Identification of Aggregation Pheromone as an Attractant for Odontothrips loti, A Serious Thrips Pest on Alfalfa.

Odontothrips loti (Haliday) (Thysanoptera: Thripidae) is one of the most serious pests on alfalfa, causing direct damage by feeding and indirect damage by transmitting plant viruses. This damage causes significant loss in alfalfa production. Semiochemicals offer opportunities to develop new approaches to thrips management. In this study, behavioral responses of female and male adults of O. loti to headspace volatiles from live female and male conspecifics were tested in a Y-tube olfactometer. The results showed that both male and female adults of O. loti were attracted to the odors released by conspecific males but not those released by females. Headspace volatiles released by female and male adults were collected using headspace solid-phase microextraction (HS-SPME). The active compound in the volatiles was identified by gas chromatography-mass spectrometry (GC-MS). The analysis showed that there was one major compound, (R)-lavandulyl (R)-2-methylbutanoate. The attractive activity of the synthetic aggregation pheromone compound was tested under laboratory and field conditions. In an olfactometer, both male and female adults showed significant preference for synthetic (R)-lavandulyl (R)-2-methylbutanoate at certain doses. Lures with synthetic (R)-lavandulyl (R)-2-methylbutanoate significantly increased the trap catches of sticky white traps at doses of 40-80 µg in the field. This study confirmed the production of aggregation pheromone by O. loti male adults and identified its active compound as (R)-lavandulyl (R)-2-methylbutanoate, providing a basis for population monitoring and mass trapping of this pest.

Semiochemicals for Thrips and Their Use in Pest Management.

Thrips (Thysanoptera) are small insects that can cause huge problems in agriculture, horticulture, and forestry through feeding and the transmission of plant viruses. They produce a rich chemical diversity of pheromones and allomones and also respond to a broad range of semiochemicals from plants. These semiochemicals offer many opportunities to develop new approaches to pest management. Aggregation pheromones and plant-derived semiochemicals are already available in commercial products. We review these semiochemicals and consider how we can move away from using them mainly for monitoring to using them for control. We still know very little about the behavioral responses of thrips to semiochemicals, and we show that research in this area is needed to improve the use of semiochemicals in pest management. We also propose that thrips should be used as a model system for semiochemically mediated behaviors of small insects that have limited ability to fly upwind.

Invasion Biology, Ecology, and Management of Western Flower Thrips.

Western flower thrips, Frankliniella occidentalis, first arose as an important invasive pest of many crops during the 1970s-1980s. The tremendous growth in international agricultural trade that developed then fostered the invasiveness of western flower thrips. We examine current knowledge regarding the biology of western flower thrips, with an emphasis on characteristics that contribute to its invasiveness and pest status. Efforts to control this pest and the tospoviruses that it vectors with intensive insecticide applications have been unsuccessful and have created significant problems because of the development of resistance to numerous insecticides and associated outbreaks of secondary pests. We synthesize information on effective integrated management approaches for western flower thrips that have developed through research on its biology, behavior, and ecology. We further highlight emerging topics regarding the species status of western flower thrips, as well as its genetics, biology, and ecology that facilitate its use as a model study organism and will guide development of appropriate management practices.

Whole-House Emission Rates and Loss Coefficients of Formaldehyde and Other Volatile Organic Compounds as a Function of the Air Change Rate.

