Bait Sprays Research Articles

Toxicity of spinosad in protein bait to three economically important tephritid fruit fly species (Diptera: Tephritidae) and their parasitoids (Hymenoptera: Braconidae).

The feeding toxicity of the natural insecticide spinosad in Provesta protein bait was evaluated for three economically important fruit fly species, the Mediterranean fruit fly, Ceratitis capitata (Wiedemann); the melon fly, Bactrocera cucurbitae Coquillett; and the oriental fruit fly, Bactrocera dorsalis Hendel. Both females and males were evaluated. Spinosad was remarkably similar in toxicity to all three fruit fly species. Male C. capitata (24 h LC50 values and 95% fiducial limits = 2.8 [2.60-3.0] mg/liter spinosad) were significantly, although only slightly more susceptible to spinosadthan females (4.2 [3.8-4.6] mg/liter). Male (5.5 [4.7-6.6] mg/liter) andfemale (4.3 [3.7-4.9] mg/liter) B. cucurbitae were equally susceptible to spinosad. Female (3.3 [3.1-3.6] mg/liter) and male (3.1 [2.9-3.3] mg/liter) B. dorsalis also were equally susceptible to spinosad. Provesta bait containing spinosad also was evaluated against two parasitoids of tephritid fruit flies, Fopius arisanus (Sonan) and Pysttalia fletcheri (Silvestri). These parasitoids did not feed on the bait, so a contact toxicity test was conducted. Significant amounts of mortality were found only after exposure of parasitoids to spinosad-coated glass vials with concentrations > or =500 mg/liter spinosad. Parasitoids were less susceptible than fruit flies to such a degree that use of spinosad in bait spray should be compatible with these parasitoid species. Because the fruit flies tested in this study were so susceptible to spinosad, this product seems to be promising as a bait spray additive and a replacement for malathion for control of these species.

Toxicity of Spinosad in Protein Bait to Three Economically Important Tephritid Fruit Fly Species (Diptera: Tephritidae) and Their Parasitoids (Hymenoptera: Braconidae)

The feeding toxicity of the natural insecticide spinosad in Provesta protein bait was evaluated for three economically important fruit fly species, the Mediterranean fruit fly, Ceratitis capitata (Wiedemann); the melon fly, Bactrocera cucurbitae Coquillett; and the oriental fruit fly, Bactrocera dorsalis Hendel. Both females and males were evaluated. Spinosad was remarkably similar in toxicity to all three fruit fly species. Male C. capitata (24 h LC50 values and 95% fiducial limits = 2.8 [2.60–3.0] mg/liter spinosad) were significantly, although only slightly more susceptible to spinosad than females (4.2 [3.8–4.6] mg/liter). Male (5.5 [4.7–6.6] mg/liter) and female (4.3 [3.7–4.9] mg/liter) B. cucurbitae were equally susceptible to spinosad. Female (3.3 [3.1–3.6] mg/liter) and male (3.1 [2.9–3.3] mg/liter) B. dorsalis also were equally susceptible to spinosad. Provesta bait containing spinosad also was evaluated against two parasitoids of tephritid fruit flies, Fopius arisanus (Sonan) and Pysttalia fletcheri (Silvestri). These parasitoids did not feed on the bait, so a contact toxicity test was conducted. Significant amounts of mortality were found only after exposure of parasitoids to spinosad-coated glass vials with concentrations ≥500 mg/liter spinosad. Parasitoids were less susceptible than fruit flies to such a degree that use of spinosad in bait spray should be compatible with these parasitoid species. Because the fruit flies tested in this study were so susceptible to spinosad, this product seems to be promising as a bait spray additive and a replacement for malathion for control of these species.

Effectiveness of GF-120 fruit fly bait spray applied to border area plants for control of melon flies (Diptera: Tephritidae).

