Potter Spray Tower Research Articles

Comparative analysis of the Potter Tower and a new Track Sprayer for the application of residual sprays in the laboratory

BackgroundEfforts to evaluate the residual efficacy of new indoor residual spraying (IRS) formulations have identified limitations with the industry standard laboratory sprayer, the Potter Spray Tower (PT). Calibrating the PT can be time-consuming, and the dosing of surfaces may not be as accurate or uniform as previously assumed.MethodsTo address these limitations, the Micron Horizontal Track Sprayer with Spray Cabinet (TS) was developed to provide higher efficiency, ease of operation and deposition uniformity equal to or better than the PT. A series of studies were performed using a fluorescent tracer and three IRS formulations (Actellic® 300CS, K-Othrine WG250 and Suspend PolyZone) sprayed onto surfaces using either the PT or the TS.ResultsDeposition volumes could be accurately calibrated for both spray systems. However, the uniformity of spray deposits was higher for the TS compared to the PT. Less than 12% of the volume sprayed using the PT reaches the target surface, with the remaining 88% unaccounted for, presumably vented out of the fume hood or coating the internal surfaces of the tower. In contrast, the TS deposits most of the spray on the floor of the spray chamber, with the rest contained therein. The total sprayed surface area in one run of the TS is 1.2 m2, and the operational zone for spray target placement is 0.7 m2, meaning that 58% of the applied volume deposits onto the targets. The TS can treat multiple surfaces (18 standard 15 × 15 cm tiles) in a single application, whereas the PT treats one surface at a time and a maximum area of around 0.0225 m2. An assessment of the time taken to perform spraying, including the setup, calibration and cleaning, showed that the cost of application using the TS was around 25–35 × less per tile sprayed. Standard operating procedures (SOPs) for calibration and use of both the Potter Tower and Track Sprayer have been developed.ConclusionsOverall, the TS represents a significant improvement over the PT in terms of the efficiency and accuracy of IRS formulation applications onto test substrates and offers a useful additional tool for researchers and manufacturers wanting to screen new active ingredients or evaluate the efficacy of IRS or other sprayable formulations for insect control.Graphical

Control of phytopathogen organisms using bioactive compounds contained in orange wax

AbstractOrange wax (OW) is a waxy waste generated in the essential oil purification process (winterization). It has no commercial value. It is discarded or burnt, polluting the environment. The present study demonstrates the possibility of applying it to control phytopathogens. The ethanol‐soluble bioactive compounds of OW were identified and quantified. The effect of orange wax extracts on the growth inhibition of phytopathogenic fungi (Fusarium oxysporum and Colletotrichum gloeosporioides) and Spodoptera frugiperda larvae was evaluated. High‐performance liquid chromatography–mass spectrometry (HPLC‐MS) and gas chromatography–mass spectrometry (GC–MS) quantified 22 bioactive compounds representing 23% (w/w) of OW. Terpineol, limonene, and eremophilene were the most abundant bioactive substances in this material. The distortion of the radial growth of the fungal hyphae was measured in a potato dextrose agar (PDA), and all tested concentrations (6.3, 12.5, 25, 50, and 100 mg/mL) inhibited the radial expansion of C. gloeosporioides. In contrast, only the OW extracts at 50 and 100 mg mL−1 inhibited F. oxysporum. Spray treatments were performed using a Potter spray tower on third‐instar Spodoptera frugiperda larvae. Spraying OW extract at 50 mg mL−1 for 10 s caused the highest larval mortality. However, third‐instar larvae were attracted to consume corn leaves moistened with extract at lower concentrations. Up to 93% of the first‐instar larvae died after eating corn leaves moistened with the extract at 50 mg mL−1. As far as the authors are aware, this is the first scientific report about the use of bioactive compounds of orange wax to control fungi. Spodoptera frugiperda could form the basis for the manufacture of new biopesticides.

Toxicity of spray adjuvants and tank mix combinations used in almond orchards to adult honey bees (Apis mellifera).