Whole-house emission rates and indoor loss coefficients of formaldehyde and other volatile organic compounds (VOCs) were determined from continuous measurements inside a net-zero energy home at two different air change rates (ACHs). By turning the mechanical ventilation on and off, it was demonstrated that formaldehyde concentrations reach a steady state much more quickly than other VOCs, consistent with a significant indoor loss rate attributed to surface uptake. The first order loss coefficient for formaldehyde was 0.47 ± 0.06 h-1 at 0.08 h-1 ACH and 0.88 ± 0.22 h-1 at 0.62 h-1 ACH. Loss rates for other VOCs measured were not discernible, with the exception of hexanoic acid. A factor of 5.5 increase in the ACH increased the whole-house emission rates of VOCs but by varying degrees (factors of 1.1 to 3.8), with formaldehyde displaying no significant change. The formaldehyde area-specific emission rate (86 ± 8 µg m-2 h-1) was insensitive to changes in the ACH because its large indoor loss rate muted the impact of ventilation on indoor air concentrations. These results demonstrate that formaldehyde loss rates must be taken into account to correctly estimate whole-house emission rates and that ventilation will not be as effective at reducing indoor formaldehyde concentrations as it is for other VOCs.

Characterization of Male-Produced Aggregation Pheromone of the Bean Flower Thrips Megalurothrips sjostedti (Thysanoptera: Thripidae).

Aggregation of the bean flower thrips, Megalurothrips sjostedti (Trybom) (Thysanoptera: Thripidae), has been observed on cowpea, Vigna unguiculata (L.) Walp. To understand the mechanism underpinning this behavior, we studied the responses of M. sjostedti to headspace volatiles from conspecifics in a four-arm olfactometer. Both male and female M. sjostedti were attracted to male, but not to female odor. Gas chromatography/mass spectrometry (GC/MS) analyses revealed the presence of two distinct compounds in male M. sjostedti headspace, namely (R)-lavandulyl 3-methylbutanoate (major compound) and (R)-lavandulol (minor compound); by contrast, both compounds were only present in trace amounts in female headspace collections. A behavioral assay using synthetic compounds showed that male M. sjostedti was attracted to both (R)-lavandulyl 3-methylbutanoate and (R)-lavandulol, while females responded only to (R)-lavandulyl 3-methylbutanoate. This is the first report of a male-produced aggregation pheromone in the genus Megalurothrips. The bean flower thrips is the primary pest of cowpea, which is widely grown in sub-Saharan Africa. The attraction of male and female M. sjostedti to these compounds offers an opportunity to develop ecologically sustainable management methods for M. sjostedti in Africa.

Effects of Pre- and Postanthesis Applications of Demethylation Inhibitor Fungicides on Fusarium Head Blight and Deoxynivalenol in Spring and Winter Wheat.

Anthesis is generally recommended as the optimum growth stage for applying a foliar fungicide to manage Fusarium head blight (FHB) and the Fusarium-associated toxin deoxynivalenol (DON) in wheat. However, because it is not always possible to treat fields at anthesis, studies were conducted to evaluate pre- and postanthesis treatment options for managing FHB and DON in spring and winter wheat. Network meta-analytical models were fitted to data from 19 years of fungicide trials, and log response ratio ([Formula: see text]) and approximate percent control ([Formula: see text]) relative to a nontreated check were estimated as measures of the effects of six treatments on FHB index (IND: mean percentage of diseased spikelets per spike) and DON. The evaluated treatments consisted of either Caramba (metconazole) applied early (at heading [CE]), at anthesis (CA), or late (5 to 7 days after anthesis; CL), or Prosaro (prothioconazole + tebuconazole) applied at the same three times and referred to as PE, PA, and PL, respectively. All treatments reduced mean IND and DON relative to the nontreated check, but the magnitude of the effect varied with timing and wheat type. CA and PA resulted in the highest [Formula: see text] values for IND, 52.2 and 51.5%, respectively, compared with 45.9% for CL, 41.3% for PL, and less than 33% for CE and PE. Anthesis and postanthesis treatments reduced mean IND by 14.9 to 29.7% relative to preanthesis treatments. The estimated effect size was also statistically significant for comparisons between CA and CL and PA and PL; CA reduced IND by 11.7% relative to CL, whereas PA reduced the disease by 17.4% relative to PL. Differences in efficacy against IND between pairs of prothioconazole + tebuconazole and metconazole treatments applied at the same timing (CE versus PE, CA versus PA, and CL versus PL) were not statistically significant. However, CA and CL outperformed PA and PL by 7 and 12.8%, respectively, in terms of efficacy against DON. All application programs had comparable efficacy against IND between spring and winter wheat types, but efficacy against DON was 10 to 16% greater for spring than winter wheat for applications made at or after anthesis. All programs led to an increase in mean grain yield and test weight relative to the nontreated check.

