فهرست مطالب ولی الله بنی عامری

The greenhouse whitefly, Trialeurodes vaporariorum, is an important pest of greenhouse plants. To prevent the problems of using chemical pesticides in the greenhouse environment, it is necessary to use non-chemical methods. This study was carried out to evaluate efficiency of different colors and to determine the best light wavelength of sticky trap on tomato plants in greenhouse, during 2019–2020. Four experiments were carried out in a completely randomized design with 6 replications to evaluate the efficiency color of the sticky trap on attraction T. vaporariorum, throughout comparison between six colors (yellow, orange, green, blue, red, and white), and to evaluation efficiency height of the sticky trap on attraction, through comparison between three heights (30, 80, and 160 cm above the ground). Finally, the daily mean of trap capture and the light wavelength of the colored traps were measured. The results showed that, the orange and yellow colors had the best efficiency with the daily mean capture of 66.96 and 65.55 T. vaporariorum per trap, respectively. The most capture of sticky colored traps, was recorded at an installation height of 160 cm, with the daily mean capture of 115 T. vaporariorum per trap. The results of spectral measurement of traps showed that, the maximum wavelength reflectance in yellow and orange sticky traps were 580 and 600 nm, respectively. According to the results of this study, orange sticky traps with a light wavelength of about 600 nm, have the best efficiency in attracting and control of the greenhouse whitefly, T. vaporariorum.

The edible mushroom mosquito Lycoriella auripila (Dip.: Sciaridae) causes quantitative and qualitative reductions in crop yield worldwide, that is, Iran. The present study was conducted to estimate the efficacy of the entomopathogenic nematode Steinernema feltiae and the bacterium Bacillus thuringiensis, separately and simultaneously, in controlling this mushroom mosquito. In the laboratory study, the efficacies of different concentrations of S. feltiae (Sf), B. thuringiensis subsp. israelensis (Bti) and Dichlorvos pesticide were investigated. Then, nine treatments, including the interaction between Sf and Bti, were performed in addition to the laboratory treatments in the field test. The mushroom production yields in the control and treatment groups were compared. Statistical analysis of data was done based on the number of whole insects caught in sticky yellow card traps and larvae attracted to potato slices. In the conducted tests, the reductions in the insect population in the treatments compared with the control were calculated. The laboratory experiments showed positive effects of all treatments on pest control. The concentrations of 1×106 IJ/m2 Sf and 2/1000 Bti had the highest mortality rate of pest larvae with 81.6 and 77.4% mean mortality, respectively. Nematode Sf at this concentratration acted better than Dichlorvos for the control of this pest. In the field measurements, the highest population decreases were recorded in Bti with 75.7% control efficacy based on yellow sticky cards and in treatments of Dichlorvos and half-dose of two-biocontrol agent based on potato slices data with 75.3 and 74.8%, respectively. No significant difference was observed between Dichlorvos and Sf treatment for the control of this pest based on yellow sticky card data in field study. The obtained results recommend using these two biological control agents to control the L. auripila mosquito in edible mushroom cultivation halls.

The Melon Aphid, Aphis gossypii, is a key pest of greenhouse cultivated cucumber which is economically important due to its wide host-range and cosmopolitan status. Due to its high potential for evolving resistant biotypes against insecticides, it is necessary to test and present new insecticides against it. This research was conducted in the greenhouses of Tehran and Yazd provinces, based on a completely randomized design with 6 treatments and 4 replications. Treatments  included pirimicarb (WP 50%)  at the rate of 1/1000 L, flonicamide (Teppeki ® WG 50%)  at the rate of 0.2/1000 L and 0.25/1000 L, pymetrozine (Chess ® WG 50%)  at the rate of 0.5/1000 L, palizin insecticide soap  at the rate of 2.5/1000 L and control (water spray). The sampling was done one day before the treatment and 3, 7 and 14 days after the treatment. Analysis of variance of data was performed by SAS software and means were compared using Duncan multiple range Test. On the third day after treatment, the mean efficacy of Teppeki (0.2/1000 L), pirimicarb, pymetrozine, Teppeki (0.25/1000 L) and palizin was 97.83%, 87.7%, 82.43%, 90.53% and 76.94%, respectively. On the seventh day after treatment, the highest and the lowest efficacies were observed in Teppeki (0.25/1000 L) and palizin treatments, which were 92.27% and 38.7%, respectively.   The mean efficacy in Yazd province, on the third day after treatment was 90.25%, 79.66%, 86.28%, 88.74% and 75.25% for Teppeki (0.2/1000 L), Teppeki (0.25/1000 L), pirimicarb, pymetrozine, palizin, respectively. In general, the new insecticide, Teppeki, has an acceptable efficacy against this pest in the greenhouse.

