Shahriar Asgari

Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a serious pest originating from South America that affects tomato production in many countries, particularly in Iran (since 2010). In this study, by using age-stage, two-sex life-table parameters, the resistance of seven tomato cultivars, namely, 'Primo Early', 'Rio Grande', 'Cal JN3', 'Petomech', 'Early Urbana Y', 'Super 2270', and 'Super Strain B' to T. absoluta, was evaluated under laboratory conditions (25 ± 1 °C, 60 ± 5% RH, and a photoperiod of 16:8 (L:D) h). Larval and pupal periods were longest on Early Urbana Y, 13.86 and 6.52 d, respectively, and shortest on Cal JN3, 10.92 and 5.5 d, respectively. The longest and shortest development times of immature stages lasted 26.42 and 20.83 d on Early Urbana Y and Cal JN3, respectively. Male and female adult longevity was longest on Early Urbana Y, 30.42 and 38.52 d, respectively, and shortest on Cal JN3, 11.67 and 18.8 d, respectively. The net reproductive rate (R0) ranged between 80.94 (Cal JN3) and 45.87 (Primo Early) offspring. The lowest and the highest values of the intrinsic rate of increase (r) and finite rate of increase (λ) were on Early Urbana Y and Cal JN3, 0.1052 and 0.1522 and 1.1109 and 1.1644 d-1, respectively. The mean generation time (T) on different cultivars varied from 30.47 to 37.28 d. Our results indicated that Cal JN3 was the most susceptible to infestation and Primo Early and Early Urbana Y were the most resistant to T. absoluta among the tomato cultivars tested.

To introduce ecologically safe acaricide, effects of essential oils derived from Cuminum cyminum (Cumin), Syzygium aromaticum (Clove), and Mentha spicata (Spearmint) were determined on Tetranychus urticae at 25±1 � C, 65±5% RH and a photoperiod of 16:8 (L:D) hour. The essential oils extracted by hydro-distillation were characterized by means of GC and GC–MS. Bioassays were performed by filter paper diffusion without allowing direct contact. Cumin, clove, and spearmint oils contained �- Pinene (29.1%), eugenol (78.5%) and carvone (59.4%), respectively, as the major compounds. The lowest LC 50 value for adults was recorded for cumin oil (3.74 µL L -1 air) followed by clove (6.13 µL L -1 air) and spearmint (7.53 µL L -1 air). The highest ovicidal activity was recorded for cumin oil (LC 50 = 7.65 µL L -1 air) followed by clove (LC 50 = 8.73 µL L -1 air) and spearmint (LC 50 = 9.01 µL L -1 air). According to repellency tests, by increasing concentration of oils, the repellency effects were increased. The most potent repellency effect was recorded for clove, followed by spearmint and cumin oils. The three extracted essential oils seem to be suitable sources of active vapors that can be used as alternatives for chemical pesticides for controlling this pest.

Scelionid wasps (Hymenoptera: Scelionidae) are powerful egg parasitoids which have an efficient role in the biological control of agricultural pests, especially pentatomids (Hemiptera: Pentatomidae). The species diversity of these beneficial insects from Isfahan province is studied in this paper. Twenty species from 2 subfamilies, Scelioninae and Telenominae, were collected and identified. In this paper, the hosts of reared parasitoids are introduced together with the synonyms of scelionid wasps.

Abstract Specifying the relationship between pests and their host plants in terms of damage is one of the basic concepts of integrated pest management (IPM) programmes. The crop loss and economic injury level (EIL) of Tuta absoluta (Lepidoptera: Gelechiidae) were determined on different tomato cultivars using gain threshold (field experiment) and regression (semi‐field experiment) methods. By assessing the crop loss in 2015 and 2016, four out of seven infested tomato cultivars had a significant yield loss in terms of weight of total fruits versus the control under the open‐field conditions. However, the total number of tomato cultivars had no significant difference to control treatment. The semi‐field experiment included six treatments (0, 2, 4, 6, 8 and 10 gravid females/plant) and examined two tomato cultivars. The tomato cages with between 6 and 10 gravid females/plant showed the highest number and weight of damaged fruits. Based on pesticide control costs, the market value of tomato and the control efficacy, we determined the EIL for T. absoluta . In the field experiment, the EIL value for T. absoluta on “Petomech,” “Cal JN3,” “Rio Grande” and “Early Urbana Y” cultivars was 4.15, 4.47, 4.70 and 5.04 larvae per plant, respectively. Based on regression equations, we calculated the EIL values for T. absoluta on “Cal JN3” and “Early Urbana Y” to be 4.75 and 5.44 larvae/plant, respectively. Crop loss assessment and EIL are necessary components of cost‐effective IPM programs and can be effective tools for making decisions about the application of pesticides against T. absoluta .

This paper deals in part with the fauna of natural enemies in corn fields and surrounding grasslands of Semnan. In a total 54 predator and parasitoid species from twelve families including, Asilidae (3), Braconidae (7), Carabidae (7), Chalcididae (2), Chrysopidae (1), Coccinellidae (5), Eulophidae (3), Ichneumonidae (8), Staphylinidae (7), Syrphidae (6), Tachinidae (4) and Trichogrammatidae (1), and four orders (Coleoptera, Diptera, Hymenoptera and Neuroptera) were collected.