Photophysics of EGFP (E222H) Mutant, with Comparisons to Model Chromophores: Excited State pK's, Progressions, Quenching and Exciton Interaction.

A novel version of the well-known and commercially successful Green Fluorescent Protein (GFP) variant known as EGFP, with an introduced E222H mutation, was produced in this laboratory. Given the current state of hypotheses about the role of glutamate 222, and the observed dominance of the phenolate absorption with an E222H variant observed from earlier study, the new mutant was considered a natural choice to investigate more fully the acid-base behavior of the chromophore in absorption and fluorescence. The bulk of this investigation concerns fitting the excitation, emission and absorption spectra to vibrational progressions of a novel 'q-deformed' type at various values of pH, and protein concentration. From these data, and from temperature-dependent fluorescence lifetime data and other experiments (with lanthanide doped gels into which H/EGFP is embedded), we construct a picture of excited inter- state conversion mechanisms, and quenching mechanisms, that attempts to explain many features of the GFP system. Graphical Abstract Hypothetical proton current loop (orange) upon excitation; electron motion in purple H/EGFP. Solid boxes about waters project toward viewer, dashed boxes project away.

Thermodynamics of imidazole-ligand binding to Ni-nitrilotriacetate in solution and covalently attached to agarose beads: imidazole, his-6 (his-tag) peptide and a new bis-imidazolo-dithiane.

A new imidazolo- and thiol-containing ligand is prepared and characterized with the intent to serve as surrogate and mimic for the canonical ligands imidazole and hexa-histidinyl peptide (his-6) in immobilized metal affinity chromatography (IMAC) [1,2] systems. The affinity of this ligand: 1,8 bis (N1,N1')imidazolo-octa-(3,6)-dithiane or bImOdS, to Ni-nitrilotriacetic acid (Ni-NTA) complex in solution is measured and compared with that of imidazole and his-6 peptide via isothermal titration calorimetry (ITC). In addition, bImOdS is compared with his-6 binding to the solid-state matrix of Ni-NTA-charged agarose beads, as employed routinely in IMAC. Results reported here include the following: (1) two imidazole moieties bind within a single Ni-NTA complex, while bImOds, being an imidazolo dimer, binds with 1:1, and his-6 peptide binds with 1:3 stoichiometry. (2) Enthalpies of reaction for imidazole and his-6 peptide are reported - these can be utilized to predict changes in affinity in IMAC systems with temperature, should protein unfolding/refolding steps in purification be desired at alternate temperatures. (3) Metal analyses of the Ni-NTA agarose beads suggests that ∼2/3 of the nickel is present in low-affinity sites, which will complicate protein separations at high protein-concentration loading. An improved procedure for subtracting ligand dilution heats from ITC analyses is presented in an Appendix.

Effect of zoledronate on the responses of osteocytes to acute parathyroid hormone.

The bone anabolic effect of parathyroid hormone (PTH) therapy is blunted when used in patients who were previously on bisphosphonate treatment. Osteocytes may play a role in the bisphosphonate silencing effect on PTH therapy since bisphosphonates have been shown to reach the lacunocanalicular system. In vivo osteocyte studies pose a significant challenge. For the current study, we developed a simple method to isolate RNA from cortical bone enriched with osteocytes. Our purpose was to investigate how zoledronate (ZA) treatment modulates the responses of osteocytes and the bone marrow (BM) to acute PTH treatment. Mice received ZA treatment for 3 months and a single PTH injection prior to death. Bone was histomorphometrically evaluated. Gene expression was assessed at the RNA level in osteocytes and BM. Endothelial progenitor cells (EPCs) and γδT cells were analyzed in the BM and blood using flow cytometry. We found that ZA treatment altered bone responses to PTH. Expression of Sfrp4, a Wnt antagonist, was significantly increased in ZA-affected osteocytes. BM EPCs were increased in response to acute PTH but not when treatment was combined with ZA. ZA treatment augmented EPCs in the BM but not in blood, which suggests that ZA treatment may have differential effects between the BM and blood. These findings indicate that osteocytes and BM EPCs in mice on ZA treatment respond differently to acute PTH from those not receiving ZA. This may partially explain the mechanisms of previous reports that ZA therapy attenuates the anabolic effect of PTH in bone.

