فصلنامه تحقیقات حشره شناسی
سال چهاردهم شماره 4 (پیاپی 56، زمستان 1401)

In this study, we performed quantum mechanics computation at density function theory level with 6-31G* basis set to construct a quantitative structure-toxicity relationship (QSTR) model for predicting lethal dose (LD50) pesticide carbamates derivatives. The best molecular descriptors were selected using genetic algorithm (GA) by MATLAB software. Then, we studied the relationship between the selected descriptors and the logLD50 of carbamate derivatives using backward-stepwise multiple linear regression (BW-MLR) and backpropagation artificial neural network (BP-ANN) models. The RDF010e, WW, and R3e descriptors were applied for modeling the GA-BWMLR and GA-BPANN models. The comparison of results illustrated that the R2 and Q2 of GA-BPANN model for all set were significantly higher than the GA-BWMLR model. The GA-BPANN model was more accurate with lower mean square error (MSE), root-mean-square error (RMSE), standard error of prediction (SEP), and absolute average deviation (ADD) values of data set for predicting the LD50 of studied carbamates.

Varroa destructor Anderson & Trueman is one of the most perilous pests of honey bee colonies around the world. So, natural products such as plant essential oils are considered as a suitable replacement for chemical compounds in pest control. This study was planned to check the respiratory killing effect of essential oils of four perennial Satureja species on Varroa destructor and Apis mellifera meda in an apiary. The sensitivity of the mite to four essential oils was according to the following, S. khuzestanica Jamzad, S. rechingeri Jamzad, S. mutica and, S. bachtiarica Bunge. The calculated LC50 values for S. khuzestanica Jamzad and S. rechingeri Jamzad were 151.6 and 161.77 ppm for Varroa mite and 328.22 and 337.7 for honey bee, respectively. Qualitative analysis of essential oils showed that the major component of the oils for all species was carvacrol. Satureja khuzestanica Jamzad and S. rechingeri Jamzad had the highest amount of carvacrol with 93.5% and 88.8%, respectively. In general, the essential oil of S. khuzestanica Jamzad and S. rechingeri Jamzad had a high ability to control Varroa mites.

American cockroach is one of the important household insects, which transmits many types of pathogens to the environment. On the other hand, the methods used to control it today are somewhat ineffective and have caused resistance in these insects.

311 adult American cockroaches were purchased from Tehran Health College. Titanium oxide nanoparticles were also purchased from Neutrino company, Tehran. Different concentrations of nanoparticles were prepared for oral and contact treatments of American cockroaches. American cockroaches were treated by contact and oral method with different concentrations of titanium oxide nanoparticles with three repetitions. The average percentage of insect mortality in different groups was compared by one-way analysis of variance and Duncan's test. Also, the average percentage of insect mortality on different days in each group was compared by analysis of variance with repeated observations.

The oral treatment of American cockroaches was more effective than the contact treatment in concentrations of 15 and 21% in all days, but the contact treatment was more effective than the oral treatment in all days except the seventh day in a concentration of 25%. In general, oral treatment was more effective than contact treatment. With increasing dose and passage of time, the mortality percentage of American cockroaches increased significantly due to contact and oral treatment with titanium dioxide nanoparticles.

The use of different nanoparticles, including titanium dioxide nanoparticles, can create a significant effect in controlling the American cockroach as a new method along with the previous methods.

Quinoline alkaloids and their derivatives have wide medical and agricultural applications. In this research, a quantitative structure- property relationship (QSPR) has been employed to predict the octanol-water partition coefficient (logP) of 76 quinoline alkaloid camptothecin (CPT) derivatives as antitumor potencies using GA-MLR method and molecular descriptors. The Gauss View 05 software was used for drawing chemical structure of the studied compounds. The geometry optimizations of the studied compounds were done by the Gaussian 09W software at B3YLP density functional theory (DFT) with 6-311G (d,p) basis set. Molecular descriptors for each of optimized structures were calculated by Dragon software in different category. In order to reduce and select the best descriptors, the Genetic Algorithm technique and stepwise multiple linear regression method was used. The pearson coefficient correlation (PCC) and the variance inflation factor (VIF) statistics were used to test the multicollinearity of descriptors in the best model. The different types of internal and external validations were used to evaluate predictive model performance. The best QSPR model is obtained with R2 value of 0.901, Q2LOO =0.919, and RMSE=0.706.     The results of statistical parameters and validations of the GA-MLR model generated were found to be satisfactory. The model revealed that octanol-water partition coefficient of CPT derivatives is influence by ATS8e (2D-autocorrelation) descriptor. This information could be used to design novel quinoline alkaloid camptothecin (CPT) derivatives as insecticide agents.

In this research, predicting the logP of 34 types different pyrethroid derivatives was studied using quantitative structure-property relationship. The logP of studied pyrethroids was modeled using the genetic algorithm based on linear regression method (GA-MLR). It was found that the three effective descriptors GATS4P, PW3 and ZM1V have a reasonable correlation with logP, and led to the creation of a model with the highest regression coefficient and the lower error. The evaluation of GA-MLR model predictive ability for test set was performed by statistical parameters such as R2= 0.862, R2adj = 0.848, F=62.296 and MSE = 0.503. Also, the value of Q2LOO= 0.861 using the cross-validation method, and the values of R2 =0.880 and 0.929 for the training and test sets respectively, in the external validation method showed a very good correlation between experimental and prediction values. It was specified that the MLR model was reliable for predicting the logP of pyrethroid insecticides, and had sufficient accuracy with the lowest error.

The common green lacewing Chrysoperla carnea Stephens. is one of the critical natural enemies of pistachio psyllid Agonoscena pistaciae Burkhardt and Lauterer. in pistachio orchards of the Kerman province of Iran. Considering the economic importance of the pistachio psyllid, knowledge of the interactions between the pesticides used and biological pest control agents in the case of pistachio psyllid is necessary to implement IPM programs. In this research, the effects of some Hexaflumoron and Flufenoxuron insecticides were investigated on some biological parameters of C.carnea in the laboratory and the growth chamber with temperature conditions of 26±1C°, Relative humidity of 70±5 and photoperiod 16 hours of light and eight the hour of darkness. The estimated LC50 values for Hexaflumoron and Flufenoxuron on first-instar larvae of the C.carnea were 1.8 µg/ml and 5.2 µg/ml, respectively. LC25, as a measure of sub-lethal effects for hexaflumoron and flufenoxuron was estimated as 0.66 µg/ml and 3.3 µg/ml, respectively. According to the analysis of variance, the duration of immature stages and the lifespan of adults in the treatment with Flufenoxuron and Hexaflumoron significantly increased and decreased at 1% compared to the control. Concerning the sublethal effects of Flufenoxuron and Hexaflumoron, the duration of the immature stages of C.carnea increased by 7.6 and 9.1%, respectively, compared to the control, and the lifespan of adult insects decreased by 6.9% and 10.6% respectively. No significant difference was detected between Flufenoxuron and Hexaflumoron in terms of the immature and adult lifespans. The LC25 values of Flufenoxuron and Hexaflumoron reduced the fertility of C.carnea by 19.7% and 33.2%, respectively. Also, the hatching rate of C.carnea eggs in contact with Flufenoxuron and Hexaflumoron decreased by 21.7% and 31.4%, respectively. Due to Flufenoxuron's lower effect than Hexaflumoron on some biological parameters of C.carnea, using Flufenoxuron is more recommended according to the integrated management of A.pistaciae.