Relationships between plants, herbivores and natural enemies can help the understanding the interaction between three-levels of integrated pest management programs. The interaction of the food chain prey (the two-spotted spider mite and western flower thrips) and predator (Neoseiulus californicus (Acari: Phytoseiidae)) and the host plants (strawberry cultivars: Marak, Yalova, Aliso, Gaviota, Sequoia, Camarosa and Chandler) were investigated. The predation rate and the presence frequency of the predatory mite on the pair of patches connected with a wax interface were compared. The type of prey did not effect on the presence frequency. In spite of the presence frequency on thrips patches, the predation rate of the predatory mite on nymph of thrips was less than two-spotted spider mite eggs. The presence frequency of the predatory mite on strawberry cultivars patches was different due to different special volatiles of strawberry cultivars. The predation rate of N. californicus between pair patches was showed significant difference, while, the number of the presence frequency among different strawberry cultivars has been differed in 61% of cases and the predation rate of the predatory mite has been differed in 52% of the cases. The presence frequency of the predatory mite on host patches were not affected by type of prey, however, the predation rate of N. californicus on preferred prey (two-spotted spider mite) was more than it on non- preferred prey (nymph of the thrips). The host plant and the prey species have an effect on the patch selection of the predatory mite and the predation rate.

The western flower thrips, Frankliniella occidentalis is one of the strawberry pest which threats the health of strawberry consumers due to the widespread use of pesticides against it. The aim of this study was to evaluate the suitability of the host plant as a substrate for oviposition and growth of stable population of O. laevigatus and thus control of western flower thrips in strawberry greenhouse. O. laevigatus laid more eggs on marigold than strawberry and green bean in both choice and no-choice experiments. The number of eggs laid on the marigold was 19.60 ± 1.16 in choice and 42.20 ± 2.92 in no-choice test, respectively. In addition population density of immature stages and adults of both thrips and predator was measured throughout the growing season of green bean, marigold and strawberry. The results showed that the density of the thrips on green bean was significantly decreased whereas the density of the predator was significantly higher on marigold. Green bean showed a higher potential than marigold as a banker plant to support the population of O. laevigatus on strawberry to reduce the western flower thrips population.

Aphids in urban ecosystems, damage host plants directly by feeding on leaves, sucking up nutrients, and weakenig the host, resulting in yield reduction. The results of a study conducted in 2016 and 2017 on the interactions between population of the rose aphid, Macrosiphum rosae and the parasitoid wasps, Aphidius rosae and Lysiphlebus fabarum indicated that in all cases, there was a positive and significant correlation between the numbers of both species of parasitoid wasps and the population of the rose aphid. As the population of aphid raised, the density of parasitoid wasps increased as well, and these parasitoids exhibited an aggregative behavior to different densities of the aphid host. The relationship between the number of rose aphid and the percentage of parasitism by A. rosae and L. fabarum wasps showed that there was a positive correlation between percentage of parasitism by these two parasitoids and aphid density. In 2016, during the spring, the highest percentage of parasitism of aphid nymphs by A. rosae wasp was 42.17 and the highest percentage of parasitism by L. fabarum wasp was 21.15. In 2017, during the spring, the highest percentage of parasitism of aphid nymphs by A. rosae wasps was 41.89 and the highest percentage of parasitism by L. fabarum wasps was 21.02. Therefore, considering the positive correlation between the population of rose aphid and the population of parasitoid wasps and the effective performance of these parasitoids in parke-shahr in Tehran, these useful agents can be efficiently employed in biological control of rose aphids.