A male-predominant cuticular hydrocarbon, 7-methyltricosane, is used as a contact pheromone in the western flower thrips Frankliniella occidentalis.

In a laboratory bioassay, adult female Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) spent more time near filter paper disks that had been exposed to adult males than near unexposed disks; this effect was not observed on disks exposed to adult females. The response could only partly be explained by the known male-produced aggregation pheromone, neryl (S)-2-methylbutanoate, suggesting the presence of an unknown male-produced compound. In gas chromatography/mass spectrometry analyses, 7-methyltricosane was detected on disks exposed to males, but not on disks exposed to females. Extracts of cuticular lipids also showed relatively large amounts of 7-methyltricosane on males, whereas only trace amounts were found on females and none on larvae. Bioassays of synthetic 7-methyltricosane showed that adults responded only after contact. The response to this compound was clearly different from that to n-tricosane or hexane-only controls. Females that contacted 7-methyltricosane on glass beads stayed in the vicinity and frequently raised the abdomen, a behavior that rejects mating attempts by males. Males stayed in the vicinity and wagged the abdomen sideways, a behavior used in fighting between males. This is the first identification of a contact pheromone in the order Thysanoptera.

CRISPR-Cas9 Editing of the Plasmodium falciparum Genome: Special Applications.

The virulence of Plasmodium falciparum has been attributed in large part to the expression on the surface of infected red blood cells of the variant surface antigen Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1). Different forms of this protein are encoded by individual members of the multicopy gene family called var. Two attributes of the var gene family are key to the pathogenesis of malaria caused by P. falciparum; the hyperrecombinogenic nature of the var gene family that continuously generates antigenic diversity within parasite populations, and the ability of parasites to express only a single var gene at a time and to switch which gene is expressed over the course of an infection. The unique attributes of CRISPR-Cas9 have been applied to help decipher the molecular mechanisms underlying these unusual properties of the var gene family, both as a source of the DNA double strand breaks that initiate var gene recombination and as a way to recruit molecular probes to specific regions of the genome. In this chapter, we describe these somewhat unusual applications of the CRISPR-Cas9 system.

Effects of cis-Jasmone Treatment of Brassicas on Interactions With Myzus persicae Aphids and Their Parasitoid Diaeretiella rapae.

There is a need to develop new ways of protecting plants against aphid attack. Here, we investigated the effect of a plant defence activator, cis-jasmone (CJ), in a range of cultivars of Brassica napus, Brassica rapa and Brassica oleracea. Plants were sprayed with cis-jasmone or blank formulation and then tested with peach potato aphids (Myzus persicae Sulzer) (Hemiptera: Aphididae) and their parasitoid Diaeretiella rapae (M'Intosh) (Hymenoptera: Braconidae). CJ treated plants had significantly lower aphid settlement than control plants in a settlement bioassay. Conversely, in a foraging bioassay, D. rapae parasitoids spent a significantly longer time foraging on CJ treated plants. Our results reveal that CJ treatment makes plants less attractive to and less suitable for M. persicae but more attractive to D. rapae in a range of brassica cultivars. It is likely that these effects are due to changes in volatile emission indicating activation of defence and presence of conspecific competitors to aphids but presence of prey to parasitoids. Increases in volatile emission were found in CJ induced plants but varied with genotype. Among the synthetic volatile compounds that were induced in the headspace of CJ treated brassica cultivars, methyl isothiocyanate, methyl salicylate and cis-jasmone were most repellent to aphids. These results build on earlier studies in Arabidopsis and show that tritrophic interactions are influenced by CJ in a wide range of brassica germplasm. The implication is that CJ is a promising treatment that could be used in brassica crops as part of an integrated pest management system.

