Objectives: The present study was prepared to investigate the impact of insect density, adult emergence of Tribolium castaneum on the secretion of Benzoquinones (BQs) consist of methyl-1,4-benzoquinone(MBQ) and Ethyl-1,4-Benzoquinone (EBQ), and accumulation of Aflatoxins (AFs) in wheat flour stored at different periods. Methods: Forty grams of wheat flour were put into small glass jars (8 cm diameter and 12 cm length). Then T. castaneum was put in each jars at rates of 10, 20 and 30 unsexed pairs of insect adult. The jars were covered with muslin cloth and the rubber band was fixed to prevent insects to escape. A glass jar without any insects served as the control. The jars lifted on bench in the laboratory for two, three and four months of storage under laboratory temperature conditions (with average 28 ± 20C and 65±5 R.H). The previous design was replicated three times. At the end of each storage period, the jars containing the flour were sieved thoroughly by 40 wire mesh size to separate the insects. The insects have been counted on the other hand wheat flour was prepared to determine MBQ, EBQ and AFs by HPLC methods. Results: The results indicated the levels of EBQ higher than MBQ in all infested samples at all insect densities (No. of insect pairs). The concentrations of MBQ in wheat flour released by ten adult pairs (10P) with the three storage periods two, three and four months were 10.42 ± 0.56, 22.38 ± 3.67, 27.06 ± 6.71µg/g, respectively. These results increased with insect densities to (30p) were 39.67 ± 0.10, 63.58 ± 2.35 and 106.24 ± 7.4 µg/g after storage periods two, three and four months, respectively. In addition to the concentrations of EBQ with (10P) were 67.45 ± 3.64, 98.0 ± 6.1 204.66 ± 5.8 µg/g with storage periods two, three and four months, respectively. In case (30P) the levels of EBQ were 376.7 ± 0.87, 570.1 ± 2.11 and 1558.66 ± 10.88 (µg/g). The highest concentration of the BQs 1664.90 ± 11.43 (µg/g) released by T. castaneum achieved with the highest adult emergence (1021 insect adult) and the highest insect density (30p) at four months storage period. In general, AFs levels enhanced with a period of storage and insect densities. Conclusion: Levels of the BQs (MBQ and EBQ) increased with an increase of storage periods and insect densities. Therefore, the presence of this insect should be prevented in stored wheat flour reducing AFs contamination is possible by storage for short time and prohibit insects which causes an increase temperature of the flour and moisture, all of which promote production of AFs.

This study aimed to evaluate different diets effects on the biological parameters of plodia interpunctella (Hubner). Three hosts namely; date, almond and peanut. Results showed that the hatchability percentage, weight per larva, pupation percentage and adult emergence percentage were the highest on almonds diet. Incubation period, generation time and life cycle were shortest in almonds. Also data indicated that almonds were the most preferred host. The efficacy of three microwave powers was investigated against two plodia interpunctella stages. The result cleared that the increase in microwave power and exposure times caused an increase in eggs and larvae reduction rate % and accordingly the microwave power more effective in larvae than egg stage. Also, results showed that there is no harmful effect on the chemical fruits characteristics under microwave treatment.

Susceptibility of four varieties of wheat (Egypt 1, Egypt 2, Gemmiza 11and Sids 12), and five rice varieties (Egypt 1, Egypt 2, Giza 179, Sakha 105 and Sakha 106) for infestation by Sitophilus oryzae (L.) and Rhizopertha dominica (F.) were evaluated in the laboratory at 28 ± 1ºc and 65 ± 5 % R.H. The results showed significant differences between various wheat varieties in the growth index of S .oryzae, it was comparatively higher in the varieties Gemmiza 11 and Egypt 1 than varieties Egypt 2 and Sids 12. Also, Egypt 1 was the least susceptible to R. dominica with lowest percent of weight loss (3.80%). In case of rice varieties data revealed that, Giza 179 and Egypt 2 varieties were the least susceptible to S. oryzae by lowest values of growth index (0.38 and 0.90, respectively) and corresponding values of weight loss (0.16 and 0.38% ,resp.), with significant differences when compared with all varieties. While, Sakha 105 variety was most resistance to R. dominica by growth index (1.27) and least value of weight loss (0.29%).A significant effect of grain moisture contents on susceptibility/resistance against S. oryzae and R. dominica .

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Field experiments were carried out at Etay El-Baroud Agric. Res. Station Farm (El-Beheira Governorate) during two successive wheat seasons (2010/11 and 2011/12) to study the relative susceptibility of some wheat cultivars to infestation with cereal aphids and glassy clover snails. The results revealed that, three cultivars; Misr 2, Giza 168 and Gemmeiza 7 had the least infestation by cereal aphids (37.3, 62.2 and 65.2 aphids/10 plants, respectively). On the other hand, three cultivars; Misr 2, Giza 168 and Gemmeiza 11 had the least infestation by glassy clover snails (5.6, 6.0 and 9.4 snails / 50x50 cm², respectively). Finally, two cultivars Misr 2 and Giza 168 proved the least infestation by cereal aphids and glassy clover snails.