Granular Bait Research Articles

Granular Bait Applications for Management of Rangeland Grasshoppers Using a Remotely Piloted Aerial Application System

Rangeland grasshoppers are an endemic species that play an essential role in the rangeland ecosystem but can cause severe economic damage when populations reach outbreak levels. Remotely piloted aerial application systems (RPAASs) offer an alternative method to carry out aerial insecticide applications in relatively small areas. The objective of this study was to investigate the efficacy of a granular bait, 2% Sevin (with the active ingredient carbaryl), applied by an RPAAS. The bait was applied on four replicated 4.05-hectare (10-acre) plots at a rate of 2.27 kg/ha (5 lbs/acre) with an RPAAS on a private ranch in New Mexico. Applications resulted in a normalized population reduction of 70.32% ± 16.54% standard error of the mean (SEM) of bait-susceptible species. Although some of the observed reduction in population may be attributed to aging, the net effect was most likely due to the ingestion of bait based on field observations of rapid mortality after ingestion and other factors, like past experience with carbaryl bait treatments on grasshoppers. Plots required at least two flights due to the Federal Aviation Administration’s (FAA) maximum takeoff weight requirement for small RPAASs. Combined, these results indicate that RPAASs can provide treatment capabilities in relatively small areas, i.e., population hotspots, preferably before outbreak levels are reached.

Suitability of containerized toxicant to control Solenopsis invicta (Hymenoptera: Formicidae) threatening cave species in Bexar County, Texas.

Several protected troglobitic invertebrate species are known to occur in caves on Joint Base San Antonio-Camp Bullis, Bexar County, Texas, United States. The United States Fish and Wildlife Service (USFWS) identified red-imported fire ant Solenopsis invicta (hereafter RIFA) (Buren 1972) as the primary threat to cave species' nutrient sources, cave crickets, Ceuthophilus secretus (Scudder 1894). Per the service's recommendations, Joint Base San Antonio-Camp Bullis currently implements boiling water mound injections with digging for RIFA control. However, treatment effectiveness is highly variable and largely dependent on the time of day, weather, and personnel diligence. Toxicants have been used for RIFA treatment throughout the world, but concerns exist that traditional applications of toxicant bait around caves might be accessible and inadvertently affect nontarget arthropods, including cricket populations. To mitigate this accessibility, physically limiting access to the toxicant from crickets may be an option. Our objectives were to (i) compare and evaluate the effectiveness of Amdro (Hydramethylnon) and Advion (Indoxacarb) granular baits housed in Ants-No-More Bait Stations (Kness MFG. Inc., Albia, IA) and (ii) evaluate the distance of effectiveness of each bait within a bait station. Ultimately, we observed a 98% reduction in RIFA mound abundance from both baits. Additionally, RIFA mounds within 10 m of the containerized toxicant were reduced by 70%. Our pilot study suggested that Ants-No-More Bait Stations are an effective way to reduce RIFA mounds by 70% if placed 10 m from each other. In practice, this could include bait stations completely covering a particular distance to a cave entrance or fewer bait stations in a ring barrier at a single radial distance to a cave entrance. Containerized toxicants may be a cost-effective and safe RIFA control option around protected cave environments, but further studies are needed to determine potential effects on nontarget arthropods, optimal bait station configuration, and potential effects of biomagnification.

Termite cuticular extracts improve acceptance of bait for controlling invasive Asian needle ants, Brachyponera chinensis.