In a field study in Hawaii, color-marked protein-deprived and protein-fed female melon flies, Bactrocera cucurbitae Coquillett, were released within canopies of unsprayed sorghum plants (a nonhost of melon flies) outside of a border area of unsprayed or bait-sprayed sorghum plants or open space that surrounded cucumbers, a favored host of melon flies. Application of bait spray to sorghum or sugarcane surrounding host plants of melon flies is a common practice for melon fly control in Hawaii. GF-120 Fruit Fly Bait spray proved very effective in preventing protein-deprived females from alighting on cucumbers (23% of released females were observed dead on bait-sprayed sorghum; 0% were observed alive on cucumbers), but proved less effective in suppressing protein-fed females (14% of released females were observed dead on bait-sprayed sorghum; 11% were observed alive on cucumbers). No females were found dead on unsprayed sorghum. Compared with open space surrounding cucumbers, the presence of unsprayed sorghum as surrounding border area neither significantly enhanced nor significantly inhibited the ability of either type of female with respect to finding cucumbers. Greenhouse cage assays revealed that compared with droplets of water, droplets of GF-120 Fruit Fly Bait spray were highly attractive to protein-deprived females within 1 h of bait spray application to sorghum, but lost about half of their attractiveness within 5 h and all of it within 24 h under the dry greenhouse conditions used for maintaining baited-sprayed sorghum plants in these assays. Laboratory cup assays showed that bait spray droplets remained highly toxic to protein-deprived females 24 h after application, but lost nearly half of their toxicity within 4 d under laboratory exposure and nearly all of it after approximately 8 mm of rainfall. Combined findings suggest that application of GF-120 Fruit Fly Bait spray to nonhost plants for melon fly control either be made often enough to overcome loss of attractiveness of bait spray droplets to females or that bait spray be applied to nonhost plants that are themselves attractive to the females.

Feeding and foraging of wild and sterile Mediterranean fruit flies (Diptera: Tephritidae) in the presence of spinosad bait.

The sterile insect technique (SIT) is used to control wild Mediterranean fruit fly introductions in California and Florida in the U.S. In the past, bait sprays containing malathion proved invaluable in treating new outbreaks or large populations before the use of SIT. Recently, a spinosad protein bait spray, GF-120, has been developed as a possible alternative to malathion, the standard insecticide in protein bait sprays. In this study, protein-deficient and protein-fed Vienna-7 (sterile, mass-reared, "male-only" strain) flies and wild males and females were evaluated to determine the effectiveness of the GF-120 protein bait containing spinosad with respect to bait attraction, feeding, and toxicology. There were no effects of diet or fly type on feeding duration in small laboratory cages. Wild flies, however, registered more feeding events than Vienna-7 males. Flies that fed longer on fresh bait died faster. Protein-deficient flies were more active and found the bait more often than protein-fed flies. Data suggest that adding protein to the diet of SIT flies may decrease their response to baits, therefore, reduce mortality, and thus, allow the concurrent use of SIT and bait sprays in a management or eradication program.

INNOVATIVE PRODUCTION SYSTEMS FOR NON-ASTRINGENT PERSIMMON

Traditional production systems for growing non-astringent persimmon throughout the world have changed rapidly in the last 10 years. New systems have been developed to grow persimmon in subtropical regions of the world. In Australia most orchards are now trained to a palmette system rather than the conventional vase shape system, allowing for easier management and growth control. In contrast, in New Zealand trees are trained to a Y trellis system to improve light interception under cloudy growing conditions. Reflective mulch is also used to further maximise light use and increase fruit heat units necessary to fully mature the fruit. Tree planting densities have increased from 400 to 800 trees per hectare. In Japan high density plantings using micro-propagated trees are being evaluated. In Australia many orchards are netted to exclude birds and fruit eating bats. Multi-purpose fruit fly exclusion netting is also being evaluated as an environmentally friendly alternative to insecticidal cover sprays. New formulations of fruit fly bait sprays with greater efficacy and longer field life have also been developed. Sporadic and erratic budbreak can be a major problem in subtropical regions where trees do receive sufficient chilling. A new range of rest-breaking chemicals such as Armobreak (akolated amine) and Waiken (fatty acid esters) can increase the percentage budbreak, flowering and yield. Excessive vegetative growth during the flowering period leads to competing sinks, reducing fruit set and fruit size. The growth retardant paclobutrazol has been shown to effectively control growth reducing tree size by about 20%. Paclobutrazol also advanced the harvest period by about 2 weeks without loss of fruit quality or storage life. Attempts at improving fruit firmness and post-harvest shelf life through foliar application of Ca have been partially successful but multiple sequential applications are necessary to be effective. Preliminary studies have shown that a new group of growth regulators, ethylene biosynthesis inhibitors, when applied 2 to 3 weeks prior to harvest, delayed fruit maturity and improved fruit size, firmness and storage life.