Aphis gossypii Glover is considered as the most important polyphagous pest of a wide range of economically important plants in fields and greenhouses. In this study, the demography of cotton aphid, reared on six different host plants, including cucumber (Cucumis sativus L. var. Beith Alpha), tomato (Solanum lycopersicum var. Falat111), eggplant (Solanum melongena var. Yummy), okra (Abelmoschus esculentus var. Clemson Spineless), squash (Cucurbita pepo var. Hybrid Rajai), and pepper (Capsicum annuum var. Bertene) was investigated using the age-stage, two-sex life table under microcosm conditions (23±2°C and 70±5% RH and a photoperiod of 16L:8D h). The results revealed the differential effect of host plants on developmental duration, fecundity, and life table parameters of A. gossypii. The shortest nymphal duration (4.57±0.177 days), the longest adult longevity (21.87±0.184 days), the highest fecundity (73.6±0.85 offspring/female), the highest intrinsic rate of increase (r) (0.369±0.006 day-1) and the lowest mean generation time (T) (11.646±0.202 days) of the aphid were obtained on squash. Furthermore, the results of the population projection revealed that the population growth of cotton aphid was higher on squash, compared to other host plants. These findings suggested that squash as the most suitable host plant for A. gossypii among the tested hosts.

A survey on the morphology and biology of the elm leaf-mining moth Bucculatrix ulmifoliae was conducted under natural conditions. The developmental periods of 1th �, 3th, 4th and 5th larval instars as well as pupa were calculated as 6.40±0.67, 1.76±0.12, 1.92±0.20, 3.51±0.37, 9.61±0.77 days, in a cage at field; and 6.40±0.66, 1.50±0.27, 1.78±0.47, 2.71±0.48, 7.64±0.33 days at the laboratory (25±2°C, RH 65±5 and 16L: 8D hours) respectively. The average life span of the moth was obtained as 23.04±1.02 days at the laboratory and 25.84±0.91 days at the field. Adults of the first generation appeared in early April. The fertile females laid their eggs underside of leaves near the midribs. Upon hatching, the first instar larva penetrates directly via base of the egg into the leaf tissue and creates the mine. B. ulmifoliae had three generations of which the second generation showed its tendency for oviposition. Third generation was observed from the first half of August, and overwintering started at the first half of September. The first and second instars mined the leaf and fed inside, while the other instars fed externally on the underside. Bucculatrix ulmifoliae has three generations a year and overwintering as a pupa in a cocoon in the crevices of barks and fallen leaves on the ground.

A serious pest of agricultural crops are two species of whitefly that (Trialeurodes vaporariorum and Bemisia tabaci), which also make damages to greenhouse crops and ornamental plants. The biocontrol agents for these pests belong to the aphelinid wasps. To date two species of the genus Encarsia and Eretmocerus are used as effective natural enemies worldwide under greenhouses condition to control whiteflies. In this project, these parasitoids were release in a commercial greenhouse (5000 m2) to control the whiteflies populations in Varamin region (east of Tehran). Releasing was either uniform or spotted, in the uniform releasing 3, 6 or 9 parasitoids was considered per square meters, but in spotted releasing, in infection point, releasing rate was increased depending on the whitefly infestation. The results showed that the population of T. vaporariorus was increase from week 9th till week 14th. However, it was decrease from 23th week onward, while the parasitism rate of E. eremicus was higher than E. formosa (more than 80%). Therefore, using of these agents (in biological control program) can control the whiteflies population throughout the season. However, in addition to a good infrastructure of the greenhouses, other biological control agents predator mite) that are released to control other pests, can feed from the whiteflies nymphs, and reduces the pest population.

