Ppm Spinosad Research Articles

Influence of temperature and humidity on the efficacy of spinosad against four stored-grain beetle species.

In the present work, we examined the insecticidal effect of spinosad, against adults of the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), the confused flour beetle, Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae) on wheat and the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae) on maize. The dose rates used were 0.01, 0.1, 0.5 and 1 ppm. The bioassays were carried out at three temperatures, 20, 25 and 30°C and two relative humidity levels, 55 and 75%. Mortality of R. dominica and S. oryzae was high even at 0.01 ppm of spinosad, reaching 100% at 55% relative humidity and 30° after 21 days of exposure. Generally, mortality of R. dominica, increased with temperature while for S. oryzae mortality increased with temperature and with the decrease of relative humidity. Moreover, for S. oryzae, mortality was low at 20°C. In the case of T. confusum, mortality was low at doses between 0.01 and 0.5 ppm even after 21 days of exposure. At 1 ppm, mortality exceeded 90% only at 30°C and only after 21 days of exposure. Mortality of P. truncatus was low on maize treated with 0.01 ppm, but increasing the dose to 0.1 ppm resulted in > 87% mortality after 14 days of exposure. In several combinations tested, spinosad efficacy notably varied according to the temperature and humidity regimes. Of the species tested, R. dominica and P. truncatus were very susceptible to spinosad, followed by S. oryzae, while T. confusum was the least susceptible.

Laboratory studies of the toxicity of spinosad and deltamethrin to Phyllotreta cruciferae (Coleoptera: Chrysomelidae)

AbstractLaboratory experiments were conducted to evaluate the contact and oral toxicity of commercial formulations of spinosad and deltamethrin to adults of the crucifer flea beetle, Phyllotreta cruciferae (Goeze). Method of exposure had a significant effect on flea beetle mortality and feeding damage to canola seedlings. Topical treatment of flea beetles with deltamethrin or different concentrations of spinosad resulted in significantly lower mortality and higher feeding damage than exposure to treated canola cotyledons. Results indicated that spinosad was more toxic by ingestion than by topical contact. Mortality from treated cotyledons was significantly higher with 60 ppm deltamethrin than with 80 or 120 ppm spinosad after 24 h exposure but not after 120 h exposure. Delayed mortality in the spinosad treatments did not result in high feeding damage; damage after 120 h was not significantly different in the spinosad and deltamethrin treatments. Low concentrations of spinosad (40 ppm) strongly inhibited feeding activity within 24 h after exposure. Mortality from spinosad was higher after beetles were exposed to treated cotyledons for 120 h than for 24 h. Mortality from spinosad, but not deltamethrin, was significantly higher at 25 °C than at 15 °C. An ionic surfactant, polyethylenimine, increased the toxicity of 40 ppm spinosad. Our study suggests that spinosad has potential for use as an insecticide against crucifer flea beetles on canola.

Spinosad, a Naturally Derived Insecticide, for Control of <I>Aedes aegypti</I> (Diptera: Culicidae): Efficacy, Persistence, and Elicited Oviposition Response

The naturally derived insecticide spinosad is a reduced-risk material that is neurotoxic to Diptera. The 24-h 50% lethal concentration by laboratory bioassay in third instars of Aedes aegypti (L.) (Diptera: Culicidae) (Rockefeller strain) was estimated at 0.026 ppm. Two identical field trials were performed in an urban cemetery in southern Mexico during the dry and wet seasons. Water containers treated with 1 or 5 ppm spinosad suspension concentrate (Tracer, Dow Agrosciences) were as effective in preventing the development of Aedes spp. (mostly Ae. aegypti) as temephos granules during both trials, whereas the bacterial insecticide VectoBac 12AS performed poorly. The half-life of aqueous solutions of spinosad (10 ppm) placed in a warm sunny location was 2.1 d, compared with 24.5 d for solutions in a shaded location. Spinosad, temephos, and VectoBac were not repellent to gravid Ae. aegypti at the concentrations tested, and no ovicidal properties were observed. The 24-h survival of neonate larvae but was reduced by 94-100% in the presence of residues carried over from the spinosad treatments, but it was not affected by residues of temephos or VectoBac. The toxicological properties of spinosad, combined with its favorable environmental profile, should encourage the detailed evaluation of spinosad as a mosquito larvicide in domestic and urban environments.

