فصلنامه تحقیقات حشره شناسی
سال نهم شماره 2 (پیاپی 34، تابستان 1396)

The acute toxicity of the acaricides spirodiclofen and spiromesifen to eggs and adult females of the two-spotted spider mite, Tetranychus urticae Koch, was evaluated in laboratory at 27 ± 2°C temperature, 70 ± 5% relative humidity (RH), and 16/8 L/D photoperiodic conditions. The residual effects of these miticides on adult females were also assessed. In these assays, eggs and female mites were treated with five different concentrations of the two acaricides: spirodiclofen (0.21, 0.41, 0.83, 1.63, and 3.26 mg/L) and (0.79, 3.78, 18.11, 86.87, and 416 mg/L), spiromesifen (0.02, 0.06, 0.18, 0.53, and 1.56 mg/L) (0.39, 4.07, 10.10, 51.27, and 260 mg/L) for egg and female adult respectively. LC50 and LC90 of the chemicals were measured and the obtained data was analysed by probit analysis. The LC50 value of spirodiclofen against egg and adult of T.urticae were 0.86, 11.95 and for spiromesifen were 0.10, 5.95 ppm respectively. Also the effects of the two acaricide residues on mortality rate of female spider mites and its predatory mite, Neoseiulus californicus McGregor, were investigated at LC90 levelfollowing 0, 1, 3, 7, 10 and 14 days’ of treatment. at The results showed that the mortality of mites increased significantly with increasing acaricide concentrations. Generally, both acaricides, especially spiromesifen, proved to be highly toxic to eggs, moderately to adult females, and slightly to predatory female mites. After seven days of treatment, mortality in mites caused by spirodiclofen and spiromesifen were 86.6% and 70%, and after two weeks, were 46.6% and 51.6%, respectively. After two weeks of treatment, acaricides had gained efficient control against two-spotted spider mites and did not have a significant negative effect on the population of N. californicus. The results suggest that both spirodiclofen and spiromesifen could be successfully used for an IPM programme acco pany with the biological control agent, N. californicus.

The sugarbeet armyworm is one of the most important pests of sugar beet in Iran. However it is considered as a polyphagous pest. Owing to the inefficacy of most commonly used insecticides for the pest control, this study evaluated the sensitivity of two populations of the third instar larvae of Spodoptera exigua from two regions of Juibar and Gharakhil (north of Iran) to the insecticides Diazinon, Chloropyrifos, and Thiodicarb using enzymatic assessment. The results showed that the esterase activitiesof the third instar larvae of Juibar and Gharakhail colonies to thiodicarb was 0.196 and 0.302, for Chloropyrifos was 0.174 and 0.314 and for Diazinon was 0.099 and 0.285 μM /min/mg protein respectively. Based on the enzymatic activity, it can be reckoned that Spodoptera exigua from Juibar are more sensitive than those from Gharakhil. Enzymatic activity at various doses of pesticides showed significant differences between doses of the insecticides in the two populations. Increasing in dose of insecticides results decreases in esterase activities in Gharakhil and increase in population of Juibar. This indicates that the population of the beet armyworm in Gharakhil region is more resistant to the applied insecticides on population of Juibar.

The Cucurbits fly Dacus ciliates (Dip.,Tephritidae) is one of the most important pest on cucurbit crops in different parts of the Khuzestan province, Iran. Population dynamics of the pest was studied on three varieties (Spring cucumber, Armenian cucumber and Fall cucurbit) in Safi Abad agricultural and natural resource research and education center of Dezful, in spring and fall, in 2009. The number of adults caught in yellow sticky traps, the eggs and larvae of different ages were counted weekly in infected fruits. The results showed that there were three population peaks of immature stages in all varieties. The highest number of adults in Spring cucumber caught was 6.65 per trap in middle of Jun and in Armenian cucumber was 4.35 in the late of Jun and in Fall cucurbit was 9.5 adult per trap in the Oct. The Iwao, s Index and Taylor, power law were applied to evaluate spatial distribution of the egg and Immature stages. Results showed that Taylor, s power law gave a better fitness result for egg and Immature stages. The results of this research could be apply in integrated pest management of cucurbit fly.

