Toxicity of propylene oxide alone and in combination with low pressure or carbon dioxide against life stages of Ephestia cautella (Walker) (Lepidoptera: Pyralidae) under laboratory conditions

A series of tests was carried out in the laboratory for comparison of the insecticidal effect of propylene oxide (PPO) alone and in combination with low pressure and/or elevated levels of carbon dioxide against eggs, larvae, pupae and adults of Ephestia cautella (Walker) (Lepidoptera: Pyralidae). All life stages of E. cautella were exposed to PPO alone and in combination with either a low pressure of 100 mm Hg or 92% CO2for 4 h at 26 ± 1 °C and 65 ± 5% relative humidity (r.h.). The results indicated that PPO alone was moderately effective with concentration x time products (Ct products) required to obtain 99% mortality of the different life stages of E. cautella ranging between 66.1 and 536.2 mg h/L. The life stages differed in their susceptibility to PPO. Eggs were the most susceptible with a LC99value of 16.5 mg/L, whereas pupae were the most tolerant with a LC99value of 134.1 mg/L. Mortality of all life stages was extremely low (1.3–18.8%), when exposed to either the low pressure or 92% CO2alone for 4 h. However, when low pressure or 92% CO2were combined with PPO, the LC50and LC99values for all stages of E. cautella were notably reduced. Combination of PPO with low pressure or 92% CO2caused reductions in the LC99values for all life stages, compared with those exposed to PPO alone. These results indicated that low pressure (100 mm Hg, equals to 13,332 Pa or 0.13 atm) and 92% CO2clearly increased the efficacy of PPO to E. cautella. By considering the overall insecticidal efficacy data, the combination of PPO with low pressure was, in all cases, more effective than the combination of PPO with CO2. © 2017 Elsevier Lt

Immediate and delayed mortality of the larger grain borer, Prostephanus truncatus (Horn), on different surfaces treated with thiamethoxam and alpha-cypermethrin

In this study, we evaluated efficacy of alpha-cypermethrin and thiamethoxam on concrete, linen and plastic surfaces, against adults of the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae), which is an important pest of stored maize in the tropics. Insect mortality was recorded after 1, 3 and 7 days of exposure. Then, separately for each initial exposure, the surviving individuals were transferred to untreated surfaces and delayed mortality was assessed again 1, 3 and 7 days later. Adult mortality on both insecticide treated linen surface was significantly lower than those on the other surfaces. Regarding delayed mortality, for adults that had been initially exposed for 7 d, complete control was detected 7 d later on plastic and concrete surfaces treated with thiamethoxam, while for alpha-cypermethrin complete mortality was detected only on plastic surface. Overall, there was a noticeable delayed mortality of P. truncatus adults, for all exposures and surfaces, which indicates that even if the insects are removed from the substrate that with either alpha-cypermethrin or thiamethoxam, delayed mortality is more likely to occur than recovery. © 2017 Elsevier Lt

Pesticide nanoformulations based on sunlight-activated controlled release of abamectin

A controlled release system that enables the sunlight-triggered release of a model agrochemical, abamectin (abm), is presented. The release system consists of polydopamine functionalized halloysite nanotubes (HNT-PDA) utilized as photothermal nanocarriers to encapsulate 25 wt % abm and 37 wt % lauric acid (LA), a phase change material, that acts as a heat-activable gatekeeper stopping or facilitating the abm release. When exposed to sunlight for 20 min at 1 and 3 sun light density, the temperature of the photothermal nanocarriers reaches 51 and 122 °C, respectively, which triggers the melting of LA and the consequent release of abm from the nanocarriers. Abm was shown to be released gradually over a period of 10 days when nanohybrids were exposed to sunlight for 6 h per day and to remain stable and kill Myzus persicae (Sulzer) (Hemiptera: Aphididae), green peach aphids, at a mortality rate of over 70% for at least 10 days. Aqueous dispersions of the LA/abm@HNT-PDA nanohybrids were studied in terms of their potential as aqueous sprayable pesticide nanoformulations and presented over 30% suspensibility, 36 mg/cm2 foliar retention, strong rainwater resistance, and a 50% mortality rate for M. persicae at a concentration of 9 mg/mL. The proposed sunlight-activated controlled release system based on photothermal, LA-functionalized HNT-PDA nanocarriers holds great potential as controlled release pesticide nanoformulations