Spinosad, a Naturally Derived Insecticide, for Control ofAedes aegypti(Diptera: Culicidae): Efficacy, Persistence, and Elicited Oviposition Response

The naturally derived insecticide spinosad is a reduced-risk material that is neurotoxic to Diptera. The 24-h 50% lethal concentration by laboratory bioassay in third instars of Aedes aegypti (L.) (Diptera: Culicidae) (Rockefeller strain) was estimated at 0.026 ppm. Two identical field trials were performed in an urban cemetery in southern Mexico during the dry and wet seasons. Water containers treated with 1 or 5 ppm spinosad suspension concentrate (Tracer, Dow Agrosciences) were as effective in preventing the development of Aedes spp. (mostly Ae. aegypti) as temephos granules during both trials, whereas the bacterial insecticide VectoBac 12AS performed poorly. The half-life of aqueous solutions of spinosad (10 ppm) placed in a warm sunny location was 2.1 d, compared with 24.5 d for solutions in a shaded location. Spinosad, temephos, and VectoBac were not repellent to gravid Ae. aegypti at the concentrations tested, and no ovicidal properties were observed. The 24-h survival of neonate larvae but was reduced by 94–100% in the presence of residues carried over from the spinosad treatments, but it was not affected by residues of temephos or VectoBac. The toxicological properties of spinosad, combined with its favorable environmental profile, should encourage the detailed evaluation of spinosad as a mosquito larvicide in domestic and urban environments.

Acaricidal Properties of Spinosad Against Tetranychus urticae and Panonychus ulmi (Acari: Tetranychidae)

Laboratory bioassays were conducted to characterize the activity of the insecticide spinosad against the twospotted spider mite, Tetranychus urticae Koch, and European red mite, Panonychus ulmi (Koch) (Acari: Tetranychidae). T. urticae females and larvae were individually placed on bean, Phaseolus vulgaris L. (Fabaceae), leaf disks treated with four rates of spinosad (25, 55, 121, and 266 ppm) and a water control. Significantly fewer T. urticae completed development on any spinosad rates (<15%) compared with the control (>85%), whereas spinosad exhibited no significant effects on P. ulmi development; 72.5 and 83.1% of P. ulmi completed development on apple (Malus pumila P. Mill, Rosaceae) leaf disks treated with 75 ppm spinosad and the control, respectively. T. urticae adult females placed on spinosad-treated disks had significantly higher mortality and lower oviposition rates compared with the water control; no significant mortality effects were observed until 3 d after placing adults on leaf disks. In choice tests where half of a bean leaf was treated with 55 ppm spinosad transversally or longitudinally, T. urticae females were repelled by spinosad and largely oviposited and fed on nonspinosad treated areas. Spinosad did not affect the behavior of P. ulmi females. When T. urticae females were released on potted bean plants (two-leaf stage) in which leaves received spinosad sprays on the adaxial or abaxial leaf surfaces, or complete spinosad coverage on one or two of the leaves, mite population increase lagged significantly behind those released on control plants. These results indicate that spinosad has significant acaricidal effects against T. urticae but not P. ulmi.

Acaricidal Properties of Spinosad Against &lt;I&gt;Tetranychus urticae&lt;/I&gt; and &lt;I&gt;Panonychus ulmi&lt;/I&gt; (Acari: Tetranychidae)

Laboratory bioassays were conducted to characterize the activity of the insecticide spinosad against the twospotted spider mite, Tetranychus urticae Koch, and European red mite, Panonychus ulmi (Koch) (Acari: Tetranychidae). T. urticae females and larvae were individually placed on bean, Phaseolus vulgaris L. (Fabaceae), leaf disks treated with four rates of spinosad (25, 55, 121, and 266 ppm) and a water control. Significantly fewer T. urticae completed development on any spinosad rates (<15%) compared with the control (>85%), whereas spinosad exhibited no significant effects on P. ulmi development; 72.5 and 83.1% of P. ulmi completed development on apple (Malus pumila P. Mill, Rosaceae) leaf disks treated with 75 ppm spinosad and the control, respectively. T. urticae adult females placed on spinosad-treated disks had significantly higher mortality and lower oviposition rates compared with the water control; no significant mortality effects were observed until 3 d after placing adults on leaf disks. In choice tests where half of a bean leaf was treated with 55 ppm spinosad transversally or longitudinally, T. urticae females were repelled by spinosad and largely oviposited and fed on nonspinosad treated areas. Spinosad did not affect the behavior of P. ulmi females. When T. urticae females were released on potted bean plants (two-leaf stage) in which leaves received spinosad sprays on the adaxial or abaxial leaf surfaces, or complete spinosad coverage on one or two of the leaves, mite population increase lagged significantly behind those released on control plants. These results indicate that spinosad has significant acaricidal effects against T. urticae but not P. ulmi.

