Activation of Protic, Hydridic and Apolar E-H Bonds by a Boryl-Substituted Ge Cation.

The synthesis of a boryl-substituted germanium(II) cation, [Ge{B(NDippCH) }(IPrMe)] , (Dipp=2,6-diisopropylphenyl) featuring a supporting N-heterocyclic carbene (NHC) donor, has been explored through chloride abstraction from the corresponding (boryl)(NHC)GeCl precursor. Crystallographic studies in the solid state and UV/Vis spectra in fluorobenzene solution show that this species dimerizes under such conditions to give [(IPrMe){(HCNDipp) B}Ge=Ge{B(NDippCH) }(IPrMe)] (IPrMe = 1,3-diisopropyl-4,5-dimethylimidazolin-2-ylidene), which can be viewed as an imidazolium-functionalized digermene. The dimer is cleaved in the presence of donor solvents such as [D ]thf or [D ]pyridine, to give monomeric adducts of the type [Ge{B(NDippCH) }(IPrMe)(L)] .

Experimental and quantum chemical studies of anionic analogues of N-heterocyclic carbenes.

A combination of quantum chemical and synthetic/crystallographic methods have been employed to probe electronic structure in two series of anionic ligands related to the well known N-heterocyclic carbene (NHC) class of donor. Analyses of (i) the respective frontier orbital energies/compositions for the 'free' ligands and the results of ETS-NOCV studies of the bonding in model group 11 complexes; and (ii) the structural metrics for (new) linear gold(i) compounds, have been used to probe the bonding in complexes of NHC ligands which incorporate a backbone-appended weakly-coordinating anion component (WCA-NHCs) and in systems featuring the isoelectronic (formally anionic) diazaborolyl ligand family. Key findings are that WCA-NHC ligands - in which the anionic component is attached to the ligand heterocycle via a methylene (CH2) spacer - offer electronic (and steric) properties which are largely unperturbed from their 'simple' NHC counterparts, while diazaborolyl donors (in which the negative charge is formally located at the boron donor atom) offer significantly stronger σ-donation and a very high trans influence.

Wrinkles and creases in the bending, unbending and eversion of soft sectors.

We study what is clearly one of the most common modes of deformation found in nature, science and engineering, namely the large elastic bending of curved structures, as well as its inverse, unbending, which can be brought beyond complete straightening to turn into eversion. We find that the suggested mathematical solution to these problems always exists and is unique when the solid is modelled as a homogeneous, isotropic, incompressible hyperelastic material with a strain-energy satisfying the strong ellipticity condition. We also provide explicit asymptotic solutions for thin sectors.

The Effects of a Modified Hot Water Treatment on Anastrepha ludens (Diptera: Tephritidae)-Infested Mango.

The Mexican fruit fly, Anastrepha ludens (Loew), is a quarantine pest in mango (Mangifera indica L.) that can be controlled by using a hot water treatment (HWT). This treatment is normally followed by a 30-min hydrocooling (HYC) process that reduces the negative effects that the treatment has on fruit quality.

Grape Juice as a Bait for Anastrepha suspensa (Diptera: Tephritidae) and Zaprionus indianus (Diptera: Drosophilidae).

In field tests conducted in south Florida to test grape juice as a bait for the Caribbean fruit fly, Anastrepha suspensa Loew, high numbers of Zaprionus indianus Gupta were captured in traps with aqueous grape juice. These experiments included comparisons of grape juice bait with established A. suspensa protein-based baits (ammonium acetate + putrescine lures, or torula yeast) or wine, a bait found previously to be attractive to Z.

Univalent gallium complexes of simple and ansa-arene ligands: effects on the polymerization of isobutylene.

Using [Ga(C6 H5 F)2 ](+) [Al(OR(F))4 ](-) (1) (R(F) =C(CF3)3) as starting material, we isolated bis- and tris-η(6) -coordinated gallium(I) arene complex salts of p-xylene (1,4-Me2 C6 H4), hexamethylbenzene (C6 Me6 ), diphenylethane (PhC2 H4 Ph), and m-terphenyl (1,3-Ph2 C6 H4): [Ga(1,4-Me2 C6 H4 )2.5 ](+) (2(+)), [Ga(C6 Me6 )2 ](+) (3(+)), [Ga(PhC2 H4 Ph)](+) (4(+)) and [(C6 H5 F)Ga(μ-1,3-Ph2 C6 H4)2 Ga(C6 H5 F)](2+) (5(2+)). 4(+) is the first structurally characterized ansa-like bent sandwich chelate of univalent gallium and 5(2+) the first binuclear gallium(I) complex without a Ga-Ga bond.