Commercial beekeepers transporting honey bees across the United States to provide almond pollination services have reported honey bee deaths, possibly due to pesticide applications made during crop bloom. Pesticides are often applied as "tank mixes", or mixtures of fungicides and insecticides combined into a single application. Spray adjuvants are often added to tank mixes to improve the application characteristics of a pesticide and include spreaders, stickers, or surfactants. The goal of this research was to determine toxicity of adjuvants to adult worker honey bees, both when applied alone and in adjuvant-pesticide tank mixtures. Field-relevant combinations of formulated products were applied to 3-day-old adult worker honey bees using a Potter Spray Tower, and mortality was assessed 48 h following exposure. Adjuvants tested included Activator-90, Attach, Choice Weather Master, Cohere, Dyne-Amic, Induce, Kinetic, LI 700, Liberate, Nu-Film P, PHT Latron B-1956, and Surf-90; fungicides tested include Luna Sensation (Fluopyram and Trifloxystrobin), Pristine (Pyraclostrobin and Boscalid), Tilt (Propiconazole), and Vangard (Cyprodinil), and insecticides tested include Altacor (Chlorantraniliprole), Intrepid 2F (Methoxyfenozide), and a positive control Mustang Maxx (Zeta-cypermethrin). Results demonstrated that exposure to some adjuvants causes acute honey bee mortality at near-field application rates, both when applied alone and in combination with pesticides. Some adjuvant-pesticide combinations demonstrated increased toxicity compared with the adjuvant alone, while others demonstrated decreased toxicity. A better understanding of adjuvant and adjuvant-pesticide tank mixture toxicity to honey bees will play a key role in informing "Best Management Practices" for pesticide applicators using spray adjuvants during bloom when honey bee exposure is likely.

Interaction of spirodiclofen, fenpyroximate, etoxazole, and imidacloprid for the control of two-spotted spider mite, Tetranychus urticae Koch

ABSTRACT The interaction relationships of a binary mixture of spirodiclofen, fenpyroximate, and etoxazole acaricides, and mixing each of these acaricides with imidacloprid were investigated on deutonymph of Tetranychus urticae using the Potter spray tower method under controlled laboratory conditions. Based on the results of bioassay tests and combination index (CI) estimates, the toxicity of the binary mixture of the tested acaricides with each other and with imidacloprid on T. urticae was lower than that of each compound alone, and the interaction of their binary mixture was the antagonistic type. The measurement of the activity level of detoxifying enzymes in T. urticae treated with the LC50 concentration of pesticides and their binary mixture showed that the highest α- and β-esterase and glutathione S-transferase (GST) activities were observed in mites treated with spirodiclofen. Additionally, the highest cytochrome P450 monooxygenases (MFO) content was detected in mites treated with a mixture of spirodiclofen and imidacloprid. The results indicated that the application of a binary mixture of the mentioned acaricides together and in combination with imidacloprid leads to inefficient control of T. urticae.

Comparative toxicity of spinetoram to Trialeurodes vaporariorum Westwood and its parasitoid Eencarsia formosa Gahan

The role of selective new generation bioisecticides, beside their effectiveness against key pests, relies on their safety to beneficial arthropods. Spinetoram, a semi-synthetic analogue of the microbial-derived bioinsecticide spinosad is registered worldwide for application in numerous crops, but assessment of its ecotoxicological risk to beneficial arthropods has scarcely been documented. Moreover, this is the first report on toxic effects of spinetoram on a pest, the greenhouse whitefly Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), and/or its successful biocontrol agent, the parasitoid Encarsia formosa Gahan (Hymenoptera: Aphelinidae). Under laboratory conditions, we assessed the acute toxicity of spinetoram insecticide (25% a.i.) to adults, nymphs and eggs of the greenhouse whitefly, as well as to parasitoid adults and pupae. In all concentration-response bioassays, the spinetoram insecticide was applied to tobacco leaves settled onto 1% agar layer in ventilated Petri dishes using a Potter spray tower. The parameters of spinetoram acute toxicity to adults of both the pest and the parasitoid were evaluated in residual contact bioassays, while whitefly eggs and nymphs, and parasitoid pupae were topically treated with a series of spinetoram concentrations, covering a range of 10-90% mortality. Lethal spinetoram effects on the parasitoid E. formosa were assessed through selectivity ratio (SR) estimations, showing the ratios beetween median lethal concentrations (LC50s) estimated for the parasitoid, and LC50s estimated for the pest. The following LC50 values were obtained: 4.593, 15.027 and 11.73 mg a.i./l for whitefly adults, nymphs and eggs, respectively, and 0.686 and 1.715 mg a.i./l for parasitoid adults and pupae, respectively. The calculated SR estimations were below 1, indicating that spinetoram insecticide is non-selective to both tested stages of the parasitoid E. formosa. A more detailed understanding of spinetoram impact on E. formosa in whitefly integrated management requires further evaluation of sublethal effects and greenhouse trials, with an emphasis on population-level responses.