Comparative Evaluation of Spinosad and Phloxine B as Toxicants in Protein Baits for Suppression of Three Fruit Fly (Diptera: Tephritidae) Species

Spinosad and phloxine B are two more environmentally friendly alternative toxicants to malathion for use in bait sprays for tephritid fruit fly suppression or eradication programs. Laboratory tests were conducted to assess the relative toxicity of these two toxicants for melon fly, Bactrocera cucurbitae Coquillett; oriental fruit fly, Bactrocera dorsalis Hendel; and Mediterranean fruit fly, Ceratitis capitata (Wiedemann) females. Field tests also were conducted with all three species to compare these toxicants outdoors under higher light and temperature conditions. In laboratory tests, spinosad was effective at much lower concentrations with LC50 values at 5 h of 9.16, 9.03, and 4.30 compared with 250.0, 562.1, and 658.9 for phloxine B (27, 62, and 153 times higher) for these three species, respectively. At 16 ppm spinosad, LT50 values were lower for all three species (significantly lower for C. capitata and B. dorsalis) than 630 ppm phloxine B LT50 values. At 6.3 ppm spinosad, the LT50 value for C. capitata (3.94) was still significantly less than the 630 ppm phloxine B LT50 value (6.33). For all species, the 100 ppm spinosad concentrations gave LT50 values of < 2 h. In comparison among species, C. capitata was significantly more sensitive to spinosad than were B. cucurbitae or B. dorsalis, whereas B. cucurbitae was significantly more sensitive to phloxine B than were C. capitata or B. dorsalis. LC50 values were reduced for both toxicants in outdoor tests, with greater reductions for phloxine B than for spinosad for B. dorsalis and B. cucurbitae. Fly behavior, though, is likely to keep flies from being exposed to maximum possible outdoor light intensities. Comparable levels of population suppression for any of the three species tested here will require a much higher concentration of phloxine B than spinosad in the bait.

Lethal and sublethal effects of the naturally derived insecticide spinosad on parasitoids of Spodoptera frugiperda (Lepidoptera: Noctuidae)

Laboratory studies were performed on the lethal and sublethal effects of spinosad on three important species of parasitoids attacking Spodoptera frugiperda (J.E. Smith) in Mexico. Reproduction of the braconid Chelonus insularis (Cresson), on treated egg masses was completely eliminated at 200 parts per million (ppm) and reduced by ∼70% at 20 ppm compared to the controls. Adult C. insularis did not avoid contact with residues on maize (200 ppm), but suffered a 7-day reduction in longevity after contact with residues. Initial toxicity of spinosad applied to a natural host of S. frugiperda was concentration dependent and resulted in 23 to 100% mortality of the eulophid Euplectrus plathypenae Howard at 25 to 200 ppm, respectively. The survival of Eu. plathypenae was initially reduced, especially in males, following contact with field weathered residues on maize (200 ppm). However, survival of both sexes rapidly returned to control values on foliage sampled after rainfall. A similar effect was observed in the mortality response of female Eu. plathypenae exposed to residues on sorghum. The ichneumonid Eiphosoma vitticolle Cresson did not avoid reproduction in S. frugiperda larvae that were externally contaminated with 200 ppm spinosad, although all spinosad-treated hosts died before the parasitoid progeny could develop. We use these results to predict the impact of spinosad applications on the foraging and reproduction of these parasitoids in the field. Such predictions require validation by field studies.

Spinosad and nucleopolyhedrovirus mixtures for control of Spodoptera frugiperda (Lepidoptera: Noctuidae) in maize

Abstract Spinosad (Dow AgroSciences) is a neurotoxin mixture produced during fermentation of a soil actinomycete that has high activity towards Lepidoptera. Diet surface contamination bioassays were performed with Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) and Spinosad alone and in mixtures. The interaction of SfMPNV + Spinosad mixtures in S. frugiperda larvae was generally independent or slightly antagonistic in nature, although weak synergism was detected in mixtures containing 3 ppm Spinosad + 20 or 70 occlusion bodies/mm 2 diet of SfMNPV. Mean time to death was not a reliable indicator of mortality over time in larvae exposed to SfMNPV–Spinosad mixtures because Spinosad killed larvae quickly whereas virus mortality occurred at a much lower rate. Therefore, threshold tolerance analysis was employed to generate time–response curves that showed two clear phases; an initial response to Spinosad until ∼100 h followed by virus-induced mortality at 120–250 h post-contamination. A field trial was performed to assess the degree of pest control achieved by SfMNPV–Spinosad mixtures applied to maize. Recovery of S. frugiperda larvae was significantly reduced in all treatments compared to recovery from control plots. The mixture of SfMNPV with 3 ppm Spinosad resulted in ca. 90% S. frugiperda control, which was 12.5–32% greater than for plots treated with SfMNPV alone. The impact of low concentrations of Spinosad on non-target arthropods present in the maize crop was evaluated in a field trial. Application of 3 ppm Spinosad had very little effect on the abundance of insect natural enemies present on maize plants, whereas application of the product label recommended rate of 200 ppm Spinosad had effects similar to those observed following application of chlorpyrifos. The use of low concentrations of Spinosad merits further study as a means of controlling lepidopteran pests either alone or in combination with other entomopathogens.

