Biological Effect of Different Concentrations of Bacillus Thurngensis Isolated From The Soils of Sawa Lake, Al Muthanna Governorate on The of Hypera postica at Different Time Periods

This study conduct in Al-Muthanna governorate to assess five concentrations of Bacillus thurngensisagonist Hyperapostica. The results showed the presence of Bacillus thurngensisin all the studied sites of Lake Sawa in Muthanna Governorate, and the rates of its presence were close to the same sites, and the rate of its presence in those sites was 35%, and its highest rate was recorded in the north and east of the lake, as it reached 40% and the lowest amounted to 30% in the two sites south and west site. The results of the study showed that five concentrations were taken from bacterial isolates of B. thuringiensisdiffered in the rates of killing larvae, pupae and adults of the insect Hyperapostica in vitro, Where the concentrate 1.7 × 103 spore/ml was characterized by a higher killing ratecompared to the four studied concentrations, the killing rates were (75.750, 71.080, 69.79, 64,361, 49.117 and 42,060)% for the first larval instar, the second larval instar, the third larval instar, the fourth larval instar, and the pupae, respectively, and the lowest killing rate recorded 6.873% at concentration 0.64 × 107after 24 hours of treatment.

Effect of Environmental Stressors on the mRNA Expression of Ecdysone Cascade Genes in Chironomus Riparius.

Chemical compounds produced by humans are continuously reaching the environment. In this work, we characterised the expression patterns of important endocrine-related genes involved in the ecdysone pathway in the fourth larval instar of the model species Chironomus riparius after exposure to three chemicals: ethinyl oestradiol (EE), nonylphenol (NP) and bis(tributyltin) oxide (TBTO). We used real-time PCR to analyse the gene expression levels of: ecdysone receptor (EcR) and ultraspiracle (usp), two genes that encode the dimerising partners of the functional ecdysone receptor; the orphan receptor ERR (oestrogen-related receptor), with an unknown function in invertebrates; and E74, an early response gene induced by ecdysteroids. We estimated the bioaccumulation potential, bioavailability and physicochemical properties of these chemicals, together with a number of other exogenous agents known to interfere with the hormonal system. We also provide a review of previous transcriptional studies showing the effect of all these chemicals on ecdysone cascade genes. This analysis provides useful data for future ecotoxicological studies involving invertebrate species.

The sex ratio of the koinobiont parasitoid Microcharops anticarsiae Gupta remains female-biased on young larvae of velvetbean in the laboratory environment

The natural parasitic behavior of parasitoids should be known by those in charge of planning strategies for the biological control of pests; therefore, the aim of the present study was to determine the larval instar of Anticarsia gemmatalis Hübner parasitized by Microcharops anticarsiae Gupta in the field and the implication of such parasitic behavior in the sex ratio in the laboratory environment. The length of each larval instar of A. gemmatalis parasitized by M. anticarsiae in the field was determined, and the egg-to-pupa period of the parasitoid and its larval instar lengths were plotted in Gantt charts. According to the chart, A. gemmatalis was parasitized at the first (15%) and second (85%) larval instars in the field, but the length of the first, second and third larval instars of this species was not affected by the parasitism by M. anticarsiae in the field; however, its fourth larval instar was extended and the fifth one was shortened in 2015 but not affected in 2016. The sex ratio of A. gemmatalis larvae parasitized by M. anticarsiae in the field was female-biased, and the sex ratio of early parasitized larvae (3-day old) in the laboratory environment was also female-biased for three cultivated generations. The ‘generation’ factor has affected the egg-to-pupa, pupal and egg-to-adult periods of M. anticarsiae, since females pupated earlier than males in the egg-to-pupa period. Based on the results, M. anticarsiae mostly parasitized the second larval instar of A. gemmatalis in the field, and parasitism in 3-day old larvae in the laboratory environment produced female-biased sex ratio in M. anticarsiae, regardless of the generation.

