فهرست مطالب میرجلیل حجازی

 Integration of different pest control tactics is a principle in modern pest management. Interaction between different tactics and possible antagonism between them then will become important. A common integration is integration of egg parasitoid, Trichogramma spp. and larvicidal microbial agent, Bacillus thuringiensis against some field crop moth-pests, particularly in bollworm-cotton system. Although sequence of application allows avoiding direct antagonism, but indirect effects on the next generation of the parasitoid via treating the target pest’s larvae is not impossible. Some direct effect via overlapping of different stages of the pest is also possible. Therefore, studying possible maternal effects on parasitoids of the next generation that are developing on B.t.-treated host larvae is required. In this study, response of T. brassicae, was studied on two kinds of hosts; first bollworm, Helicoverpa armigera eggs laid by those females that treated by LC20 of B. thuringiensis in third instar. The second one control (untreated) individuals. Life history parameters were compared between the two groups by two-sided t-test. No significant difference was observed between the two groups. It means that B.t. had no undesirable effect on T. brassicae. The mean value of R0, rm and T were 41.22 ± 3.85 female/female/generation, 0.3545 ± 0.009 /d and 10.49 ± 0.19 d as average of the two treatments. Thus, B. t. is safe for integration with Trichogramma application programs.

Integration of different pest control tactics into a larger program is a principle in modern IPM. Interaction between different tactics and possible antagonism between them then will become important. A popular integration is integration of egg parasitoids, Trichogramma spp. and larvicidal microbial agent, Bacillus thuringiensis Berliner against some field crop moth-pests, particularly in bollworm-cotton system. Although sequence of application allow avoiding direct antagonism, but indirect effects on the next generation of the parasitoid via treating the target pest’s larvae is not impossible. Some direct effect via overlapping of different stages of the pest is also possible. Therefore, studying possible maternal effects on parasitoids of the next generation that are developing on B.t.-treated host larvae is required. In this study, response of Trichogramma brassicae Bezdenko, was studied on two kinds of hosts; first bollworm, Helicoverpa armigera Hubner eggs laid by those females that treated by LC20 of B. thuringiensis in third instar. The second one control (untreated) individuals. Life history parameters were compared between the two groups by two-sided t-test. Fortunately no significant difference was observed between the two groups. It means that B.t. had no undesirable effect on T. brassicae. The mean value of R0, rm and T were 41.22 ± 3.85 female/female/generation, 0.3545 ± 0.009 /d and 10.49 ± 0.19 d as average of the two treatments. Thus, B. t. is safe for integration into Trichogramma application programs.

Vegetable leaf miner,Liriomyza sativae Blanchard (Diptera: Agromyzidae), is one of the most economically important pests of agricultural products, including vegetables and ornamentals. The larvae feed on leaf mesophyll and reduce photosynthesis and yield. Identifying more effective insecticides and choosing the suitable treatment method can be very important in managing this pest. In this study, the insecticidal effect of chlorantraniliprole, spirotetramat, dimethoate and diazinon were investigated on 1 st instar larvae of L. sativae. The study was conducted under greenhouse condition at 26 ± 2°C, 60 ± 10% RH and 16: 8 (L: D) h photoperiod. Preliminary experiments were performed to compare the insecticidal effects of leaf and root treatment of each insecticide. Leaf treatment was performed using leaf dipping method and soil treatment carried out by adding a certain amount of insecticide solution into the soil of each pot. Lethal concentrations were estimated for the treatments which caused higher mortality of the larvae. The results showed that only soil treatment of dimethoate (LC50: 53.73 mg ai L-1) was more effective than its leaf treatment (LC50: 162.91 mg ai L-1). The LC50 values for leaf treatment of chlorantraniliprole, spirotetramat and diazinon were 0.24, 6.11 and 53.72 mg ai L-1, respectively. Considering the results of the bioassays, treatment of plant leaves by chlorantraniliprole and spirotetramat, and treatment of plant soil by dimethoate are proposed as effective insecticides and suitable treatments to control this pest.