The Asian needle ant, Brachyponera chinensis, is an invasive ant currently spreading in urban and natural habitats throughout the eastern United States. Recent studies have documented the negative impact of B. chinensis on native ecosystems and human health, yet effective control strategies are lacking. Control difficulties are, in part, due to the unique biology of B. chinensis, which is a predatory ant and a termite specialist. Given that subterranean termites are an important nutritional resource for B. chinensis, the current study evaluated the potential of termite cuticular extract to improve the target-specificity and efficacy of commercial bait used for B. chinensis control. The efficacy of bait augmented with termite cuticular extracts was evaluated in laboratory and field trials. In laboratory assays, B. chinensis colonies were offered granular bait treated with termite cuticular extract. Results demonstrated that the acceptance of commercial bait is significantly increased by the addition of termite cuticular extract or synthetic (Z)-9-pentacosene, a major component of termite cuticular extract. Foraging activity of Asian needle ants was significantly greater on baits augmented with termite cuticular extract or (Z)-9-pentacosene relative to standard bait. Furthermore, bait augmented with termite cuticular extract worked substantially faster relative to standard bait. To evaluate population effects, field studies were conducted in forested areas invaded by B. chinensis. Bait treated with termite cuticular extract scattered on the forest floor provided rapid control of B. chinensis and ant densities throughout the treated plots declined by 98% within 14 days. The incorporation of termite cuticular extracts and individual cuticular hydrocarbons such as (Z)-9-pentacosene into traditional baits used for B. chinensis control may offer a novel tool to manage this increasingly problematic invasive ant. © 2023 The Author. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Study on feeding behavior and biological sound of Sebastes schlegelii

The construction of marine ranches can enrich and conserve the fishery resources and improve the marine ecosystem, which helps realize the sustainable utilization of these resources. Sebastes schlegelii is a major breeding and releasing fish species in the marine ranches of North China. Its behavioral characteristics can be understood better by researching its vocalization, which will provide data support for constructing acoustic taming marine ranches with S. schlegelii as the target fish species. However, there are few studies focusing on its sounds and behaviors. Therefore, based on the passive acoustic monitoring technology, the audios of underwater noises made by S. schlegelii were extracted using an AQH hydrophone. The high-definition internet protocol camera was used to monitor the behavior change of S. schlegelii. Then, by collating and replaying the collected audios and videos, the feeding behavior and biological noises of S. schlegelii were matched to analyze their relationship. Results are as follows: (1) The noise of chewing settling granular baits (Φ5.0 mm) has a main frequency band and sound pressure level of 2000~4500 Hz and 96.53 ± 0.65 dB, respectively; in this feeding process, the main frequency band and sound pressure level of the swimming noise are 25~400 Hz and 95.63 ± 0.38 dB, respectively; the values are 500~700 Hz and 97.34 ± 4.91 dB, respectively, for the noise of flapping the water with the tail. (2) The sound signals emitted by S. schlegelii are mostly presented as single pulses during normal habitation or ingestion of baits on the surface of the water tank. However, S. schlegelii will attack and fight against each other when scrambling for baits, during which these signals are presented as continuous pulses. To sum up, the vocalization of S. schlegelii is closely related to feeding activities, and the sounds produced under different behaviors have specific biological significance.

Mortality of leaf-cutting ants with salicylic acid

Strategies for the control of leaf-cutting ants have mainly involved granular baits based on fipronil and sulfluramid as active ingredients, which are commonly coated with attractive citrus-based substances. Their constant use and the lack of alternatives in the market may favor the perception of these substances by ants, causing rejection for foraging and consequent difficulty in their control. In this respect, this study examined the mortality of leaf-cutting ants of the genera Atta and Acromyrmex subjected to direct application with dry powders, in laboratory conditions. As a preliminary treatment, a commercial antiseptic talc powder (C. A. P. T.) was used, followed by isolated treatments that corresponded to its components with potential insecticidal action, namely, salicylic acid, sulfur, boric acid, zinc oxide, in addition to an inert talc powder (Quimidrol®) as the control. For each treatment, 40 (worker) ants, whose activity was reduced due to remaining in a refrigerator prior to the treatment, were placed in transparent crystal polystyrene (‘Gerbox’ type) and were sprinkled with a salt shaker. The ants were kept at 25 ± 2 °C, under a 12-h photophase, and cumulative mortality was recorded every 24 h, considering dead ants as those that were unable to maintain the natural position of their body, i.e., even dying ants were considered dead when they exhibited no reaction when touched by a paintbrush. When sprinkled on ants, C. A. P. T. causes 40% mortality in both species 24 h after application. Subsequent studies of the components of this commercial product have found that when sprinkled on both Atta sexdens rubropilosa and Acromyrmex crassispinus, salicylic acid causes 100% mortality of workers in the first 24 h. This result provides a new prospect of control through a low environmental-impact product, representing an alternative for control in nests in the field that can contribute to the integrated control of ants.