Apis florea F. and Apis mellifera L. are two honey bee species in Iran. Distribution of Apis florea starts from Paveh in Kermanshah province (located in west of Iran) and ends to Sistan-Baluchestan province (located in south east of Iran). The current study was carried out by collecting 1400 worker bees from 14 different colonies located in southern regions of Iran. The samples were kept in sterile test tubes containing normal saline. The specific media were used to isolate Lactobacillus bacteria from digestive tracts of the bees. Biochemical tests and DNA extraction were done to identify the colonies. In addition, the colonies were characterized by sequencing 16S rRNA gene using specific primers (27F and 1492R). Since bacterial diversity in digestive tracts is of the approaches for classifying insects from phylogenetic point stand, sequencing was done on 43 colonies of bacteria. The results showed that eight isolates were related to three species (Lactobacillus kunkeei, Lactobacillus plantarum and Lactobacillus apis). Basis on the results, the dwarf honey bee in Iran phylogenetically clustered in five distinct clades in terms of bacterial diversity in digestive tracts. The clades were: 1): Roudan, Bandar-Abbas, Iranshahr 2) Jiroft, Kahnuj, Bushehr, Ahwaz, Dehloran 3) Gachsaran 4) Jahrom, Fasa, Behbahan and 5) Qeshm population. Furthermore, the results indicated that Lactic acid bacterias found in digestive tracts depends on nectar and pollen feeding by this wasp in the geographically different localities.

Mites are one of the largest and most diverse subclasses of Arachnida with a worldwide distribution. The order includes 456 families and more than 56000 species. In this study mesostigmatic soil mite fauna was studied as indicators of biodiversity in soil beneath 20 different plants selected from Eram botanical garden located in Shiraz (Fars province in Iran). Regular sampling of the selected soil areas performed as a year (between 2014-2015). A total of 4874 mite specimens of 50 species belonging to 32 genus from 19 families were collected. Species diversity was calculated using Simpson index of diversity and Shannon-Wiener index. The highest and lowest species diversity observed in Redhorse chestnut and Lavender in this investigation two speciments Sessiluncus n.sp. and Zercon n.sp. were new for the science.

Codling moth Cydia pomonella L. (Lep., Tortricidae) is the most important pest in iranian apple orchards. In order to avoid the unnecessary usage of chemical pesticides, using pheromone traps is the most effective control way. We have used these traps in 4 areas of different altitudes in Urmia villages. We counted the trapped insects twice a week. The results showed that this pest has three full generations in Urmia and their maiden appearance is in late April, with each generation peak in late May, mid-July and mid-August. The results show the best time to counter the pest is in the first generation, 5 to 7 days after flight peak and the 2nd and 3rd generations 4 to 5 days after flight peak.

Leopard moth, Zeuzera pyrina is a key pest of walnut in Iran. In this study, the efficiency of mating disruption by commercial product ZEUTEC was evaluated in East Azerbaijan and Ghazvin provinces. The study was conducted in 10 plots each with the area of one hectar mostly covered with walnut trees.Half of the plots were used as treatment applying ZUTEC and half for control (without any control method of leopard moth). In each treatment plots 300pheromon edispenser were attached on each tree and three pheromone traps were also installed in eah of all plots before emerging the adults at the beginning of the season. The number of larval entrance holes on 8 one-year-old branches of 15 trees, located at the center of each plot, was counted at the end of summer to assess the damage caused by the pest in experimental plots. The mean number of larva entrance holes on each branch were compared in different treatments by t- test. The pheromone traps did not capture any adult in the plots where mating disruption pheromone was performed during the experiment in both provinces while the traps caught the adults in the control plots. This result confirmed the efficiency of this product for mis-orientation of the males. The mean number of larval entrance holes on branches in plots with pheromone mating disruption and control were respectively 1.693±0.169, and 4.39±0.232 in Ghazvin province, and 0.174±0.037, and 1.696±0.134 in East Azarbaiejan province which were significantly different. (P

The sweet potato whitefly, Bemisia tabaci (Genn.) (Biotype A) (Hem: Aleyrodidae) is a major pest of field crops, vegetables and ornamental plants. In this research, the effect of several extraction methods (percolation, maceration, sonication, water bath and soxhlet) on mortality effect offine leaved fumitory, Fumaria parviflora on adults of Bemisia tabaci with leaf dip test were studied. Methanol 3% were used as negative control treatment respectively and tomato as host plant. The calculated LC50 value for above extraction methods were 54.78, 85.04, 85.18, 139.33 and 344.69 g/l respectively and dosage-response gradient was estimated 1.34 ±0.30, 1.08±0.28, 1.0 ± 0.26, 1.39±0.43 and 0.92±0.20 respectively. The results showed that percolation plant extract of F. parviflora had the highest mortality on adult of B. tabaci. It seems that the percolationmethod is the best method to extract chemical compounds to be used against the cotton whitefly. Using this extactct may be a useful strategy against the pest in Integrated Pest Management.