Comparison of the Efficacy of Different Food Attractants and Their Concentration for Melon Fly (Diptera: Tephritidae)

The relative attractiveness of six commercially available protein hydrolysates and the influence of their concentration were evaluated in field cages by a release-capture method of lab-reared melon fly adults, Bactrocera cucurbitae (Coquillett). Buminal, Corn Steepwater, Hym-Lure, Pinnacle, Nulure, and SolBait were tested for both sexes of the melon fly. The tested products exhibited clear differences in attractiveness. SolBait was the most effective protein hydrolysate. Pinnacle and Corn Steepwater also gave promising results. A general tendency for an increase in effectiveness with increasing concentration within the range 0.5 to 10% was shown. This study will allow pest control practitioners to choose more effective attractants for use in bait sprays to control the melon fly thus reducing the intensive use of insecticides currently practiced in Reunion island and enabling the development of Integrated pest management (IPM) methods for cucurbit crops.

Comparison of the efficacy of different food attractants and their concentration for melon fly (Diptera: Tephritidae).

The relative attractiveness of six commercially available protein hydrolysates and the influence of their concentration were evaluated in field cages by a release-capture method of lab-reared melon fly adults, Bactrocera cucurbitae (Coquillett). Buminal, Corn Steepwater, Hym-Lure, Pinnacle, Nulure, and SolBait were tested for both sexes of the melon fly. The tested products exhibited clear differences in attractiveness. SolBait was the most effective protein hydrolysate. Pinnacle and Corn Steepwater also gave promising results. A general tendency for an increase in effectiveness with increasing concentration within the range 0.5 to 10% was shown. This study will allow pest control practitioners to choose more effective attractants for use in bait sprays to control the melon fly thus reducing the intensive use of insecticides currently practiced in Reunion island and enabling the development of Integrated pest management (IPM) methods for cucurbit crops.

The efficacy of an improved form of the mass‐trapping method, forthe control of the olive fruit fly, Bactrocera oleae (Gmelin) (Dipt., Tephritidae): pilot‐scale feasibility studies

Abstract: The efficacy of an improved form of the mass‐trapping method for the control of the olive fruit fly, Bactrocera oleae (Gmelin) was tested for 4 years in a pilot test at Tanagra Voeotia, Greece. Improvements consisted of the extension of the active life of the toxic trap used, active life referring both to its attracting and killing properties, as well as in trap deployment, which combined efficacy and low cost. The method was compared to bait sprays applied from the ground, which constitutes the current standard method for the control of this pest. Both pest population density and fruit infestation levels, the main parameters used for the evaluation of the two methods were considerably lower during all 4 years of tests in the orchards protected by mass trapping compared with those in the orchards protected by bait sprays. Furthermore no complementary measures were required in the mass‐trapping orchards for acceptable crop protection, which was not the case under certain conditions, prior to the introduction of the recent improvements. The cost of the mass‐trapping method was approximately US$ 0.40 per tree per year compared with US$ 0.35 for bait sprays (figures of the Greek Ministry of Agriculture). However, the mass‐trapping method reduces the amount of insecticide used for olive protection by 99.5% (15 mg a.i. per tree per year as opposed to 3 g in the case of bait sprays). A considerable reduction in the cost of the mass‐trapping method is expected with the extension of its use and the mass production of materials used, especially traps.