Neoseiulus californicus is an effective predatory mite to control of the spider mites. The functional response of three-day old mated female feeding on densities of Frankliniella occidentalis larvae (1,2,4,8 and 16) was studied on seven commercial strawberry cultivars (‘Sequoia’, ‘Chandler’, ‘Camarosa’, ‘Marak’, ‘Aliso’, ‘Yalova’ and ‘Gaviota’) and predation interference of this predator in (1,2,4,8 and 16) densities of the predatory mites on constant density of prey (40 larvae of thrips) were studied. These tests were conducted under laboratory condition (27±1˚C, 16L: 8D photoperiod and 70-80% RH). The predatory mite exhibited type Π on seven strawberry cultivars tested with Rogers equation. The attack coefficient and handling time were estimated on different strawberry cultivars (on ‘Sequioa (0.01, 4.77 hours), on ‘Chandler (0.03, 4.37 hours), ‘Camarosa’ (0.03, 5.49 hours), ‘Marak’ (0.03, 5.16 hours), ‘Aliso’ (0.02, 4.91 hours), ‘Yalova’ (0.05, 4.54 hours) and ‘Gaviota’ (0.02, 4.65 hours). The predatory mite ability in predation on F. occidentalis larvae on ‘Chandler’ and ‘Yalova’ were more than the other tested cultivars. It may be due to less trichome density on these cultivars or secondary chemical compounds. The relationship of logarithm of predator density and the logarithm of per capita searching efficiency was significant. The rate of predation increased as the host density increased and the predator decreased. These results emphasize the importance of the host plant characteristic for optimizing the predatory mite use in biological control of pests.

Neoseiulus californicus (McGregor) is a predatory mite that can control spider mites. The effect of seven strawberry cultivars (including: ‘Marak’, ‘Yalova’, ‘Aliso’, ‘Gaviota’, ‘Sequoia’, ‘Camarosa’ and ‘Chandler’) on the growth and development of N. californicus was studied in the laboratory conditions (27 ± 1 °C, 70 ± 5% RH and 16L: 8D photoperiod). There was significant difference in the number of trichomes on the leaves of strawberry cultivars. Life table parameters were analyzed based on age˗ stage, two˗sex life table. Egg incubation and protonymphal duration were significantly different when the predator was reared on different cultivars. There was no significant difference of total longevity among different cultivars. The longest preoviposition period was observed on ‘Aliso’ (1.70 days). The fecundity rate on ‘Gaviota’ and ‘Sequioa’ (6.90 and 8.91 eggs, respectively) was lower than other cultivars tested. The highest intrinsic rate of increase (0.20 day-1) and fecundity rates (13.29 eggs) were on ‘Chandler’, which might be due to the higher nutritional quality of Tetranychus urticae Koch reared on it or its low density of trichomes. Among the seven strawberry cultivars ‘Sequoia’, ‘Gaviota’ and ‘Yalova’ were recognized unsuitable for development and reproduction of N. californicus.

Application of botanical-pesticides especially during fructification reduces the health impacts of organic pesticides. Efficacy of different doses of GC-mite (0.3, 0.5 and 1 ml/lit water) with a short pre-harvest interval were investigated in the control of active stages of Tetranychus urticae and Aculops lycopersici in comparison with hexythiazox (10% EC( with the dose of 0.5 ml/lit and abamectin (1.8% EC) with the dose of 0.75 ml/lit on greenhouse cucumber and tomato. Experiment was conducted in a Randomized Complete block design with six treatments and three replications in a long row of 10 to 20 meters of planted crops. Treatments were sprayed when an average of 5 spider mites/under side of cucumber leaf and 10 eriophyid mites/cm2 in the middle portion of underside of tomato leaves were observed. Sampling of live mites was done randomly by collection of 30 leaves from each host plant at the interval periods of one day before and 1day (except cucumber), 3, 7, 14 days after treatments. Statistical analyses of mortality percentage of the treatments were performed by SAS software and grouping was performed by Duncan multiple range test. Although mean mortality% of T. urticae between treatments was not statistically significant (p.0.05) at different intervals, but the mortality% of 0.3 and 0.5 ml/lit of GC-mite increased from 71.48% and 66.66% at day 3 to more than 98% at day 14. The effects of 0.3 and 1 ml/lit of GC-mite in control of A. lycopersici also recorded an increase in mortality% from 60.82% and 67.11% at one day after spraying to 87.08% and 92.90% at 7 days after spraying and decreased at 14th day after spraying. The most suitable and effective spraying time of various doses of GC-mite is at the beginning of the activity of both the pests’ population in the greenhouses.

