Potter Spray Tower Research Articles

Occurrence of Pyrethroid Resistance in Pear Psylla (Homoptera: Psyllidae) Populations from Southern Ontario

Adult pear psylla, Cacopsylla pyricola Foerster, from the Niagara peninsula of Ontario were tested for susceptibility to pyrethroid insecticides from 1980 to 1989. A Potter spray tower was used. Results of tests at IS, 22, and 30°C indicated a negative temperature-toxicity relationship for permethrin and fen vale rate. Resistance to pyrethroids (first discovered in 1986 at levels of approximately 50-fold for permethrin at the LC50) has become widespread in the Niagara region. Resistance extends to all types of pyrethroids but is highest to fenvalerate (approximately 140-fold). Combinations of permethrin and potential synergists piper only but oxide or DEF did not increase the toxicity to resistant populations, suggesting that resistance was due to an insensitive target site or kdr-like mechanism. In one resistant population studied over 4 yr without further selection with pyrethroids, resistance declined from 54-fold to approximately 3D-fold after 1 yr and stabilized at 20-30-fold.

Topical Toxicity of Insecticides to First-instar Black Vine Weevil (Coleoptera: Curculionidae)

A microapplication technique was developed to generate and apply a minute droplet (0.028 μl) containing technical-grade insecticide to first-instar Otiorhynchus sulcatus (F.). Toxicities of insecticides, in decreasing order, were as follows: carbofuran, aldicarb, terbufos, azinphosmethyl, bendiocarb, fenvalerate, diazinon, thiofanox, oxamyl, isazophos, chlorpyrifos, acephate, and isofenphos. Similar results were obtained with carbofuran, terbufos, aldicarb, and bendiocarb applied topically in a Potter Spray Tower.

Toxicity of Insecticides to Predators of Rice Brown Planthoppers, Nilaparvata lugens (Stål) (Homoptera: Delphacidae)

Insecticides, at the N. lugens LD50 level, were applied in the Potter's spray tower and as a foliage spray to determine their selective toxicity to predators of N. lugens. These included a mirid bug, Cyrtorhinus lividipennis; the ripple bug, Microvelia atrolineata; and the spider Lycosa pseudoannulata. In the Potter's spray tower test, cypermethrin and deltamethrin were highly toxic to the three predator species on contact. Deltamethrin was toxic to C. lividipennis and M. atrolineata when they fed on treated N. lugens prey. Endosulfan and ethylan were not very toxic to the three predators. When the predators were placed on sprayed plants, only deltamethrin was toxic to L. pseudoannulata and M. atrolineata , whereas all of the insecticides were toxic to C. lividipennis , with BPMC being the least and deltamethrin the most toxic. Of the commercially available insecticides, acephate, BPMC, carbophenothion, and endosulfan were the least toxic to natural enemies.

Susceptibility of Rice Planthoppers Nilaparvata lugens and Sogatella furcifera (Homoptera: Delphacidae) to Insecticides as Influenced by Level of Resistance in the Host Plant

The susceptibility of the whitebacked planthopper, Sogatella furcifera , and the brown planthopper, Nilaparvata lugens , to insecticides is affected by the level of varietal resistance in the host plants on which they are reared. Hoppers reared on moderately resistant rice varieties had lower LD50 values when topically treated, and higher mortality when sprayed in the Potter spray tower and when placed on sprayed plants, than did those reared on susceptible varieties.

DETECTION OF CYHEXATIN RESISTANCE IN TWOSPOTTED MITE, TETRANYCHUS URTICAE KOCH (ACARINA: TETRANYCHIDAE) IN AUSTRALIA

AbstractTwo laboratory cultures of Tetranychus urticae were established with material collected from 3 apple orchards at Shepparton, Victoria and from one orchard near Griffith, N.S.W. Cyhexatin was tested against females of each strain and a susceptible reference strain, using a Potter spray tower. Both strains were 7.5X resistant to cyhexatin at the LC50 level compared with the susceptible strain.

Effectiveness of Insecticides Against the Mexican Bean Beetle1

The contact action of 21 insecticides was evaluated against 1st instars of Epilachna varivestis Mulsant by using a Potter spray tower. All insecticides were toxic to larvae, and differences were indicated by tabulated values of the LD50 and LD95, as well as their confidence limits. The most toxic materials were the synthetic pyrethroids, carbofuran, methomyl, and carbaryl. The least toxic, malathion, still gave 93% mortality at 100 mg of AI/liter. The same insecticides tested against eggs of E. varivestis gave less uniform mortality. The four pyrethroids were effective at low dosages, and 11 other insecticides prevented hatching when applied at levels ca. 10 times higher than the larval LD95 Azinphosmethyl, malathion, phosmet, endosulfan, and methomyl had little or no effect at 1,000 mg of AI/liter. Laboratory efficiency of insecticides was related to present recommendations for field control, and suggestions are presented for future field tests.

