arsalan jamshidnia

Tomato leafminer Tuta absoluta Meyrick (Lep: Gelechiidae) is one of the most important pests affecting tomato cultivation in Iran. Given its wide spread distribution, it becomes necessary to apply an effective management method. The high damage inflicted by this pest on tomato crops has historically led farmers to use chemical pesticides for quick control, resulting, in pesticide overuse and the development of resistance, rather than effective control against the tomato leafminer. Planting resistant cultivars to agricultural pests considered as one of the most important strategies for the cost-effective production of healthy products and the reduction of pesticide consumption. This study investingates the egg laying preferences of T. absoluta on 15 different tomato genotypes resulting from the hybridization (crossing) of two commercial cultivars, Sakhiya and Eshkol, using a free choice test under greenhouse conditions. Additionally, trichome density and chlorophyll content were assessed in the studied genotypes. The results revealed that Eshkol 52-2 (2), Sakhiya 9-2 (3) and Sakhiya 8-2 (3) exhibited the highest rates of egg laying, while Eshkol 52-7(2) and Eshkol 52-4 (2) showed the lowest. Furthermore, the genotypes with higher egg-laying rates were associated with lower trichome density. However, the chlorophyll content in Eshkol 52-2 (2), which had the most egg-laying rate, was notably high. Conversely, Sakhiya 9-2 (3) and Sakhiya 8-2(3), which also demonstrated relatively high egg-laying rates, exhibited lower chlorophyll content. The chlorophyll content in the genotypes Eshkol 52-7 (2) and Eshkol 52-4 (2), was relatively low but also the egg laying rate was low.

The egg parasitoid wasp, Telenomus busseolae Gahan (Hym.: Platygastridae) is the most important natural enemy of sugarcane stem borers in sugarcane growing area of Khuzestan province. In order to know the parasitism rate of T. busseolae in plant crops compared with first ratoon crops an investigation was carried out in Amir-Kabir Agro-industry in southern Khuzestan. In this study six plant and six ratoon cane fields of commercial sugarcane cultivar, CP69-1062 was selected and sampling of sugarcane borers (Sesamia spp.) egg batches was made monthly from April to November. The results indicated that field age and sampling time has a significant effect on egg batch densities of sugarcane borers and parasitism of eggs by T. busseolae. The lowest egg batch density was observed in April and the highest was recorded in September both in plant crops and first ratoon crops. In plant crops the lowest egg parasitism rate (43.5 %) was observed in July, whereas the highest rate (84.4 %) was observed in April.  In the first ratoon crops the lowest rate of parasitism (38.8 %) was observed in June and then increased to 87.3 % in November. The percentage of adult emergence of T. busseolae was not significantly influenced by crop age and sampling time.There was no significant difference of progeny sex ratio in the two investigated crop ages, but sampling time significantly influenced on progeny sex ratio. The results of this study provide useful information on the population fluctuations of T. busseolae in plant and ratoon crops of sugarcane.

The sugarcane stem borers, Sesamia spp. are the main pests of sugarcane in Khuzestan province of Iran. In order to evaluate the stem borers infestation in plant and ratoon crops, two field experiments were carried out in Amir-Kabir Agro-industry in south of Khuzestan province. In the first experiment, at plant cane fields during three consecutive years, and in the second experiment at different crop ages (plant, first ratoon and second ratoon) at the same time stalk and internode infestation by sugarcane borers were determined. Results in both experiments indicate percent of stalk and internode infestation by stem borers in plant crops significantly increased than ratoon crops. The findings of this research can be used in management of sugarcane stem borers.

Indian meal moth Plodia interpunctella Hübner (Pyralidae) is one of the most important pests of storage products in Iran, which is controlled by chemical fumigants. The use of plant essential oils and their compounds can be a suitable alternative to conventional fumigants due to their low risks to mammals. The present study invesrigates the mortality, inhibition of alpha-amylase enzyme, and the total protein content of Indian meal moth larvae (Plodia interpunctella (Hübner)) affected by saffron petal extract with high concentration of anthocyanin under experimental conditions. The concentrations have been 500, 690, 1000, 1380, and 2000 ppm, used against the fifth-instar ‎larvae of the pest in four replications within 24 and 48 h. The lethal concentration to kill fifty percentage of larvae (LC50) by saffron petal extract after 24 and 48 hours is estimated to be 2244.950 and 1434.828 ppm, respectively. Alpha-amylase enzyme activity in the fifth instar larvae of Indian meal moth, treated by saffron petal extract, has been significantly different from the control. The highest activity of the alpha-amylase enzyme in pest larvae treated by saffron petal extract has been recorded with 83.1%, and the inhibitory rate of this enzyme has been 21.8%, which is significantly different from control. Also, the amount of protein in the larvae affected by this extract significantly differs from the control groups. Therefore, due to its fumigant toxicity and the alpha-amylase inhibitory activity of Indian meal moth larvae, saffron petal extract can be considered for additional researches on managing this pest based on an ecological principle.