Laboratory and experimental hut trial evaluation of VECTRON ™ T500 for indoor residual spraying (IRS) against insecticide resistant malaria vectors in Burkina Faso.

Background: Malaria cases in some areas could be attributed to vector resistant to the insecticide. World Health Organization recommended insecticides for vector control are limited in number. It is essential to find rotational partners for existing Indoor Residual Spraying (IRS) products. VECTRON ™ T500 is a novel insecticide with broflanilide as active ingredient. It has a mode of action on mosquitoes completely different to usually used. The aim of this study was to determine the optimum effective dose and efficacy of VECTRON TMT500 against susceptible and resistant strains of Anopheles in Burkina Faso. Methods: VECTRON™T500 was sprayed at 50, 100 and 200 mg/m² doses onto mud and concrete blocks using Potter Spray Tower. The residual activity of broflanilide was assessed through cone bioassays 1 week and then monthly up to 14 months post spraying. Its efficacy was evaluated at 100 and 150 mg/m² against wild free-flying mosquitoes in experimental huts on both substrates. Actellic 300CS was applied at 1000 mg/m² as reference product. Cone assays were conducted monthly, using susceptible and resistant mosquito strains. Results: In the laboratory, VECTRON ™T500 showed residual efficacy (≥80% mortality) on An. gambiae Kisumu up to 12 and 14 months, respectively, on concrete and mud blocks. Similar results were found with 100 and 200 mg/m² using An. coluzzii pyrethroid resistant strain. In experimental huts, a total of 19,552 An. gambiae s.l. were collected. Deterrence, blood-feeding inhibition and exophily with VECTRON™ treated huts were very low. At 100 and 150 mg/m², mortality of wild An. gambiae s.l. ranged between 55% and 73%. Monthly cone bioassay mortality remained >80% up to 9 months. Conclusions: VECTRON™ T500 shows great potential as IRS formulation for malaria vector control. It can be added to the arsenal of IRS products for use in rotations to control malaria and manage mosquito insecticide resistance.

Laboratory and experimental hut trial evaluation of VECTRON ™ T500 for indoor residual spraying (IRS) against insecticide resistant malaria vectors in Burkina Faso

Background: Malaria cases in some areas could be attributed to vector resistant to the insecticide. World Health Organization recommended insecticides for vector control are limited in number. It is essential to find rotational partners for existing Indoor Residual Spraying (IRS) products. VECTRON ™ T500 is a novel insecticide with broflanilide as active ingredient. It has a mode of action on mosquitoes completely different to usually used. The aim of this study was to determine the optimum effective dose and efficacy of VECTRON TM T500 against susceptible and resistant strains of Anopheles in Burkina Faso. Methods: VECTRON™T500 was sprayed at 50, 100 and 200 mg/m² doses onto mud and concrete blocks using Potter Spray Tower. The residual activity of broflanilide was assessed through cone bioassays 1 week and then monthly up to 14 months post spraying. Its efficacy was evaluated at 100 and 150 mg/m² against wild free-flying mosquitoes in experimental huts on both substrates. Actellic 300CS was applied at 1000 mg/m² as reference product. Cone assays were conducted monthly, using susceptible and resistant mosquito strains. Results: In the laboratory, VECTRON ™ T500 showed residual efficacy (≥80% mortality) on An. gambiae Kisumu up to 12 and 14 months, respectively, on concrete and mud blocks. Similar results were found with 100 and 200 mg/m² using An. coluzzii pyrethroid resistant strain. In experimental huts, a total of 19,552 An. gambiae s.l. were collected. Deterrence, blood-feeding inhibition and exophily with VECTRON™ treated huts were very low. At 100 and 150 mg/m², mortality of wild An. gambiae s.l. ranged between 55% and 73%. Monthly cone bioassay mortality remained >80% up to 9 months. Conclusions: VECTRON™ T500 shows great potential as IRS formulation for malaria vector control. It can be added to the arsenal of IRS products for use in rotations to control malaria and manage mosquito insecticide resistance.

