aref marouf

Herbal essential oils are known as suitable alternative for controlling pests due to low toxicity, fast decomposition and environment- friendly. This study aimed to examine the insecticidal effect of two herbal essential oils, i.e. Eucalyptus globulus and Iranian thyme (Zataria multiflora), on potato aphid. In the current study
Herbal essential oils were extracted by distillation with water using a clevenger device. The biometric experiments were performed on adult insects in 6 concentrations of eucalyptus, including 2000, 6000, 10000, 20000, 16000, 20000 ppm and in 6 concentrations of thyme, including 4000, 8000, 10000, 15000, 20000, 24000 ppm. The amount of losses in each experiment was counted during 24 hours after the experiment initiation.
According to the results of the probit data analysis, the values of LC50 and LC90 ​​for eucalyptus essential oil were 4699 and 37106 ppm, respectively, and for thyme essential oil, these values ​​were 11944 and 45620, respectively. In the present research, the highest fatality rates (loss percentage) for eucalyptus essential oil at a concentration of 20000 ppm and for thyme essential oil at a concentration of 24000 ppm were to 88.71% and 79.54%, respectively.
As the LD50 of eucalyptus and thyme essential oils were lower than the dosages of chemical insecticides and considering the phenomenon of resistance due to chemical insecticide, it seems that the herbal essential oils such as eucalyptus and thyme can be appropriate alternatives for chemical insecticides in the pest control program in the future.

The Indian meal moth, Plodia interpunctella (Hubner), is one of the main economic pests of stored products, including dried figs, in Iran and the world. In this research, the effect of different doses of gamma radiation (50-1000 Gy) and temperature (20-35 ± 1 °C) was investigated on the life stages of P. interpunctella. The results showed that P. interpunctella eggs and adults exposed to gamma radiation (50 Gy) died after a short time. Therefore these stages are so sensitive to gamma radiation and were not used for further investigation on a combination of gamma radiation and temperature. In all temperatures, the survival period of larvae significantly decreased with increased radiation doses, especially at 600, 800, and 1000 Gy. Similarly, at 33 and 35 °C, low gamma radiation doses (50, 100, and 200 Gy) caused early larval mortality. In all temperatures, doses of 800 and 1000 Gy of gamma radiation resulted in 100% mortality of pupae; thereby, adult emergence declined to zero. However, in lower radiation doses of 50, 100, and 200 Gy and at 35 °C, the pupal mortality increased to 70, 70, and 83.33%, respectively. Results are promising for the integrated management of P. interpunctella on dried figs in storage.

The insecticidal efficacy of three Iranian diatomaceous earth (DE) deposits obtained from Maragheh, Mamaghan, Khorasan Jonoobi mines and a commercial formulation, Sayan®, was assessed against adults of Callosobruchus maculatus F. (Coleoptera: Bruchidae). Cowpea grains were treated with four concentrations including 200, 600, 1000 and 1500 mg/kg and each concentration replicated four times. Experiments were carried out at 28±1˚C and 55±5% R.H. in continuous darkness. The mortality was counted after 2, 5, and 10 days of exposure. After 10 days, all adults were removed from vials, and the vials were left at the same conditions for an additional 35 days, to evaluate the progeny production. The mortality percent increased with increasing concentration level and time exposed to each concentration. Mamaghan, Khorasan Jonoobi and Maragheh DE deposits have the most insecticidal toxicity against adults after 10 days of exposure, respectively. The concentration 1000 mg/kg of these DEs was sufficient enough to suppress C. maculatus progeny production. Therefore, Iranian DE deposits may be applied as a suitable tool in stored products pest management programs.

This study was conducted to evaluate the susceptibility of two stored product pests, Tribolium confusum (Col., Tenebrionidae) and Oryzaephilus surinamensis (Col., Silvanidae) treated with two Iranian fungal isolates of Metarhizium anisopliae Sorokin, Saravan (DMEI001) and Nour (DMEI002), based on two bioassay methods, suspension and dry conidia. After mass production of fungal isolates under laboratory conditions (16:8 photoperiods, 28± 1°C, 65±5% R.H) and preparing main suspension, five different conidial concentrations were prepared separately based on the logarithmic distances and then each insect were treated by immersing them in five milliliter of conidial suspensions for five second. In dry conidia bioassay method, to prepare the appropriate dosages, one gm dry conidia was blended with 10 milliliter Tween 80 and then the number of its conidia was calculated. Finally, five concentrations of each isolates were prepared, separately. All experiments were carried out in four replicates and for each replication 20 adult (7-10 days old) of each species were treated, separately. The results showed that in both bioassay methods, Saw-toothed grain beetle was more susceptible to both fungal isolates and Saravan isolate with LD50, 2.37×105 and 5.35×104 in suspension method and 9.5×109 and 8.2×108 conidia per milliliter in dry spore method on red flour beetle and sow-toothed grain beetle, respectively had higher pathogenicity than Nour isolate. In comparison of two bioassay methods, the suspension method had higher efficacy than dry conidia method for both fungal isolates.

Pimpinella anisum L. belongs to Apiaceae family. The samples of vegetative and reproductive organs at different stages of development were gathered and investigated by cell-histology methods. The investigation of the anatomical structure of vegetative organs showed that the secretory ducts are arranged between the parenchymal tissues of the leaf. Section of flower buds revealed that anthers had 4 pollen sacs, the division of pollen mother cell was of the simultaneous type, microspore tetrads were of tetragonal type and the tapetum layer was secretory. The study of the ultrastructure of pollen grains with SEM showed that they had 3 pores. The ovary was found to be two-chambered and two-carpeled the ovule to be anatropous and to have one membrane. In embryogenic investigation it was found that the embryos were globular, cotyledonary and torpedo-shaped and the transition between globular embryos to cordate embryos was found. The vegetative organs were observed to have the general structure of dicotyledons. The development patterns of ovule and embryo sac follow the Polygonum type. Tetrahedral microspore tetrads were observed. The ultrastructure of pollens was found to be similar to those of Smyrnium, a genus of Apiaceae family. All stages of embryogenesis were covered in this study.

Life table of almond moth, Cadra cautella Walker was studied on four main dry and semi-dry date palm varieties (Deyri, Zahedi, Piarom, and Rabbi) of Iran under laboratory conditions. Data were analyzed based on the age-stage, two-sex life table theory. Duration of total preadult stages was 42.54, 45.79, 51.48 and 50.41 days on Deyri, Zahedi, Piarom, and Rabbi, respectively. The highest fecundity of female almond moth on date palm varieties was 245.29 eggs on Zahedi. The intrinsic rate of increase (rm) on different varieties of date palm ranged from 0.069 d-1 (on Piarom) to 0.105 d-1 (on Deyri). The highest net reproductive rate (R0) was on Deyri (95.81 offspring) and the lowest value was on Rabbi variety (42.37 offspring). Our results showed that the highest rm, the largest fecundity and the shortest generation time of almond moth were observed on Deyri variety. It was concluded that among date palm varieties, Deyri was the most favorable host plant for almond moth reproduction performance.