Biodiversity is an expression of the biological community and ecosystem levels of organized life, Mesostigmata are the predators of small arthropods and nematodes in soil habitats, Quality and quantity of the species and number each individual depending on soil and vegetation management strategies or the presence of other disorders such as human activities. In this study, soil quality studied with indicators of biodiversity in a 52 Hectare park in the north east of Tehran. The location divided to the 7 areas that was representative of vegetation and geographical location, regular sampling of the soil areas performed as a year. The total number of mites was 6167 belonging to 80 species. Species diversity in areas 1-7 and the whole area using Simpsons index of diversity and Shannon-Wiener index, species richness with Menhinicks index and Margalefs diversity index and evenness with Peet and Hill was calculated. The highest and lowest species diversity observed in areas 1 and 3, respectively, which correlated with soil moisture, pH and diversity of vegetation and management practices applied on the soil. The greatest species diversity in the region in the third quarter and the lowest species diversity were observed in the first quarter of the year, which is consistent with weather conditions and soil moisture. To determine correlations between each indicator of species richness and diversity with both evenness index in each sampling point the Pearson test was used.

Mites are one of the largest and most diverse subclasses of Arachnida with a worldwide distribution. The order includes 456 families and more than 56,000 species.
In this study, mesostigmatic soil mite fauna was studied as indicators of biodiversity in the 52-hectare Police park of the city of Tehran, Iran. The area of the park was divided into 7 sections in terms of their vegetational and geographical properties. Soil samplings were conducted through theyear and a total of 6167 mite specimens of 80 species were collected. Species diversity was calculated using Simpsons index of diversity and Shannon-Wiener index. Species richness was estimated using Menhinicks index and Margalefs diversity index and species evenness calculation was based on Peet and Hill.
Cheiroseius sp., Halolaelaps sp., Oplitis sp., Asca sp., Androlaelaps aegypticus, Pergamasus falculiger, Gamasiphis pulchellus, Cosmolaelaps lutegiensis, Macrocheles insignitus, Euandrolaelaps karawaiewi, Lasioseius youcefi, Proctolaelaps pygmaeus, Macrocheles peniculatus, Iphidozercon gibbus, Antennoseius masoviae, Pergamasus crassipes and Neogamasus cervicornis are reported here from Tehran for the first time. Uroseius (Apinoseius) sp. is new to Iran.

The Western flower thrips Frankliniella occidentalis, an important greenhouse pest, has acquired rapid resistance to the chemical pesticides. Therefore, biological control is worth consideration as an alternative control method. Among the biological control agents, entomopathogenic fungi showed to be quite successful in some occasions. In this study, three Iranian isolates of Metarhizium anisopliae (‘DEMI001’, ‘DEMI002’ and ‘DEMI003’) were bioassayed for their lethal effects on the adults of the F. occidentalis, in vitro. The ‘DEMI002’ and ‘DEMI003’ had the lowest and highest LC50 at concentrations of 3.06 ´ 104 and 1.90 ´ 105 conidia/ml, respectively. Also, the isolate ‘DEMI002’ had the lowest LT50 of 4.39 ± 2.13 days at the concentration of 106 conidia/ml. The mean comparison showed that there was a significant difference between DEMI002 and DEMI003 in terms of virulence at most of the concentrations. Consequently, the ‘DEMI002’ can be considered as a promising tool in biological control programs of the F. occidentalis.

Serpentine leafminer, Liriomyza trifolii (Burgess) is one of the most important pests of vegetables, especially on cucurbit in greenhouses. A study was conducted to determine the efficacy of some insecticides including acetamiprid (Mospilan® SP 20%) at the rate of 750 g/ha, abamectin (Vertimec® EC 1.8%) at the rate of 600 ml/ha and cyromazin (Trigard® WP75%) at the rates of 100 and 200 g/ha in the first year of the studies and at the rates of 200, 300 and 400 g/ha in the second year of the studies on L. trifolii. All the experiments were conducted in a completely randomized block design with 4 replicates. In the first year 3 days after applying the insecticides abamectin and cyromazin (200 g/ha) showed 78.37% and 75.21% mortality, respectively while acetamiprid showed 11.30% mortality which is the lowest effect against the pest larvae. In the second year of the experiments after two times of sampling (8 and 12 days after spraying), abamectin showed 100% and 94.32% mortality and cyromazin (200 g/ha) with 99.64%and 98.14% mortality, cyromazin (300g/ha) with 97.27% and 99.22% and cyromazin (400g/ha) with 98.90% and 100% mortality were the most effective insecticides, while acetamiprid with 20.96% and 37.81% mortality, did not show considerable efficacy.

