فصلنامه تحقیقات حشره شناسی
سال یازدهم شماره 3 (پیاپی 43، پاییز 1398)

The fauna the subfamilies Ichneumoninae and Cryptinae (Hymenoptera: Ichneumonidae) was studied in Mazandaran province, north of Iran during 2016. Sampling was done using 8 Malaise traps which were installed in three altitude layers. Totally, 126 and 64 specimens were collected from the subfamilies Cryptinae and Ichneumoninae, respectively representing 25 species into 20 genera. Of them four genera and five species are recorded for the first time from Iran as following: Acrolyta Förster, 1869, Ceratophygadeuon Viereck, 1924, Eudelus Förster, 1869 and Mevesia Holmgren, 1890, Ceratophygadeuon varicornis (Thomson, 1884), Chirotica maculipennis (Gravenhorst, 1829), Eudelus gumperdensis (Schmiedeknecht, 1893), Mevesia arguta (Wesmael, 1845) and Virgichneumon albilineatus (Gravenhorst, 1829). Also a checklist of subfamilies Ichneumoninae and Cryptinae in Iran is provided. With new data of current research, the number of identified species of the subfamily Cryptinae of Iran and of the Hyrcanian forests biome increased to 128 and 39 species and for Ichneumoninae increased to 191 and 115, respectively.

The flower bugs genus Orius Wolff, 1811 (Hemiptera: Anthocoridae) in Fars province is reviewd. These insects are useful and important as natural members of the predatory fauna and as biological control agents in many agroecosystems. The Orius specimens were collected from different regions of Fars province (southern Iran) during 2016-2019, and put in alcohol 75% mix of Glycerin 5%.  Then males' genitalia and females' copulatory tubes were mounted on slides by Hoyer’s medium to examine and illustrate the detailed characters. In this research Eight species are recognised, one of them Orius piceicollis (Linberg,1936)and subspecies Orius laevigatus maderensis (Reuter,1884)are new records for Iran. Diagnoses, habitus and DIC images of species including both male and female genitalia are provided. However identifying these insects has been based on identifying the male’s genitalia, but    upon the results of this investigation, female copulatory tubes, along with a male paramer characters can be used as a reliable character for identification of genus Orius species.

Stethorus gilvifrons is one of the most important monophagus predators of Tetranychus urticae. In this study, demographic parameters of S. gilvifrons were compared between solitary and group (5 pairs of the predator) rearing systems feeding on different developmental stage of T. uricae at 27±1°C temperature, 60±10% RH and a photoperiod of 16:8 h. L:D. In order to start experiments, 120 eggs (< 24 h. old) were selected randomly from the laboratory culture of S. gilvifrons for each treatment. The data were analyzed based on the age-stage, two-sex life table theory. Developmental times of the incubation period, larval, pupal, and total immature stages of S. gilvifrons were 3.92±0.08, 6.52±0.14, 2.98±0.06, 13.59±0.14 days, respectively, in solitary rearing system. In the case of group rearing, developmental time of S. gilvifrons for the mentioned developmental stages were 3.51±0.06, 6.85±0.21, 2.85±0.11, and 13.18±0.21 days, respectively. Moreover, estimated values of intrinsic rate of increase (r), finite rate of increase (λ), mean generation times (T), net reproductive rate (R0) and Gross reproduction rate (GRR) were (0.1219; 0.1455 day-1), (1.1297; 1.1567 day-1), (30.23; 19.88 day-1), (39.92; 18.08 offspring/individual), (265.38; 88.37 females/female/generation), respectively in solitary and group rearing systems. According to the obtained results, demographic parameters of the S. gilvifrons were affected by the number of the individuals in the arena, and population growth was less in the group rearing system, in comparison with solitary rearing condition. These findings can be useful for improving mass rearing of S. gilvifrons and biological control programs of Tetranychids.

