Journal of Entomological Society of Iran
Year:2018 | Volume:38 | Issue:3 (75)|Papers Count:8

Following sugarcane production extension in Khuzestan province, some pests appeared in sugarcane fields and sugarcane stem borers, Sesamia spp. were the most important among them. Development, reproduction and life table parameters of the parasitoid wasp, Telenomus busseolae Gahan on the sugarcane stem borer Sesamia cretica Lederer were studied at five constant temperatures (20, 25, 28, 30 and 35± 1° C, 60± 5% RH and a photoperiod of 16L: 8D h. ). The duration of pre-adult stage decreased with increasing temperature from 26. 67 days at 20° C to 10. 25 days at 35° C. The oviposition period was 4. 16, 4. 6, 4. 99, 4. 04 and 3. 31 days at 20, 25, 28, 30 and 35° C, respectively, with females laying an average of 56. 37, 65. 45, 98. 59, 57. 44 and 33. 86 eggs, respectively, at these five temperatures. Life table data were analyzed using an age-stage, two-sex life table method. The intrinsic rate of increase (r=0. 262 day-1), finite rate of increase (λ =1. 3 day-1) and net reproductive rate (R0=49. 28 offspring/individual) were greatest at 28° C. The shortest mean generation time (T=12. 17 day) was recorded at 35° C. The results of the current study indicated that temperature is one of the most important factors on life table parameters of T. busseolae. Also the optimum temperature for population growth of this parasitoid was 28° C, therefore this temperature suggests for mass rearing of T. busseolae.

This study aimed to predict population of Coccinella septempunctata in the field using artificial neural network. The data was collected from a four-hectare field in years of 2013-2014 in the area of Badjga Shiraz. In this model, the input variables were, longitude and latitude and population changes of Coccinella septempunctata was used as the outcome variable. The neural network type used, was Group Method of Data Handling (GMDH) that optimized by genetic algotithm. To evaluate the ability of GMDH neural networks to predict the spatial distribution of the species, statistical comparison of the parameters such as mean, variance, statistical distribution and coefficient determination of linear regression between predicted values and actual values was used. Results showed that in training and test phases of GMDH, there was no significant effect between variance, mean and statistical distribution of actual and predicted values, and the coefficient of determination of 0. 98 indicates the high accuracy of this neural network in predicting the density of this species. The drawn maps showed that the distribution of this natural enemy is patchy.

The tomato leaf miner moth Tuta absoluta Meyrick is an invasive pest of tomato which damages this crop economically in greenhouse and field conditions. Due to the endophytic feeding habits of larvae and the high fecundity, the resistant populations has developed. Based on the effect of chemical pesticides on the mating disruption efficacy, it is therefore possible to exploit novel approaches on the use of insecticides against this pest. In this study, the efficacy of 3 insecticides, imidaclopride, indoxacarb and NeemAzal, with different mode of action, in 4 concentrations (0, 1, 10, 100 μ g/ml) were assayed on Electroantennogram response of antennal receptors of 2-3 days old males to sex pheromone. The antennal responses rate to sex pheromone were measured during 6 time intervals, after insecticide spray and were calculated as inhibitory percentage in comparison to the response rate before spray and the data was analysis by repeated measure method. The results showed a significant difference between different concentrations of each insecticides compared to the control, the time of EAG assay and also the interaction effects of these factors, while, there was no significantly difference between tested pesticides. All insecticides were inhibited the antennal response in range of 18-20%. There was a dose-dependent relationship between concentration levels of each insecticides and the highest inhibition percentage was calculated in 100 μ g/ml. The results confirmed the inhibitory effect of the tested insecticides on the antennal receptors leading to disruption of their response to sex pheromone.

Management of the olive fruit fly using environmentally friendly methods includes strategies based on lure and kill and/or mass-trapping to reduce the damage to fruits. The purpose of this study was to evaluate the efficiency of some attractive materials to lure and capture olive fruit fly. Four trials and eight replications were conducted in an olive grove in Roudbar, Iran in 2016 and 2017. The treatments were: 1) yellow sticky trap, 2) yellow sticky trap + Pheromone, 3) Mcphail + Protein hydrolyzate, 4) Mcphail + Propylene vanilla based solution. Traps were visited weekly and the data were analyzed using SAS software. The results of the first year (2016) showed that treatment 4 with other treatments had a significant difference in terms of attracting male and female insects, and treatment 1 had the highest non-target insects attracted with an average of 38. 8 ± 25. 8. In the second year, treatment 2, total male and females and male insects captured were significantly different with other treatments, but non-target insects with an average of 68. 55 ± 7. 23 and treatment 1 with a mean of 77. 58± 9. 16 were at the same statistical level and treatment 4 with an average of 0. 96 ± 0. 27 had the highest incidence of female insects. Treatment 4 had the highest mean in attracting female insects and the lowest number of non-target insects in the two years of study. This trend was the same in two years of study in terms of mean number of insects captured per week in different treatments. As a whole, it had no adverse effects on the bio-diversity of olive groves and lowest price in comparison with other treatments. It can be concluded that this treatment along with pheromone traps can be used in monitoring and control of the pest.