Laboratory and experimental hut trial evaluation of VECTRON™ T500 for indoor residual spraying (IRS) against insecticide resistant malaria vectors in Burkina Faso

Background: Malaria cases in some areas could be attributed to vector resistant to the insecticide. World Health Organization recommended insecticides for vector control are limited in number. It is essential to find rotational partners for existing Indoor Residual Spraying (IRS) products. VECTRON™ T500 is a novel insecticide with broflanilide as active ingredient. It has a mode of action on mosquitoes completely different to usually used. The aim of this study was to determine the optimum effective dose and efficacy of VECTRONTM against susceptible and resistant strains of Anopheles in Burkina Faso. Methods: VECTRON™ was sprayed at 50, 100 and 200 mg/m² doses onto mud and concrete blocks using Potter Spray Tower. The residual activity of broflanilide was assessed through cone bioassays 1 week and then monthly up to 14 months post spraying. Its efficacy was evaluated at 100 and 150 mg/m² against wild free-flying mosquitoes in experimental huts on both substrates. Actellic 300CS was applied at 1000 mg/m² as reference product. Cone assays were conducted monthly, using susceptible and resistant mosquito strains. Results: In the laboratory, VECTRON™ showed residual efficacy (≥80% mortality) on An. gambiae Kisumu up to 12 and 14 months, respectively, on concrete and mud blocks. Similar results were found with 100 and 200 mg/m² using An. coluzzii pyrethroid resistant strain. In experimental huts, a total of 19,552 An. gambiae s.l. were collected. Deterrence, blood-feeding inhibition and exophily with VECTRON™ treated huts were very low. At 100 and 150 mg/m², mortality of wild An. gambiae s.l. ranged between 55% and 73%. Monthly cone bioassay mortality remained >80% up to 9 months. Conclusions: VECTRON™ shows great potential as IRS formulation for malaria vector control. It can be added to the arsenal of IRS products for use in rotations to control malaria and manage mosquito insecticide resistance.

Acute Toxicity of Fungicide-Insecticide-Adjuvant Combinations Applied to Almonds During Bloom on Adult Honey Bees.

Beekeepers report significant honey bee deaths during and after almond bloom. These losses pose a major problem for the California almond industry because of its dependence on honey bees as pollinators. The present study aimed to determine if combinations of pesticides applied during almond bloom during daylight hours were a possible explanation for these losses. In this study we aimed to mimic the spray application route of exposure to pesticides using a Potter Spray Tower to treat adult honey bees with commonly encountered pesticides and pesticide combinations at multiples of the maximum recommended field application rates. Tested insecticides included Altacor® and Intrepid®, and tested fungicides included Tilt®, Pristine®, Luna Sensation®, and Vangard®. Synergistic toxicity was observed when the fungicide Tilt (active ingredient propiconazole) was applied with the insecticide Altacor (chlorantraniliprole), though neither caused significant mortality when applied independently. The study also looked at the effect of adding a spray adjuvant, Dyne‐Amic®, to pesticide mixtures. Dyne‐Amic was toxic to honey bees at concentrations above the maximum recommended field application rate, and toxicity was increased when combined with the fungicide Pristine (pyraclostrobin and boscalid). Addition of Dyne‐Amic also increased toxicity of the Tilt and Altacor combination. These results suggest that application of Altacor and Tilt in combination with an adjuvant at the recommended field application rates could cause mortality in adult honey bees. These findings highlight a potential explanation for honey bee losses around almond bloom, emphasize that the safety of spray adjuvants to bees should not be assumed, and provide support for recommendations to protect bees from pesticides through application at night when bees are not foraging. Environ Toxicol Chem 2022;41:1042–1053. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Adulticidal Activity of Coffee Essential Oils against Two Fruit Fly Species (Tephritidae) under Laboratory Conditions

The aim of this study was to evaluate the adulticidal effects of green coffee oil (GCO) and roasted coffee oil (RCO) on two species of fruit flies (Tephritidae) include Ceratitis capitata (Wiedemann) and Anastrepha fraterculus (Wiedemann). Adult flies of both species were exposed to GCO and RCO at 2%, 3%, and 4% dilutions in water under Potter spray tower. In general, exposure to GCO and RCO at the three dilutions resulted in higher numbers of dead adults of both species compared to the control populations. The mortalities increased substantially between 60–90 minutes after initial exposure. The 2% GCO dilution reached a maximum of 77.0% corrected mortality of A. fraterculus at 360 minutes. In general, the toxic effect of coffee oils occurred more rapidly in C. capitata than in A. fraterculus. GCO (2% and 3%) and RCO (2%) showed promising results for fruit fly management.