Test of vitality of fungus Beauveria bassiana (Bals.) Vuill. Eggs and larvae of moth Figs Ephestia cautella (Walk.) (Lepidoptera: Pyralidae)

The results showed the effect of different concentrations (1x 104, 1x 106, 1x 108) Spore / ml aqueous suspension of commercial isolation of the fungus Beauveria bassiana (Bals.) Vuill. on eggs and second and fourth larval instars of the moth figs Ephestia cautella (Walk.) Under laboratory conditions. The lowest hatching rate at 1 x 108 spore / ml was 15.3% after 5 days of treatment and was 60.7% at a concentration of 1 x 104 spore / ml. The rest of the larvae were followed until they reached the stage of the pupa and the adult. The mortality for the second larval instar were highest at 1 x 108 spore / ml after 7 days of treatment reaching 85.22%, The lowest rate is 5.6% after 2 days of treatment at 1 x 104 spore / ml concentration. The concentration of 1x 108 spore / ml had the highest effect after four days of treatment on the fourth larval instar the mortality was 89.6%. The lowest percentage pupation was 52.7%, and the lowest adults emerging was 50.2%.

First Record of Cheiloneurus clαviger (Thomson) (Hymenoptera: Encyrtidae) on Corfu Island

During an ongoing research programme on Saissetia oleae (Oliv.) (Homoptera: Coccidae) and its parasites on the island of Corfu, the presence of the hyperparasite Cheiloneurus clαviger (Thomson) (Hymenoptera: Encyrtidae) was recorded, for the first time, in samples of parasitized Saissetia oleae in 1991. The identification of C. clagiver was made by the junior author. The adults of Cheiloneurus clαviger emerged from S. oleae females parasitized by Metaphycus lounsburyi (How.) (Hymenoptera: Encytridae), after they were placed in plastic capsules. Tables 1 and 2 give the number of adults of S. oleae, C. claviger and M. lounsburyi that emerged from S. oleae at two experimental fields. M. lounsburyi is one of the main parasitoids of S. oleae acting as an internal parasite of the fourth larval instar. The numbers of C. claviger emerged were very low compared with the numbers of M. lounsburyi, indicating that at present C. claviger is not a serious limiting factor for the population of M. lounsburyi. The presence of a group of coarse bristles at the apex of the scutellum and the long marginal vein of fore wings are the peculiarities of the genus Cheiloneurus. The incomplete infuscation of the fore wings and the colour of the antennae with only the 5th funicular segment blackish can easily allow the discrimination of C. claviger females from those of congeneric species. Cheiloneurus clαviger is reported as a hyperparasitoid of several coccids of economic impor tance mainly via other encyrtid parasitoids. In Italy, C. claviger has been found to act as a hyperparasite of Kermesidi (genus Kermes) which infest Pinoideae. Previous reports on the entomophagous fauna of S. oleae on Corfu do not include C. claviger and it is assumed that the hyperparasitoid has been introduced rather recently. The actual role oil the parasitic complex of S. oleae and the distribution of this hyperparasite on the island should be further investigated.

The Efficiency of Terpenes Extracts of Eucalyptus Camaldulensis Seed to control Larval Stage of Callosobruchus maculates (Coleoptera:Bruchidae)

The current study has beenconduced to evaluate the effect of extracted crude terpens at the concentrations of 6,8% of seeds of Eucalyptuscamaldulensison the 4th larval instar oftheCallosobruchusmaculates and the percentage of the cowpea seed germination.The Results showed that the terpens extract of the concentration of 8% increases the mortality rate of the fourth larval instar and it reach to 63.3%, and then decrease of to 26.6,20% at concentration of 6%and forcontrol treatment respectively The percentage of adult emergence reduces to 0% at the concentration of 8% compared with control treatment in which it reach to 66.6%. The extraction atbothconcentrations 6,8% does not affect the germination rate

Life Cycle Patterns, Density, and Frequency of Deformities in Chironomus Larvae (Diptera: Chironomidae) over a Contaminated Sediment Gradient

Along a gradient of contamination in Lake Vossemeer (where contaminated sediments from the River Rhine are deposited out), Chironomus cf. plumosus larvae occurred at lower population densities and with higher frequencies of deformities as the contamination levels increased. At the least polluted sites, the frequency of larval deformities was elevated only slightly compared with reference levels. At these sites, C. cf. plumosus had a bivoltine life cycle and overwintered in the fourth larval instar stage. At moderately contaminated sites, the percentage of prepupal larvae was significantly lower in spring and the development of pupae delayed by 2 wk. At heavily contaminated sites, larval densities were strongly reduced and no pupae were observed at all. Under such conditions, population density seems to be a suitable additional indicator of toxic stress. The frequency of deformed larvae was higher from November to April than from July to October. Maximum frequencies were observed during emergence of the overwintering generation, suggesting that the period between February and April may be the most suitable period for the assessment of this parameter.