The nucleotide and protein sequences and phylogenetic relationships between the genes encoding seven cytochrome P450 enzymes for the entomopathogenic fungus Beauveria bassiana strain ATCC90517 existed in the gene bank were assessed. Based on BLASTN results, the highest identity of the seven sequences was observed with the genes of B. bassiana strain ARSEF (84-100%) and then the fungi Cordyceps militaris and Isaria fumosorosea (76-89%), which was according to the BLASTP results. Calculating the percentage of sequence identity with each other using the SIAS program showed that only the amino acid sequences related to CYP52X1 and CYP52G11 genes had more than 47% identity and put in the same family (CYP52). Sequences associated with different families had identity less than 44%. The phylogenetic trees plotted using software IQ-tree v.1.6 based on the nucleotide and amino acid showed that CYP53A26 and CYP617N1 were most closely matched to each otherand put in a separate group. Other P450 genes were also in the same group. Determination of the protein characteristics and motifs of seven enzymes of cytochrome P450 in the fungus B. bassiana is very important and necessary due to their role in iron binding. The presence of various amino acids with different properties in the motifs has been able to increase the host range of this fungus in controlling pest insects.

The application of chemical pesticides to control plant pests causes contamination of soil, air and surface and underground water, resulting in damage to non-target species and humans. Non-chemical pest control methods included physical, biological and genetic control and the broad based integrated pest management have been advocated as the ways to reduce pesticide contamination in environment. One of the physical pest control methods is the use of acoustic (sound or ultrasound) electronic devices that act as pest repellers, pest chasers, pest deterrents, disruptors of pest mating and pesticides. Scientists have identified and classified different species of insects by patterning of the bio acoustic signals that insects produce for sexual communication or react to them for escaping from the predators. Also, by emission of synthetic sound of insects, they cause disruption in the mating of insects or attract the opposite sex and capture them to reduce the population of pests. Research has shown that acoustic control can be used as an effective and low cost supplement to chemical control of pests. Some studies of acoustic control of insect pests are mentioned in this review.

In this research, Quantitative Structure–Activity Relationship (QSAR) studies have been used to predict activities of organochlorine pesticides. Firstly, the chemical structure of molecules was drawn with the Gauss view 05 program and optimized at Hartree–Fock level of theory and 6-31G* basis sets using Gaussian 09 software. The physiochemical properties namely octanol-water partition coefficient (logP) and toxicity (log LD50) are taken from the scientific web book. The dragon software has been used for the calculation of molecular descriptors. The suitable descriptors were selected with the aid of the genetic algorithm (GA) and backward techniques. At the next step, the relationship between molecular descriptors and the activities was investigated by multiple linear regression (MLR) method. In order to build and test QSAR models, a data set of organochlorine pesticides was randomly separated into 2 groups: training (80%) and test (20%) sets. The models were evaluated with regression parameters: correlation coefficient (R), squared regression coefficient (R2), adjusted correlation coefficient (R2 adj) and root mean squared error (RMSE). For the predictive ability and verification of the models are discussed by using Leave-One-Out (LOO) cross-validation and external test set. The external prediction accuracy of the obtained models was examined using the above regression parameters. Results of validations and high statistical quality of models indicate that generated GA-MLR models are reasonable QSAR models. These models help to delineate the important descriptors responsible for predicting their activities.

In this study, the fauna and biodiversity of thrips of wheat and barley fields was investigated in different environmental conditions, moderate cold climate (Eyvan city) and moderate tropical climate (Darreh Shahr city) in Ilam province, Iran. sampling was carried outweeklyand barley fields. Totally, eightthrips species belonging to six genera and four families were identified. Amongst them, Haplothrips tritici (Kurdjumov, 1912) was the dominant species the abundance of 46.47% and 84.68% in wheat fields, and Thrips tabaciLindeman, 1889was the dominant species the abundance of52.22% and 10.3% in barley fields in Eyvan and Darreh-Shahr cities, respectively. The results showed that Shannon-Wiener, Simpson and Margalef's indices of thrips species in field crops of Eyvan city (moderate cold climate) were significantly higher than those of Darreh-Shahr city (moderate tropical climate), but Evenness was not different significantly between wheat and barley fields in Eyvan and Darreh-Shahr. In general, biodiversity of thrips species in moderate cold climate (Eyvan city) was higher than that of moderate tropical climate (Darreh-Shahr city).