn rootworm (Diabrotica v. virgifera) adults: situation in Romania 2008.

Romania is part of the southeast European expansion zone of the invasive rootworm species Diabrotica v. virgifera LeConte (Col.: Chrysomelidae) (WCR). The pest originated in North America and reached Belgrade airport with US foreign aid air shipments prior to 1992. Today, about 20 years after its introduction, WCR is a major maize pest which regionally causes economic damage to maize. However, it also can colonize secondary hosts which complicates IPM efforts. Basis for sound management is a reliable monitoring system. The easiest and cheapest way is to use Metcalf type monitoring traps for the mobile adults. Sex pheromones and plant kairomones for trapping are commercially available. Traps can be either bought or cheaply prepared. Metcalf traps with adhesive and lure cost about 15 cents per piece. So state-wide trapping is no longer a problem for less affluent countries. Results from two independent locations in 2008 report flight curves and attractively of secondary hosts like Sorghum spp. in relation to the principle host Zea mays. In addition, high capacity traps baited with pheromone are surprisingly effective, and, in combination with the chemically inert, absorptive silica powder AL 06, will be considered as future alternatives in cases where frequent monitoring is unfeasible and were a large holding capacity is indicated.

Experiences with population dynamics of Diabrotica virgifera virgifera LeConte in the Swiss canton of Ticino up to 2007.

The Western corn rootworm (WCR) Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae) is a vexing alien invasive insect pest. It occupies the attention of entomologists in most countries of Europe and beyond. In spite of numerous research advances (e.g., Diabrotica symposium at Engelberg, Switzerland 2004) its behavior is still incompletely understood and cannot be predicted for a specific growing season with any degree of certainty. Nonetheless, by comparing several years in sequence a somewhat consistent and coherent picture is emerging that is subject of this contribution. The Ticino province received first beetles from the major infestation in Lombardy in 2000 across the geographically open border at Chiasso. The rapid advance of WCR in northerly direction along the river valleys of Ticino and Misox posed a threat to cantons north of the mountain chain of the Alps and beyond, a scenario outlined by Bertossa (2004), Wudtke et al. (2005) and subsequent papers. Following the Swiss Federal rule of crop rotation obligation around infested regions introduced in 2001, the rapid increase in population density leveled off. Careful monitoring by both Metcalf type pheromone and kairomone baited sticky traps and Hungarian traps provided a reliable tool for judging the success of any quarantine measures taken up until 2007. (1) Trends in population development of 2006 were confirmed. (2) However, for reasons not well understood, the overall population encountered in 2007 was significantly smaller in Ticino and neighboring areas of Lombardy, Italy, but also in other areas south of the Alps. This may be a consequence of the rather mild winter 2006-2007. (3) At the mountain pass of Monte Ceneri (some 600 m above sea level) no beetles were trapped in 2007, while 3 WCR were seen in 2006. (4) No new WCR were encountered in Swiss cantons north of the main chain of the Alps. (5) Metcalf sticky traps proved to be 4-5 times as sensitive as Hungarian traps used for comparison. By and large, mandatory crop rotation was beneficial in reducing WCR populations in Ticino and avoided or delayed northbound spread of WCR.

Diabrotica virgifera virgifera LeConte: inconspicuous leaf beetle--formidable challenges to agriculture.