Comparision of different application methods to biological control Hypothenemus hampei

There are several studies that deal with the problem of infestation by Hypothenemus hampei in Coffeea arabica. However, the ways of applying products based on entomopathogenic fungi are the same as those used for chemicals. The objective of the research was to comparison different methods of application of Beauveria bassiana against H. hampei. The experiments were developed in laboratory, with blastospores and B. bassiana airborne conidia powders were carried out. Application methods based on immersion, Potter Spray Tower and walking on treated surface. Were three experiments were carried out for each method. Bioassays’design comprised seven treatments (including the control), with five repetitions (each) and 25 beetles per repetition. Suspensions were standardized at 2.4×109, 1×109, 5×108, 1×108, 5×107 and 1×107conidia.mL-1. Conidia powder presented initial concentration of 1.14×1010and it was standardized at 1.14×109; 5.7×109; 1.14×108; 5.7×107; 1.14×107 and 5.7×106 conidia.g-1. A simultaneous test was also carried outbased to the three application methods; treatment comprised conidia powder concentration of 1x108 and the control. Data were subjected to analysis of variance, which was followed by Tukey test (P<0.05) and, CL50, in the SPSS 12.1 software. The mortality better rates of H. hampei exposed to B. bassiana IBCB66 were1×108(immersion), 1×109 (Potter Spray Tower) and 1×108(walking), where as mean LC50were 6.1×108, 4.1×108, 2.4×108conidia.mL-1for each method, respectively. The highest mortality rate was recorded in the walking tests on the conidian powder at a concentration of 1×108 conidia.g-1 for the three repetitions of the method and also in the simultaneous test. Key words: Blastospores; Conidian powder; Mortality; Suspensions.

Selectivity of Entomopathogenic Fungi to Chrysoperla externa (Neuroptera: Chrysopidae).

Simple SummaryAgricultural crop systems have adopted integrated management as a model of success in pest control; however, chemical control is still prioritized. The use of pesticides incorrectly and excessively has provided a reduction in natural enemies, selection of resistant populations and resurgence of pests. Chrysoperla externa is a predator found in several regions in Brazil that preys on different pest insects. Entomopathogenic fungi Beauveria and Metarhizium also stand out for causing epizootics on pests. Both predators and entomopathogens can simultaneously act as pest control; thus, verifying the selectivity of entomopathogenic fungi to predators increases the potential for biological control through synergism and conservation of natural enemies in the agroecosystem. Considering the control potential of these different biological control agents, in this study we evaluated the selectivity of Beauveria bassiana, Metarhizium anisopliae and Metarhizium rileyi to the larvae of this predator. The results provide evidence that the biological development of larvae of C. externa is not influenced by the entomopathogenic fungus. These species of fungi can be recommended, aiming at a management of populations of arthropod pests, with low effect on C. externa when it is present in the agrosystem.We aimed to evaluate the selectivity of entomopathogenic fungi to larvae of Chrysoperla externa (Neuroptera: Chrysopidae). For this purpose, Beauveria bassiana (strain ESALQ PL63), Metarhizium anisopliae (strain ESALQ E9) and Metarhizium rileyi (strain UFMS 03) were assessed at different concentrations (1 × 107, 1 × 108 and 1 × 109 conidia mL−1). The control treatment consisted of distilled water and Tween80 0.01. The treatments were applied with a Potter spray tower using two different methodologies: direct application (DA) and dry film (DF). Up to 96 h after application, no treatment provided a larval mortality above 3%. After 120 h, only B. bassiana induced significant mortality in all instars, with rates of 26%, 17% and 10% for first, second and third instar larval periods, respectively. There was no difference regarding to the application method or concentration of conidia. The percentage of individuals that revealed changes in the length of the larval and pupal periods varied among different treatments with entomopathogenic fungi and control treatments, application methodologies and concentrations. Despite B. bassiana revealing a higher mortality than M. anisopliae and M. rileyi on larvae of C. externa, these three entomopathogenic fungi may be used in association with C. externa for sustainable pest management.

Biocidal radiuses of cycloxaprid, imidacloprid and lambda-cyhalothrin droplets controlling against cotton aphid (Aphis gossypii) using an unmanned aerial vehicle.