Compatibility of Beauveria bassiana (Balsamo) with hexaflumuron, chromafenozide, chlorfluazuron, phosalone, garlic extract and pepper extract was studied at the laboratory condition. In details, 75, 150, 300 and 500 µl of the insecticides and extracts were incorporated into 100 ml of liquefied potato dextrose agar (PDA) culture medium. Seven, 15, 17 and 19 days after treatment, diameter of the colonies was measured and compared in the treatments and control. In the second part of the study, the effects of B. bassiana, chromafenozide, chlorfluazuron, phosalone, garlic extract, pepper extract, hexaflumuron, azadirachtin and B. bassiana + garlic extract, were determined on alfalfa leaf weevil Hypera postica (Gyllenhal), pea aphid Acyrthosiphon pisum Harrisand the two species of coccinellids including Hyppodamia variegata (Goeze) and Coccinella undecimpunctata L. under field conditions. Experiments were conducted using randomized complete block design with four replicates. A sampling was conducted a day before treatments and three samplings were conducted 1, 3 and 7 days after treatments. The Efficacy of treatments was calculated using Henderson-Tilton's formula. The results indicated that garlic and pepper extracts were compatible with B. bassiana and those can be used simultaneously in pest management programs. Three days after treatment, efficiency of garlic and pepper extracts, hexaflumuron and B. bassiana + garlic extract was significantly higher on young larvae of H. postica than other treatments and those can be considered in this pest management programs. Chromafenozide, azadirachtin and hexaflumuron had > 50% efficiency on pea aphid population. Among these insecticides, hexaflumuron may be recommended for pea aphid control due to its relatively low effects on the lady beetles.

Use of pesticides as an important part of integrated pest management programs has principal role in control of tomato leafminer, Tuta absoluta (Meyrick). Therefore, evaluating the efficacy of insecticides and introducing new effective compounds are important for management of this pest. Eggs and 2nd instar larvae of tomato leafminer are the main stages exposed to insecticide sprayings. This study was conducted to determine the susceptibility of eggs and 2nd instar larvae of T. absoluta to five insecticides. LC50 values obtained for spinosad, chlorantraniliprole, indoxacarb, abamectin, and zeta-cypermethrin for 2nd instar larvae were 0.08, 0.09, 10.8, 0.29 and 232.2 mg ai/L respectively. The eggs were treated with LC50s of these insecticides for 2nd instar larvae to assess their ovi-larvicidal effects. Mortality of the egg/neonates in chlorantraniliprole, spinosad, indoxacarb, abamectin, zeta-cypermethrin treatments and control were 88.8, 76.8, 58.1, 35, 50.5 and 14.6 %, respectively. The results revealed that spinosadand chlorantraniliprole had strong ovicidal and larvicidal activities; and if perform equally well in large scale greenhouse and field conditions, they may be considered in T. absoluta management programs.

Cotton bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) is one of the important pests of agricultural products in the world, including Iran. In this study, the sublethal effects of Bacillus thuringiensis Berliner subsp. kurstaki (Bacillales: Bacillaceae) were evaluated on third instar larva of H. armigera under laboratory conditions 26±1 °C, 65±10% RH and 16:8 (L:D) photoperiod. The LC20 value of B. thuringiensis on 3rd instar larva of H. armigera was 9.8 × 105 IU/L. The mean female longevity and fecundity in control and Bt-treatment were 16.63 ± 1.05 and 13.88 ± 1.05 days and 1336.83 ± 147.68 and 1029 ± 147.68 eggs respectively that in both cases, there was a significant difference. In control and Bt-treatment, the net reproductive rate (R0) were 582.22 ± 51.89 and 126.38 ± 27.78 f/f/g, the intrinsic rate of natural increase (rm) were 0.1442 ± 0.002 and 0.1082 ± 0.004 f/f/d, the finite rate of increase (λ) were 1.155 ± 0.003 and 1.114 ± 0.004 f/f/d, the mean generation time (T) were 44.16 ± 0.62 and 44.73 ± 0.62 d and the doubling time (DT) were 4.80 ± 0.08 and 6.41 ± 021 d respectively. Except the mean generation time (T), other population parameters of H. armigera showed a significant difference between control and Bttreatment. The results indicated that the B. thuringiensis have high potential to reduce the cotton bollworm population and can be recommended for reducing the use of pesticides in the areas where the pest is present.