Mating behaviour, mate choice and female resistance in the bean flower thrips (Megalurothrips sjostedti).

Many species of thrips (Thysanoptera) in the family Thripidae form mating aggregations, but the adaptive significance of these aggregations and the extent of male and female mate choice is poorly understood. We studied the mating behaviour of the bean flower thrips Megalurothrips sjostedti (Trybom) (Thysanoptera: Thripidae), which forms male aggregations and occurs across sub-Saharan Africa. We tested whether males choose mates by female age or mating status. No-choice mating bioassays with one male and one female were used to simulate the way males usually encounter only one female at a time in aggregations in the field. Virgin females violently resisted mating attempts by males, but we found no compelling evidence to establish whether this was indiscriminate or was screening suitable males. Younger males (1-2 days old) did not discriminate females by age (1-2 or 7-10 days old), but older males (7-10 days old) avoided mating with older females. Any male choice by female mating status (virgin or mated) was weak or absent. The mating behaviour of M. sjostedti shows broad similarities with that of other thrips species that form aggregations, but also shows some distinct and novel differences, which can help our understanding of the adaptive significance of aggregations.

Heterokaryotic nuclear conditions and a heterogeneous nuclear population are observed by flow cytometry in Phytophthora infestans.

A simple and reliable method for preparation of whole nuclei of a common oomycete, Phytophthora infestans, is described for laser flow cytometry. The ease of preparation, the absence of detectable debris and aggregates, and the precision in determinations of DNA content per nucleus improve interpretation and understanding of the genetics of the organism. Phytophthora infestans is the pathogen that causes potato and tomato late blight. The genetic flexibility of P. infestans and other oomycete pathogens has complicated understanding of the mechanisms of variation contributing to shifts in race structure and virulence profiles on important agricultural crops. Significant phenotypic and genotypic changes are being reported in the apparent absence of sexual recombination in the field. Laser flow cytometry with propidium iodide is useful in investigating the nuclear condition of the somatic colony of field strains of P. infestans. The majority of the studied strains contain a single population of nuclei in nonreplicated diplophase. However, mean DNA content per nucleus varies considerably among isolates confirming the heterogeneity of the nuclear population in regard to C-value, for field isolates. Nuclear DNA content varies from 1.75x to 0.75x that of nuclei in a standard strain from central Mexico. Some strains contain two to three populations of nuclei with differing DNA contents in the mycelium and are heterokaryons. Such a range in DNA content suggests DNA-aneuploidy, but direct confirmation of aneuploidy will require microscopy of chromosomes. Heterokaryosis and populations of nuclei of differing DNA content necessarily confound standardized assays used worldwide in crop breeding programs for determination of race profiles and virulence phenotypes of this important pathogen.

Complete genomic sequence of a Tobacco rattle virus isolate from Michigan-grown potatoes.

