The result revealed that the peak of population density of cabbage aphid Brevicoryne brassicae was 523.20 individuals/plant on 21 March in edges of rapeseed field and was 1141.67 individuals/plant in center of the field. Results revealed that population density of cabbage aphid in rapeseed fields surrounded by cover crops significantly were low compared with that of monoculture rapeseed. The location of rapeseed plants (in edges or in center) significantly affected (p<0.05) the tested pest density, e.g. optimum density was 146.69 individuals/plant in the center of the field. Whereas was 93.32 in the edges. Effect of the interaction between location and surrounding vegetation was significant on aphid density, which their population density reached the maximum level, i.e. 325.4 individuals/ plant in the center of monoculture rapeseed field, Whereas minimum density was recorded, i.e. 46.74 individuals/plant in the rapeseed surrounded by clover. In regard to the population density of parasitoid Diaeretiella rapae, results showed that its density reached 1.70 mummies/ plant in the edges of rapeseed surrounded by onion. This treatment considerably exceeded the rapeseed surrounded by clover and monoculture rapeseed in which parasitoid density counted 0.45&0.60 mummies/ plant respectively. Population density of coccinellids ranged between 0.18 & 0.42 individuals/ plant for the edges or center of the fields of the treatments, without considerable differences between them..
Duration of each developmental stage of the house dust mite Dermatophagoides pteronyssinus together with the mortality percentage were observed at a combination of five different temperatures namely 20C°, 22.5C°, 25C°, 27.5C° and 30C° and four different humidities namely 55%, 75%, 85% and 95% r. h. Results showed that temperature had the greatest effect on the life cycle period. The higher the temperature the shorter the life cycle was aid versa verea. On the other hand, humidity seems to be less effectiveness, though at the higher temperature and humidity no development was occured. Mortality among all temperatures and humidities appeared nearly the same, but at higher temperature and higher humidity and because of mould g
... Show MoreThe unemployment is considered from the most danger problems that our society face them in current time & in the near future , because it makes prodigality for element of human being , particularly age of youth who have ability to work & producing , that resulted in negative effects forecast to dire consequences social and economical dangers . In the same time as will be stated in our explanation in the following in our research , because the unemployment has ability to help to prepare good environment to grow crime , actions of violence that mostly are main cause to decrease living level of majority of citizens & in increasing numbers who became under poverty , the unemployment is economical problem as it is psycholo
... Show MoreBackground: The bond strength of endodontic sealers with dentin is a very important property for maintaining the integrity and seal of the root canal filling. The aim of this study was to evaluate and compare the effect of various irrigants (QMix, 17% EDTA and 2.5% NaOCl) on the push-out bond strength of AH plus and Bioceramic sealers. Materials and methods: Forty eight freshly extracted maxillary first molars human teeth with striaght palatal root were used in the study. The collected samples were randomly divided into three groups of equal sample size (n=16), according to the final irrigation regimen as follows: Group (1): QMix 2 in 1, Group (2): 17% ethylenediaminetetraacetic acid, Group (3): 2.5% sodium hypochloride. All samples were
... Show MoreUnderstanding the effects of fear, quadratic fixed effort harvesting, and predator-dependent refuge are essential topics in ecology. Accordingly, a modified Leslie–Gower prey–predator model incorporating these biological factors is mathematically modeled using the Beddington–DeAngelis type of functional response to describe the predation processes. The model’s qualitative features are investigated, including local equilibria stability, permanence, and global stability. Bifurcation analysis is carried out on the temporal model to identify local bifurcations such as transcritical, saddle-node, and Hopf bifurcation. A comprehensive numerical inquiry is carried out using MATLAB to verify the obtained theoretical findings and und
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