Impact of the fire ant pesticide AMDRO on loggerhead turtle nest productivity and seafinding orientation

Invasive fire ants prey on a variety of organisms in the southeastern USA, including the pipped eggs and hatchlings within sea turtle nests. The granular fire ant bait AMDRO® (active ingredient hydramethylnon) is currently used at some rookeries to protect nests, but no studies have been conducted to determine if the pesticide negatively impacts the eggs or the hatchlings. We examined the pesticide’s effect on loggerhead (Caretta caretta) nests at Juno Beach, Florida, USA, specifically targeting how exposure affected hatching success, hatchling emergence success, and the ability of the turtles to orient visually from the nest to the sea. Pesticide granules were placed within a 30 cm diameter circle on the sand directly above the nest during the final 5-10 days of incubation, representative of its typical application at nesting beaches. Cornmeal granules in soybean oil and untreated natural nests served as controls. AMDRO had no significant effect on hatching success or emergence success, nor did it result in any deficiencies in hatchling orientation accuracy. However, the pesticide and cornmeal control attracted other predators (Atlantic ghost crabs and avian species), in addition to fire ants, to the nest site, thus revealing the nest’s location and potentially increasing its vulnerability. Consequently, we suggest that its usage may not be beneficial at sites where predators other than ants are especially abundant.

Potential Health Risk to Humans Related to Accumulation of Brodifacoum and Bromadiolone in the Wheat Grown on Rodenticide Contaminated Soil

Abstract The aim of this study was to determine in a model experiment the potential residues of bromadiolone and brodifacoum in the wheat grown on soil treated with these rodenticides and to compare them with the respective acceptable daily intake (ADI) in order to obtain information lacking in the scientific literature. The study focused on the level of residues of chronic rodenticides Broder G, with the active ingredient brodifacoum, and DERATION G, with the active ingredient bromadiolone, in wheat (Triticum spp.). The preparations were used in the form of granular bait. In the wheat grown on the soil treated with 100 g.m−2 of the preparation BRODER G, the brodifacoum residues ranged from 0.012 to 0.0218 mg.kg−1, while the treatment of soil with 500 g.m−2 resulted in residues ranging between 0.0344 and 0.0436 mg.kg−1. When using the preparation DE-RATION G, bromadiolone residues ranged between 0.012 and 0.018 mg.kg−1 after the treatment of soil with 100 g.m−2 and between 0.030 and 0.0428 mg.kg−1 after the treatment with 500 g.m−2. We observed that the acceptable daily intake was exceeded significantly in all of the cases and the residual levels depended on the rodenticide dose. In the case of brodifacoum, the ADI was exceeded more than 700-fold at a dose of 100 g.m−2 and more than 1400-fold at a dose of 500 g.m−2 of soil. With bromadio-lone, the ADI was exceeded 150-fold at a dose of 100 g.m−2 and more than 350-fold at a dose of 500 g.m−2. This indicates the risk to consumers from such crops.

Evaluation of a bait for ant management in tropical fruit crops in Espírito Santo, Brazil

Research is being conducted in Espirito Santo, Brazil, to evaluate the use of a granular bait containing abamectin for control of ants associated with mealybugs that infest pineapple and other crops (coffee and cocoa) to reduce pest mealybug populations and mealybug wilt disease of pineapple. Results indicate that granular bait containing abamectin (0.01%) may be useful for control of ants in pineapple and coffee fields.