Toxicity, persistence, and efficacy of spinosad, chlorfenapyr, and thiamethoxam on eggplant when applied against the eggplant flea beetle (Coleoptera: Chrysomelidae).

A laboratory bioassay was developed for determining the toxicity of spinosad, chlorfenapyr, and thiamethoxam against the eggplant flea beetle, Epitrix fuscula Crotch, on eggplant foliage. Four days after initial exposure, LC50 values were 1.99, 2.50, and 0.88 ppm for spinosad, chlorfenapyr, and thiamethoxam, respectively. By dividing the recommended field rate in ppm by the LC50 value, a field toxicity ratio was determined and ranged from 13.5 for spinosad to 73.9 for thiamethoxam. The high ratios suggest that field rates for all three insecticides could likely be reduced. This was supported by field studies in 2000 in which reduced rates of spinosad and thiamethoxam significantly reduced flea beetle numbers on eggplant. Mortality produced by thiamethoxam occurred more quickly than that for the other tested materials as shown with LT50 values of 1.8, 3.0, and 3.6 and days for thiamethoxam, chlorfenapyr, and spinosad, respectively. Persistence studies indicated that while all three of the tested compounds initially produced high levels of mortality, chlorfenapyr and thiamethoxam produced 50% or greater mortality after 6 d. Our data suggest that future management strategies for E. fuscula on eggplant can be successfully altered to meet the changing needs of the producer. Spinosad was recently registered, is effective against the E. fuscula, and offers a viable alternative to carbamate and pyrethroid insecticides. Thiamethoxam and chlorfenapyr offer high levels of toxicity to E. fuscula and upon registration will offer additional effective tools for management.

Toxic Effects of Spinosad on Predatory Insects

Spinosad (Dow AgroSciences) is a mixture of tetracyclic-macrolide compounds produced by a soil actinomycete and has been classified as a bioinsecticide. Spinosad is highly active against Lepidoptera but is reported to be practically nontoxic to insect natural enemies. We assessed the impact of Spinosad in a granular maize-flour formulation on a selection of insect predators over periods of 2–14 days. In all cases, the quantities of Spinosad used were less than the maximum recommended rates given on the product label. Adults of Aleochara bilineata Gyllenhal (Coleoptera:Staphylinidae) suffered a high prevalence of mortality following consumption of 1000 or 2000 ppm Spinosad active ingredient (a.i.), but little mortality at 200 ppm. Larvae of Chrysoperla carnea (Stephens) (Neuroptera:Chrysopidae) did not consume the granular formulation and suffered little overall mortality. After 14 days of exposure, the earwig, Doru taeniatum (Dohrn) (Dermaptera:Forficulidae), suffered 48% mortality in the 1.2 ppm Spinosad treatment increasing to 98% in the 1200 ppm Spinosad treatment compared to 20% in controls. Earwigs suffered 86% mortality/intoxication 72 h after feeding on Spinosad-contaminated Spodoptera frugiperda J. E. Smith (Lepidoptera:Noctuidae) larvae. A field trial was performed to compare applications of commercial granular chlorpyrifos and Spinosad in maize-flour granules (200 and 2000 ppm a.i.; 4.8–48 g a.i./ha, respectively) or as an aqueous spray (160 ppm a.i.; 48 g a.i./ha) on earwigs held inside gauze bags. Mortality of earwigs on control plants was less than 15% at 2 days postapplication compared to 33% on plants treated with granular chlorpyrifos, 83% on plants sprayed with 160 ppm Spinosad, and 91–95% on plants treated with 200–2000 ppm Spinosad granules, respectively. Further mortality in the 24-h period postsampling ranged from <5% in control treatments, to 9% in the chlorpyrifos treatment, and to 55–65% in the Spinosad spray and granule treatments. We conclude that Spinosad cannot be considered to have an environmental safety profile similar to most established biological insecticides.