Journal of Entomological Society of Iran
Year:2018 | Volume:38 | Issue:1 (73)|Papers Count:9

Today, with the advance statistical techniques and neural networks, predictive models of distribution were rapidly developed in ecology. Due to the difficulty of sampling, there are usually not enough samples in such studies. Therefore, in order to predict and mapping the distribution of Coccinella septempunctata used the combination of the Kriging method with multilevel perceptron neural networks (MLP) combined with genetic algorithm at the farm level. Population data of pest was obtained in 2014 by sampling in 221 fixed points in the alfalfa farm of Bajgah. The data was interpolated by ordinary Kriging method with spherical variogram, which had the best performance, and introduced as a neural network input. To evaluate the ability combined geostatistics with optimized artificial neural network by genetic to predict the distribution used statistical comparison parameters such as mean, variance, statistical distribution and between predicted values and actual values. Results indicating that there was non-significant difference between statistical parameters such as average, variance, statistical distribution and also coefficient of determination in the observed and the estimated Coccinella septempunctata density. Our map showed that pest distribution was patchy.

Potato tuber moth, Phthorimaea operculella Zeller, is one of the important pests of potato, causing damage on leaves, stem, and tubers. Type of fertilizer may affect the population of the pests feeding on the plant. In this study, the effect of some organic fertilizers including vermicompost, humic acid, a mixture of vermicompost and humic acid, and nanocomposites bio-organic was investigated on biological traits of potato tuber moth. The experiments were carried out on potato leaves, cv. Agria in a growth chamber. Results showed that nearly all the biological parameters of potato tuber moth were significantly affected by fertilization. The shortest larval period was in the control and the longest one was on humic acid and nanocomposites bio-organic. The longevity of the males ranged from 10. 21 to 18. 68 days and that of females varied from 12. 94 to 23. 20 days on different treatments. The females of the pest had the least total fecundity on humic acid. The intrinsic rate of natural increase (rm) of the potato tuber moth ranged from 0. 096 to 0. 119 day-1 on different treatments. Counting the number of trichomes of the leaves of different treatments showed that the highest density of trichomes was on humic acid. The results of this study showed that humic acid has better potential for decreasing the population of the pest and it can be used in the IPM programs.

The ladybird, Oenopia conglobata contaminata is one of the important predators of some aphids in Iranian orchards. Pomegranate green aphid, Aphis punicae Passerini (Hem.: Aphididae) is the most common pests of pomegranate trees, existing in all pomegranate orchards in Iran. In order to determin the suitable areas for release of O. conglobata, the factors of temperature, humidity, rainfall, height, and prey frequency were selected as the most important criteria. Analysis of the data was carried out based on the Analytic Hierarchy Process (AHP) and the spatial geostatistical database of GIS. The results indicated that, nearly 32% of the province's regions, including some parts of Taft, Abarkuh and Mehriz, were perfectly suitable for release. The possible reasons are the position of the orchatds between the highlands and the plains, causing intensify in pressure difference and createing air currents from the mountain to the plains and vice versa. Furthermore, nearly 59% of the province's areas, such as the major part of Ardakan, Bahabad and Bafgh, were determined as completely unsuitable for release. The reasons might be the high average temperature and the lack of adequate prey.

Foraging behavior of subterranean termites is strongly influenced by environmental conditions and is related directly to termite damages. The seasonal changes in foraging activity of subterranean termits can affect the efficacy of baiting method in a management program. The subterranean termite, Anacanthotermes vagans (Hagen) (Isoptera: Hodotermitidae)is an important urban pest with economic damage in central and southern regions of Iran. The objective of this study was to determine the effect of seasonal changes on foraging activity and wood consumption in Yazd over a two-year period (June 2013 to May 2015). Foraging variations were monitored according to three variables including active stations, foraging population and wood consumption. 85 monitoring and 15 feeding stations monthly inspected. The results showed that foraging activity of A. vagans, is completely seasonal and begins after a quarterly stop in March and was highest from July to August. Comparison of foraging activity pattern changes with mean of temperature fluctuations and monthly precipitation showed seasonal changes in foraging activity is directly related to temperature. In addition, it appears the sharp decline in winter temperature may reduce the population of colony.

Microcerotermes diversus Silvesteri is the most destructive termite pest among subterranean termites in tropical and subtropical regions, including Khuzestan province. In this research, effect subletral concentrations of fenoxycarb (500, 2500 and 5000 ppm) were studied on protein, lipid and carbohydrates contents in termite workers under laboratory conditions. The protein, lipid, sugar and glycogen were determined in milligram per gram of fresh weight. The concentration of 500 ppm had the greatest effect on energy sources with decreases in the amount of protein by 45. 51%, lipid 63. 34%, and energy content 59. 93% compared to the controls. Also amount of sugar 37. 20% and glycogen 17. 04 % increases compared to the controls. Reduction in the energy content due to fenoxycarb effect can reduce survivorship in the termite.