Application of <i>Clostridium Botulinum</i> Toxin Type D to Control Plateau Zokors in Qinghai–Tibet Plateau Pastoral Areas

The feasibility of Clostridium botulinum toxin type D as a novel biological rodenticide to control plateau zokors was explored. In this study, Horn’s method was used to determine the gavage LD50 of C. botulinum toxin type D to plateau zokors. Modified Karber metho was employed to determine the oral LD50 of granular and wheat baits. Results showed that the gavage LD50 was 5840 MLD/kg (the reliable line is 3430–9950 MLD/kg) and the oral LD50 values of granular and wheat baits were 0.8339 and 1.319 g/kg, respectively, which indicated that plateau zokors are sensitive to this toxin. The palatability of wheat and homemade granular baits to plateau zokors was measured. Selective feeding coefficients were 1.33 and 1.10, whereas nonselective feeding coefficients were 0.81 and 0.60, respectively. A plot experiment of different toxin concentrations to kill zokors showed that homemade granular bait (10000 MLD/g) had the best effect. The average efficiency rate was 89.83%. This study showed the feasibility of controlling plateau zokors by using botulinum toxin type D.

RESISTÊNCIA DE ISCAS GRANULADAS, DISTRIBUÍDAS A GRANEL E EM MICROPORTA-ISCAS, À AÇÃO DA UMIDADE EM PLANTIO DE <i>Pinus taeda</i> NO PLANALTO SUL-CATARINENSE

Os programas de controle para formigas-cortadeiras do gênero Acromyrmex na região sul do Brasil são pouco estudados, tendo suas informações embasadas no controle do gênero Atta e aos danos causados por formigas-cortadeiras em plantios de Eucalyptus spp. Esta falta de informações sobre controle de formigas-cortadeiras leva algumas empresas florestais de Santa Catarina à repetição de padrões que não são adequados às infestações e às espécies de formigas-cortadeiras que ocorrem neste Estado. Com isso, ocorre uma distribuição inadequada de iscas granuladas a granel, nas quatro estações do ano, que acabam degradadas pelo excesso de umidade provocado pela neblina e pelas precipitações constantes que ocorrem na região. Diante deste quadro, os experimentos deste trabalho tiveram como objetivos: identificar as espécies de formigas-cortadeiras; determinar a densidade de formigueiros por unidade área; analisar e avaliar a influência das estações do ano e da precipitação em cada estação sobre a conservação e degradação das iscas granuladas à base de sulfluramida (0,3%) distribuídas a granel e na forma de microporta-iscas. Para tanto, foram instalados experimentos na Fazenda Dois Irmãos, de propriedade da empresa Florestal Rio Marombas Ltda., em áreas de plantios de Pinus taeda L., localizados no município de São Cristóvão do Sul, no planalto sul do estado de Santa Catarina. Concluiu-se que: A única espécie de formiga-cortadeira encontrada na área avaliada é Acromyrmex crassispinus (FOREL, 1909); Na área experimental encontram-se 17 formigueiros, a média é de 0,94 formigueiros por hectare, com área aparente menor que 1 m² cada um; a umidade da região do planalto sul-catarinense degrada as iscas granuladas distribuídas a granel; as iscas granuladas distribuídas a granel permanecem conservadas sete dias na primavera e três dias nas demais estações do ano; as iscas granuladas distribuídas em microporta-iscas permanecem conservadas 15 dias no verão e 30 dias nas demais estações do ano; os microporta-iscas apresentam maior resistência à umidade no campo em relação às iscas granuladas distribuídas a granel; a abertura dos microporta-iscas, provocada pelo consumo parcial das iscas, que é uma característica das formigas Acromyrmex spp., acelera a deterioração das iscas restantes em seu interior.

How do groups of red imported fire ants (Hymenoptera: Formicidae) feed on a droplet of sugar water?