Laboratory and Field Evaluation of Insecticides to Protect Grape Clusters from Adult Rose Chafer12

Over 3 growing seasons, 14 insecticides were evaluated for the control of adult Macrodactylus subspinosus (F.) on ‘Concord’ grapes at N. Kingsville and Wooster, OH. In 1976, contact toxicity studies were conducted using a Potter spray tower to compare relative toxicity of 7 compounds. In this preliminary test, azinphosmethyl was most active and methoxychlor the least. In subsequent tests, 3 different systems were used to determine control in field trials based on number of adult rose chafers present on treated vines, index rating of damage sustained to clusters, and bioassay by confining chafers on treated leaves. The bioassay method appeared to be the most satisfactory and was fairly simple to execute. Highest degree of control after 7 days, using bioassay, was obtained with microencapsulated methyl parathion, methoxychlor, and Alfa-tox® (20% methoxychlor plus 10% diazinon). Azinphosmethyl also gave good results for the 1st 3 days but broke down considerably before the 7th day.

Contact Toxicity of Seven Insecticides To Rose Chafer Adults, 1976

Abstract Adults of the rose chafer were collected from grape blossom buds in a sandy area near North Kingsville, Ohio, just prior to bloom. These insects were brought to O.A.R.D.C. to test their susceptibility to a broad range of insecticides. They were held 24 hr at the holding conditions indicated below, prior to being treated. Methoxychlor had given poor results in the area of collection. Stock solutions (1%) of all materials tested were prepared from technical grade materials using a mixture of acetone and olive o i l , 19:1 (vol/vol), as the solvent. Two replicates of 10 beetles each, selected at random, were anesthetized with ether and placed on filter paper in 9-cm glass petri dishes. Each replicate was sprayed with 5 ml of the insecticides at one of the concentrations in a Potter spray tower. Checks consisted of 2 sets of 10 beetles each sprayed with the solvent. Treated beetles were removed from petri dishes and placed in paper cups with a moist wick of 5% honey-water and covered with a glass petri dish and held at 24° t 1,5°C and 6 0% RH. Treatments were made on June 17 and mortality readings were made 24 hours later.

Contact Toxicity of Seven Insecticides To Strawberry Sap Beetle Adults, 1976

Abstract Adults of the strawberry sap beetle were collected on overripe strawberries in a commercial strawberry field near Akron, Ohio. These beetles were brought to O.A.R.D.C. to test their susceptibility to several classes of insecticides. They were held 24 hr at the holding conditions indicated below, prior to being treated. Stock solutions (1 %) of each material tested were prepared from technical grade materials using a mixture of acetone and olive o i l , 19:1 (vol/vol), as the solvent. Two replicates of 10 beetles each, selected at random, were anesthetized with ether and placed on filter paper in 9-cm glass petri dishes. Each replicate was sprayed with 5 ml of the insecticides at one of the concentrations in a Potter spray tower. Checks consisted of 2 sets of 10 beetles each sprayed with the solvent. Treated beetles were removed from petri dishes and placed in paper cups with a moist wick of 5% honey-water and covered with a glass petri dish and held at 24° ± 1.5°C and 60% RH. Treatments were made on July 27, July 29 or September 13. Mortality readings were made 24 hr after treatment.

Contact Toxicity Studies, 1975

Abstract Four replications of 25 adult insects each were treated in a Potter's spray tower. All insecticides were applied as 0.04% sprays in a volume of 2 ml and at a vacuum pressure of 10 psi except for monocrotophos and monocrotophos + mevinphos which were applied as 0.05% sprays. After treatment insects were placed in a 500 ml beaker containing a 10-day old seedling and held at a temperature of 27∓1°C. Mortality was determined at 1 and 48 hr after treatment (HT). Mortality values were adjusted using Abbott's formula.

