فصلنامه تحقیقات حشره شناسی
سال دوازدهم شماره 2 (پیاپی 46، تابستان 1399)

The Khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae), is a serious pest of cereal grains such as wheat. In the present research, the lethal and sublethal effects of essential oils (EOs) from Piper nigrum L. and Artemisia khorassanica Podl. were determined against 1st instar larvae of T. granarium. To study the sublethal effects, 1st instar larvae were exposed to the LC30 of each EO, and the life table parameters of the surviving insects were assessed. Artemisia khorassanica (LC50: 39.88 μl/liter air) had higher fumigant toxicity for T. granarium when compared to P. nigrum (LC50: 71.46 μl/liter air). Furthermore, the insecticidal effects of A. khorassanica (LT50: 13.51 h) were faster than P. nigrum (LT50: 15.75 h). Significant differences in the larval and pupal durations were observed in the EO treatments when compared to the control. In addition, the exposure to sublethal concentration of the EOs tested significantly reduced immature survival rate, adult longevity and fecundity. The net reproductive rate (R0), intrinsic rate of increase (r) and finite rate of increase (λ) was significantly affected by EOs tested being lowest in the insects exposed to A. khorassanica. According to our findings, both EOs tested, especially A. khorassanica, are useful for the effective control of T. granarium in warehouses.

The greenbug, Schizaphis graminum Rondani (Hemiptera: Aphididae) is one of the most important pests of wheat plants can restrict the production of this crop by sucking on the sap and transmistting pathogenic viruses. Detoxifying enzymes play a very important role in detoxifying chemical compounds in many living organisms. These enzymes exposed to chemical compounds are as biomarkers, and they have varying degrees of sensitivity to chemical compounds due to biochemical differences in pesticide detoxification. In the study, bioassays were examined by immersing wheat leaves in its insecticidal solution at a temperature of 27±2°C, a relative humidity of 65 ±10% and 16 hours light and 8 hours darkness photoperiod. The sublethal concentrations effect (LC10 and LC30) of thiachlopride and aforia has been evaluated on the life table parameters and the detoxifying enzymes activity of S. graminum. Esterase, glutathione S-transferase and acetylcholinesterase activity were measured as detoxifying enzymes. According to the obtained results, the lethal mean concentrations were calculated 212.7 and 203.9 mg (ai) L-1 for aphids exposed to thiacloprid and eforia, respectively. Among the treatments, LC30 concentration was the highest toxicity compared with other treatments. The LC30 concentration effects of both insecticides were significantly increased the induction of beta-esterase and glutathione S-transferase (GST) enzymes of S. graminum. Also, the activity of alpha-esterase and acetylcholinesterase did not significant different with increasing sublethal concentrations than control. The results showed that the sublethal concentrations of the two incecticides, thiacloprid and eforia, had a negative effect on the life tables parameters of S. graminum and they can be identified by detoxifying enzymes as biochemical markers.

Saw toothed grain beetle (Oryzaephilus surinamensis) is one of the serious and destructive foods pests.it is a polyphagous insect, which feeds from variety of products. Nowadays, using plant-based combination instead of artificial insecticides usage, especially in storage pests, has received much attention. In the present research,  the effects of repllency and Oviposition deterrence of extract (concentration:240,320,400,480,560 (µl/l air ) )and powder (mix of 2 grams powder with 2 grams of wheat seeds) leaves and flowers of Acroptilon repence and Sophora aculeopoides was evaluated on final instar larvae and adult insects . The experiments were done in a dark room with the temperature range of 30±5°C and 70-75% relative humidity. The output results indicate that the extract and powder of the studied plants are effective on the repllency and oviposition deterrence of saw toothed grain beetle, and the effects of the extract and powder of A.repence on the desired parameters are greater than the S. aculeopoides of the expression. The results showed that the percentage of repllency and oviposition deterrence in the extracts of both plants were increased with concentration-increment. Intense insects reacted more in comparison with larvae against extracts and powders. The information obtained from this study could be helped the storekeeper for storing the warehouse products in a long-term and controlling the damages of saw toothed grain beetle.

