PLANT PEST RESEARCH
Year:2016 | Volume:6 | Issue:1|Papers Count:7

The Tomato leaf miner is a polyvoltine pest native to South America and is a universal threat to tomato. This pest was first reported from Orumieh but nowadays it has been reported from all tomato fields of Iran. In order to control this pest, various pesticides including organophosphorous and pyrithroid insecticides are used continuously which caused the insect to develop resistance, contamination of products to pesticides residue and contamination of the environment. Thus, the aim of the current study was to study the effect of semi-purified proteinaceous extract of triticale seeds on α-amylase activity of the insect. Seed proteinaceous extract was obtained by NaCl solution and it was semi-purified using ammonium sulfate. Enzyme assay indicated that the insect amylase inhibition is dependant to the extract dose which is used i.e. with increasing inhibitor dose the amount of enzyme inhibition increased. For example, when 0.5 μg seed extract protein was used only 31% enzyme inhibition was achieved and when 8.0 μg seed extract protein was used 66% enzyme inhibition was obtained. In monitoring pH it was found that the highest inhibition was obtained at pH 8.0 and beyond this pH the amount of enzyme inhibition reduced. Gel assay confirmed our enzyme assay results which were done by Elisa reader instrument i.e. with increasing inhibitor concentration amylase band intensity decreased.

Mediterranean flour moth (MFM), Ephestia kuehniella Zeller, is considered as one of the most commonly used host for parasitoids mass rearing including Habrobracon hebetor (Say) (Hym.: Braconidae) and Trichogramma brassicae Bezdenko (Hym.: Trichogrammatidae). In this research, eight different diets with novel ingredients were applied in laboratory conditions (25±1oC, 60±5% RH and 14L: 10D) for mass rearing of the MFM. The results showed that the kind of diets had effect on development and reproduction of the MFM. The highest mean number of emerged adults, weight of 10 adults, weight of 100 eggs along with the shortest developmental time (from egg to adult emergence) of MFM, without any significant difference, were related to four diets including A: wheat flour, wheat bran, barley flour, yeast and glycerin, B: wheat flour, wheat bran, barley flour, yeast bread and glycerin (ratios: 41.5: 2: 43.5 : 3: 10%, respectively), C: wheat flour, wheat bran, yeast bread and glycerin (ratios: 82: 3: 10: 5%, respectively), D: wheat flour, corn flour and barley flour (with equal ratios: 33: 33: 33%). In contrast, the mean number and weight of emerged adults were significantly lower in the rest of diets. The longest developmental time (from egg to adult emergence) and highest immature mean mortality were occurred for diet G containing corn flour and diet F containing wheat flour, respectively. Therefore, the diets A, B, C, and D were proposed as the most appropriate media for mass rearing of the MFM, E. kuehniella.

The predatory bug, Andrallus spinidens Fabricius (Hemiptera: Pentatomidae), is a potential biological control agent of lepidopterous larvae in the rice fields of Iran. In the present research, the sublethal effects of the entopmopathogenic fungus, Beauveria bassiana were studied on the cellular energy allocation (CEA) of this predator. Conidia suspensions were prepared in five concentrations of 104, 105, 106,107 and 108 conidia ml-1. Fifth-instar nymphs of A. spinidens were immersed in fungal suspensions for 10 seconds. After bioassay and data analysis, the effect of LC30 of B. bassiana were investigated at 25±2 °C, 60%±10% relative humidity and a photoperiod of 16:8 h (L: D). The amounts of available energy (including carbohydrate, glycogen, lipid and protein), energy consumption and cellular energy allocation were estimated. No significant difference was observed in the amounts of available and consumption energies in the treated insects (68.53±0.028 and 6.10±0.01 j/insect, respectively) compared with control (79.61±0.03 and 6.63±0.01 j/insect, respectively). Estimation of cellular energy allocation showed that treated bugs had a lower amount of energy (11.22±0.75 j/insect) compared with control (12±0.37 j/insect), but difference did not cause statistically significant. According to the present study, the sublethal concentration of B. bassiana (3×105 conidia ml-1) was not caused any significant effect on the biochemical parameters of A. spinidens.

