Coordinated \u3ci\u3eDiabrotica\u3c/i\u3e Genetics Research: Accelerating Progress on an Urgent Insect Pest Problem

Diabrotica spp. (western, northern, and Mexican corn rootworms) represent the main pest complex of continuous field corn, Zea mays (L.), in North America. The western corn rootworm, Diabrotica virgifera virgifera LeConte, also has become the main pest of continuous corn in Central and Southeastern Europe since its introduction near Belgrade 15–20 years ago, and it represents a major risk to Western Europe. It has already caused economic losses in Eastern Europe, and Western countries such as France have committed large expenditures for containment and/or eradication. Rootworm larvae feed on corn roots, and damaged plants are more susceptible to drought and disease, have decreased yield, and are prone to lodging. A recent economic analysis estimates that costs of control and yield loss are about $1.17 billion a year in the United States. Crop rotation and chemical control have been the primary management strategies, but the western corn rootworm is becoming increasingly difficult to control because of its sequential ability to evolve resistance to almost all management strategies that have been used. The recent deployment of transgenic Bt corn in the United States for controlling Diabrotica pests has raised concerns that rootworms will develop resistance to this technology as well, unless appropriate resistance management strategies are developed and practiced

Coordinated \u3ci\u3eDiabrotica\u3c/i\u3e Genetics Research: Accelerating Progress on an Urgent Insect Pest Problem

Diabrotica spp. (western, northern, and Mexican corn rootworms) represent the main pest complex of continuous field corn, Zea mays (L.), in North America. The western corn rootworm, Diabrotica virgifera virgifera LeConte, also has become the main pest of continuous corn in Central and Southeastern Europe since its introduction near Belgrade 15–20 years ago, and it represents a major risk to Western Europe. It has already caused economic losses in Eastern Europe, and Western countries such as France have committed large expenditures for containment and/or eradication. Rootworm larvae feed on corn roots, and damaged plants are more susceptible to drought and disease, have decreased yield, and are prone to lodging. A recent economic analysis estimates that costs of control and yield loss are about $1.17 billion a year in the United States. Crop rotation and chemical control have been the primary management strategies, but the western corn rootworm is becoming increasingly difficult to control because of its sequential ability to evolve resistance to almost all management strategies that have been used. The recent deployment of transgenic Bt corn in the United States for controlling Diabrotica pests has raised concerns that rootworms will develop resistance to this technology as well, unless appropriate resistance management strategies are developed and practiced

Coordinated \u3ci\u3eDiabrotica\u3c/i\u3e Genetics Research: Accelerating Progress on an Urgent Insect Pest Problem

Diabrotica spp. (western, northern, and Mexican corn rootworms) represent the main pest complex of continuous field corn, Zea mays (L.), in North America. The western corn rootworm, Diabrotica virgifera virgifera LeConte, also has become the main pest of continuous corn in Central and Southeastern Europe since its introduction near Belgrade 15–20 years ago, and it represents a major risk to Western Europe. It has already caused economic losses in Eastern Europe, and Western countries such as France have committed large expenditures for containment and/or eradication. Rootworm larvae feed on corn roots, and damaged plants are more susceptible to drought and disease, have decreased yield, and are prone to lodging. A recent economic analysis estimates that costs of control and yield loss are about $1.17 billion a year in the United States. Crop rotation and chemical control have been the primary management strategies, but the western corn rootworm is becoming increasingly difficult to control because of its sequential ability to evolve resistance to almost all management strategies that have been used. The recent deployment of transgenic Bt corn in the United States for controlling Diabrotica pests has raised concerns that rootworms will develop resistance to this technology as well, unless appropriate resistance management strategies are developed and practiced

Dimensionality cross-over in magnetism: from domain walls (2D) to vortices (1D)

Dimensionality cross-over is a classical topic in physics. Surprisingly it has not been searched in micromagnetism, which deals with objects such as domain walls (2D) and vortices (1D). We predict by simulation a second-order transition between these two objects, with the wall length as the Landau parameter. This was conrmed experimentally based on micron-sized ux-closure dots