Univalent Gallium Complexes of Simple and ansa-Arene Ligands: Effects on the Polymerization of Isobutylene.

Using [Ga(C H F) ] [Al(OR ) ] (1) (R =C(CF ) ) as starting material, we isolated bis- and tris-η -coordinated gallium(I) arene complex salts of p-xylene (1,4-Me C H ), hexamethylbenzene (C Me ), diphenylethane (PhC H Ph), and m-terphenyl (1,3-Ph C H ): [Ga(1,4-Me C H ) ] (2 ), [Ga(C Me ) ] (3 ), [Ga(PhC H Ph)] (4 ) and [(C H F)Ga(μ-1,3-Ph C H ) Ga(C H F)] (5 ). 4 is the first structurally characterized ansa-like bent sandwich chelate of univalent gallium and 5 the first binuclear gallium(I) complex without a GaGa bond. Beyond confirming the structural findings by multinuclear NMR spectroscopic investigations and density functional calculations (RI-BP86/SV(P) level), [Ga(PhC H Ph)] [Al(OR ) ] (4) and [(C H F)Ga(μ-1,3-Ph C H ) Ga(C H F)] {[Al(OR ) ] } (5), featuring ansa-arene ligands, were tested as catalysts for the synthesis of highly reactive polyisobutylene (HR-PIB).

Comparison of torula yeast and various grape juice products as attractants for Mexican fruit fly (Diptera: Tephritidae).

Early research investigating attractants for the Mexican fruit fly, Anastrepha ludens Loew, during the 1930s indicated that fermentation products were effective attractants for Mexican fruit flies and other tropical Tephritidae, but that attraction to fruit components was only of academic interest. Tests reported here were carried out on populations of Mexican fruit flies from 2004 to 2011. Trapping experiments carried out at sites in the states Nuevo Leon and San Luis Potosi compared grape juice, reconstituted grape concentrate and powdered grape mixes, and torula yeast extract in orchards at each site.

Changes in free amino acids and polyamine levels in Satsuma leaves in response to Asian citrus psyllid infestation and water stress.

The effects of biotic and abiotic stresses on changes in amino acids and polyamine levels in Satsuma orange (Citrus unshiu; cultivar Owari) leaves were investigated. Asian citrus psyllids Diaphorina citri (Kuwayama) (ACP) infestation was used to induce biotic stress while a water deficit was imposed to induce abiotic stress. Potted trees were infested by placing 50 psyllids on 3 citrus leaves enclosed in nylon mesh bags for 5 d.

Host status of Meyer and Eureka lemons for Anastrepha ludens.

Host status for Mexican fruit fly (Anastrepha ludens (Loew)) was examined under laboratory conditions in cage infested Eureka and Meyer lemons. Our approach was to allow females to oviposit on the two cultivars in separate laboratory cages with aluminum foil covering to restrict the areas where females had access to fruit surface. Fruit of each cultivar were placed in covered trays for incubations and at approximately weekly intervals, fruit were removed, dissected, and live and dead eggs and larvae tabulated in each tissue of the fruit.

Multimodal cues drive host-plant assessment in Asian citrus psyllid (Diaphorina citri).

Asian citrus psyllid (Diaphorina citri) transmits the causal agent of Huanglongbing, a devastating disease of citrus trees. In this study we measured behavioral responses of D. citri to combinations of visual, olfactory, and gustatory stimuli in test arenas.

Host status of grapefruit and Valencia oranges for Anastrepha serpentina and Anastrepha ludens (Diptera: Tephritidae).

Anastrepha serpentina (Wiedemann) (Diptera: Tephritidae) is sporadically captured in the Rio Grande Valley of Texas. Although its preferred hosts are in the Sapotaceae family, several varieties of Citrus, including grapefruit and oranges are listed as alternate hosts. Although Mexican fruit fly, Anastrepha ludens (Loew), is known to be a major pest of Citrus, doubt exists as to the status of Citrus as a breeding host for A.

Grapefruit as a host for the West Indian fruit fly (Diptera: Tephritidae).

The most common hosts for the West Indian fruit fly, Anastrepha obliqua (Macquart) (Diptera: Tephritidae) are fruit in the family Anacardiaceae (mango [Mangifera L.] and mombin [Spondias L.] species).