Trissolcus djadetshkoe (Hym.: Scelionidae) is an inferior egg parasitoid of sunn pest Eurygaster integriceps Puton (Hem.: Scutelleridae) in Iran wheat fields. This is reason that why this species is less considered in biological control as well as research programs. However a parasitoid with a minor effect is not necessarily an unimportant species. Although this species is an eligible mortality factor in many parts of Iran, it is the second abundant species of northwest of Iran. Its efficacy was studied in terms of life history parameters in laboratory (26±1 ºC, 50±10% RH, and 16: 8 h photoperiod). The sex ratio, net replacement rate and intrinsic rate of increase were 0.57±.03, 39.8±2.9 and 0.212±0.004 respectively. Efficacy of this species was compared to other egg parasitoids of the sunn pest.

Colorado potato beetle is one of the most important insect pests of potato plants. Frequently and prolonged use of chemical pesticides for controlling this pest, has caused environmental pollution, pest resistance to pesticides and destruction of natural enemies. Some herbal extracts are more degradable and relatively safer than most of the synthetic insecticides and can be used as suitable alternatives in integrated management of Colorado potato beetle. In this study, the effects of leaf extracts of Juglans regia, Sambucus ebulus, Artemisia annua, Satureja sahendica and Salvia sahendica were studied on 2nd instar larvae of Colorado potato beetle, Leptinotarsa decemlineata in laboratory conditions at 26 ± 2 °C, 55±5% RH and a photoperiod of 16:8 (L:D). Potato leaves were treated with 0.625, 1.25, 2.5, 5 and 10% concentrations of the plant extracts using leaf- dipping method. Control leaves were dipped in either methanol or distilled water only. Each treatment consisted of 20 up to 24 h old 2nd instar larvae and had three replicates. Mortality of the larvae was recorded 24, 48, 72 and 96 hours after treatment. The results showed that extracts of Juglans regia, Satureja sahendica and Artemisia annua were more toxic to 2nd instar larvae of the Colorado beetle than Salvia sahendica and Sambucus ebulus. Ninety six hours after treatment, 10% concentration of J. regia, S. sahendica and A. annua caused 93.33, 91.67 and 73.33% mortality and 5% concentration of these extracts caused 58.9, 100 and 48.2% mortality in Colorado potato beetle larvae, respectively. As expected, the mortality decreased with decreasing concentrations. According to the high mortality percent, especially in high concentrations, the extracts of these plants, can be used as potential botanicals for integrated management of Colorado potato beetle.

Trissolcus djadetshkoe Rjachowsky (Hym.: Scelionidae) is an egg parasitoid of sunn pest Eurygaster integriceps Puton (Hem.: Scutelleridae) in Iran. Searching efficiency of this species was determined in a functional response context. Effect of female insemination as well as parasitism experience was also investigated. Host densities of 2, 4, 7, 14, 28 and 56 eggs were offered to a single female in 20, 20, 15, 15, 10 and 10 replications in a 24 h experiment in 1.5×10 cm vials. Virgin vs. inseminated females as well as inexperienced vs. experienced ones were used in two sets of experiments. All experiments were conducted in a growth chamber (26±1 ºC, 50±10% RH, 16: 8 h photoperiod). Logistic regression and nonlinear regression model of random search were used for analysis. All parasitoid responses were type III. Experienced females showed lower parasitism in all densities. Maximum attack rate estimates were 14 in experienced females vs. 34 in inexperienced ones. It seems that previous reproductive efforts have depleted energy of the females. A lighter difference was observed in virgin females over inseminated ones (25 vs. 17). This difference probably concerns with costs of sex allocation for inseminated mothers.