Unmanned aerial vehicles (UAVs) are a recently advanced aerial spraying technology. However, the median lethal number of droplets (LN50 ) and biocidal radiuses (r50 ) of insecticides droplets sprayed by UAVs are still unknown. Therefore, we evaluated the LN50 and r50 of cycloxaprid, imidacloprid and lambda-cyhalothrin droplets associated with adjuvant controlling against Aphis gossypii. A small UAV and Potter spray tower (PST) were used to generate different size of droplets (Dv0.5 = 185 ± 5 and 43 ± 2 μm). The mortality of A. gossypii showed a droplet density-dependent process. At the concentration of 5 g L-1 , the LN50 of lambda-cyhalothrin, imidacloprid and cycloxaprid droplets sprayed by the UAV were only 49.2, 34.6 and 19.7 droplets cm-2 , respectively, and the r50 were 0.57, 0.68 and 0.90 mm, respectively. The LN50 values were negatively correlated with insecticide concentrations, but the r50 values increased with the increasing concentrations. Although cycloxaprid is less toxic to A. gossypii than lambda-cyhalothrin, cycloxaprid had a larger r50 than lambda-cyhalothrin due to its translocation ability. Furthermore, cycloxaprid had a relatively larger r50 than imidacloprid because it is more toxic to A. gossypii. Moreover, adjuvant silwet DRS-60 can significantly increase the r50 of droplets. Our results revealed that the r50 of a droplet was higher than its droplet size at tested concentrations. Smaller droplets generated by the PST had relatively higher insecticidal potential. The median lethal dose (LD50 ) and translocation ability of insecticides and spray adjuvant contributed to their r50 . Therefore, ultra-low-volume spray with UAVs is feasible to control cotton aphids. © 2020 Society of Chemical Industry.

Canopy spray deposition and related mortality impacts of commonly used insecticides on Drosophila suzukii Matsumura (Diptera: Drosophilidae) populations in blueberry.

Insecticide applications in blueberry production systems play a crucial role in the control of Drosophila suzukii populations. Here, quantitative spray deposition patterns were obtained under replicated field experiments in blueberry during two field seasons with three sprayers, i.e. cannon, electrostatic, and air-blast. Seven insecticides were tested (at 6 hours using a Potter spray tower) to determine the mortality data for adult D. suzukii. Spray deposition and mortality data for adult D. suzukii were used to create model simulations for insect populations. Model simulations included field deposition rates of sprayers and insecticide mortality as factors. Simulations were applied in different combinations with five applications over a 6-week period. Relative deposition rates for the cannon sprayer were elevated in the upper zones of the canopy, whereas for the air-blast sprayer, deposition was greater in the bottom zones. Electrostatic spray deposition was relatively uniform within the six canopy zones. Clear trends in D. suzukii laboratory mortality were found with lowest to highest mortality recorded for phosmet, spinetoram, spinosad, malathion, cyantraniliprole, zeta-cypermethrin, and methomyl respectively. Maximum D. suzukii population impacts, as shown by model outputs, were observed with air-blast sprayers together with zeta-cypermethrin. The electrostatic sprayer had the least variable canopy deposition among the three types of spray equipment, and the air-blast sprayer had the highest overall deposition rates. This study provides new hypotheses that can be used for field verification with these spray technologies and insecticides as key factors. © 2019 Society of Chemical Industry.

Toxicity Aqueous Extract of Castor Bean (Ricinus communis) to Maconellicoccus hirsutus (Green) (Hemiptera: Pseudococcidae)

The objective of this study was to evaluate the insecticidal effect of aqueous extract of castor bean (Ricinus communis) cake for the control of Maconellicoccus hirsutus. The toxicity tests were performed in the laboratory. Subsequently lethal concentrations 50 and 90% (LC50and LC90, respectively) were estimated. Tween80® + distilled water was used as surfactants and solvent respectively. The assay was performed in petri dishes containing a Coffea canephora leaf disc. The spraying was carried out in Torre de Potter spray tower. The extract was toxic to mealybug and the mortality data was adapted to the probit model. Estimates of LC50 and LC90 were 5.32% and 29.30%, respectively. It was concluded that the aqueous extract of R. communis cake is promising for the management of M. hirsutus.