At present, the use of chemical pesticides is the main method of insect control. The use of nano-green technology in the production of new pesticides can be considered and used as a complementary method for pest control. Therefore, in the present study, silver nanoparticles (AgNPs) synthesized from Citrus sinensis orange peel extracts. The synthesized nanoparticles were characterized with UV- visible spectroscopy, X- ray Diffraction, and Transmission Electron Microscopy.The insecticidal effects of silver nanoparticles on Bird cherry-oat aphid, Rhopalusiphum padi L. were conducted under laboratory conditions in a completely randomized design with three replicates of each replication including 20 adult aphids with five concentrations (12.5, 25, 50, 100, 169 ppm) by Filter paper residue. The LC25, LC50 and LC90 of the green synthesized AgNPs against aphids were 8.11 ppm, 30.08 ppm and, 362.61 ppm, respectively. The effects of silver nanoparticles on the liver and kidney tissues of 32 mice were performed in four concentrations (0, 42, 48, 169 ppm) for three months by intraperitoneal injection. Histological examination of the liver and inflammatory cells, hyperaplasia of copper cells, digestion, and degeneration in the liver cells, and increased number of lymphocytes in the kidney tissue were observed. Also, SGOP, SGPT and ALK enzymes increased (p <0.05) in exposure to silver nanoparticles. In general, the results of this study indicate that the use of silver nanoparticles due to its widespread use has adverse environmental effects.

The aim of this study was to the economic assess of biological control  application approach in important date pests biological control. The model used in this research was Pemberton model. Based on the model findings and taking into account the net return on investment and total expenditure that carried out over a period of 18 years, the rate of returns on investment for biological control of spider mite the lesser, the and long horned beetle of date were 61.9, 29.4 and 16.8 respectively. The net profit to expense ratio for biological control of important pests was more than one, so that the bill of two pre-release periods (the first 9 years) and the post-release period (the second nine years) were estimated at 92.6, 35.2 and 22.5 trillion Rials were for Spider mite, the lesser moth and horned beetles, respectively. s. Economic factor is an important factor in the planning of biological control of date pests. According to the research results supporting biological pest control programs, and its successful implementation requires, knowledge managers, planners, investors and operators with economic benefits of investment in this area. From the perspective of economic experts is an important factor, according to the financial resources needed to support the elimination of pesticides to control pests biologically important dates assigned. The government can minimized the price risk of a date palm pest biological control agents by manufacturers guarantee to dates.

Family Anthocoridae, are as biological control agents in many agroecosystems. The seasonal abundance and distribution of Orius species were determined from different crops, trees, flowers and weeds in Fars province during 2016-2018. In this study Orius  albidipennis (Reuter), Orius laticollis discolor (Reuter), Orius laticollis laticollis (Reuter), Orius  horvathi (Reuter), Orius  minutus (Linnaeus), Orius vicinus (Ribaut), Orius  retamae Noualhier, Orius laevigatus inaequalis*Wagner, Orius laevigatus laevigatus (Fieber), Orius laevigatus maderensis* (Reuter), Orius niger aegyptiacus Wagner, Orius niger niger (Wolff), Orius  piceicollis* (Lindberg) were collected on different 63 host plants from 50 regions in Fars province. Among them the species and subspecies marked with * were new records for Iran. The Simpson diversity indices of Spring, Summer, Fall and Winter seasons were 3.954, 4.082, 3,793 and 1 respectively. Seasonal diversity of Orius spp. In Summer were significantly higher than other seasons. O. niger niger was found to be active throughout the year. The other species of Orius were collected in spring, summer and autumn, O. piceicollis, O. retamae and O. laevigatus inaequalis were only active in summer. O. niger niger and O. albidipennis were the most collected Anthocorid species. From results it is concluded that O. niger niger and O. albidipennis are well adapted to the geographical conditions and plant biodiversity in Fars province. Therefore, they could be considered as biological control agents in fields.

The present study was carried out under a complete randomised block design with 3 replications in one of the pastures of Chapar Quimeh village, under Gonbad-e-Kavous district. The pesticides used in this research are included, malathion 57% EC at the rate of 500 and 1000 cc per hactare, deltamethrin 2.5% EC at the rate of 200 and 500 cc per hactare and lambda cyhalothrin 23% EC at the rate of 100, 150 and 200 cc per hactare. The results showed that the highest reduction of pest population was obtained due to use of lambda cyhalothrin 200 and 150 cc per hactare and the least reduction by the application of malathion 500 cc per hactare. According to the highest reduction of Moroccan locust that was obtained in application of lambda cyhalothrin treatment it can be conluded that this pesticide is suggestible in Gonbad-e-Kavous district and malathion pesticide due to the least reduction of pest, is not suggestible in this region.