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This study investigated the potential effect of cold plasma on reducing residues of pesticides diazinon and chlorpyrifos in apples and cucumbers and its effects on property of products. Two separate concentrations of each pesticide with 500 and 1,000 ppm were prepared and the samples were inoculated by dipping them into the solutions. All samples treated with pesticides were exposed to cold plasma in a monopole cold plasma apparatus (DBD) run at 10 and 13 kV voltages. Liquid-liquid extraction (LLE) was used to remove pesticide residues from the samples. Eventually, high-performance liquid chromatography (HPLC) was used to measure the amount of pesticides in the samples. Also, to investigate generated metabolites, extracts were injected into a GC/MS apparatus. In addition, the effects of cold plasma on humidity, tissue hardness, color and the sugar percentage of products were analyzed. The results revealed that treatment of samples with cold plasma considerably reduced pesticide residues without leaving any traces of harmful or toxic substances. Furthermore, it did not have any undesirable effects on the color and texture of the samples. The efficiency of this method increased with higher voltage and longer exposure time. In general, the best results were obtained by the combination of 500 ppm concentration, 10 min exposure and 13 kV voltages. The residues of diazinon were reduced better than the residues of chlorpyrifos. Apples were detoxified much better than cucumbers. Also, cold plasma treatment transformed diazinon and chlorpyrifos pesticides into their less toxic metabolites. The results showed that with increased voltage and longer exposure time, cold plasma caused few changes in moisture and glucose content, texture hardness and color of products. Th ere were no significant difference between treated samples and control in all treatments.

Essential oils as alternative synthetic pesticides for pest management of foodstuffs have recently received increased attention. Controlled and slow release formulations of essential oils are used to enhance their efficiency. Two volatile essential oils of Mentha piperita L. and Salvia officinalis L. were investigated for release rate and mortality percentage by fumigant toxicity against 1st instar larvae of Plodia interpunctella. Electrospinning was used to incorporate various concentrations of essential oils in nanofibers. The essential oils can be released from the nanofibers for long periods of time, from several days to several weeks. Poly(lactic acid) was used as a green polymer carrier and the essential oils were incorporated into the nanofibers (8-15v/v% PLA). Insecticidal bioassay revealed that oil-loaded nanofibers (NFOs) were more toxic than pure essential oils (PEOs) against tested larvae. The LC50 and LT50 of NFOs were 1.2 and 4 times, respectively, more than PEOs. Our results indicated that PEOs completely lost their insecticidal activity after 14 days, whereas at the same period, NFOs had an average of 93% mortality when applied against P. interpunctella. Therefore, it can be concluded that nanofibers improved the persistence of the oil. This study presents S. officinalis has more toxicity and M. piperita had more persistence for controlling the larvae of indian meal moth.

The contact insecticidal activity of in natura and maltodextrin/Angum gum nanoencapsulated essential oils of Eucalyptus globulus Labill and Zataria multiflora Bioss was evaluated against the third instar larvae of Ephestia kuehniella (Lepidoptera: Pyralidae). The essential oil from E. globulus exhibited an average yield of 1.19%, and presented 1,8-cineol (59.08%) as the major component, while Z. multiflora essential oil, with an average yield of 1.5%, was characterized by thymol (26.12%) and carvacrol (25.31%) as the main components. The encapsulated particles presented spherical morphology with regular and homogeneous external surfaces, ranging from 60 to 130 nm in diameter. Laboratory bioassays estimated the contact LC50 of in natura and encapsulated essential oils as 13.07 and 1.34 µL L−1 for E. globulus and 1.47 and 5.87 µL L−1 for Z. multiflora, respectively. The results presented here, which are probably the first to be reported, suggested that essential oil nanoencapsulation represents an efficient method for enhancing both insecticidal activity and the durability of the active ingredients for sustainable pest management. [ABSTRACT FROM AUTHOR]

In this study, 94 staphylinid species of 59 genera belonging to four groups (omaliin, tachyporin, oxyteline and staphylinin) and 13 subfamilies (including, Dasycerinae, Omaliinae, Proteininae, Pselaphinae, Oxytelinae, Piestinae, Oxyporinae, Steninae, Paederinae, Staphylininae, Phloeocharinae, Tachyporinae and Aleocharinae) were collected from different regions of Iran.