Many previous studies have focused on the foraging behaviors and strategies of the red imported fire ants, Solenopsis invicta Buren on solid food or granular bait; little attention has been paid to how liquid sugar is fed upon. In the present study, behavioral responses of S. invicta to 25% sucrose water droplets were observed. Five foraging patterns were identified in S. invicta colonies under laboratory conditions: (i) no feeding, no sucrose water feeding was observed; (ii) surround feeding, ants surrounded and fed along the edge of the sucrose droplet; (iii) stacked feeding, ants stacked and fed along the edge of the sucrose droplet; (iv) droplet-break feeding, ants broke the liquid droplet and sucked sucrose water that spread on surface of the substance or soil particles previously transported by ants; and (v) cover feeding, whole surface of the sucrose droplet was covered by layers of feeding ants. This is the first time cover feeding in S. invicta has been reported, which obviously requires more ants compared to the other patterns. In addition, individual ants were tracked in videos under laboratory conditions, and behavioral repertoires that led to stacking, covering and droplet-breaking were identified and described. The field investigation showed that surround feeding was most frequently performed by S. invicta foragers; however, cover feeding was not observed under field conditions during this study. Both laboratory and field studies showed colony-level variations in sugar-water feeding.

Successful treatment of metaldehyde toxicosis with intravenous lipid emulsion in a dog

The aim of the present report is to describe a novel successful treatment approach for metaldehyde poisoning in a dog: intravenous lipid emulsion therapy (ILE). A 2.5-month-old female Labrador Retriever was referred to the Emergency Department following deliberate ingestion of a metaldehyde-containing granular bait. Severe continuous tonic-clonic activity, muscle tremors, loss of consciousness, diffuse congestion of the oral mucosa, tachycardia, tachypnoea and nystagmus were observed upon admission. Additional intravenous administration of a 20% lipid emulsion resulted in normalization of the vital signs and complete neurological recovery. To the authors’ knowledge, this is the first report describing ILE in the treatment of canine metaldehyde intoxication and the first description of a case of metaldehyde poisoning in a dog in Romania. Considering the severity of the neurological signs and the fact that no specific antidote is known, treatment can be significantly challenging to the veterinary practitioner. This finding should be included in metaldehyde poisoning therapy protocols, especially when severe clinical signs fail to respond to symptomatic treatment.

Laboratory and Field Evaluation of Zyrox Fly Granular Bait Against Asian and German Cockroaches (Dictyoptera: Blattellidae).

The Asian cockroach (Blattella asahinai Mizukubo) was introduced to Florida in 1986 and has since spread throughout the Southeastern United States. Blattella asahinai is a peridomestic pest and high population densities in residential areas can become a nuisance, especially when adults fly into homes. Few studies to date have been conducted on Asian cockroach control, and we evaluated the efficacy of Zyrox Fly Granular Bait and Maxforce Complete Granular Insect Bait against this species in the laboratory compared with the closely related German cockroach (Blattella germanica (L.)). In no-choice and two-choice assays with both species, Zyrox bait and Maxforce bait achieved nearly 100% mortality within two and five days, respectively. We also tested Zyrox bait against B. asahinai in an invasive field population in North Carolina at the label rate (2 g/m(2)) and at approximately three times the label rate (6.9 g/m(2)), and found that broadcast applications at both rates reduced populations by an average of 64 and 92%, respectively, for 35 d after the initial application. Zyrox Fly Bait appears to be effective against the Asian and German cockroaches, and could be another tool in an integrated pest management program, if its label could be extended or the active ingredient (cyantraniliprole) formulated into a cockroach bait.

