الفهرس 
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Abstract
Effect of some biological agents on Tribolium confusum (duVal) and Rhizopertha dominica (F.) (Coleoptera) infesting certain stored grains of wheat cultivars
The present study aimed to investigate the following:
1. Susceptibility of some wheat varieties against Rhyzopertha dominica (F.) and Tribolium confusum insects.
2. Efficacy of some bioagents as pesticides against tested stored product insects.
3. Repellence effects of two entomopathogenic fungi mixed with insecticides.
4. Protective ability effects of two entomopathogenic fungi on stored wheat.
The results could be summarized as follows:
1. Susceptibility of some wheat cultivars to tested stored products insect
Certain Egyptian flour wheat varieties were assessed in order to determine their appropriate level of susceptibility to Rhyzopertha dominica (F.) and Tribolium confusum (du Val). Free choice test for attraction of insect adults was used in the first experiment at time interval ranged from 0.25 to 5 days post infestation. At days, results showed that the lowest attracted numbers of R. dominica adults were 5.00 and the highest ones were 22.67 for SAKL1 and SIDS1varieties, respectively. The varieties can be arranged descendently according to the attracted numbers of R. dominica as follow: SAKL8, SAKL1, BACANORA, DEBEIRA, GIZA168, GIZA164, SIDS6 and SIDS1. The descending order results obtained for T. confusum appeared similar. Statistical analysis demonstrated significant difference between the numbers of the eight varieties. In the second experiment, the numbers of F1 and the duration of offspring of each stage were determined. Based on the Dobie Index (D.I.) for R. dominica, the wheat varieties of SAKL 8, DEBEIRA, BACANORA and SAKL 1 were found to be resistant, while the SIDS 1 and SIDS 6 varieties have a moderate resistant. In the case of T. confusum all varieties showed a degree of resistance, except SAKL 8 and SIDS 1 that showed a moderate resistant. The BACANORA cultivar showed the lowest D.I. value in the two tested insect species. The obtained results can give a better understanding to the stored-grain managers regarding the prospective differences in wheat susceptibility to the infestation of R. dominica and T. confusum.
2. Efficacy of some bioagents as pesticides against tested stored product insect
The toxicities of two entomopathogenic fungi Beauveria bassiana (Balsamo) Vuillemin and Metarhizium anisopliae (Metchnikoff) were conducted in laboratory conditions by mixing their formulation with seeds against the adult of Callosobruchus maculatus (Fabricius), Rhyzopertha domonica (Fabricius), Tribolium confusum Jacquelin du Val adults. The results cleared that C. maculatus was the most susceptible species toward the tested materials, while T. confusum showed the highest tolerance against B .bassiana and M. anisopliae. The LC50 values of B. bassiana and M. anisopliae recorded 23, 25; 79.8, 46; 330, 3083 ppm against C. maculatus, R. dominica and T. confusum, respectively. B. bassiana was more toxic than M. anisopliae by 9.75 folds against T. confusum. Otherwise, M. anisopliae was more toxic than B. bassiana by 1.75 fold to R. dominica. While, C. maculates has the same susceptibility toward the two fungi. The highest LT50 value recorded 17.9 days with M. anisopliae against T. confusum, while the lowest one was 2.6 days with B. bassiana against C. maculates. Residues results cleared that T. confusum was the most tolerant adults against insects toward two insecticides. Spinosad had higher effect than malathion by 30.00, 8.33, 8.07 times against, R. dominica, C. maculates and T. confusum; respectively. The highest LT50 value recorded 4.0 days with spinosad against R. dominica, while the lowest value was 0.2 days with malathion against C. maculatus.
In conclusion, spinosad, B. bassiana and M. anisopliae revealed as good alternative candidates in controlling C. maculatus, R. dominica, T. confusum compared with malathion.
3. Repellence effects of two entomopathogenic fungi mixed with insecticides
By using the mixture of fungus formulation and insecticides with wheat grains as repellent choice test against R. dominica, the repellency factors were 83.98 and 45.33 with spinosad + B. bassinana and methoxyfenozide+ M. anisopliae. The reduction of untreated wheat grains was significantly affected when they were infested with R. dominica than grains treated by B. bassiana or M. anisopliae.
4. Protective ability effects of two entomopathogenic fungi on stored wheat
Percentage of weight loss increased in the untreated wheat grains and it increased gradually with increased infestation levels. The pecentages of lossess caused by T. confusum adults infestation in grain reached about 3.17 to 10.87% 3.45 to 10.9% for R. dominica in the control. In corrospodin, these lossess in the grains treated were 0. 2 to 2.16% for T. confusum, while with R. dominica were 2.5 to 11.23%.
In calculating the protective ratios of B. bassiana or M. anisopliae, the highest ratios recorded with T. confusum.
In conclusion the present results suggested that stored grain managers should be familiar with prospective differences in wheat susceptibility to R. dominica and T. confusum. This investigation can recommend that SAKL 8 and BACANORA wheat cultivars have the highest resistant genes to insect infestations than cultivated GIZA 164. This could be introduced as good candidates as for storage or for transfer genes against R. dominica and T. confusum. The studies suggest that entomopathogenic fungi M. anisopliae and B. bassiana have repplent effects when used as mixture with spinosad against R. dominica. M. anisopliae and B. bassiana could be used as protectant agent for wheat grain from T. confusum infestation. Spinosad, M. anisopliae and B. bassiana showed a good promised and alternative candidate over malathion. Also these results should be considered in controlling C. maculatus, R. dominica, T. confusum especially in the integrated pest management program (IPM).