In this study, lethal effects of indoxacarb and methoxyfenozide were assessed on Colorado potato beetle. To do the bioassays, potato leaflets were dipped in aqueous suspensions of the insecticides and the larvae were transferred on the leaflets after drying. The results were recorded 24 and 72h after treatment for indoxacarb and methoxyfenozide, respectively. LC50 of methoxyfenozide for the 1st instars was 80.6 mg ai/l and LC50 values for indoxacarb were 4.5, 6.85, 9.42 and 7.28 mg ai/l for 1st, 2nd, 3rd and 4th instars, respectively. LC50 value of methoxyfenozide for 1st instar was relatively high; therefore lethal concenteration was not estimated for next instars. Because of the importance of sublethal effects in insect growth regulators (IGRs) application, the sublethal effects were evaluated for methoxyfenozide by using its LC1 and LC7. First instars were fed on treated leaves for 48 or 96h and then on untreated leaves; and were monitored until adult stage. Fecundity of these adults was evaluated. The number of larvae developed to prepupae and adults was significantly lower in sublethal concentrations of methoxyfenozide compared with control. The treated larvae did not reach next generation. The results indicated that indoxacarb and methoxyfenozide were effective against Colorado potato beetle; and if they perform equally well in the field, they can be suitable candidates for management of this important pest.

Beet armyworm، Spodoptera exigua (Hübner) is an important pest of field crops with a wide range of host plants. Using safer insecticides with different modes of action and lower possibility of development of resistance such as insect growth regulators (IGRs) would be useful for effective control of this pest. In this study، effects of three IGRs namely methoxyfenozide، lufenuron and flufenoxuron were assessed on 1st instar larvae of S. exigua. To investigate the effect of insecticides، bioassays were performed using diet incorporation and leaf dipping methods. Mortalities were recorded 144 h after treatment. The LC50 values obtained for methoxyfenozide، flufenoxuron and lufenuron were 0. 154، 0. 254 and 2. 398 mg ai/l، in diet incorporation method; and 1. 302، 0. 427and 3. 510 mg ai/l in leaf dipping method، respectively. Comparison of the LC50 values for the insecticides revealed that the LC50 values for the treated insecticides were significantly different in both bioassay methods. The results indicated that in both bioassay methods، lufenuron had the lowest toxicity against the 1st instars of beet armyworm. It was revealed that all insecticides tested were effective against 1st instars of beet armyworm at low concentrations. If similar results are obtained in field conditions، due to fewer unwanted effects of these insecticides، they can be considered in beet armyworm control programs.

Green lacewing، Chrysoperla carnea (Stephens)، is an important predator of arthropod pests such as aphids، psyllids، thrips and whiteflies. Toxicity of endosulfan، imidacloprid and indoxacarb was assessed on male and female C. carnea in the laboratory. Contact bioassays were carried out in glass Petri dishes. The LC50 values for indoxacarb، imidacloprid and endosulfan were 0. 011، 0. 053، and 0. 343 g AI/L for males، and 0. 019، 0. 098 and 0. 398 g AI/L for females، respectively. Males were more sensitive than females to all three insecticides. To assess the sublethal effects، using IOBC (International Organization for Biological Control) method، adults were treated with LC25 of each insecticide. Analysis of variance did not show significant differences among treatments regarding the developmental time of the first، second and third instars، pupae and sex ratio. Differences between treatments and control were significant regarding pre-oviposition، oviposition and post-oviposition periods، fecundity، fertility، longevity of male and female. Mean longevity for control، imidacloprid، endosulfan and indoxacarb were 30 ± 2. 3، 24. 3 ± 3. 3، 21. 3 ± 2. 4 and 19. 7 ± 1. 4 days for males، and 36. 9 ± 2. 5، 31. 8 ± 2. 9، 27. 7 ± 1. 7 and 26. 7 ± 2. 6 days for females، respectively. The highest and the lowest rates of fecundity were 540 ± 49 and 206 ± 42 in control and indoxacarb، respectively. Based on the IOBC classification method، imidacloprid، endosulfan and indoxacarb were slightly harmful (%30 < Total Effect Index < %79) against adults. The adult stage was very sensitive to indoxacarb، imidacloprid and endosulfan. Hence، these insecticides should not be applied when the density of adults is high in the field.