Tobacco rattle virus (TRV) causes stem mottle on potato leaves and necrotic arcs and rings in potato tubers, known as corky ringspot disease. Recently, TRV was reported in Michigan potato tubers cv. FL1879 exhibiting corky ringspot disease. Sequence analysis of the RNA-1-encoded 16-kDa gene of the Michigan isolate, designated MI-1, revealed homology to TRV isolates from Florida and Washington. Here, we report the complete genomic sequence of RNA-1 (6,791 nt) and RNA-2 (3,685 nt) of TRV MI-1. RNA-1 is predicted to contain four open reading frames, and the genome structure and phylogenetic analyses of the RNA-1 nucleotide sequence revealed significant homologies to the known sequences of other TRV-1 isolates. The relationships based on the full-length nucleotide sequence were different from than those based on the 16-kDa gene encoded on genomic RNA-1 and reflect sequence variation within a 20-25-aa residue region of the 16-kDa protein. MI-1 RNA-2 is predicted to contain three ORFs, encoding the coat protein (CP), a 37.6-kDa protein (ORF 2b), and a 33.6-kDa protein (ORF 2c). In addition, it contains a region of similarity to the 3' terminus of RNA-1, including a truncated portion of the 16-kDa cistron. Phylogenetic analysis of RNA-2, based on a comparison of nucleotide sequences with other members of the genus Tobravirus, indicates that TRV MI-1 and other North American isolates cluster as a distinct group. TRV M1-1 is only the second North American isolate for which there is a complete sequence of the genome, and it is distinct from the North American isolate TRV ORY. The relationship of the TRV MI-1 isolate to other tobravirus isolates is discussed.

Characterization of LP-Z Lipoprotein Particles and Quantification in Subjects with Liver Disease Using a Newly Developed NMR-Based Assay.

BACKGROUND: Lipoprotein particles with abnormal compositions, such as lipoprotein X (LP-X) and lipoprotein Z (LP-Z), have been described in cases of obstructive jaundice and cholestasis. The study objectives were to: (1) develop an NMR-based assay for quantification of plasma/serum LP-Z particles, (2) evaluate the assay performance, (3) isolate LP-Z particles and characterize them by lipidomic and proteomic analysis, and (4) quantify LP-Z in subjects with various liver diseases. METHODS: Assay performance was assessed for linearity, sensitivity, and precision. Mass spectroscopy was used to characterize the protein and lipid content of isolated LP-Z particles. RESULTS: The assay showed good linearity and precision (2.5-6.3%). Lipid analyses revealed that LP-Z particles exhibit lower cholesteryl esters and higher free cholesterol, bile acids, acylcarnitines, diacylglycerides, dihexosylceramides, lysophosphatidylcholines, phosphatidylcholines, triacylglycerides, and fatty acids than low-density lipoprotein (LDL) particles. A proteomic analysis revealed that LP-Z have one copy of apolipoprotein B per particle such as LDL, but less apolipoprotein (apo)A-I, apoC3, apoA-IV and apoC2 and more complement C3. LP-Z were not detected in healthy volunteers or subjects with primary biliary cholangitis, primary sclerosing cholangitis, autoimmune hepatitis, or type 2 diabetes. LP-Z were detected in some, but not all, subjects with hypertriglyceridemia, and were high in some subjects with alcoholic liver disease. CONCLUSIONS: LP-Z differ significantly in their lipid and protein content from LDL. Further studies are needed to fully understand the pathophysiological reason for the enhanced presence of LP-Z particles in patients with cholestasis and alcoholic liver disease.

Experienced males recognise and avoid mating with non-virgin females in the western flower thrips.

The western flower thrips Frankliniella occidentalis (Thysanoptera: Thripidae) is a major insect pest on a wide range of crops throughout the world. There are several unexplained aspects of the mating behaviour, particularly in relation to male-male competition and mate choice. The objectives of the study were to test whether males can detect the mating status of females and whether males avoid mating with previously mated females. Experiments involved either 'experienced' adults taken from a laboratory culture, which had been exposed to high densities of thrips, or virgin adults reared individually. Experienced males mated readily with virgin females, but avoided mating with experienced females. Virgin males showed much less discrimination between females. Avoidance of mating with experienced females is likely to be widespread because it occurred in populations from both the United Kingdom and Kenya. Experienced males also mated with dead virgin females, but avoided mating with dead experienced females, which ruled out the possibility that behavioural differences between the females were responsible. To test whether males could detect whether or not females had mated, virgin females of the same age from the same cohort were either mated once or not mated. Experienced males mated with the dead females that were virgin and avoided mating with the dead females that differed only in that they had mated once shortly before. This showed that males recognise whether or not a female has mated and avoid mating with previously mated females. This avoidance by males suggests that mated females are not usually subjected to high levels of male harassment. The most likely explanation of the avoidance is that males produce an antiaphrodisiac pheromone that is applied to females during mating.