Pink stem borer, Sesamia creticaLed, is one of the most important pests of sugarcane and maize in Iran. Insecticidal properties of essential oils of four cumin ecotypes, namely Fars-Sivand (FS), North Khorasan-Shirvan (KS), Kerman-Kuhbanan (KK), and Kerman-Rafsanjan (KR), has been evaluated against 4th instar-larvae of S. cretica in a completely randomized design with four replications. Larval mortality at 27±2 °C, relative humidity of 65±5%, and 16:8 hours light: darkness period is recorded after 72 hours. Results show that all cumin ecotypes have been toxic to the pest, with the lowest LC50 value, obtained from the essential oil of KR ecotype (2725 ppm) followed by KK, FS, and KS ecotypes (2777, 3099, and 8390 ppm, respectively). The chemical analysis of essential oils tested by GC-MS shows that m-cymene in the KR ecotype has been higher than other cumin ecotypes. Therefore, the high toxicity of KS ecotype compared to other cumin ecotypes can be related to the presence of such compounds. According to the present study’s results, the essential oils of cumin ecotypes are potentially a great substitute for chemical insecticides in the integrated management of S. cretica.

Following sugarcane production extension in Khuzestan province, some pests appeared in sugarcane fields and sugarcane stem borers, Sesamia spp. were the most important among them. Development, reproduction and life table parameters of the parasitoid wasp, Telenomus busseolae Gahan on the sugarcane stem borer Sesamia cretica Lederer were studied at five constant temperatures (20, 25, 28, 30 and 35±1°C, 60±5% RH and a photoperiod of 16L:8D h.). The duration of pre-adult stage decreased with increasing temperature from 26.67 days at 20°C to 10.25 days at 35°C. The oviposition period was 4.16, 4.6, 4.99, 4.04 and 3.31 days at 20, 25, 28, 30 and 35°C, respectively, with females laying an average of 56.37, 65.45, 98.59, 57.44 and 33.86 eggs, respectively, at these five temperatures. Life table data were analyzed using an age-stage, two-sex life table method. The intrinsic rate of increase (r=0.262 day-1), finite rate of increase (λ=1.3 day-1) and net reproductive rate (R0=49.28 offspring/individual) were greatest at 28°C. The shortest mean generation time (T=12.17 day) was recorded at 35°C. The results of the current study indicated that temperature is one of the most important factors on life table parameters of T. busseolae. Also the optimum temperature for population growth of this parasitoid was 28°C, therefore this temperature suggests for mass rearing of T. busseolae.

The sugarcane stem borer, Sesamia cretica Lederer, is one of the most economically important pests of sugarcane in Khuzestan province, southwest Iran. The egg parasitoid Telenomus busseolae Gahan significantly affect S. cretica population in the field. Host age is an important factor of host acceptance and suitability for egg parasitoids. We examined the ability of T. busseolae to parasitize and develop in S. cretica eggs of different ages. In a no choice laboratory experiment, we measured the effect of host age (12, 36, or 60 h old) on parasitism rate and offspring fitness characteristics such as survival, development time, sex ratio, size, and progeny longevity and fecundity. Results revealed that the suitability of host eggs decreased as host age increased. Exposure of parasitoids to 12h old eggs resulted in higher percentage parasitism, higher acceptance, higher survival and larger body size of parasitoid progeny. Progeny that emerged from 12h old eggs had also higher longevity and fecundity than those emerged from other host ages tested.

