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.

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

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.

The leafminer, Liriomyza sativae Blanchard, is distributed around the world and is an important pest of vegetables and ornamentals. Given the resistance potential of the leafminer to current insecticides, the use of resistant plant cultivars and parasitoids could be effective integrated pest management (IPM) strategies against it. Cucumber (Cucumis sativus L.) is a preferred host for this insect. Seventeen cultivars of cucumber have been evaluated to study resistance mechanisms to L. sativae. All cucumber cultivars were evaluated in screening tests in greenhouse with indices such as the number of leafminer stings, the number of larval mines, the proportion of larval mines to leafminer stings, and the rate of injury. Significant differences (p < 0.01) were found among cultivars, as well as significant correlations among all evaluated indices. Cucumber cultivars were ranked by the cluster method based on all measured characters and were classified into four groups: susceptible, semi-susceptible, semi-resistant, and resistant. Trials of antibiosis resistance of cucumber cultivars were conducted in a growth chamber and were evaluated with biological indices of insect activity including oviposition period, larval and pupal duration, percentage of larval and pupal mortality, and the sex ratio among selected cultivars. Significant differences were found for all indices except pupal weight and the sex ratio. The cultivars were analyzed by the cluster method based on all measured characters and were divided into three groups including sensitive, slightly resistant, and semi-resistant. No cultivar was immune to injury.