Efficacy of native isolates of Metarhizium anisopliae and Beauveria bassiana against the invasive ambrosia beetle, Xylosandrus germanus Blandford (Coleoptera: Curculionidae: Scolytinae)

The invasive ambrosia beetle, Xylosandrus germanus Blandford (Coleoptera: Curculionidae: Scolytinae), is one of the most significant pests in hazelnut orchards in Turkey. Chemical control of the beetle is very difficult, because it spends the majority of its life in the sapwood of host trees. In this study, entomopathogenic fungi (EPF), Metarhizium anisopliae (TR-106 isolate), and Beauveria bassiana (TR-217 isolate) were tested against the female adults of X. germanus under laboratory conditions by two different methods. In the first method, conidial concentrations (1 × 106 and 1 × 108 conidia ml−1) of the fungal isolates were directly applied to the beetles in Petri dishes (2 ml per dish), using a Potter spray tower. In the second method, the same conidial concentrations were applied on a sterile hazelnut branch placed in the Petri dishes, and then, beetles were released in dishes. The Petri dishes were incubated at 25 ± 1 °C and 75 ± 5% RH, 16:8-h light:dark photoperiod. Lethal time values (LT50 and LT90) for the isolates were calculated, using Probit analysis. As a result, LT50 and LT90 values of M. anisopliae isolate at 1 × 108 conidia ml−1 were 4.43 and 6.01 days, respectively, at the beetle application method and 3.97 and 5.68 days, respectively, at the branch application method. LT50 and LT90 values were 6.03 and 10.80 days, respectively, at 1 × 108 conidia ml−1, when B. bassiana was applied directly on the beetles and 5.96 and 11.79 days at the same concentration, when it was applied on the branch application method. M. anisopliae at 1 × 108 conidia ml−1 caused 100% mortality rate at the end of the 8th day in the two application methods. The mortality rates when applying 1 × 108 conidia ml−1 of B. bassiana recorded 64% and 80% by the end of the 8th day on branch and insect application methods, respectively. The efficiency of 1 × 106 conidia ml−1 of the isolates was lower than 1 × 108 conidia ml−1 against X. germanus in both application methods. This study showed that the isolates of TR-106 and TR-217 had a significant potential as biological control agents against X. germanus.

Water-soluble food dye of Allura Red as a tracer to determine the spray deposition of pesticide on target crops.

Quantification of spray deposition on a target crop is of vital importance to optimize pesticide application. In traditional determinations of spray deposition, a large amount of organic solvent is used to extract pesticides from the target crops. In this study, a water-soluble food dye of Allura Red was developed as a tracer to determine pesticide spray deposition on a rice target crop. The addition of Allura Red does not obviously alter the physicochemical properties of pesticides (viscosity, density and surface tension) and droplet spectra. An ultra-performance liquid chromatography (UPLC) analytical method was developed and validated to determine the deposition amount of Allura Red on rice plants. Method accuracy and precision for Allura Red were found to be satisfactory with recoveries of 96.07% to 107.48%. To validate the method, comparative deposition analyses were carried out using representative systematic and non-systematic pesticides (nitenpyram and chlorothalonil) under the same spraying scenarios using a Potter spray tower. Allura Red and pesticides showed comparable deposition under the same application conditions with ratios from 0.98 to 1.21. A field trial using an unmanned aerial vehicle sprayer further indicated that the deposition rates for Allura Red and nitenpyram on rice seedling were 13.04% and 11.07%, with corresponding relative standard deviation values (n = 5) of 16.39% and 18.79%. A laboratory test and field trial confirmed that the developed method of using Allura Red as a tracer for spray deposition assessment is feasible and practicable. © 2019 Society of Chemical Industry.

Efficacy of entomopathogenic fungi against the stored-grain pests, Sitophilus granarius L. and S. oryzae L. (Coleoptera: Curculionidae)