In the universe of entomology with its close to one million described and an estimated ten million undescribed species, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysometidae), the Western corn rootworm (WCR), is one of the economically most important pests. It causes annual treatment costs and damages of a billion dollars in the US (Metcalf 1986). Similar costs are predicted for Europe which the beetle invaded 15 years ago. Due to lack of natural enemies it is now expanding its territory at a rapid rate. With prior experience gained in Illinois, USA, and subsequent largely unsuccessful efforts to stop the pest in Europe, eradication efforts, although attempted in France and in the Veneto region of northern Italy, are not a viable sustainable strategy for the future nor a long term solution. Crop rotation, so far one of the best cultural management options of practicing entomologists, is beginning to show weaknesses specificly on Glycine max (Shaw et al. 1978, Levine et al. 2002, Spencer et al. 2005, Kiss et al. 2005, Tollefson and Prasifka 2006). WCR also was discovered on alternative hosts such as Cucurbita pepo in Slovenia (Hummel et al. 2007a, 2007b), C.maxima in Hungary (Moeser and Vidal 2001), and Serbia (Baca 1993, Baca and Berger 1994, Baca unpublished 1998, Baca 2007). WCR thus turns out to remain a challenge to general entomolog'sts, agricultural and ecological entomologists, geneticists, epidemiologists, crop protection engineers, phytosanitary services and economists alike. WCR and H. sapiens today are reaching a labile ecological equilibrium of coexistence, with new surprises on both sides in the "arms race" just waiting around the corner. Most experts will agree that WCR is in Europe to stay and is readily expanding from here to Asia and Africa if given the slightest chance.- The really unsolved question remains how to manage WCR sensibly, economically, and sustainably, and how and where to train a new generation of capable, reliable, all round entomological pest managers needed for the future.

Microwave-assisted steam distillation with simultaneous liquid/liquid extraction of pentachlorophenol from organic wastes and soils.

An efficient method for extracting pentachlorophenol (PCP) from organic solid matrices and soils using direct excitation of the fresh samples by microwave energy is presented. Steam-volatile PCP partitioned into the organic solvent n-hexane within the closed extraction vessel, resulting in recovery rates of 85-92% from aged samples. Condensed water provided a boundary layer between extract and sample thus preventing any contact of PCP with and re-partitioning into the sample. Duration of the microwave-assisted process was 35 min. Crude extracts were derivatized by heptafluorobutyric anhydride (HFBA) to improve selectivity and sensitivity resulting in detection limits of 1-2 micro g kg(-1). GC-MS/MS analyses proved that suitable extracts with only minor impurities were obtained. Common sample treatment steps like drying, thorough grinding, frequent transferring, and tedious clean-up, and concentration procedures which all can cause certain losses of analyte were minimized. The efficiency of the method was verified by comparison with an established ultrasonic extraction procedure. This microwave-assisted pressurized steam distillation with simultaneous partition into an organic phase thus provides a streamlined and efficient strategy which requires no additional investment in standard equipment for microwave-assisted extractions (MAE). Degradation of analytes at longer extraction times must be taken into account.

Distribution of MCA-coated grits in maize fields after high wheel tractor application for disrupting orientation of Diabrotica virgifera virgifera LeConte.

High wheel tractor applications of 4-methoxycinnamaldehyde (MCA)-coated corn granules ('grits') were conducted in Ruski Krstur (Serbia) in summer 2001 in a 5 ha corn field. Grits are a by-product after corn is harvested and separated from the cob and used as a carrier medium to disseminate MCA into the corn field. MCA is a kairomone mimic derived form Cucurbita maxima (Duchesne) used to disrupt orientation of Diabrotica virgifera virgifera LeConte towards different MCA and pheromone baited traps. The ultimate goal is to investigate the use of MCA as a mating disruptant. MCA was dissolved in an organic solvent and mixed in a cement machine with the grits. Grits were applied at rates of 17.39, 17.1 and 12.45 kg/ha on July 4th, July 19th and August 3rd. Before the impact of MCA as a disruptant can be addressed, the distribution patterns of MCA coated grits have to be thoroughly investigated. They were evaluated by counting girts deposited in 16 or 20 plastic dishes of 30-cm diameter positioned along 2 rows through the field directly after the grit application by tractor. Additionally, grits deposited on corn plant surface such as leaves, leaf axils and corn cobs were counted. Total number of grits collected in plastic dishes revealed even application rates at the first and second application but not on the third application date. Number of grits collected on plant surfaces were significantly different from each other regarding each application date. Altogether, grit distribution in the dishes as well as on the plant surface was variable. However, distribution patterns achieved so far hold promise to disseminate MCA coated grits into corn fields for orientation disruption or mating disruption of D. virgifera virgifera.