Biological and demographic parameters of the mealybug ladybird, Cryptolaemus montrouzieri (Mulsant) were evaluated on citrus mealybug, Planococcus citri (Risso) and obscure mealybug, Pseudococcus viburni (Signoret) under 24 ± 2 ºC, 80 ± 5% relative humidity and a photoperiod of 16:8 (L: D) h. The mealybugs had a significant effect on developmental time and reproductive and demographic parameters of the ladybird. Life span (egg to adult death) was obtained 220.85 ± 5.78 and 119.44 ± 2.1 days when fed on Pl. citri and Ps. viburni, respectively. However, mean number of eggs per female (fecundity) and mean percent of egg hatching were significantly higher on Ps. viburni than on Pl. citri. In addition, values of intrinsic rate of increase (rm), finite rate of increase (λ) andnet reproductive rate (R0) were significantly higher on Ps. viburni than on Pl. citri.The values of intrinsic rate of increase were estimated 0.081and 0.094 day-1 on Pl. citri and Ps. viburni, respectively. Results of this study suggested that the obscure mealybug is a more suitable prey than the citrus mealybug as the ladybird displayed shorter developmental time, and higher fecundity and growth rate when fed with obscure mealybug.

Onion thrips is a key pest of vegetable crops. Chemical control is a conventional controlmethod of onion thrips. The infested fields to onion thrips are usually treated several times each year. This study was conducted in the laboratory conditions to find the effective insecticides by using the filter paper bioassay. Cypermethrin EC10%, deltamethrin EC2.5%, diazinon EC60%, oxymatrine AS 0.6%, and spinosad (Tracer® SC240) were used in the bioassay. The filter papers were dipped in sequential concentrations of the insecticides The median lethal concentration (LC50) of insecticides was determined on 4 day-old adult thrips at 24 hours after treatments. The LC50 values of the insecticides were included 38.08, 3.08, 47.4, 2.43 and 4.8 a.i. μg/ml respectively. Oxymatrine and diazinon had the highest and lowest toxicity on T. tabaci respectively. Thus, oxymatrine can be considered as a new effective insecticide against onion thrips with low risk on environment and human.

was conducted weekly and the second plot was considered as the control (no pest control measures applied). The total number of mines (mean±SE) bearing live and dead larvae and parasitism percentage of leaf miner larvae/plant were 26.61±5.54, 35.32±7.42 and 39.00±7.00, respectively in release treatment of the first greenhouse. The same parameters estimated to be 95.37±12.95, 4.60±0.92 and 5.00±2.00, respectively for the control at the same greenhouse. Similarly, in the second greenhouse above mentioned parameters for release treatment (3.16±0.66, 4.69±0.92 and 40.00±7.00 respectively), was significantly different with those of the control (12.83±1.63, 1.89±0.60 and 8.00±2.00). The activity of parasitoid was increased following the increase of ambient temperature and pest population at the end of the sampling period.

Appropriate functional response to prey or host densities is one of the important criteria for evaluating the efficacy of natural enemies in biological control programs. Cryptolaemus montrouzieri Mulsant is one of the main predators of citrus mealybug,Planococcus citri (Risso). In this research, the functional response of fourth larval instars and the female adults of this ladybird to different densities of second and third instars and female adults of citrus mealybug was studied under laboratory conditions. All experiments were carried out inside incubator with 25±1˚C, 80±5 %RH and photoperiod of 14 L:10 D hours. Individual fourth larval instars and female adults of ladybird were kept separately at densities of 4, 6, 8, 16, 20, 30, 40, 50 and 60 preys for 24 hours. Duration of each experiment was 24 hours and all experiments were carried out in 6 replications. A logistic regression was used to determine the type of functional responses and a nonlinear regression was used to fit Rogers and Holling’s equations to data for estimating searching efficiency (a) and handling time (Th) parameters. The results showed that the functional responses of fourth larval instars to different densities of second and third instars and the female adults of citrus mealybug were type III, III and II respectively, while the functional responses of the female adult ladybird to different densities of second and third instars and the female adults of prey were type II, III and II respectively. The rates of searching efficiency (a) for fourth larval instars of ladybird on second and third instars and the female adults of prey were estimated 0.0126, 0.0165 and 0.002, and the rates of handling time (Th) were obtained 0.701, 1.012 and 2.05, respectively. The rates of searching efficiency of female ladybirds on second and third instars and the female adults of prey were estimated 0.048, 0.013 and 0.098 and the rates of handling time were obtained 0.177, 0.843 and 2.79, respectively.