Mediterranian flour moth, Ephestia kuehniella, is a cosmopolitian pest of stored grain products, particularly flour. The development and reproduction of E. kuehniella, were investigated at two photoperiod (continuous darkness and 16L: 8D photoperiod) under laboratory condition (30± 0. 5 ° C and 50± 5 % RH). The result indicated that egg, larval and pupa development time at continuous darkness and 16L: 8D photoperiod were significantly differ. The photoperiod affected the emergence pattern and longevity of female and male. The mean number of eggs laid by E. kuehniella at continuous darkness and 16L: 8D photoperiod were 160. 54± 28. 67 and 163. 53± 32. 29 respectively but they were not significantly different. These data allow us a better insight into E. kuehniella population dynamics, and these finding can be used to optimize rearing system.

Some essential oils and plant extracts potentially possess insecticidial properties against Sweetpotato whitefly, Bemisia tabaci Gen.; however, the practical and commercial use of these compounds have not developed due to their volatility and instability. In this study, essential oils of Rosmarinus officinalis L., Mentha piperita L. and Eucalyptus globules L. and extract of Thymus vulgaris L., were formulated as micro and nano-emulsion, and their insecticide efficiency and oviposition inhibitory effects were tested under greenhouse conditions. First, bioassey tests were done using the leaf dipping method, on 2nd and 3rd nymphal instar and LC90 was estimated. Then, the oviposition inhibitory test with choice test method (by measuring the index of laying on plants), as well as eggs mortality rate, and all nymphal and pupa mortality rate at a concentration of LC90 were calculated, in comparison with herbal soap Palizin® distilled water and control (without any treatments). Nano-emulsion treatment containing all essential oils (2% of each ) at a concentration of LC90, had a high toxicity of 3. 1208 mg/l on 2nd and 3rd nymphal instar in comparison with other treatments. Also, this treatment with an average of 18. 2% had the lowest egg percentage per treated plant, indicating the highest oviposition inhibitory activity. Moreover, this treatment showed an average egg mortality of 25. 0%, while, in nymphal and pupal satge, average mortality of 51. 6% was recored. Micro-emulsion treatment containing essential oils and extracts (2% of each essential oils and 20% of extract) also exhibited acceptable effects (the above parameters were 3. 4617 mg/l, 23. 3%, 42. 3% and 74. 0% respectively). The efficacy of these two treatments was higher than herbal soap Palazin® and other treatments, thus these two treatments can be used in the Integrated Pest Management, after doing the complementary tests.

The influence of three host plants, cucumber, tomato and eggplant on functional response of Encarsia formosa was investigated at different densities of early fourth nymphal instar of Trialeurodes vaporariorum under laboratory conditions at 25 ± 1° C, 65 ± 5% RH and a photoperiod of 16: 8 (L: D) h. Whitefly nymphs were offered to the parasitoids in densities of 2, 4, 8, 16, 32, and 48 on leaf disks (8-10 cm2) in 12 replicates. After 24 hours, the parasitoids were removed and the number of parasitized as well as the killed nymphs by host feeding activity was recorded. Logistic regression results showed a type II functional response for both types of "parasitism" and "parasitism + host feeding" activities in all three host plants. There were no significant differences between attack rates (a) across three host plants, but the handling time (Th) estimated on tomato was significantly shorter than those estimated on cucumber. The attack rate of E. formosa in "parasitism" activity on cucumber, tomato and eggplant was 0. 2580± 0. 0963, 0. 3895± 0. 1331 and 0. 3283± 0. 1368 h-1 and handling time was 0. 6870± 0. 0810, 0. 3364± 0. 0399 and 0. 5584± 0. 0692 h, respectively. Based on the results, it seems that tomato is the most suitable plant for the parasitism and host feeding activities of E. formosa to control of the greenhouse whitefly T. vaporariorum in greenhouse conditions.

Mites of the family Pachylaelapidae Berlese, 1913 are a group of predatory mites with free-living species, feeding on arthropods and soil-inhabiting nematodes. Identification of these mites is difficult, because of morphological similarities in a significant number of species and also the fact that new taxons descriptors have referred to some morphological features that have not sufficient distinction criteria to differentiate them from close taxons. Therefore, the use of new identification methods can be helpful in this context. In the present study, along with identification, based on morphological characteristics and size (morphometric identification), we used a molecular method, based on the sequencing of the internal transcribed spacer (ITS) gene to identify two species Olopachys compositus Koroleva, 1976 and Olopachys caucasicus Koroleva, 1976. After DNA extraction, ITS region were amplified and sequenced, using the appropriate primers and afterward the sequences were recorded in GeneBank. Alignment of sequences was performed and the genetic differences between species was calculated as 2. 3 percent. As a result of these investigations, in addition to the separation of the two species O. compositus and O. caucasicus based on morphological differences, the molecular method also well confirmed the difference between these two species.