An outbreak of the sugarcane whitefly (Neomaskellia andropogonis Corbett) recently occurred in sugarcane fields in Khuzestan Province of Iran. This pest sucks plant sap producing large amounts of honeydew. In Khuzestan Province, populations of all developmental stages increase from early August until late November. At this time, when sugarcane is at the ripening stage, nymphs suck the sap, and in cases of severe infestation, retard the growth of sugarcane plants. In this study, we investigated the biology of the pest on different cultivars of sugarcane and under different temperatures. Also, we conducted experiments to determine the damage caused by the pest in the field. Mean pre-adult developmental times were 24.09, 28.06, 27.27 and 26.64 days on CP69-1062, CP57-1062, CP48-103 and NCO-310 cultivars, respectively, and only female progeny were produced. Mean longevity of females on the four cultivars was 6, 8.49, 4.15 and 4.60 days, respectively. Adult females laid an average of 61.80, 58.80, 41.10 and 39.38 eggs on the four cultivars, respectively. Results show that the optimum temperature for development of different stages of N. andropogonis is 30±1°C during the day and 25±1°C at night, and at this temperature, egg and nymphal duration (including first, second, third instars and pupae) and adult longevity were 6.2, 17.0 and 7.6 days, respectively. Females of cultivar CP69-1062 laid an average of 50.09 eggs. Analysis of data on the quality of damage (including Brix, pol and refined sugar factors) shows that damage was inversely and significantly correlated with the number of infested leaves. Whitefly damage differed among cultivars; and, based on the quality of damage, early maturing cultivars were more susceptible to whitefly damage. We collected two parasitoid wasps from nymphs—Encarsia inaron (Walker) (Hym.: Aphelinidae) and Eretmocerus delhiensis Mani (Hym.: Aphelinidae). To the best of our knowledge, this is the first study to assess the biology, damage and natural enemies of N. andropogonis on sugarcane in Iran.

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In this article, the biology and fertility life table parameters of the cabbage aphid, Brevicoryne brassicae (L.) (Hemiptera: Aphididae), were studied on cauliflower leaves, Brassica oleracea var. botrytis (Brassicales: Brassicaceae), of the cultivars Smilla, Snow mystique, White cloud, Buris, Galiblanka, Snow crown, SG, and Tokita. This study was conducted under controlled conditions: 25 ± 2°C, 65 ± 5% relative humidity (RH), and 16:8 (L:D) h photoperiods. Statistical analysis showed that there was a significant difference ( P  < 0.05) between the different growth stages and the mean number of laid nymphs. Further, the maximum and minimum growth periods were observed on Galiblanka and Buris cultivars, respectively. The shortest nymphal instar growth period was observed on the Smilla cultivar (6.70 d), and the longest lifespan was seen on the White cloud (8.10 d). The Smilla cultivar (39%), in an adult emergence stage, and the SG (88%) revealed the lowest and highest rates of survival, respectively. Aphids reared on the Smilla cultivar were found to have increased due to the high intrinsic ( rm ) and finite (λ) rate of increase and the low doubling time (DT). The results indicated that the application of cultivars affecting adult reproductive parameters could be a good solution to cabbage aphid control management.

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Two-spotted spider mite, Tetranychus urticae Koch, is one of the most important pests of agricultural products that have a global distribution. Now, the control is dependent on the use of chemical pesticides. The effects of the sublethal concentrations (LC 10 and LC 25 ) of the essential oil of Cinnamomum zeylanicum were evaluated on some parameters of the life table of the pest, at the constant temperature of 30°C, relative humidity of 40 ± 5% and photoperiod of 16L: 8D. Our results showed that the essential oil of cinnamon is effective on female adult stage. Lethal concentration at which 50% mortality (LC 50 ) for the essential oils is from C. zeylanicum on female adult mite was 23.39 μl/L air. Sublethal concentrations of the essential oil of C. zeylanicum also impair the natural biology of the mite. Concentrations of sublethal of essential oil decreased age-specific fertility (m x ) of T. urticae compared with the control. Sublethal concentrations (LC 10 and LC 25 ) have reduced the life expectancy (e x ) in egg stage. Sublethal effects of the essential oil of C. zeylanicum and its impact on T. urticae management are discussed.