Colorado potato beetle, Leptinotarsa decemlineata is one of the major insect pests of potato. Toxicity of spinosad, as a bio-rational insecticide, was investigated against various developmental stages of this pest. Bioassays were conducted by using the eggs, neonates, first, second, third and fourth instar larvae and adults. The potato leaves were impregnated with different concentrations of spinosad and applied for the adults and different larvae bioassays. The eggs were tested through dipping its masses into the insecticide solutions. LC50 values of neonates, first, second, third and fourth instar larvae and unsexed adults after 24 hours were 2.06, 3.19, 4.75, 6.46, 20.24 and 11.97 ppm (of commercial formulation), respectively. Results show that spinosad did not possess any ovicidal effects and the fourth instar larvae and neonates were the most tolerate and the most susceptible stages, respectively. Susceptibility of the neonates (up to 24 hrs after hatching) was significantly higher than first instar larvae (24-48 hrs after hatching). Developmental stages of Colorado potato beetle differentially responded to this insecticide. Since the control of L. decemlineata mostly relies on early season measures against the most susceptible stage(s), by considering no ovicidal effect, our results propose a limited interval, for avoiding the high tolerant larvae.

The cotton bollworm (CBW)، Helicoverpa armigera (Hübner) is a major pest of cotton in Iran. Nowadays، integrated control of CBW is done using Bacillus thuringiensis Berliner and Trichogramma or Habrobracon. To determine indirect effects of the bacteria on Habrobracon hebetor (Say)، its life table in two treatments of cotton bollworm، one a control (larvae fed by normal artificial diet without Bt) and the other Bt treated (the 3rd instar larvae of CBW that fed by artificial diet involving LC20 concentration of B. thuringiensis) at 26±1 ˚C، 65±5% RH and 16:8 (light: darkness) was studied. Intrinsic rate of increase (rm)، finite rate of increase (λ)، net reproductive rate (R0)، mean generation time (T)، doubling time (DT) for control and Bt treatment were evaluated as 0. 2051±0. 017، 0. 1644±0. 017 d-1، 1. 227±0. 021،1. 178±0. 021 d-1، 61. 863±17. 60، 28. 32±6. 81 per generation، 20. 10±0. 70، 20. 33±0. 70 d، 3. 37±0. 15، 4. 21±0. 36 d، respectively. The life expectancy of H. hebetor at the beginning of the cohort life was 25. 5 and 16. 83 d in control and Bt treatment، respectively. The results suggested that B. thuringiensis has an inverse effect on biological parameters of H. hebetor and caused a decrease in parasitism as well as intrinsic rate of increase.

In this research, adult lacewings were reared in the greenhouse on an artificial diet. The larvae were fed by the eggs of Mediterranean flour moth. Sub-lethal effects of endosulfan, imidacloprid and indoxacarb were assessed using demographic toxicology method on adult lacewings at concentrations of 317, 46 and 9 mg AI/lit (as LC25), respectively. Most of the biological parameters of the lacewing, except mean age of fecundity and gross hatch rate, were significantly affected by the insecticides. The gross fecundity rate in control, imidacloprid, endosulfan and indoxacarb-treated insects were 618, 492, 313 and 279 eggs per female; indicated that the parameter was reduced significantly by imidacloprid and endosulfan treatments compared to the control. The stable population parameters were affected by the treatments. The intrinsic rates of increase (rm) values were 0.179, 0.161, 0.157 and 0.136 female offspring per female per day in control, imidacloprid, endosulfan and indoxacarb-treated cohorts, respectively. In general, the sublethal toxicity ranking of the treatments was as follows: imidacloprid< endosulfan < indoxacarb. We concluded that the adult lacewing was sensitive to endosulfan and indoxacarb.