Efficacy of the five native entomopathogenic fungi (EPFs), Beauveria bassiana, Isaria fumosorosea, Lecanicillium muscarium, Metarhizium anisopliae, and Simplicillium lamellicola, against adults of the stored-grain insect pests, Sitophilus granarius and Sitophilus oryzae (Coleoptera: Curculionidae), was evaluated under laboratory conditions at two different temperatures. Conidial suspensions (1 × 108 conidia ml−1) of the fungi were directly applied to both the pests in Petri dishes (2 ml per dish), using a Potter spray tower. All the dishes were incubated both at 20 and 25 °C in 16 h light/8 h dark and in 75 ± 5% relative humidity (RH). Dead individuals were counted daily, following treatments, for 7 days. Lethal time values (LT50 and LT90) for EPFs were calculated. The results demonstrated that the mortality rates varied according to both the temperature and the tested EPFs. The highest effect among EPFs at (1 × 108 conidia ml−1) concentration on S. granarius at 20 °C at the end of day 7 was showed by I. fumosorosea (92.69%) and M. anisopliae (90.35%), followed by the other EPFs. Similarly, M. anisopliae and I. fumosorosea were the most effective ones with 90.48 and 84.21% mortality rates, respectively, at 25 °C. However, while M. anisopliae (85.68%) showed the highest effect among all the EPFs applied on S. oryzae at 20 °C, B. bassiana with a mortality rate of 93.66% was the most effective one at 25 °C. LT50 values for I. fumosorosea and M. anisopliae were 2.75 and 2.88/days, respectively, and LT90 values were 4.17 and 4.47/days, respectively, at 20 °C for S. oryzae. However, LT50 values for M. anisopliae on S. granarius in both temperatures were the lowest. This study indicated that M. anisopliae and I. fumosorosea had a significant potential as a biological control agent against S. granarius and S. oryzae. Further studies are necessary to evaluate the efficacy of the isolate on the pests under storage conditions.

Insecticidal effect of plant extracts on common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Aphalaridae)

The common pistachio psylla, Agonoscena pistaciae (Hemiptera: Aphalaridae) is one of the most detrimental pests to pistachio trees. Nowadays various pesticides are used to control the common pistachio psylla, but extensive pesticide spraying against this pest over a period of several years has overpowered its natural enemies. The plant’s byproducts come as an alternative ecologically more compatible in substitution to the synthetic insecticides. This work aims to evaluate the insecticidal potential of herbal extracts of fruit peels of Citrus sinensis and Citrus reticulata, seeds of C. sinensis and Rubia tinctorum, and leaves of Lawsonia inermis against common pistachio psylla. Five concentration 40, 47, 56, 67 and 80 µl/ml, of these plant extracts were sprayed on the fifth instar nymphs of common pistachio psylla by Potter Spray Tower under laboratory conditions (26 ± 2 °C, 60–70% RH and a photoperiod of 16L: 8D h). Results showed significant differences among the treatments of the plant extracts and between the concentrations. The LC50 values of C. sinensis peels, C. reticulata peels, C. sinensis seeds, R. tinctorum seeds and L. inermis leaves were 62.04, 38.84, 43.60, 59.01 and 33.99 µl/ml, respectively. Also, all extracts showed the greatest mortality effect in 80 µl/ml concentration. According to these results, these plant extracts may use as herbal pesticides chemical control programme of common pistachio psylla.

Efficacy of native entomopathogenic fungus, Isaria fumosorosea, against bark and ambrosia beetles, Anisandrus dispar Fabricius and Xylosandrus germanus Blandford (Coleoptera: Curculionidae: Scolytinae)

The efficacy of the native entomopathogenic fungus, Isaria fumosorosea TR-78-3, was evaluated against females of the bark and ambrosia beetles, Anisandrus dispar Fabricius and Xylosandrus germanus Blandford (Coleoptera: Curculionidae: Scolytinae), under laboratory conditions by two different methods as direct and indirect treatments. In the first method, conidial suspensions (1 × 106 and 1 × 108 conidia ml−1) of the fungus were directly applied to the beetles in Petri dishes (2 ml per dish), using a Potter spray tower. In the second method, the same conidial suspensions were applied on a sterile hazelnut branch placed in the Petri dishes. The LT50 and LT90 values of 1 × 108 conidia ml−1 were 4.78 and 5.94/days, for A. dispar in the direct application method, while they were 4.76 and 6.49/days in the branch application method. Similarly, LT50 and LT90 values of 1 × 108 conidia ml−1 for X. germanus were 4.18 and 5.62/days, and 5.11 and 7.89/days, for the direct and branch application methods, respectively. The efficiency of 1 × 106 conidia ml−1 was lower than that of 1 × 108 against the beetles in both application methods. This study indicates that I. fumosorosea TR-78-3 had a significant potential as a biological control agent against A. dispar and X. germanus. Further studies are necessary to evaluate the efficacy of the isolate on the pests under field conditions.