The Attractiveness of Toxic Bait is not Always Accompanied by Increased Mortality in Laboratory Colonies of Argentine Ants,Linepithema humile(Hymenoptera: Formicidae)

The Argentine ant, Linepithema humile, is a globally known invasive ant species responsible for widespread biodiversity and economic loss, thus there is a growing need to control and preferably locally eradicate these ants from invaded environments and households. We evaluated the attractiveness and toxicity of six commercial baits containing hydramethylnon, imidacloprid and pyriproxyfen targeting Argentine ants, and differing in bait formulation. Hydramethylnon granular baits were most effective, killing workers (85–100% worker mortality) and queens (63–75 %) in the laboratory within 24 h. Workers were most attracted to and consumed the most of the imidacloprid gel bait, but, contrary to previous studies, mortality on this bait was low. The pyriproxyfen bait was least effective in killing workers, as was expected, and was the least consumed of all baits.We advocate the use of a fine granular hydramethylnon formulation for the effective control of Argentine ants. The attractiveness and consumption of the ...

Developmental toxicity of metaldehyde in the embryos of Lymnaea stagnalis (Gastropoda: Pulmonata) co-exposed to the synergist piperonyl butoxide

Metaldehyde is a widely used molluscicide in countries where damage to crops from slugs and snails is a major problem associated with warm and wet winters. In the UK it is estimated that over 8% of the area covered by arable crops is treated with formulated granular bait pellets containing metaldehyde as the main active ingredient. Metaldehyde is hydrophilic (log Kow=0.12), water soluble (200mg·L−1 at 17°C) and has been detected in UK surface waters in the concentration range of typically 0.2–0.6μg·L−1 (maximum 2.7μg·L−1) during 2008–2011. In the absence of chronic data on potential hazards to non-target freshwater molluscs, a laboratory study was conducted to investigate the impact of metaldehyde on embryo development in the gastropod Lymnaea stagnalis (RENILYS strain) and using zinc as a positive control. L. stagnalis embryos were exposed to metaldehyde under semi-static conditions at 20±1°C and hatching success and growth (measured as shell height and intraocular distance) examined after 21d. Exposure concentrations were verified using HPLC and gave 21d hatchingNOEC and hatchingLOEC mean measured values of 36 and 116mgMET·L−1, respectively (equal to the 21d shell heightNOEC and shell heightLOEC values). For basic research purposes, a second group of L. stagnalis embryos was co-exposed to metaldehyde and the pesticide synergist piperonyl butoxide (PBO). Co-exposure to the PBO (measured concentrations between 0.47–0.56mg·L−1) reduced hatching success from 100% to 47% and resulted in a 30% reduction in embryo growth (shell height) in snail embryos co-exposed to metaldehyde at 34–36mg·L−1 over 21d. In conclusion, these data suggest mollusc embryos may have some metabolic detoxication capacity for metaldehyde and further work is warranted to explore this aspect in order to support the recent initiative to include molluscs in the OECD test guideline programme.

Comparison of Different Protocols for Control of the Red Imported Fire Ant,Solenopsis invictaBuren (Hymenoptera: Formicidae), in Orange County, California, Including a List of Co-occurring Ants

Abstract. The Orange County Vector Control District treats infestations of red imported fire ants, Solenopsis invicta Buren, with two granular baits, Amdro Pro and Distance, at residences with the ant. Some treatments are subcontracted to pestmanagement professionals who received red imported fire ant certification by the Orange County Vector Control District. During this study, we compared four treatment protocols and assessed their efficacy at suppressing red imported fire ants. At the first post-treatment survey at 3 months, homes in three of the protocols received a single treatment of Amdro Pro. Homes in two of the protocols subsequently received either one follow-up treatment with Distance at 3 months or two follow-up treatments with Distance at 3 and 6 months, respectively. Homes in the fourth protocol received a single treatment of a 50:50 mixture of Amdro Pro and Distance. Most reinfestation by red imported fire ants occurred within the first 3 months after the initial treatment, with failure ran...

Compatibility of the Parasitoid Wasp Spalangia endius (Hymenoptera: Pteromalidae) and Insecticides against Musca domestica (Diptera: Muscidae) as Evaluated by a New Index.