The greenhouse whitefly, Trialeurodes vaporariorum (Westwood), has been well established in the greenhouse ecosystems and is one of the most important pests on various greenhouse crops worldwide. Because of its high fecundity and resistance to commonly used pesticides, a study was conducted to examine the effectiveness of conventional insecticides of neonicotinoid compounds. In this study, the whiteflies on the ornamental plant genus Gerbera were collected from a greenhouse in the city of Mahalat and reared on tobacco under laboratory conditions at 25 ± 2ºC and 60 ± 5% Rate of humidity (RH) and a photoperiod of 16: 8 h (L: D). The toxicity of three neonicotinoid insecticides including imidacloprid SC35% (Confidor), thiamethoxam SC21.6% (Actara) and dinotefuran SG20% (Starkle) on the adults and first instar nymphs of T. vaporariorum, was evaluated using leaf dipping bioassay method. The susceptibility of adults was assessed at 24 hour post-treatment. The LC50 values of imidacloprid, thiamethoxam and dinotefuran for adults were 130.48, 52.89 and 93.55 ppm (a. i.) respectively. The mortality of immature stages was assessed at 72 hour post-treatment. The LC50 values of imidacloprid, thiamethoxam and dinotefuran for the first instar nymph were 26.65, 12.62 and 15.48 ppm (a. i.) respectively. The results suggest that all insecticides are more toxic on first instar nymphs than adults while thiamethoxam has the highest toxicity. The insecticides dinotefuran and imidacloprid can effectively control the adults and first instar nymphs as well.

Aggregation response of the predatory bug Orius niger (Wolff) at different densities (5, 10, 20, 30, 40 and 50) of the second instar nymphs of Thrips tabaci Lind. was examined on a cucumber leaf disc as a patch. The number of predatory bugs and their allocated time per patch was recorded. The index (µ), in Hassell & May, at all densities of the predator (1, 2, 4, 8, 16 and 32) appeared greater than zero and, was indicative of its tendency to aggregate in the patches where a higher density of prey occurred. The percentage time spent by the predatory bug at different patch densities of T. tabaci showed that it allocated more time in patches with higher densities of prey.

Serpentine leaf miner is one of the serious pests of vegetable crops in greenhouse and open fields، especially on cucumber and tomato. Reduction of synthetic insecticides’ use in order to minimize pesticide residues on these crops is an important basis of food safety. Application of bio-insecticides، especially neem products’ oil، is a very important alternative. Investigation on the efficacy of the commercial neem extract formulation with different concentrations was experimented on cucumber under greenhouse conditions. In the first year، experiments were performed in a completely randomized blocks design with six treatments and three replications. Five treatments included various concentrations of NeemAzal-T/S including 0. 25، 0. 5، 0. 75، 1 and 1. 5 ml/m2 and the sixth one was control without any chemicals. The results showed that on the third and seventh day of the treatment with concentrations of 0. 75، 1 and 1. 5 ml/m2، more than 80% mortality was observed، which shows a significant difference with 0. 25 and 0. 5 ml/m2 treatments. In the second year، the efficiency of two concentrations (1 and 1. 5 ml/m2) of NeemAzal-T/S was evaluated in comparison with chlorpyrifos، abamectin and permethrin. Results revealed that efficiency of the two neem concentrations had no significant difference compared with chlorpirophos and abamectin. Therefore، it could be concluded that NeemAzal-T/S could be successfully recommended to replace the chemical insecticides.