gh.r. golmohammadi

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.

Background and Objectives Tetranychus urticae, as the two-spotted spider mite, is considered as one of the most important and destructive herbivorous mites in farms and greenhouses, which is very important to control due to its wide host range. The damage caused by agricultural pests combined with the harmful effects of synthetic chemicals used in their control can be mitigated or eliminated by using botanicals, which are derived from renewable resources including a mixture of various bioactive ingredients. Therefore, finding a suitable alternative way for controlling this pest is necessary by considering the resistance to acaricides, as well as undesirable effects of chemical compounds. The present work aims to evaluate microcapsule essential oil of Mentha piperita and its lethal and sublethal toxicity to T. urticae. Materials and Methods Laboratory bioassays were used for evaluating the sublethal effects of peppermint essential oil microcapsules on biological and population parameters of T. urticae. The life table parameters of T. urticae were conducted on leaf discs under laboratory conditions at 25 ± 2°C, 60 ± 5% relative humidity, and a photoperiod of 16:8 (L: D) hours. Then, the duration of each stage, developmental time, and survival were observed and recorded daily. In addition, the raw data were analyzed based on age stage two-sex life table theory with MS-Chart. Results Based on the results, microcapsules of Menthe piperita caused a significant reduction in fecundity and longevity. Those treated with LC20 and LC30 had a significant reduction at net reproductive rate, compared to those treated with LC10 and untreated ones. The intrinsic and finite rate of increase reduced significantly in higher concentration compared to the control. In addition, the mean generation time decreased significantly at the upper dose, compared with LC10. Discussion Botanic acaricides can be used for controlling Tetranychus urticae, and the microencapsulated formulation of these products makes them more stable. Familiarity with the chemical nature of the bio-active pesticide/acaricidal compound can be considered in future research which can play a role in developing an effective and environmentally friendly treatment against spider mites, leading to a decrease in reliance on synthetic pesticides/acaricides. The results of this study can be used in designing the mentioned pest management programs by considering the detrimental effects of M. piperita essential oil microcapsule on some biological parameters of T. urticae.

Background and Objectives The lacewings are predatory insects which are widely used in biological control programs. Meanwhile, the green lacewing, Chrysoperla carnea Stephens (Neuroptera: Chrysopidae), has attracted considerable attention as a promising biological control agent for greenhouse and field pests. Green lacewing is considered as an important bio-control agent due to its geographical distribution, broad host range, potency of suitable compatibility in agro-ecosystems, high searching ability, easy mass rearing in laboratory, high reproductive potential and broad resistance to numerous insecticides especially in larval and pupa stages. In this regard, it is highly important to reduce the consumption of the conventional pesticides which are compatible with predators and have low negative effects on beneficial organisms. In addition, life tables should be highlighted as the most reliable and effective technique for assessing the fitness of a population. Among the methods for selecting suitable pesticides in integrated pest management (IPM) programs, evaluating all of its effects on the different biological parameters of both sexes is the prime tool for population ecology studies. Materials and Methods Laboratory bioassays were investigated to evaluate the sub-lethal effects (LC30) of thiamtoxam, imidacloprid, and acetamiprid on biological characters and population parameters of C. carnea. The sub-lethal effects of thiamtoxam, imidacloprid, and acetamiprid on the demographic parameters of green lacewing were evaluated in vitro at 25±2° C, relative humidity of 65±5%, and light period of 8:16 h (light: dark). The raw data were analyzed based on two-sex life table analysis. Results All sub-lethal concentrations caused a significant decrease in oviposition period, total fecundity, longevity, and total life span in comparison to the control. Maximum and minimum mean lifespans of C. carnea individuals were observed in the untreated group and LC30 concentration of thiamtoxam. Total fecundity varied from 208.7 (offspring/individual) in treatment with LC30 thiamtoxam to 302.3 (offspring/individual) in the control treatment. The intrinsic and finite rates of increase (r, λ) were not affected by the imidacloprid concentration. The net reproduction rate (R0) reached its lowest level (141.1 offspring /individual) in acetamiprid treatment. Discussion The adaptability of pesticides with biological agents is one of the major concerns of IPM practitioners. Hence, it is essential to have necessary information about the action mode of pesticides on non-target insects. Furthermore, finding efficient biological control agents is considered as the first step in developing biological control programs. Therefore, the effects of sublethal concentrations of thiamtoxam, imidacloprid, and acetamiprid in combination with C. carnea were discussed in order to design integrated management programs.