Neutron and proton drip lines using the modified Bethe-Weizsacker mass formula

Proton and neutron separation energies have been calculated using the extended Bethe-Weizsacker mass formula. This modified Bethe-Weizsacker mass formula describes minutely the positions of all the old and the new magic numbers. It accounts for the disappearance of some traditional magic numbers for neutrons and provides extra stability for some new neutron numbers. The neutron and proton drip lines have been predicted using this extended Bethe-Weizsacker mass formula. The implications of the proton drip line on the astrophysical rp-process and of the neutron drip line on the astrophysical r-process have been discussed.Comment: 5 pages, 2 figure

Chemical ordering in magnetic FePd / Pd(001) epitaxial thin films induced by annealing

Chemically disordered FePd epitaxial layers are grown at room temperature by molecular beam epitaxy on a Pd(001) buffer layer and then annealed in order to induce the chemically ordered L10 (AuCu I) structure. Contrary to what is observed in the case of ordering during growth above room temperature, the ordered structure appears here with the three possible variants of the L10 phase. The ratio of the three different variant volumes is set by the residual epitaxial strain in the layer before annealing. It thus explains that for long annealing times, the long-range order parameter associated with the L10 variant with c along the (100) growth direction saturates at a value close to 0.65, and never reaches unity. Magnetic consequences of the ordering are studied

Nuclear break-up of 11Be

The break-up of 11Be was studied at 41AMeV using a secondary beam of 11Be from the GANIL facility on a 48Ti target by measuring correlations between the 10Be core, the emitted neutrons and gamma rays. The nuclear break-up leading to the emission of a neutron at large angle in the laboratory frame is identified with the towing mode through its characteristic n-fragment correlation. The experimental spectra are compared with a model where the time dependent Schrodinger equation (TDSE) is solved for the neutron initially in the 11 Be. A good agreement is found between experiment and theory for the shapes of neutron experimental energies and angular distributions. The spectroscopic factor of the 2s orbital is tentatively extracted to be 0.46+-0.15. The neutron emission from the 1p and 1d orbitals is also studied

Low Energy States of 3181Ga50^{81}_{31} Ga_{50} : Elements on the Doubly-Magic Nature of 78^{78}Ni

Excited levels were attributed to $^{81}_{31}$Ga$_{50}$ for the first time which were fed in the $\beta$-decay of its mother nucleus $^{81}$Zn produced in the fission of $^{nat}$U using the ISOL technique. We show that the structure of this nucleus is consistent with that of the less exotic proton-deficient N=50 isotones within the assumption of strong proton Z=28 and neutron N=50 effective shell effects.Comment: 4 pages, REVTeX 4, 5 figures (eps format

European populations of \u3ci\u3eDiabrotica virgifera virgifera\u3c/i\u3e are resistant to aldrin, but not to methyl-parathion

The western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is a major pest of cultivated corn in North America and has recently begun to invade Europe. In addition to crop rotation, chemical control is an important option for D. v. virgifera management. However, resistance to chemical insecticides has evolved repeatedly in the USA. In Europe, chemical control strategies have yet to be harmonized and no surveys of insecticide resistance have been carried out. We investigated the resistance to methyl-parathion and aldrin of samples from nine D. v. virgifera field populations originating from two European outbreaks thought to have originated from two independent introductions from North America. Diagnostic concentration bioassays revealed that all nine D. v. virgifera field populations were resistant to aldrin but susceptible to methyl-parathion. Aldrin resistance was probably introduced independently, at least twice, from North America into Europe, as there is no evident selection pressure to account for an increase of frequency of aldrin resistance in each of the invasive outbreaks in Europe. Our results suggest that organophosphates, such as methyl-parathion, may still provide effective control of both larval and adult D. v. virgifera in the European invasive outbreaks studied

Excited states of 19N and 21O

(18O, 19N) and (18O, 21O) nuclear reactions on a 18O target provide measurements of excited state energies at 1.12 and 1.59 MeV for 19N and at 1.35 and 3.00 MeV for 21O. The 19N mass is remeasured as 15.856 ± 0.050 MeV