MONITORING THE ATTACK PRODUCED BY THE SPECIES CAMERARIA OHRIDELLA DESCHKA-DIMIĆ IN CRAIOVA AREA

Cameraria ohridella Deschka-Dimić is an invasive, monophagous species, extremely dangerous for the ornamental chestnut trees.Following the observations we made, it can be concluded that the southern exhibition is preferred by the larvae of the species Cameraria ohridella Deschka-Dimić, so for observation made in July 2019 the values were 3.6 mines/leaf and 8.7 mines/leaf in August, and this year it was 3.9 mines/leaf for July, reaching 8.9 mines/leaf in August, an indicator that increased rapidly over the time between the two observations and  followed by the leaves with eastern exposure and western.We also noticed that the lowest values of the average number of mines/leaf/foliole were reached on the leaves with northern exposure

The essential spectrum of the Neumann–Poincaré operator on a domain with corners

Exploiting the homogeneous structure of a wedge in the complex plane, we compute the spectrum of the anti-linear Ahlfors-Beurling transform acting on the associated Bergman space. Consequently, the similarity equivalence between the Ahlfors--Beurling transform and the Neumann-Poincare operator provides the spectrum of the latter integral operator on a wedge. A localization technique and conformal mapping lead to the first complete description of the essential spectrum of the Neumann-Poincare operator on a planar domain with corners, with respect to the energy norm of the associated harmonic field

RESEARCH REGARDING THE INTEGRATE MANAGEMENT OF THE VINE MOTH (Lobesia botrana Den et Schiff.) AT THE DEALURILE CRAIOVEI VINEYARD

The vine moth Lobesia botrana Den et Schifff. Is one of the main pest of the Dealurile Craiovei vineyard, the damages produced by this pest can reach 25-30%. The integrate management of the vine moth is an alternative to the excessive chemification in order to control the viticultural ecosystem during the past years, this paper frame within this curent. During 2004-2006, the climatic conditions has been favourable for the develop of the Lobesia botrana species, in 2004 there has been recorded 4 maximum flights coresponding to 3 complete generations and the fourth one incomplete, in 2005 and 2006 there has been recorded 3 maximum flights coresponding for same number of generations. The attack medium frequency, of the vine moth, recorded in 2004 has been of 20,66%, 19,0% in 2005, and of 17,83% in 2006. The attack medium frequency during 2004-2006 has been of 19,2% . The efficiency of the control treatments has been ranged between 94,6% and 89,4%. The highest efficiency of 94,6% has been recorded at the V2 variant, there has been used only chemical products, followed by the V3 variant (91,4%) there has been used chemical products for controling the first 2 generations I and II of the vine moth and an biological product for the third generation III, and the fourth variant V4 (89,7%) there has been used the pyretroid product Bulldock 025 EC for controling the first generation, and the biological product Foray 48B (Biobit XL) for controling the second generation II and 8 pheromonals traps (atraBOT/ha) for controling the third generation III. For the fifth variant V5 there has been used the product Calypso 480 SC, an metamorphosis inhibitor for the arthropods, for controling the first generation and then the biological product Dipel 2xWP for the second generation II and 8 pheromonals traps (atraBOT/ha) for the third generation, at this variant there has been recorded the lowest efficiencyt 89,4%

THE EFFECT OF SOME INSECTICIDES ON THE LADY BUG (Coccinella 7-punctata L.)

In Romania unfortunatly the use of insecticides for controling the pest it’s made without any respect for the beneficial fauna. One of the most known beneficial species encountered in almost any agricultural biotope it’s the lady bug Coccinella 7 punctata. The lady bug Coccinella 7 punctata it’s an predatory species that fed especially on aphids species and play an essential role in the biological control of these species. This paper present the research regarding the effect of some insecticides used for controling the mealy plum aphid Hyalopterus pruni Geoffr., to the lady bug Coccinella 7 punctata in the conditions from central Oltenia, at the Banu Maracine Didactical Station. The experience has been set up during 2005 - 2006, in a plum orchard from the Banu Maracine Didactical Station, of the University of Craiova. In order to study the effect of some insecticides on the lady bug there has been made observation in orchards as well in laboratory conditions.  The direct toxic action of the insecticides on the lady bug has been esatblished in field at 24, 48 and 72 hours after the apply of the treatments, counting the dead larva and adults. The effect of the insecticides through feeding with intoxicated aphids, has been establish in laboratory at 24, 48 and 72 hours

