Nutritional indices of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) on different host plants including chickpea (cultivars Arman, Hashem, Azad, and Binivich), common bean (cultivar Khomein), white kidney bean (cultivar Dehghan), red kidney bean (cultivar Goli), cowpea (cultivar Mashhad), tomato (cultivar Meshkin) and potato (cultivars Agria and Satina) were studied under laboratory conditions (25 ± 1 °C, 65 ± 5% RH, 16:8 L:D). Third instar larvae reared on potato Agria showed the highest efficiency of conversion of digested food (ECD) and efficiency of conversion of ingested food (ECI) (50.800 é 0.104% and 13.630 ± 0.016%, respectively). Approximate digestibility (AD) values of the fourth instar larvae were highest (92.651 ± 0.004%) and lowest (57.140 — 0.049%) on chickpea Azad and potato Agria, respectively. The fifth instar larvae fed on tomato Meshkin and white kidney bean Dehghan had the highest consumption index (CI) (3.717 ± 0.091) and relative consumption rate (RCR) (1.620 ± 0.074), respectively. Whole larval instars showed the highest ECI and ECD values on potatoes Satina (14.640 ± 0.014%) and Agria (21.380 ± 0.015%), respectively, and the lowest of both values on tomato Meshkin (ECI: 5.748 ± 0.002% and ECD: 7.341 ± 0.002%). The results of nutritional indices and the cluster analysis indicated that tomato Meshkin was an unsuitable host for feeding of H. armigera.

Digestive proteolytic and amylolytic activities and feeding responses of fifth instar larvae of Helicoverpa armigera (Hübner) on different host plants including chickpea (cultivars Arman, Hashem, Azad, and Binivich), common bean (cultivar Khomein), white kidney bean (cultivar Dehghan), red kidney bean (cultivar Goli), cowpea (cultivar Mashhad), tomato (cultivar Meshkin), and potato (cultivars Agria and Satina) were studied under laboratory conditions (25 +/- 1 degrees C, 65 +/- 5% RH and a photoperiod of 16:8 [L:D] h). Our results showed that the highest protease activity in optimal pH was on cultivar Dehghan (8.717 U/mg) and lowest one was on Meshkin (3.338 U/mg). In addition, the highest amylase activity in optimal pH was on cultivar Dehghan (0.340 mU/mg) and lowest was on Meshkin (0.088 mU/mg). The larval weight of fifth instar H. armigera showed significant difference, being heaviest on Binivich (125.290 +/- 5.050 mg) and lightest on Meshkin (22.773 +/- 0.575 mg). Furthermore, the highest and lowest values of food consumed were on Goli (362.800 +/- 27.500 mg) and Satina (51.280 +/- 4.500 mg), respectively. In addition, the lowest values of prepupal and pupal weight were on Meshkin (32.413 +/- 0.980 and 41.820 +/- 1.270 mg, respectively). The results indicated that tomato (Meshkin) was unsuitable host for feeding fifth instar larvae of H. armigera.

The potato tuber moth Phthorimaea operculella is a serious pest of potato both in the field and storage that makes great problem in storage. Farmers routinely rely on chemical insecticides that could be hazardous for human health and environment. Insecticide resistance of P. operculella has been reported all over the world, so botanical origin materials may serve as proper alternative materials for controlling the pest. Natural products are generally preferred because of they are less harmful to non-target organisms, eco-friendly and biodegradable. In the present study, ovicidal activity of essential oils (EOs) of basil, European pennyroyal, lavender, mint, oregano and savoury and oviposition-deterrent activity of methanolic extracts of fumitory, lavender, licorice and oregano were investigated on P. operculella. Probit analysis showed that EOs of Lavandula angustifolia revealed the highest activity (LC 50 value 0.4 μL/L air). Fumitory extract elicited the highest reduction in percentage of laying eggs. The results indicated that these medicinal plants could be effective for declining damage of P. operculella in storages.

The alfalfa weevil, Hypera postica (Gyllenhal), feeds almost exclusively on alfalfa, Medicago sativa L. in most region of the world where forage crop is grown. It has been investigated the population density and spatial distribution of alfalfa weevil on alfalfa in Ardabil during 2010. Using a 0.25 m2 quadrate sample unit a reliable sample size was 65, with maximum relative variation of 15%. The relative variation (RV) of the primary sampling data was 13.6. The highest population density of the alfalfa weevil was recorded on 17th April. To estimate the spatial distribution pattern of this pest, data were analyzed through index of dispersion, Lloyd’s mean crowding, Morisita’s index and two regression models (Taylor’s Power Law and Iwao’s Patchiness Regression). Taylor’s model showed an aggregated distribution pattern for all life stages. Iwao’s patchiness regression indicated that larvae, adult and total life cycle had aggregated spatial distribution (tc < tt), while pupae of alfalfa weevil exhibited a random pattern. The index of dispersion and Lloyd’s mean crowding methods indicated an aggregated distribution for this insect. Spatial distribution parameters of this species are used to outline a sampling program as well as to estimate population density of H. postica development stages. Optimum sample sizes for estimates of larval density, at three levels of precision, are presented.

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Habrobracon hebetor Say is one of the most important ectoparasitoids of the larval stage of many invasive agricultural pests such as noctuid and pyralid moths. Lethal and sublethal effects of carbaryl and abamectin were assessed on the ectoparasitoid H. hebetor in laboratory conditions. Dose-response bioassays were carried out on immature and adult stages by using dipping and contact residue methods, respectively. LC 50 (lethal concentration for 50%) values of carbaryl and abamectin were 31.19 and 4.16 mg a.i. l -1 on larval stage and 12.6 and 4.42 mg a.i. l -1 on adults, respectively. In order to assess the sublethal effects, adult wasps were exposed to an LC 30 of each insecticide and then the demographic parameters of live wasps were studied. The results showed that the intrinsic rate of increase (r m ), finite rate of increase (k), net reproductive rate (R 0 ) and gross reproductive rate (GRR) were significantly affected by the insecticides. The highest and the lowest r m values were 0.23 and 0.17 in control and carbaryl-treated insects, respectively. The sex ratio of H. hebetor offspring was not significantly affected by either insecticide. The results showed that carbaryl had more adverse effects on population parameters of the parasitoid compared to abamectin. Field studies are needed to determine the total effects of the pesticides on H. hebetor.

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