Surfactant Quantity and Deposit Particle Size Influence Direct Spray and Residual Deposit Toxicity of Chlorpyrifos to Hetiothis punctigera13

In laboratory experiments, chlorpyrifos 22.4% wt/wt and 40.8% wt/wt EC both containing 8% wt/wt surfactant and 2 chlorpyrifos 25% wt/wt WP, one containing 3% wt/wt and the other 10% wt/wt surfactant were compared for toxicity to 4th instars of Heliothis punctigera (Wallengren). Formulations were diluted appropriately with water and direct spray and residual deposit applications made with a Potter Spray Tower. Each application was of 2 ml at 60 cm Hg pressure. The LC50 of 0.0419% wt/vol 48 h after direct spray application for the EC having the higher ratio of surfactant to active ingredient was significantly lower than 0.0521% wt/vol for the EC having the lower ratio. The LC50 of 0.0523% wt/vol 48 h after direct spray application for the wp having the higher ratio of surfactant to active ingredient was significantly lower than 0.0844% wt/vol for the wp having the lower ratio. After 48 h of exposure to residual deposits the LC50 was 0.0263% wt/vol for deposits of larger particles, ca. 8 μm, given by 40.8% EC significantly higher than 0.0145, 0.0144, and 0.0183% wt/vol for deposits of smaller particles, ca. 4 and 3 μm, given by 22.4% EC and two 25% WP, respectively.

Status of Insecticide Resistance in Japanese Beetle in Ohio—1974123

Adults of Popillia japonica Newman from 30 golf courses in Ohio were tested for evidence of resistance to cydodiene insecticides. Concentrations of 0.001, 0.01, 0.1, and 1.0% aldrin or dieldrin were applied using a Potter Spray tower. The results showed that 7 of 30 populations were highly resistant to aldrin or dieldrin and one showed incipient resistance to dieldrin.

THE TOXICITY OF INSECTICIDES BY CONTACT AND SOIL TREATMENT TO TWO SPECIES OF GROUND BEETLES (COLEOPTERA: CARABIDAE)

AbstractAdults of predatory carabid beetles (Coleoptera: Carabidae) of the species Stenolophus comma Fabricius field-collected from light traps were bioassayed against several soil insecticides along with laboratory reared larvae of the predatory carabid Pterostichus melanarius Illiger. Adult S. comma beetles were exposed to serial dilutions of insecticides using a Potter spray tower; larvae of P. melanarius were exposed to insecticidally treated Plainfield sand. Fensulfothion, phorate, methomyl, carbofuran, and O,O-diethyl-S(tertbutylthio) methyl phosphorodithioate (Counter®) proved to be highly toxic to adult S. comma with a 0.01% solution causing mortalities > 65%. In the bioassay of P. melanarius larvae, Counter®, phorate, heptachlor, aldrin, and O-(2-chloro-1-(2,5-dichlorophenyl)vinyl) O-methyl ethylphosphonothioate (WL 24073) produced mortalities > 75% at 0.1 p.p.m. in Plainfield sand. The Pterostichus larvae which are probably important as predators of pest insects appear quite susceptible to several important soil insecticides. Chlorfenvinphos, leptophos, and p,p′-DDT were fairly innocuous to both adults and larvae.

Toxicity of twenty-nine insecticides to Folsomia candida: laboratory studies.

The suitability of Folsomial candida Willem for screening 29 insecticides was assessed y direct contact action in a Potter spray tower and in a Plainfield sand. Similar assays were done with 2 pre- and posttreatment temperatures, 13±1°C and 24±1°C. Methomyl, dieldrin, heptachlor, and duPont 1642 (methyl N-(carbamoyloxy) thioacetimidate), were more toxic by direct action when the insects were held at 13°C than at 24°C after treatment at 21±2°C, No insecticides appeared to be more toxic by direct contact at 24°C than at 13°C. In soil, 8 insecticides (Dyfonate® ( O -ethyl S -phenyl ethylphosphollodithioate), N-2596 ( S -( p -chlorophenyl) O -ethyl ethylphosphonodithioate), disulfoton, carbofuran, chlorpyrifos, endrin, diazinon, and chlorfenvinphos (2-chloro-1-(2,4-dichlorophenyl) vinyl diethyl phosphate) were more toxic at 24°C than at 13°C. The toxicity of methomyl and heptachlor in soil was negatively correlated with temperature. The species fulfilled the basic requirements of an organism for bioassay.

Toxicological studies on cutworms. 8. Toxicity of three insecticides to the various stages in the development of the darksided cutworm.

Laboratory tests were conducted to determine the toxicity of 3 insecticides. DDT, Dursban® ( O,O -diethyl O -(3,5,6-trichloro-2-pyridyl) phosphorothioate), and galecron® ( N′ -(4-chloro- O -tolyl) N′,N′ -dimethylformamidine), to the various stages in the life cycle of Euxoa messoria (Harris). The insecticides were applied topically using a Potter spray tower. The results indicated that DDT was effective against the early larval stages, but ineffective against the later larval stages, eggs, pupae, and adults. Dursban was effective against eggs, early larval stages, and adults, but ineffective against the later larval stages and pupae. Galecron was highly selective and was effective only against the eggs.