Prediction of the Leaf Primordia of Potato Tubers Using Sensor Fusion and Wavelength Selection.

The sprouting of potato tubers during storage is a significant problem that suppresses obtaining high quality seeds or fried products. In this study, the potential of fusing data obtained from visible (VIS)/near-infrared (NIR) spectroscopic and hyperspectral imaging systems was investigated, to improve the prediction of primordial leaf count as a significant sign for tubers sprouting. Electronic and lab measurements were conducted on whole tubers of Frito Lay 1879 (FL1879) and Russet Norkotah (R.Norkotah) potato cultivars. The interval partial least squares (IPLS) technique was adopted to extract the most effective wavelengths for both systems. Linear regression was utilized using partial least squares regression (PLSR), and the best calibration model was chosen using four-fold cross-validation. Then the prediction models were obtained using separate test data sets. Prediction results were enhanced compared with those obtained from individual systems' models. The values of the correlation coefficient (the ratio between performance to deviation, or r(RPD)) were 0.95(3.01) and 0.9s6(3.55) for FL1879 and R.Norkotah, respectively, which represented a feasible improvement by 6.7%(35.6%) and 24.7%(136.7%) for FL1879 and R.Norkotah, respectively. The proposed study shows the possibility of building a rapid, noninvasive, and accurate system or device that requires minimal or no sample preparation to track the sprouting activity of stored potato tubers.

Solvent Stokes' shifts revisited: application and comparison of Thompson-Schweizer-Chandler-Song-Marcus theories with Ooshika-Bakshiev-Lippert theories.

The "classical" treatment of solvent Stokes' shifts has been with us for 50 years or more. Twenty-five years ago, aided by new statistical mechanical underpinnings of liquid-state theory, Chandler and others [Thompson, M.; Schweizer, K.; Chandler, D. J. Chem. Phys. 1982, 76, 1128-1135. Schweizer, K.; Chandler, D. J. Chem. Phys. 1983, 78, 4118-4125. Song, X.; Chandler, D.; Marcus, R. J. Phys. Chem. 1996, 100, 11954-959.] developed newer approaches to predicting solvent shifts. I employ these here in a direct comparison with the older methods for three molecules of general interest in four different solvents. I also suggest new routes to future methods that may retain the advantages of both methods.

Reduced translucency and the addition of black patterns increase the catch of the greenhouse whitefly, Trialeurodes vaporariorum, on yellow sticky traps.

The greenhouse whitefly Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) is a pest of a wide range of vegetable and ornamental crops in greenhouses around the world. Yellow sticky traps are highly attractive to flying adults and so are frequently used to monitor the pest. Our aim was to test whether changes in trap translucency or the addition of printed black patterns could increase the catch on yellow sticky traps in greenhouses. Field trials were carried out in commercial crops of strawberry and tomato under glass over three years. Reduced trap translucency increased trap catches by a factor of 1.5 to 7.0 and the catch increased significantly for both females and males. Spectrometer measurements showed that the increased catch was consistent with an increased landing stimulus from a colour opponency mechanism i.e. the ratio of energy from 500-640 nm to the energy from 300-500 nm. Printed black patterns increased trap catches on specific types of trap, by a factor of 1.4 to 2.3, and the catch increased significantly for both females and males. The patterns increased trap catch on moderately translucent traps, but decreased trap catch on less translucent traps. The evidence points to a contrast/edge effect of pattern, but laboratory experiments are needed to clarify this. Exploitation of these translucency and pattern effects could improve the efficacy of yellow traps for monitoring and mass trapping in crops.