First data of statistic and ecological behavior of orthoptera insects in arid region (Southern West of Algeria).

The activity developed in vast areas of northwest africa causes serious invasions of different species of orthoptera insect which poses a great danger to agriculture and thus to nutrition of peoples and animals in general. In (Algeria), FAO considers the regions of naama, tindouf, adrar and bechar in Algeria as the theater of signaling of swarms and intervention. In this article, we want to shed light on the peculiarities of this insect (orthoptera), its statistics, its species and the families it belongs to in the arid region called naama (southwestern Algeria). The study of orthoptera in the arid region of naama (southern west of Algeria) conducted at three stations (Mecheria, Ben ammar) and the wetland of (Ain ben khelil) during the period from august 2015 until august 2017 allowed to identify nineteen (19) species divided into two sub-orders ensifera and caelifera. They are divided into five families (Tettigonidae, Gryllidae Pamphagidae, Acrididae, and Pyrgomorphidae). Acrididae family is the largest with five species. Oedipodinae subfamily is the most numerous genera and species it includes four (4) different types genders and seven species (7). The highest diversity index of the shannon-weaver is obtained at the wetland ain ben khelil is 2.12 bits, followed by the station of ben ammar with 2.06 bits and station of mecheria remains in third with 1.89 bit values of fairness are close to one corresponding to populations in balance entered them. The determination of species, genders and families of this population is based on several morphological criteria such as the shape of the pronotum, and the color of membranous wings and the shape of the hind legs.

Why orthoptera fauna resist of pesticide? First experimental data of resistance phenomena.

Orthoptera are capable of threat of agriculture, human health and resists to all pesticides used. This problem is become an objectif of many research's. Pesticide resistance is the adaptation of insects to this materials resulting in decreased susceptibility to that chemical. In other hand, insects develop a resistance through natural selection such chemically transformation, physiological phenomena and genetic. In our study, natural chitin was extracted from cuticle of orthoptera insect (southern of Algeria) using a chemical strategy consists on hydrochloric acid, sodium hydroxide and hydrogen peroxide. The average yield of extracted chitin (96.95% w) indicates that the cuticles of orthoptera are a rich source of chitin. Cuticle exhibit a heterogeneous morphology characterized by a compact structure with well-defined fibrous. For extracted chitin and after demineralization, we can appreciate important changes in the surface of material. We observed round shaped black spots indicated that they are composed almost exclusively by K2O and CaO (cuticle) in the other hand we observed several white taches behind black spots, here we suggest that white taches present chitin extracted. The most resistant orthoptera are the ones to survive and transform their properties by chemical process such as transformation of chitin to chitosan and physiological development such as age. In this study, we have found that the first generation has a great resistance to insecticides. After insecticide application we observed a descendant's resistance decreased a larger because sensitive insects have been selectively killed. After repeated applications resistant insects may comprise the minority. Finally we can said, insecticide resistance can be found in many types and we can conclude that physiological resistance and chemical resistance coexist together and cannot separate. In the physiological resistance, the insect populations may develop the ability to avoid or reduce lethal insecticide exposure. In contrast, chemical resistance refers to modification mechanisms, including reduced cuticle penetration and decreased or increased target site sensitivity. The extracted chitin sample and chitosan were characterized by several characterizations such as X-ray diffraction, scanning electron microscopy SEM, FTIR and 1HRMN spectroscopy.

Analysis of experimental data of environmental cement prepared by fly ash of eggs shell and sand dune for reduction of carbon dioxid.

In the recent years, the dominant cementitious materials have been industrial by products such as fly ash. This present data describes some of the cementitious products that are attracting attention in the global research community and the properties and characteristics of these materials that affect their performance such durability, mechanically properties and reduction of carbon dioxid (CO2). The present investigation deals with the chemical synthesis of cementitious material using fly ash of eggs shell rich in calcium(Ca) and sand dune(southern west of Algeria) rich in silica(SiO2).The composition of geopolymers synthesized are the most compressive resistant with a maximum stress of 49.71 MPa, the most flexible (E = 2.63 GPa) and the most ductile (εr = 65.42%).The characteristic properties of the chemically synthesized cementitious materials were analyzed by the chemical composition analysis XRF, XRD and SEM analyses.