Efficacy of Spinosad Bait Sprays to Control Mediterranean and Caribbean Fruit Flies (Diptera: Tephritidae) in Commercial Citrus in Florida

A serious infestation of Mediterranean fruit fly in Florida in 1997 and 1998 led to the widespread aerial and foliar application of malathion-bait sprays. Public concerns over property damage, environmental impact and public health led to the immediate need and acceptability of alternative pesticide/bait combinations. Preliminary work with spinosad, a derivative of a soil microorganism developed by Dow AgroSciences, in combination with a new bait (SolBait) showed promise. To ensure that this product would be effective in Florida for fruit fly control, three field tests were conducted using aerial and/or foliar applications. Results indicated that sprays with spinosad-SolBait provided comparable and significant control levels for sterile Mediterranean and Caribbean fruit flies in comparison to standard malathion with NU-LURE® or SolBait treatments by aerial or foliar application. In one test, honey bees and hives were exposed to sprays in the treatment area and no significant treatment differences were observed in hive condition or brood. Insufficient data on effects of treatments on naturally occurring and introduced beneficial insects were collected for statistical analysis but it appears no harmful effects were observed.

Potential for Areawide Integrated Management of Mediterranean Fruit Fly (Diptera: Tephritidae) with a Braconid Parasitoid and a Novel Bait Spray

The braconid wasp, Fopius arisanus (Sonan), a biological control agent for Mediterranean fruit fly, Ceratitis capitata (Wiedemann), was studied in coffee, Coffea arabica L. Fopius arisanus, comprised 79.3% of the total parasitoids (7,014) recovered from fruits collected at three small coffee farms. Data from seasonal host/parasitoid studies at a large coffee plantation also suggested that the most effective natural enemy of C. capitata in coffee may now reside in Hawaii. The original parasitoids introduced into Hawaii for C. capitata control (Diachasmimorpha tryoni (Cameron), Tetrastichus giffardianus Silvestri, and Dirhinus giffardii Silvestri) are now rare. Abundance of F. arisanus with respect to other parasitoids collected was influenced by elevation (274, 457, 610 m). Fopius arisanus was the dominant parasitoid at all three elevations, Diachasmimorpha longicaudata (Ashmead) occurred consistently, and T. giffardianus was abundant only at low elevation. The impacts on C. capitata and F. arisanus populations of bait sprays containing malathion, spinosad, or phloxine B applied to coffee were also evaluated. All three bait sprays suppressed C. capitata populations. Spinosad and phloxine B bait sprays appeared less harmful to the wasp than malathion. Fopius arisanus offers the potential for areawide management of C. capitata that includes biological control and integration with more environmentally safe chemical controls such as spinosad and phloxine B bait sprays.

Different Control Measures Against the Insect Pests of Bitter Gourd (Momordica charantia L.)

Different control measures, viz., M.Y. (Muhammad Yousuf) Strategy (Pressurized water spray), Cultural practice (Picking and burrying of infested fruit) and Diptrex (trichlorfon) as cover and bait spray with Protein hydrolysate were tested for their effectiveness against the insect pests of bitter gourd (Momordica charantia L.) M.Y. Strategy gave better control of whitefly (Bemisia tabaci) as compared with Diptrex and Diptrex plus Protein hydrolysate. In case of melon fruit fly (Bactrocera cucurbitae), Diptrex was the most effective followed by Diptrex plus Protein Hydrolysate and cultural practice but the M.Y. Strategy showed no effect.

Field tests of environmentally friendly malathion replacements to suppress wild Mediterranean fruit fly (Diptera: Tephritidae) populations.

This article reports a large-scale field test of two environmentally friendly malathion replacements on wild populations of the Mediterranean fruit fly, Ceratatis capitata (Wiedemann): spinosad, a bacteria-derived toxin, and phloxine B, a red dye with phototoxic properties. The comparison test was conducted on 11 coffee fields infested with wild populations of Mediterranean fruit fly on the Hawaiian island of Kauai with 8-wk protein bait sprays with and without toxicants. To assess effectiveness, adults were trapped and larval infestation levels were evaluated with fruit collections. Malathion was found to be the most effective treatment. However, the two replacements gave significant levels of control, and because they are environmentally safer, should be considered for eradicating incipient populations of this invasive species of fruit fly. Cage tests were also conducted to ensure that the wild flies consumed the bait and to assess how long the bait-toxicant combination remained effective in the field. Although spinosad and phloxine B were found to be effective up to 1 wk, malathion remained effective at least 2 wk.