The pistachio psylla, Agonoscena pistaciae Burckhardt & Lauterer (Hem.: Psyllidae), is the most important pest of pistachio orchards in Iran. It causes quantitative and qualitative reduction of the product. Different concentrations, 4 (+dimethicone) and 8 per thousand of silica, and 4 (+dimethicone), 6 (+dimethicone), and 8 per thousand of diatomaceous earth (DE) were sprayed on the whole canopy to evaluate its effectiveness on different life stages of A. pistaciae in the field. Sampling was carried out at 3, 8, 13-, 18-, 21-, and 28-days post-treatment. The results showed that DE8 had a decreasing effect on eggs, nymphs, and adults with a 96.4%, 80.2-93.7%, and 86.6% effectiveness. It was most effective on the eggs of A. pistaciae. Including dimethicone in some treatments increased the effectiveness of treatments in the density reduction of pests, but it needs further studies. Therefore, the use of DE may be an effective strategy in the integrated management of A. pistaciae. [ABSTRACT FROM AUTHOR]

Edible insects are considered as an alternative protein source for consumption in many countries and special attention has been given to their microbiological safety. In this study, larvae of dried yellow mealworm Tenebrio molitor were collected and subjected to various drying techniques, namely, sun-drying (T1), boiling for 30 s with subsequent 24 h drying at 60 °C (T2) and boiling for 1 min with subsequent 48 h drying at 70 °C (T3). A variety of bacteria were isolated from the dried samples and were analysed based on biochemical, pathogenicity characteristics and molecular analysis. Results showed that the bacteria were Escherichia coli, Enterococcus gallinarum, Staphylococcus succinus, Bacillus cereus, Bacillus atrophaeus and Cronobacter sp. Two important pathogenic bacteria were also identified and assigned as E. coli and B. cereus. Total bacterial populations in T1, T2 and in the ready product were 2.19 × 105 CFU·g-1, 2.16 × 105 CFU·g-1 and 2.04 × 105 CFU·g-1, respectively. T3 was the most effective drying method with no bacterial growth. These results indicate that a short heating treatment is an effective approach to eliminating bacteria, except for Gram-positive endospore-forming bacteria. Otherwise, some hygienic practices and proper processing methods are necessary to treat the larvae before consumption. [ABSTRACT FROM AUTHOR]

The effect of monoterpenoid 1,8-cineol on the toxicity and physiology of elm leaf beetle, Xanthogaleruca luteola Müller under laboratory conditions (26 ± 1°C, 65 ± 10% RH and 16L : 8D h) was investigated. Initially, LC30 and LC50 values of the constituent were estimated to be 23.5 ppm and 31.9 ppm for the last instar larvae after 48 h, respectively. Significant changes were observed in the values of relative growth rate (RGR), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD), approximate digestibility (AD) and consumption index (CI) between control and treated larvae with 1,8-cineol. The amounts of protein, glucose and urea decreased in the treated larvae in comparison with control. Similar findings were observed in the activities of alkaline phosphatase and lactate dehydrogenase while the activities of glutathione S-transferase and esterase significantly increased in the treated larvae using CDNB and a-naphtyl acetates as the substrates. Morphological and histological changes brought about by 1,8-cineol in the present study are indicative of growth inhibition targeting specific organs such as those of reproduction. We believe that 1,8-cineol can be considered as a safe and environmentally friendly compound. [ABSTRACT FROM AUTHOR]

Phenoloxidase (PO) plays a key role in insects’ immunological and physiological processes. In this study, PO from hemolymph ofDociostaurus maroccanus,which is an important pest of crops in the world, is purified in three steps: ammonium sulfate precipitation, gel-filtration and ion-exchange chromatography. The biochemical properties of PO were characterized usingl-dihydroxyphenylalanine (l-DOPA) as a substrate. The optimal pH and temperature of the purified enzyme were 7 and 35 °C, respectively. A single band with a molecular weight of 73 kDa was appeared using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) assay. The effects of ions and chemical materials showed that enzyme activity was significantly inhibited by Zn2+. IC50values of inhibitors on PO activity were determined as 13.14, 32.41 and 48.2 μM for 4-hexylresorcinol, kojic acid and quercetin, respectively. The inhibitory potencies (i.e. I50of each inhibitor/I50of 4-hexylresorcinol) of 4-kojic acid and quercetin were determined to be 2.44 and 3.66, respectively. The inhibition type of PO by 4-hexylresorcinol was obtained as competitive inhibitor, kojic acid and quercetin were found to be mixed inhibitors. Biochemical characterization of PO, as one of the most important enzymes in immune system of insect, is essential for achieving new and safe methods for pest control. [ABSTRACT FROM PUBLISHER]

The effects of maize and sugarcane were studied on the demographic parameters ofSesamia nonagrioidesunder controlled environmental conditions. Life table parameters were estimated using age-stage two-sex life table method. Total developmental times of immature stages were 53.51 ± 0.42 and 39.58 ± 0.14 days on maize and sugarcane, respectively. The fecundity values were found to be 93.07 ± 2.94 and 122.95 ± 6.72 eggs/female on maize and sugarcane, respectively. Based on the analysis, the intrinsic rates of increase (r) and the mean generation time (T) ofS. nonagrioideswere determined as 0.0909 ± 0.0027 and 0.0579 ± 0.0021 day−1; 42.09 ± 0.21 and 56.83 ± 0.63 days on sugarcane and maize, respectively. Consequently, the sugarcane was a better host for development and population increase ofS. nonagrioidesthan maize. These results can be used to predict population dynamics of the pest on the natural hosts and to improve mass rearing technique on natural diets in insectariums. [ABSTRACT FROM AUTHOR]