In current study, pathogenicity of two pathogenic fungi, Beauveria bassiana Vuellemin and Metarhizium anisopliae Sorokin were assessed on adults of elm leaf beetle, Xanthogaleruca luteola with four concentrations 105, 106, 107 and 108 spore/ml and control treatment using immersion and spraying methods. The experiments were conducted at controllable conditions, 25±1°C, 75±5% RH and photoperiod 12:12 h in growth chamber. Mortality rate in both methods in all treatments were recorded during 10 days. The values of LC50 and LC90 for B. bassiana were 2.7×106 and 7.72×106 spore/ml in immersion method and were 7.75×106 and 35.05×106 spore/ml in spraying method while these values for M. anisopliae were 2.68×106 and 7.99×106 spore/ml in immersion method and were 8.36×106 and 46.8×106 spore/ml in spraying method, respectively, it shown higher pathogenicity of B. bassiana in comparison with M. anisopliae. The lowest LT50 and LT90 for B. bassiana at concentration 108 spore/ml were 3.39 and 13.12 days while these values for M. anisopliae were 4.51 and 15.03 days respectively. The result shows that B. bassiana in both methods immersion and spraying causes more mortality during shorter time compare to M. anisopliae. According to findings of the current study, both fungi B. bassiana and M. anisopliae can be used in integration with other non-chemicals method for control of elm leaf beetle.

The greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hem., Aleyrodidae) is a cosmopolitan and polyphagous insect that attack a wide range of crops. In this study, the biological parameters of parasitoid wasp, Eretmocerus delhiensis Mani (Hym., Aphelinidae) on T. vaporariorum were evaluated. The experiments were conducted at 25±1°C, 65±5% RH and a photoperiod of 16: 8 h (L: D) in growth chamber. Based on the results of our studies, all of parasitoid progeny were female and there was no male progeny. Adult emergence, pre-oviposition, oviposition and post-oviposition period, developmental time and longevity of female parasitoid were 71 %, 15.03±0.32, 0.46±0.06, 4.2±0.12, 1.04±0.08, and 5.71±0.13 and 20.74±0.5 days, respectively. Also, other parameters such as; daily fecundity, total fecundity, daily host feeding, and total host feeding were 3.04±0.11 and 17.43±0.17 eggs 1.07±0.05, and 6.40±0.35 nymphs, respectively. Regression analysis revealed that host feeding had a significant effect on oviposition of this parasitoid. Therefore, the parasitoid wasp E. delhiensis not only parasitize their hosts but also kill them through host feeding. These results suggest E. delhiensis has the potential to be used as a biological control agent in greenhouse whitefly management.

The greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hem.: Aleyrodidae) is a polyphagous and key pest that causes damaging to wide range of crops. The parasitoid wasp, Eretmocerus delhiensis Mani (Hym.: Aphelinidae) is a syn-ovigenic and thelytokous species that parasitizing greenhouse whitefly nymphs. In order to evaluation parasitoid wasp, Eretmocerus delhiensis Mani (Hym.: Aphelinidae) in control of greenhouse whitefly demography parameters of E. delhiensis on greenhouse whitefly on tomato cultivar Super-Chief at temperature 25±1°C, 65±5 % RH and a photoperiod 16:8 h (L: D) in growth chamber were studied. For calculation of population growth parameters Age- Stage, Two-Sex Life table was used. The result showed that oviposition period, longevity and fecundity for this parasitoid were 4.2±0.12 d, 20.74±0.5 d and 17.43±0.17 offspring respectively. Based on results of the life table, demography parameters consisting of net reproductive rate (R0), gross reproductive rate (GRR) were 12.11±0.94 and 31.43±1.85 offspring per female, intrinsic rate of increase (rm), finite rate of increase (λ), were 0.16±0.0059 d-1, 1.17±.007 d-1 and mean generation time (T) and doubling time (DT) of E. delhiensis were 15.66 d and 4.354/d respectively. Based on our results, this parasitoid is a promising candidate for greenhouse whitefly control.

Functional response of Stethorus gilvifrons Mulsant on different densities of adult female mite Oligonychus sacchari McGregor on tree commercial cultivars of sugar cane (CP 48-103
CP 57-614 and CP 69-1062) was studied under laboratory conditions. Results of logistic regression revealed a type III functional response for all cultivars. According to the results searching efficiency of S. gilvifrons on CP 48-103, CP 57-614 and CP 69-1062 varying from 0.012- 0.60, 0.014- 0.70 and 0.014- 0.70 per h and the handling time was 0.366, 0.307 and 0.350 h, respectively.