Development of a low-cost pupal release strategy for Sterile Insect Technique (SIT) with Queensland fruit fly and assessment of climatic constraints for SIT in rural New South Wales

Sterile pupae of Queensland fruit fly (Qfly) Bactrocera tryoni (Froggatt) were released to suppress wild Qfly populations at 3 sites in New South Wales and to assess a pupal release strategy using the bed technique. Sterile pupae were released from September 1997 to June 1998 from sand and vermiculite beds. A total of 24.6 million pupae were released with a male recapture rate of 0.101% (not corrected for adult emergence rate). Adult emergence rates were 25% at Tullibigeal; 39% at Ungarie and 46, 41, 71 and 54% respectively at 4 locations at Lake Cargelligo (mean 46%). Corrected recapture rates using cue-lure traps were 0.88% at Tullibigeal, 0.08% at Ungarie and 0.15% at Lake Cargelligo (mean 0.21%). When wild fly populations increased at Lake Cargelligo, a bait spraying program was used which substaintially reduced the catches of both sterile and wild flies in traps. Analyses using the CLIMEX model showed that the climate at Lake Cargelligo town (with irrigation) was suitable for fruit flies. CLIMEX indicated that the unmodified rural environment was unsuitable for fruit fly survival due to a summer moisture deficit. The Meats daily survival rate decrement of 58–72% was similar to that found for some similar studies in Australia but lower than for certain other release programs. No significant bird or ant predation was observed.

Efficacy of Different Bait Sprays for Suppressing Fruit Fly on Cucumber

Efficacy of Different Bait Sprays for Suppressing Fruit Fly on Cucumber

Suppressing oriental fruit fly populations with phloxine B-protein bait sprays

The oriental fruit fly, Bactrocera dorsalis (Hendel), is a tephritid fruit fly that is a serious pest of a wide range of tropical fruits. Populations of oriental and other fruit fly species are often suppressed by utilizing aerial or ground sprays of hydrolysed protein bait mixed with malathion. Although proven to be efficacious, spraying food bait mixed with malathion in urban areas is strongly opposed by the public because of perceived public health and environmental risks. To suppress the population level of oriental fruit fly in a guava orchard in Hawaii, we used the light-activated xanthene dye, phloxine B (2′,4′,5′,7′ -tetrabromo-4,5,6,7-tetrachlorofluorescein, disodium salt), as an alternative to malathion in protein bait sprays. Because phloxine B must be ingested to be toxic, it is expected that phloxine B bait sprays will have less impact on non-target insects than the contact insecticide malathion. Evidence of suppression of oriental fruit fly population in the treatment orchard was provided by both protein bait trap catches and assessment of fruit infestation. This suppression was achieved even though there was an unsprayed guava orchard on two sides of the small (less than 2.0 ha) sprayed orchard. These results, combined with results for other fruit fly species (presented elsewhere), indicate that phloxine B-protein bait sprays can be effective in suppressing populations of several different fruit fly species and that phloxine B is a potential replacement for malathion in bait sprays for tephritid fruit fly suppression/eradication programs.

Cold Torpor and Flight Threshold of Anastrepha suspensa (Diptera: Tephritidae)

The Caribbean fruit fly, Anastrepha suspensa (Loew), is a pest of quarantine significance of many subtropical fruits in Florida. Fly free zones which require bait spraying with malathion when fly populations reach actionable levels, have been developed. Bait sprays also are used whenever new introductions of fruit fly species occur. Bait sprays will not be effective if the target population is immobile due to cold. The purpose of this study was to develop temperature thresholds for laboratory-reared and wild Anastrepha suspensa through controlled laboratory studies. This research determined that the cold torpor threshold for Caribbean fruit fly was 11.4C, and the flight threshold for 50% of the population was about 20C. It also was determined that the flight threshold of wild flies did not differ significantly from that of laboratory reared flies. Bait spray experiments and regular treatments could be scheduled to avoid cold periods when flies are not active.

Removal of malathion residues on lettuce by washing.

