نشریه نامه انجمن حشره شناسی ایران
سال چهل و یکم شماره 1 (پیاپی 85، بهار 1400)

The carob moth, Ectomyelois ceratoniae Zeller, is the most important pest on   pomegranate fruits and has several overlapping generations per year in Iran. This paper investigated the use of a mechanistic model for describing the effect of the control strategy on the size of the total population of the carob moth. The analytical solution of mechanistic model was written in the form of a logistic probability density function by Matis et al. (2006). The logistic probability density function fits this carob moth data very well for control and treatment fields (r2=0.91 and 0.95). The parameters of the model are the predicted peak size, Nmax, the predicted time of peak, tmax, and an approximate per capita birth and death rate, all of which are important in practical application. In general, this paper demonstrates the utility of analyzing carob moth population data using mechanistic models and their underlying rate parameters.

The stem borers, Sesamia spp. (Lepidoptera: Nocuidae) are the most important pest insects on sugarcane and maize in Iran. Biological control using its egg parasitoid wasp, Telenomus busseolae Gahan, is the main recommended controlling method for the pest. On the other hand, mass rearing of T. busseolae is strongly depended on mass rearing of its natural hosts. Current study was conducted to determine probability of mass rearing of Sesamia nonagrioides Lefèbvre using semi-artificial diet under laboratory conditions. The effect of a semi-artificial diet on life table parameters of the mentioned species in comparison with two natural diets, maize and sugarcane was studied under laboratory conditions. Life table construction and related parameters estimation were carried out using two-sex life table analysis procedure. According to the results, there was statistically difference among estimated values of the life table parameters among examined natural and semi-artificial diets. Total developmental period of S. nonagrioides were 53.51, 39.58, and 51.88 days on maize, sugarcane, and semi-artificial diets, respectively and there was no statistically significant difference between maize and semi-artificial diets. Estimated values for intrinsic rate of increase (r), as the most important life table parameter, were 0.0579, 0.09090and 0.0700d-1 on maize, sugarcane, and semi-artificial diet, respectively. Regarding intrinsic rate of increase, by statistically placing semi-artificial diet in the second group between two natural hosts of corn and sugarcane, its proper quality to meet the nutritional needs of the target species was confirmed. Considering all of the results and acceptable values of the life table parameters, examined semi-artificial diet is recommended for mass rearing of S. nonagrioides.

Field and laboratory surveys were carried out to study the biology of cotton thistle leaf miner, Pegomya terebrans (Rondani) in Urmia region. The results showed that the host plant species of this fly are restricted to three species of plants belonging to tribe Cynareae (Asteraceae), including Italian thistle Carduus pycnocephalus L. and two species of cotton thistle namely Onopordum acanthium L. and O. leptolepis DC.. The species has only one generation per year and hibernates as adults. After overwintering, adults become active and mate in late March. Fertile females begin oviposition in early April. The eggs are laid either singly or in groups of up to five in irregular shape under the leaves of the host plants. Depending on the daily temperature, they hatch within 6-10 days and young larvae immediately bores into the leaf and begins consumption in tissues between the leaf surfaces. The species has three larval instars and larval developmental time is 21 to 27 days in natural conditions. The full grown third instar larvae fall to the ground and pupate in the soil at a depth of 1 to 3 cm which its period lasts 4 to 5 months. The emergence of flies begins in mid-October and continues until late-November. They remain inactive for about five months in autumn and winter and become active in early spring, again. The larvae of P. terebrans were parasitized by Biosteres spinaciae (Thomson) in the studied region. Parasitic association between B. spinaciae and P. terebrans is reported for the first time.

The tomato leafminer Tuta absoluta (Meyrick) is one of the main pests of tomato in Yazd province. Successful prediction of population fluctuations is one of the key aspects of pest management programs. Geographic information systems have been successfully used to determine actual and potential distribution areas of the pests. High-risk areas of pest prevalence were determined based on the Analytic Hierarchy Process (AHP) model using ArcMap and ArcCatalog softwares, and Arc GIS sub-software was used to create spatial databases and geographical analysis of the regions. Parameters of altitude, rainfall, temperature, plant hosts and humidity were used to analyses of the effective factors on pest distribution. The results showed temperature by a final weight of 0.431 is the most important factor affects pattern of the pest distribution. The cultivated area, humidity, height and rainfall had a final weight of 0.376, 0.107, 0.056 and 0.030, respectively. The results showed Yazd, Khatam, Bahabad, Ashkzar, Nodooshan and Robat are high risk areas of the pest.

Regarding the importance of greenhouse productions and high activity of pests including Trialeurodes vaporariorum under greenhouse conditions, the management of this pest requires ecological studies with a new approach. Therefore, due to the influence of the host plant characteristics on biological performance of greenhouse whitefly, the current research was performed to predict and estimate the values of its population growth parameters including net reproduction rate (R0) and intrinsic rate of population increase (rm). Estimation was based on some morphological features of the host plants using a MLP artificial neural network. The network was optimized with a genetic algorithm. The R0 and rm values of T. vaporariurum were calculated on two host plants, Cucumis sativus L. and Cucumis metuliferus May. Moreover, density and length of the leaf trichomes, density and area of leaf stomata cell of the lower leaf surface and the amount of leaf chlorophyll of each host plant was measured. The MLP neural network with optimal algorithm was designed. In order to evaluate the MLP neural network the T-test, F-test and Kolmogorov-Smirnov test were used to compare mean, variance, and statistical distribution, respectively. The obtained coefficient of determination (R2 = 0.9621) and probability level (P > 0.773) of statistical tests indicated high accuracy and capability and high generalizability of the MLP neural network for estimating R0 and rm of greenhouse whitefly.

Nabis pseudoferus is a major biocontrol agent of sucking pests and caterpillars. Life history parameters, consumption rate and cold storage of N. pseudoferus on three diets; Aphis gossypii, Ephestia kuehniella eggs, and Aphis gossypii + Ephestia kuehniella eggs were estimated at 25 ± 1°C temperature, 60 ± 10% R.H. and a photoperiod of 16:8 h. (L:D). The results revealed that the intrinsic rate of increase (r) were 0.033 ± 0.003, 0.043 ± 0.003 and 0.062 ± 0.002 day-1 which was significantly different in terms of feeding diets. Data analysis showed that the net predation rate (C0) of N. pseudoferus by feeding on cotton aphid and mixed diets of cotton aphid + Ephstia kuehniella eggs were 1347.95 ± 276.77 and 2259.62 ± 145.54, respectively. Additionally, hatching rate of N. pseudoferus eggs after cold storage at 5°C for 7, 14 and 21 days were 72.22, 69.23 and 69.23%, respectively. These results could be useful for optimizing rearing procedure of N. pseudoferus.

The hemocytes of insects are one of key components of immune system of insects against various stresses such as temperature changes. in hemolymph of Scrobipalpa ocellatella, Five types of identified hemocytes were prohemocytes (PRs), plasmatocytes (PLs), granulocytes (GRs), oenocytoids (OEs) and spherulocytes (SPs). The effect of different thermal stresses was also investigated for 24 hours on cellular defense of fifth instar larvae. At 28 and 30 °C, total hemocyte count (THC), GRS and OES of larvae was increased significantly compared to the control (20±1 °C). Also, chill stress (4 °C) showed a significant decrease in THC, PLs and GRS compared to the control. These findings could be used as a base for further investigation on the immunology studies of beet moth.