Cell membranes are very sensitive to low temperatures and undergo changes and adaptations to prevent this damage. One of the most common changes is the increase in unsaturated to saturated fatty acids ratio of phospholipids, which leads to increase the fluidity of membranes at low temperatures. In this study, overwintering pupae of the large cabbage white, Pieris brassicae were collected during November 2014 to April 2015. To investigate the metabolic quiescent, changes in respiratory gases (O2 and CO2) and respiration rate (CO2/O2) were measured using GC. After extracting the whole body lipids, phospholipids were separated from other lipids by solid phase extraction (SPE) and then fatty acids and their changes were investigated using the GC. Respiration rate decreased about 30% from 0. 9 in November to 0. 6 in February and March, indicating that metabolism has reached to its lowest level during these period and insect has been in deep pupal diapause. Two 16-carbon and four 18-carbon fatty acids were identified in cell membranes. During winter, the highest decrease was observed in two saturated fatty acids C16: 0 and C18: 0 and the highest increase occurred in C16: 1. In general, unsaturated /saturated fatty acids ratio increased about 40 percent during the winter months. The results indicated that in spite of decreasing metabolism level in the whole body, in order to enhance the cold-hardiness, dynamic changes occurred in cell membranes, allowing insect to adapt successfully to winter hard conditions.

The Mediterranean pine engraver, Orthotomicus erosus (Wollaston) (Coleoptera: Curculionidae: Scolytinae), is one of the most important pests of pine trees in Kermanshah. Attack and feeding of this pest destroy the floem tissues under the bark of the infected trees and disrupt the plant sap flow, causing the death of infected trees. The purpose of this study was to predict and mapping the distribution of O. erosus using multi-layer perceptron neural networks combined with genetic and imperialist competitive algorithms in Kermanshah. The sampling of pine trees was done in 2015-2016 in Kermanshah. To evaluate the ability of the used neural networks to predict the distribution was used statistical comparison the parameters such as mean, variance and statistical distribution between actual and predicted values by multi-layer perceptron neural networks combined with genetic and imperialist competitive algorithms. Results showed that in training and test phases, was no significant differences between average, variance and statistical distribution of actual and predicted data that indicates the high accuracy and the ability of neural networks to map the distribution of this pest in Kermanshah. The R2 values revealed that imperialist competitive algorithm had a higher accuracy to estimate the density of O. erosus compared with the other two methods. In addition, the comparison of the coefficients of the R2 between different neural networks and geostatistics method showed that all three neural network models predicted the distribution pattern of O. erosus better than the geostatistics method. The maps drawn by all three neural networks showed that the distribution of this pest was cumulative. The results obtained from the geostatistics method represented the cumulative distribution of the pest.

In the present study, sublethal effects (LC10=21, LC20=52 and LC30=100 ppm) of Bifenazate (Floramite® 24% SC) on biological parameters of the most important phytophagous mite, Tetranychus urticae Koch, was evaluated under laboratory conditions. Data analysis was performed using Age-stage two sex life table theory. Our results revealed that immature development of treated deutonymphs of T. urticae was not significantly affected by sublethal treatments. Female longevity was affected by sublethal concentrations and the highest value for this period was recorded at control (23. 36 day). Furthermore, total fecundity was also negatively affected in female mites developed from treated deutonymphs and the lowest value was obtained at LC30 (27. 02 egg). We also present data supporting that the sublethal effects could carry over to the next generation. Accordingly, sublethal concentrations reduced the net reproductive rate (R0), and there were significant differences among the values of this parameter at all treatments tested when compared with control (control=57. 93, LC10=49. 17, LC20=41. 50 and LC30=32. 87 offspring/individual). The intrinsic (r) and finite (λ ) rates of increase were also significantly lower in mites treated with sublethal concentrations. The highest estimated values for r and λ were recorded at control (0. 208 and 1. 232 day-1, respectively). Finally, with the reduce rate of development observed for individuals treated with sublethal concentrations, the mean generation time (T) was significantly higher in individuals exposed to any concentration tested (control=19. 48, LC10=19. 80, LC20=20. 10and LC30=19. 45 day). Our data underline the importance of considering the role of sublethal effects when attempting to evaluate the total impacts of specific pesticide on an insect pest population and its progeny.

A larval parasitoid of alfalfa seed chalcid, Bruchophagus roddi (Gussakovskii) was collected during a survey on alfalfa seed chalcid from an alfalfa field in Zanjan, Iran in July 2017. This parasitoid is first recorded from Iran. It was identified as Baryscapus bruchophagi (Gahan) (Hym.: Eulophidae).