Seasonal abundance of adults of Coccinella septempunctata L. (Coleoptera: Coccinellidae) parasitized by coccinellid parasitoid, Dinocampus coccinellae (Schrank) (Hymenoptera: Braconidae) in Kahramanmaras province

WOS: 000267629100003In this study, seasonal abundance of adults of Coccinella septempunctata L. (Coleoptera: Coccinellidae) parasitized by coccinellid parasitoid, Dinocampus coccinellae (Schrank) (Hymenoptera: Braconidae) in three different regions (Central, Andirin and Goksun district) in Kahramanmaras province were determined. This study indicated that parasitism rates of D. coccinellae on C. septempunctata adults varied greatly in the districts and seasons. Low parasitism rates were observed on hibernating adults or newly emerged adults of C. septempunctata from hibernation sites in two districts (Goksun and Andirin) while high parasitism rates were observed in Central district. There was only one peak of D. coccinellae on the adults of C. septempunctata in all three districts throughout the season. Timing of peaks in Goksun and Andirin district was found to be different from that in Central district. The maximum parasitism rate was higher in Central (27%) and Andirin (24%) district than that in Goksun (16%) district. Parasitism rate on the both hibernated (27%) and new generation (23.5%) adults of C. septempunctata in Central district was reached the important levels. In conclusion, this study indicated that the mortality of C. septempunctata adults due to parasitism of D. coccinellae especially in Central district of Kahramanmaras could have an impact on developing populations of C. septempunctata in the spring

Efficacy of gaseous ozone at high concentrations against Plodia interpunctella (Hubner) and Ephestia cautella (Walker) in Almond

WOS: 000373701000008In this study efficacy of gaseous ozone at high concentrations and short exposure time against all life stages of Plodia interpunctella (Hubner) ve Ephestia cautella (Walker) (Lepidoptera: Pyralidae) in almond was investigated under laboratory conditions. All life stages of E. cautella and P. interpunctella placed at the top and bottom position of 1.3 kg almond in fumigation chamber were exposed to two different concentrations (8.35 and 33.33 mg/l) of ozone flush treatment at 30 minute intervals for 6 hour. The results of biological tests indicated that ozone treatment at 33.33 mg/l concentration resulted in % 100 or nearly % 100 mortalities of only adult and pupa stage of E. cautella and all life stages of P. interpunctella placed at top position of the almond. However, ozone treatments at lower concentration (8.35 mg/l) caused nearly % 100 mortalities of only adult and pupa stage of P. interpunctella at placed at top position of the almond. It was clear that ozone treatments at low concentration (8.35 mg/l) resulted in significantly lower mortalities of all life stages of E. cautella and P. interpunctella than those at high concentration (33.33 mg/l). Generally, in all ozone treatments the mortalities of tested insects placed at top position of the almond were higher than those placed at bottom position of the almond. Notably, it was hard to kill the larvae and eggs of E. cautella and P. interpunctella placed at bottom position of the almond. Moreover, it was found that E. cautella was more tolerant to ozone treatments than P. interpunctella except their egg stage. In conclusion, this study shows that ozone treatment at high concentrations and short exposure time could not be effective alternative to methyl bromide for the rapid disinfestations of the almonds since it did not cause the complete mortality of all life stages of E. cautella and P. interpunctella on almond

The use of ozone gas for the control of insects and micro-organisms in stored products

In this review paper, we analyze the potential of using ozone as an alternative pest control technology for use in stored products, and we also illustrate data on the efficacy of ozone against micro-organisms and its effect on qualitative characteristics and properties of the treated commodities. Ozone application is currently attracting attention, particularly due to the fact that a) there are no residues on the product and b) there is no need for aeration to remove the gas. Novel industrial applications and improvements in ozone technology together with new regulatory actions worldwide have emerged in recent years, making its use in the food industry easier and applicable in a wide range of cases. This review paper presents available literature on ozone in relation to its use against pests and other organisms, but also to its different application techniques and for large scale viability. © 2014 Elsevier Ltd. All rights reserved