One of the most important aphids on pomegranate trees is pomegranate aphid, Aphis punicae (Hem.: Aphididae). To determine the effect of temperature on biological characters of A. punicae, its fertility life table was studied by leaf cages on pomegranate leaves in four temperatures (19, 22, 25 and 27oC). Also effect of pomegranate cultivars on seasonal fluctuations and life table parameters of A. punicae were investigated by weekly sampling from infested trees of ten cultivars in natural conditions and by using leaf cages on leaves of three cultivars (Shishepag, Robab, Shahreza) in greenhouse, respectively. Results showed that the estimated intrinsic rate of increase was significantly different between four temperatures and its highest value found in 27°C. Also, field results indicated that aphid density was significantly different between tested cultivars and the highest and lowest aphid densities were observed in Robab Shiraz and Rodbar cultivars, respectively. Based on estimated parameters of the fertility life table, the highest intrinsic rate of increase and finite rate of increase and also the lowest mean nymphal development time and mean generation time were occurred on Shishe-pag cultivar followed by Robab cultivar that indicated these cultivars are more suitable for development and population growth of pomegranate aphid.

Greenbug Schizaphis graminum Rondani is one of the most important pests of grain, especially wheat, which plays an important role to transfer some of plant pathogenic viruses. In this research, the biological parameters of S. graminum on wheat cultivar (Roshan) and Lines (R1-3 and R2-23) were studied at 25±1oC, 60±5% RH and a photoperiod of 16: 8h (L: D) in a growth chamber. No significant difference in mean generation time (T) of wheat aphid was observed on cultivar and lines studied; while other population growth parameters showed significant differences among three treatments. The intrinsic rate of increase (r), finite rate of increase (λ) and Net reproductive rate (R0) were 0.352 day-1, 1.422 day-1 and 41.24 female offspring on R2-23 line; 0.288 day-1, 1.334 day-1 and 22.20 female offspring on R1-3 line and 0.294 day-1, 1.342 day-1 and 27.5 female offspring on Roshan cultivar, respectively. Based on population growth parameters, it can be concluded that Roshan cultivar and R1-3 line compared with R2-23 line have Lower susceptibility to S. graminum.

This research was carried out during 2011 and 2012 in a randomized complete block design (RCBD) with 4 trade formulations of protein hydrolyzates (1-Agriscence, 2- Bio-Cebo, 3- Cera-Trap liquid, 4- Esmelfol) in 3 replicates in a pomegranate orchard in Shiraz city. Traps were checked weekly and the numbers of captured Mediterranean fruit fly (med fly) and non-target insects were recorded. Data were analyzed and treatments means compared with Duncan multiple range test. Results revealed significantly differences among treatments at probability level of one percent in all evaluated factors. Averages weekly captured of med fly in treatments were 3.75, 3.80, 9.77, and 2.48 flies, respectively. Average weekly captured of non - target insects in treatments were 18.80, 43.38, 56.23, and 56.93 insects, respectively. Traps baited with Agrisence had the maximum captured of Chrysopa sp. (40.86 numbers) and showed significant differences with other treatments. The maximum captured moths were observed in traps baited with Bio- Cebo (6.07 numbers) and Agrisence (5.41 numbers). In conclusion, Cera-trap is recommended as the best treatment for mass trapping of med fly in pomegranate orchards in Shiraz region.

In this study the effect of different temperatures on functional response and prey consumption of predatory mite, Phytoseius plumifer fed on adult stages of Rhyncaphytoptus ficifoliae was determined. Four constant temperatures (15, 20, 25 and 30 ± 1oC) and six prey densities (2, 4, 8, 16, 32 and 64 individuals) were used during a 24-h period in functional response experiments. Also the effect of six constant temperatures (15, 20, 25, 30, 35 and 37 ± 1oC) on prey consumption of P. plumifer on adult stages of R. ficifoliae was determined. Using the logistic regression, the type II functional response was determined for P. plumifer adult female at all tested temperatures. The type II Rogers' model was used to estimate the values of the searching efficiency (a) and handling time (Th). The maximum and minimum searching efficiency of P. plumifer were 0.101 h-1 at 25oC and 0.030 h-1 at 15ºC, respectively. The handling time decreased with increasing temperature from 15 to 25oC and the minimum value of Th was observed at 25°C (0.53 h), with increasing temperature to 30°C, handling time increased again (0.74 h). The minimum and maximum daily prey consumption of whole immature stages of P. plumifer were observed at 15ºC (12.15±0.06) and 25ºC (31.60±0.93), respectively. The maximum value of the total consumed prey by adult female of P. plumifer on adult stages of prey was 1049.9±15.5 that observed at 25ºC. The finding of this study showed that the different stages of P. plumifer fed on adult stages of R. ficifoliae and it can be considered as an appropriate biological agent in control of this pest.