Insecticide Contamination of Rooms and Equipment Used to Rear the Oriental Fruit Moth1

Parathion escaping from a Potter spray tower in a laboratory room contaminated this room and an adjoining office and shortened the usual 15-day life of caged adult oriental fruit moths, Grapholitha molesta (Busck), to 4–8 days. A spray of malathion in a greenhouse compartment contaminated screen cages with similar effects. Contamination persisted for at least 3 weeks. Washing cages in solutions of sal soda or trisodium phosphate adequately cleaned lightly contaminated cages but not those with heavier desposits of parathion. Moths dying in the contaminated cages and in others treated with known amounts of parathhion, malathion, azinphosmethyl, Banol® (3,4-xylenol, 6-chloro-methylcarbamate), carbaryl, DDT, endosulfan, Imidan® ( O, O -dimethyl S -phthalimidomenthyl phos-phorodithioate) had swollen abdomens as a result of inflation of the crop, presumably with air Parathion produced similar symptoms in adults of the codling moth, Carpocapsa pomonella (L.), and the red-banded leaf roller, Argyrotaenia velutinana (Walker.)

Relative Toxicity of Parathion and Kelthane to the Predacious Mite Phytoseiulus persimilis Athias-Henriot and its Prey, Tetranychus urticae Koch, (Acarina: Phytoseiidae, Tetranychidae) in the Laboratory

AbstractThe relative toxicity of Kelthane (1,1-bis (p-chlorophenyl) -2,2,2-trichloroethanol), and parathion to Phytoseiulus persimilis Athias-Henriot and its prey, Tetranychus urticae K. (= telarius (L.)), was determined using a Potter Spray Tower. Parathion was found to be far more toxic to P. persimilis than was Kelthane. The LD50 values for Kelthane were 0.051% and 0.29% for T. urticae and P. persimilis respectively, and for parathion were 0.050% and 0.0044% respectively. The LD95 values bore a similar relationship to each other. The two materials were equally toxic to T. urticae. Therefore, use of Kelthane rather than parathion in an environment where P. persimilis and T. urticae were interacting would favour the beneficial species. The statistical aspects of the test method are discussed.

Comparison of the Toxicity to Insects of Certain Insecticides Applied by Contact and in the Soil1

The toxicity of 9 insecticides relative to a standard insecticide (dieldrin = 1.00) was determined: a) by direct application of the insecticides to the test insects using a Potter spray tower; and b) by exposing the test insects to insecticidal residues incorporated into a fieldmoist Beverly fine sandy loam. First-instar nymphs of the common field cricket, Gryllus pennsylvanicus (Burmeister) , were used as test insects. The relative toxicity of the insecticides when applied as contact sprays was parathion 2.72, mevinphos (Phosdrin®) 2.70, Zectran® (4- dimethylamino-3,5-xylyl methylcarbamate) 2.32, aldrin 0.50, diazinon 0.44, heptachlor 0.42, DDT 0.19, chlordane 0.10, trichlorfon (Dylox® ) 0.09. When applied to the soil the relative toxicities were aldrin 2.13, heptachlor 2.00, diazinon 0.64, parathion 0.50, chlordane 0.41, DDT 0.10, Zectran 0.04, trichlorfon 0.017, and mevinphos 0.0084. Aldrin, heptachlor, and chlordane were approximately 4 times as toxic in soil as compared with the direct contact application, diazinon 1.5 times as toxic, DDT 0.5 as toxic, parathion and trichlorfon approximately 5 times less toxic, Zectran 58 times less toxic, and mevinphos 320 times less toxic. Experiments with fumigant toxicity indicated that, at the concentrations used, all the materials with the exception of DDT volatilized from a metal surface to an extent sufficient to cause 95% to 100% fumigant mortality over a 24-hr period. When equivalent amounts of insecticide were incorporated into the soil aldrin, heptachlor, chlordane, trichlorfon, and mevinphos were moderately volatile. Diazinon, parathion, and dieldrin were less volatile, while Zectran and DDT were virtually nonvolatile. It was suggested that the effectiveness of the cyclodiene insecticides aldrin and heptachlor in soils is due to the fact that they act as both contact and fumigant poisons; that diazinon and parathion were more strongly adsorbed by soil than the cyclodiene insecticides, thus rendering them less effective as both contact and fumigant poisons; and that the low toxicity of mevinphos and trichlorfon could be attributed to the influence of soil moisture.