Sunn pest is considered as the most important insect pest of wheat and barley in Iran. Different studies have shown that various biotic and abiotic factors affect sunn pest populations. These factors can influence the population density of the pest which in turn can play a role in the control of the pest. In this study the relationship between sunn pest population fluctuations and climatic conditions, the area under wheat and barley cultivation as well as the area under chemical control was investigated. In addition, the possible influence of overwintering adults’ weight and environmental factors on sunn pest mortality in the overwintering sites was studied. Field data were collected from six infested counties of East Azarbaijan province, including Tabriz, Bostanabad, Sarab, Mianeh, Heris and Hashtrood during three study years. From the variables under study, only mean weights of the overwintering insects, altitude, mean monthly minimum relative humidity, as well as rainfall during the months of December, January, February and March indicated significant relationships with sunn pest mortality in the overwintering sites. The relationship between the area under wheat and barley cultivation and sunn pest population changes was not significant but there was a close relationship observed between the area under chemical control and sunn pest population fluctuations. Similar studies in other regions with long history of sunn pest outbreaks will produce valuable information that can be helpful in predicting sunn pest outbreaks.

The common green lacewing is a known biocontrol agent because of its wide geographical distribution, high compatibility with different agricultural systems, high searching ability and ease of rearing. Adults and larvae were reared on artificial diet and eggs of Anagasta kuehniella (Zell.) respectively. The toxicity of insecticides was assessed on eggs (dipping method), third-instar larvae (contact method), and pupae (topical application) of Chrysoperla carnea Stephens. In order to study the sublethal effects, the third-instar larvae were treated with recommended field rate of each insecticide. The effects of the insecticides were assessed using demographic toxicology methods. Rearing conditions were 26 ± 2ºC, 60 ± 10% relative humidity and a photoperiod of 16: 8 h (L: D). The results revealed that the insecticides did not affect eggs even at doses higher than recommended field rates. The LD50 values, of endosulfan, imidacloprid and indoxacarb for pupal stage were estimated to be 144, 33, and 21 µg ai/insect respectively. Since the insecticides did not affect the third-instar larvae at the recommended field rate, the LC50 was not estimated for this stage. The results showed that, only net reproduction rate (R0) was significantly affected by treatments. The highest and lowest amounts of rm were 0.176 and 0.152 for control and indoxacarb treatmnets respectively. Based on both acute toxicity and demographic toxicology methods, the rate of toxicity of the tested insecticides was as follows: indoxacarb > endosulfan > imidacloprid.

Cotton bollworm, Helicoverpa armigera (Hübner) is a polyphagous pest which attacks a wide variety of agricultural crops. Habrobracon hebetor Say is one of the most important natural enemies of H. armigera in Iran. Adults of H. hebetor were obtained from insectary of Plant Protection Bureau of Bilehsavar in Ardabil Province and reared on Anagasta kuehniella larvae in laboratory. Rearing condition was 6 ± ˚C, 70 ± 5 % RH, and photoperiod of 6: 8 hours (L: D). The effect of field recommended doses of Hexaflumuron, Profenofos, Spinosad and Thiodicarb were assessed on immature stages and the adult emergence of H. hebetor. Profenofos, Spinosad and Thiodicarb caused 7.6, 9, and 9.5 % reduction in adult emergence, respectively, and were classified as moderately harmful pesticides based on International Organization of Biological Control (IOBC) pesticide classification method. Hexaflumuron with 9.87 % reduction in adult emergence in spray method was classified as harmless.