This study investigated the potential effect of cold plasma on reducing residues of pesticides diazinon and chlorpyrifos in apples and cucumbers and its effects on property of products. Two separate concentrations of each pesticide with 500 and 1,000 ppm were prepared and the samples were inoculated by dipping them into the solutions. All samples treated with pesticides were exposed to cold plasma in a monopole cold plasma apparatus (DBD) run at 10 and 13 kV voltages. Liquid-liquid extraction (LLE) was used to remove pesticide residues from the samples. Eventually, high-performance liquid chromatography (HPLC) was used to measure the amount of pesticides in the samples. Also, to investigate generated metabolites, extracts were injected into a GC/MS apparatus. In addition, the effects of cold plasma on humidity, tissue hardness, color and the sugar percentage of products were analyzed. The results revealed that treatment of samples with cold plasma considerably reduced pesticide residues without leaving any traces of harmful or toxic substances. Furthermore, it did not have any undesirable effects on the color and texture of the samples. The efficiency of this method increased with higher voltage and longer exposure time. In general, the best results were obtained by the combination of 500 ppm concentration, 10 min exposure and 13 kV voltages. The residues of diazinon were reduced better than the residues of chlorpyrifos. Apples were detoxified much better than cucumbers. Also, cold plasma treatment transformed diazinon and chlorpyrifos pesticides into their less toxic metabolites. The results showed that with increased voltage and longer exposure time, cold plasma caused few changes in moisture and glucose content, texture hardness and color of products. Th ere were no significant difference between treated samples and control in all treatments. [ABSTRACT FROM AUTHOR]

Essential oils as alternative synthetic pesticides for pest management of foodstuffs have recently received increased attention. Controlled and slow release formulations of essential oils are used to enhance their efficiency. Two volatile essential oils of Mentha piperita L. and Salvia officinalis L. were investigated for release rate and mortality percentage by fumigant toxicity against 1st instar larvae of Plodia interpunctella. Electrospinning was used to incorporate various concentrations of essential oils in nanofibers. The essential oils can be released from the nanofibers for long periods of time, from several days to several weeks. Poly(lactic acid) was used as a green polymer carrier and the essential oils were incorporated into the nanofibers (8-15v/v% PLA). Insecticidal bioassay revealed that oil-loaded nanofibers (NFOs) were more toxic than pure essential oils (PEOs) against tested larvae. The LC50 and LT50 of NFOs were 1.2 and 4 times, respectively, more than PEOs. Our results indicated that PEOs completely lost their insecticidal activity after 14 days, whereas at the same period, NFOs had an average of 93% mortality when applied against P. interpunctella. Therefore, it can be concluded that nanofibers improved the persistence of the oil. This study presents S. officinalis has more toxicity and M. piperita had more persistence for controlling the larvae of indian meal moth. [ABSTRACT FROM AUTHOR]

An α-amylase with molecular weight of 73 kDa was purified from midgut ofDociostaurus maroccanususing ammonium sulfate precipitation, gel filtration, and ion exchange chromatography. The optimal pH and temperature were 6 and 45 °C, respectively. As calculated using Lineweaver–Burk plots, theKmwas about 0.62 mM and theVmaxwas 1.113 (μmol/min/mg protein). Mn2+, Hg+, Zn2+and ethylene diamine tetraacetic acid (EDTA) decreased α-amylase activity ofD. maroccanus, whereas the addition of K+, Na+, Fe2+, Ba+, Mg2+, Ca2+and Co2+increased enzyme activity. Alpha-amylase inhibitors (AI1, AI2) with molecular weights of 43 kDa and 29 kDa, respectively, were purified from the seeds ofPhaseolus vulgarisand its inhibitory effect on purified α-amylase ofD. maroccanuswas investigated. These inhibitors inhibited theD. maroccanusgut α-amylase activity significantly. [ABSTRACT FROM AUTHOR]

The cosmopolitan Indian meal moth,Plodia interpunctellaHübner (Lep.: Pyralidae), is a serious pest that causes economic damages to many strategic stored products. Plant protease inhibitors (PIs) have been shown to play essential roles in regulating proteolytic processes in insects. Plant PIs have been recently considered as a potential safe weapon against insect pests either through their direct assay or by expression in transgenic plants. Proteinaceous extracts were obtained from the seeds of two medicinal legumes plants namely, Senna (Cassia angustifolia) and Fenugreek (Trigonella foenum-graecum). Larval digestive trypsin ofP. interpunctellawas inhibited in treatments with these inhibitors up to 99.79 ± 7.5 and 61.29 ± 2.2%, respectively, by usingNα-benzoyl-DL-arginine-p-nitroanilide substrate. Total proteolytic inhibitory activity ofP. interpunctellalarval midgut was studied in both absence (control line) and presence of the extracts taken from Senna and Fenugreek seeds. Several thick bands (a–d) were detected very close to each other’s in control line. The width of detected bands was reduced in samples treated by both inhibitors. [ABSTRACT FROM PUBLISHER]