Malathion (S-1,2-bis(ethoxycarbonyl)ethyl O,O-dimethyl phosphorodithioate), a broad-spectrum insecticide, was used in California to eradicate infestations of the Mediterranean fruitfly (Medfly-Ceratitis capitata) (Segawa 1991). Under the eradication program, malathion in a protein-sugar bait was applied by helicopters over extensive agricultural and residential areas where many of the over 260 host plants susceptible to Medfly infestation could be found (Foote 1993). Homeowners were concerned about consuming fruits and vegetables grown in home gardens that were exposed to the bait sprays. Water rinsing or washing has been reported to remove malathion residues from vegetables (Smith et al. 1955, Wallis et al. 1957). The extent to which pesticide residues could be removed from treated produce by washing may be influenced by a variety of factors such as the chemical properties and formulation type of the pesticide, the nature of the commodity, the length of time that the residue has been on the commodity’s surface, and the rinsing time and rinsing agents used (Smith et al. 1955).

Toxicity of anethole and its effects on egg production of Ceratitis capitata Wied. (Dipt., tephritidae)

SummaryWe report the effects of anethole on adult Ceratitis capitata Wied. (Diptera, Tephritidae) which cause serious damage to fruit crops. Because of the toxicological and environmental pollution due to the indiscriminate use of organophosphates against the endophagous larvae, the control of this pest is now mainly directed against the adults, by the application of bait sprays. Considerable toxic effects have been obtained by oral administration to adults of nutritive formulations containing 5% anethole with some hydrolised commercial proteins. In this test we observed high values of mortality (85% after 24 h) and a total inhibition of reproductive activity. The toxic effect produced by oral administration of the compound tested appears to be correlated to irreversible damage to the gut of the medfly.These results acquire a particular importance in view of the introduction of alternative methods for the control of the medfly. In particular, our objective is the testing of relevant formulations of this active principle in field. The use of anethole combined with protein baits, which can be used in the open field, is therefore particularly promising.

Economic Evaluation of Three Alternative Methods for Control of the Mediterranean Fruit Fly (Diptera: Tephritidae) in Israel, Palestinian Territories, and Jorda

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), is a major pest of fruit crops in the Mediterranean Basin countries. If no control measures are applied in Israel, Palestinian Territories, and Jordan against this pest, the annual fruit losses are estimated to be about U.S. $365 million, which is more than half the total revenue produced by fruits considered to be Mediterranean fruit fly hosts in these countries. Under the current control programs, the direct damage (yield loss and control costs) and indirect damage (environmental impact and market loss) amount to U.S. $192 million per year. This amount could increase each year if the current control programs are kept. The aim of this study was to evaluate, on a regional basis, the economic returns of 3 improved alternative Mediterranean fruit fly control methods using a 9-yr time frame. The control alternatives include population suppression using bait sprays, population suppression using massive release of sterile male flies, and population eradication also using massive releases of sterile male flies. For each option, an action plan was prepared which includes intensity, frequency and timing of sampling (trapping and fruit gathering), control (bait sprays and sterile male releases), and postcontrol (quarantine and emergency capacity) techniques. For the economic evaluation costs and benefits at net present value are computed for each control option to estimate the economic indices. Results indicate that the 3 area-wide control options are technically and economically feasible and all are better than the current control programs. For each option, the economic returns on a medium and long term are discussed, along with the environmental impact. Over the 9-yr time frame, the greatest economic return is from the sterile male suppression option. Over a much longer time frame, the greatest return is for the sterile male eradication option.

Laboratory toxicity of a photo activated dye mixture to six species of beneficial insects

AbstractThe toxicity of a mixture of two photoactive dyes, Phloxine B and Uranine, was determined for six species of beneficial insects in the laboratory. The dye had no measurable contact toxicity to any test insect. The dye, when mixed in protein baits, was significantly more toxic than the bait alone to Chrysopa carnea Stephens, Cryptolaemus montrouzieri Mulsant, Delphastes pusillus Le Conte and Goniozus legneri (Gordh). The toxicity of all dye and bait mixtures was significantly less to all test insects than that of the malathion and bait mixtures. Substituting the dye mixture for malathion in protein bait sprays used to eradicate exotic fruit flies from the United States should significantly reduce the kill of non‐target beneficial insects.