The mixed problem for the Laplacian in Lipschitz domains

We consider the mixed boundary value problem or Zaremba's problem for the Laplacian in a bounded Lipschitz domain in R^n. We specify Dirichlet data on part of the boundary and Neumann data on the remainder of the boundary. We assume that the boundary between the sets where we specify Dirichlet and Neumann data is a Lipschitz surface. We require that the Neumann data is in L^p and the Dirichlet data is in the Sobolev space of functions having one derivative in L^p for some p near 1. Under these conditions, there is a unique solution to the mixed problem with the non-tangential maximal function of the gradient of the solution in L^p of the boundary. We also obtain results with data from Hardy spaces when p=1.Comment: Version 5 includes a correction to one step of the main proof. Since the paper appeared long ago, this submission includes the complete paper, followed by a short section that gives the correction to one step in the proo

THE BIOLOGICAL CYCLE OF THE PLUM MEALY APHID (Hyalopterus pruni Geoffr.) ON THE CLIMATIC CONDITIONS FROM S.D. BANU MĂRĂCINE, CRAIOVA

The plum mealy aphid Hyalopterus pruni Geoffr. is one of the main pest of the plum orchard at the S. D. Banu Maracine. An important link for controling this pest is the knowledge of the biological cycle, in order to establish the best moment for the treatments. The plum mealy aphid is an migratory species, with an holocyclic, dioecious development. This species produce damages in the plum orchard from Europe, Asia and northern Africa. The main host plant is the plum tree or other species belonging to the Prunus genra and as secondary host the plum mealy aphid prefere different graminaceae species as: Phragmites, Calamagrostis, Agrostis, etc. The research regarding the biology and ecology of the plum mealy aphid has been made at the Didactical Station Banu Maracine, Craiova, in a plum orchard, Stanley variety. During the 3 years of research the period for layings eggs has oscilated between 23 days in 2004 and 31days in 2002.The development of the fundatrix, has been framed between 24 days in 2004 and 29 days in 2003. In 2002 the development of the fundatrix has been completed after 26 days. During the climatic conditions of 2002-2004, there has been developed 4 generations of wingless aphid (2002 and 2004), respectively 5 generations in 2003. These 4, 5 generations have phased from the second or third decade of April untill the second half of July. From our observations regarding the development on the secondary host plants, it come out that the first generation has completed it development, function the climatic conditions, in 7 to 11 days. There has been phased 8-9 generations of winged and wingless form, untill September and even October. The last generation has ensured the appearance of the sexuparae form, which has migrated in the plum orchard and give birth to the sexuale forms. The laying of hibernating eggs, begun in October, phasing to the first decade of November

Discrete exterior calculus (DEC) for the surface Navier-Stokes equation

We consider a numerical approach for the incompressible surface Navier-Stokes equation. The approach is based on the covariant form and uses discrete exterior calculus (DEC) in space and a semi-implicit discretization in time. The discretization is described in detail and related to finite difference schemes on staggered grids in flat space for which we demonstrate second order convergence. We compare computational results with a vorticity-stream function approach for surfaces with genus 0 and demonstrate the interplay between topology, geometry and flow properties. Our discretization also allows to handle harmonic vector fields, which we demonstrate on a torus.Comment: 21 pages, 9 figure

Finite Element Convergence for the Joule Heating Problem with Mixed Boundary Conditions

We prove strong convergence of conforming finite element approximations to the stationary Joule heating problem with mixed boundary conditions on Lipschitz domains in three spatial dimensions. We show optimal global regularity estimates on creased domains and prove a priori and a posteriori bounds for shape regular meshes.Comment: Keywords: Joule heating problem, thermistors, a posteriori error analysis, a priori error analysis, finite element metho

STUDIES ON THE USEFUL ENTOMOFAUNA IN SOME VEGETABLE CROPS IN SOUTH OF OLTENIA

Vegetable crops have been the most important technological group that is grown in our country. Due to their multiple importance, vegetable crops have received increased attention both from the scientific and technical point of view. In our country, research on useful entomofauna began after 1929, when the first entomology research unit was set up, namely the "Entomology Station" within the Instituteof Agronomic Research in Romania (Institutul de Cercetări Agronomice din România - I.C.A.R.). This paper aims to bring a great contribution of scientific data regarding useful entomofauna. The research has been conducted in the private stationary unit in Amărăştii de Jos, using three methods of collecting the entomofauna and namely the Barber type soil trap, the frappage method and method of capture by using the entomological net.All the entomofauna collected from the vegetable ecosystem has been subjected to detailed analyzes of the systematic group to which each species belongs.The research has identified 390 species belonging to 7 orders with 15 families. Most species belong to the Scarabaeidae families (5 species), followed by the Chrysomelidae family with 4 species, the Acrididae, Aphididae, Pentatomidae, Cetoniidae, Pieridae and Noctuidae families, each with 3 species, with the rest of the families having 1-2 species