High hydrostatic pressure at low temperature as a quarantine treatment to improve the quality of fruits.

Application of high hydrostatic pressure has been proposed as an alternative quarantine process for the Mexican fruit fly, Anastrepha ludens Loew (Diptera: Tephritidae), one of the most important insects infesting mangoes, citrus fruits, and other fruits in Mexico and other Latin American countries. The present study was performed to determine the effect of high pressure treatments at 0 degrees C on the survivorship of eggs and larvae of this pest. The effect of time and pressure level at near-freezing temperatures on the egg hatch and survival of larvae is discussed.

Honey bee foraging preferences, effects of sugars, and fruit fly toxic bait components.

Field tests were carried out to evaluate the repellency of the Dow AgroSciences fruit fly toxic bait GF-120 (NF Naturalyte) to domestic honey bees (Apis mellifera L.). GF-120 is an organically registered attractive bait for tephritid fruit flies composed of spinosad, hydrolyzed protein (Solulys), high-fructose corn syrup (ADM CornSweet 42 high-fructose corn syrup, referred to as invertose sugar or invertose here), vegetable oils, adjuvants, humectants, and attractants.

Effects of bait age and prior protein feeding on cumulative time-dependent mortality of Anastrepha ludens (Diptera: Tephritidae) exposed to GF-120 spinosad baits.

A fruit fly bait to attract and kill adult fruit flies, GF-120, was tested in cages to determine effects of pretreatment diet and bait aging before use on cumulative mortality rates of Mexican fruit fly, Anastrepha ludens (Loew) (Diptera: Tephritidae). Protein-starved and protein-fed, 9-d-old flies both experienced varying overall cumulative mortality at 4, 8, 24, and 48 h. Pretreatment diet had no significant effect on mortality.

Fruit fly (Diptera: Tephritidae) host status determination: critical conceptual, methodological, and regulatory considerations.

Although fruit fly host status determination/designation lies at the heart of strategic decisions on national and international trade of fruit and vegetables, all attempts thus far to define host plant status have been contentious and as a result long-standing disputes between commercial partners throughout the world have lingered over decades. Part of the problem is that too little effort has been devoted to understanding the underlying mechanisms involved in host plant use by fruit flies and that instead economic and political interests usually prevail. Here we review the most important evolutionary, biological, ecological, physiological, and behavioral aspects that drive host use by fruit flies, and then construct a flow diagram rooted in these fundamentals that outlines a series of steps and definitions to determine if a particular fruit or vegetable (and cultivars thereof) is a natural host, or a conditional (potential, artificial) host, or a nonhost.

Development of bait stations for fruit fly population suppression.

The application of insecticides is an essential component for eradication or management of fruit fly pests. Impact on nontarget organisms and public rejection of areawide pesticide applications have been major concerns in managing these programs. Bait stations have been proposed as alternative treatments in areas where broadcast insecticides are not acceptable.

Nontarget impact of spinosad GF-120 bait sprays for control of the Mexican fruit fly (Diptera: Tephritidae) in Texas citrus.

Bait sprays containing the toxicant spinosad (GF-120) were applied to citrus groves in the Rio Grande Valley of Texas where Mexican fruit flies were detected in surveillance traps. The sprays were applied as a supplement to a continuous sterile insect release program. Sterile fly captures were 47-63% lower in the treated groves compared with control groves.

Adult diet and male-female contact effects on female reproductive potential in Mexican fruit fly (Anastrepha ludens Loew) (Diptera tephritidae).

Wild strains of fruit flies (Diptera: Tephritidae) placed into laboratory rearing conditions are subjected to selection pressures caused by the diet, cages, density of flies, and other factors. Selection that changes mating behavior of the strain may result in less effective males released in sterile insect programs. Tests were performed to examine the effects of protein in diet and adult interactions on egg production and mating during sexual maturation of the Mexican fruit fly (Anastrepha ludens Loew) in laboratory cages.

Age estimation of Mexican fruit fly (Diptera: Tephritidae) based on accumulation of pterins.

A common method of aging adult flies, fluorescence spectrometry, was used to monitor the increase of overall pterine titer in head extracts of Anastrepha ludens (Loew). Accumulation of fluorescent compounds was measured as a function of chronological age of flies maintained at 17 and 27 degrees C. Although relative fluorescence increased with age, field studies revealed that this phenomenon could not be used for accurate age estimation, as relative fluorescence did not increase predictably with age over the entire life span.