Various insecticides for the control of the house fly Musca domestica L. were tested for compatibility with a biological control agent, the pupal parasitoid Spalangia endius Walker. Bioassays used the mode in which each organism was expected to be harmed by the insecticides, a surface contact bioassay for S. endius and a feeding bioassay for M. domestica. A Pesticide Compatibility Index (PCI) was created that allows comparison of LC50 values when the mode of exposure to a pesticide differs. First LC50 values were converted into units of prescribed dosages (LPR=LC50-to-prescribed dosage ratio). This study used dosages from labels of granular baits. PCI is the ratio of LPRbiological control agent to LPRpest. For these PCI values, order of compatibility with S. endius was spinosad>thiamethoxam>inotefuran>methomyl>imidacloprid. That spinosad was better than imidacloprid or methomyl, both for parasitoid survival and for killing flies, is consistent with conclusions from the LC50 values. Permethrin and nitenpyram were also tested, but their PCIs were not calculated. Permethrin is prescribed as a contact insecticide against flies rather than being consumed as a bait, and nitenpyram has not been formulated as a fly insecticide. Compared with the other insecticides in terms of LC50 values, permethrin was moderately toxic to S. endius but one of the most toxic for M. domestica, whereas nitenpyram was least toxic for both S. endius and the flies.

Ants (Hymenoptera: Formicidae) Associated withDiaphorina citri(Hemiptera: Liviidae) and their Role in its Biological Control

After the arrival of the Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae) in Florida, several studies mentioned the presence of ants where D. citri was present, but there was no clarification of their specific interaction with the psyllid. The goal of this study was to elucidate the role of ants in the biological control of D. citri by observing ant behavior and by determining if ant presence, modified by exclusion manipulations, affected parasitism of D. citri by Tamarixia radiata (Waterston, 1922) (Hymenoptera: Eulophidae), an introduced parasitoid of the psyllid, when the insect was infesting orange jasmine, Murraya paniculata (L.) Jack (Sapindales: Rutaceae) and Persian lime, Citrus latifolia Tanaka (Sapindales: Rutaceae). During a preliminary survey on M. paniculata in Homestead, Florida, we observed 2 ant species in association with D. citri, i.e., the big headed ant, Pheidole megacephala Fabricius, and the rover ant, Brachymyrmex obscurior Forel. In 2 ant exclusion experiments, using a 2-cm-wide barrier of Tanglefoot®, P. megacephala was the only ant species found in M. paniculata while P. megacephala, B. patagonicus and Solenopsis invicta Buren were observed in C. latifolia. The number of P. megacephala found in the unprotected flushes in M. paniculata fluctuated between 0.15 and 0.5 per flush while in C. latifolia the number of ants, pooled across species, varied between 1.44 and 6.61. In M. paniculata flushes from Tanglefoot-treated plants, 20.36% of the nymphs were parasitized by T. radiata compared to 0.39% parasitism in untreated control flushes where ants had not been excluded. Fifty-eight percent of the psyllid nymphs were parasitized in the C. latifolia Tanglefoot® ant-exclusion flushes compared with 8.57% parasitism in the non-exclusion control. An additional experiment using the ant bait Extinguish Plus® (Hydramethylnon 0.365% S-Methoprene 0.250%) applied to the soil surrounding the trunk showed that the use of a granular bait can help to reduce ant populations and consequently increase the percentage parasitism of the Asian citrus psyllid.

Effect of Scattered and Discrete Hydramethylnon Bait Placement on the Asian Needle Ant

The Asian needle ant (Pachycondyla chinensis Emery) is invading natural and disturbed habitats across the eastern United States. While recent studies document the impact of P. chinensis on native ecosystems and human health, effective control measures remain unknown. Thus, we evaluated the field performance of a hydramethylnon granular bait, Maxforce Complete Granular Insect Bait, dispersed in clumps or scattered against P. chinensis. We also measured the effect of this bait on P. chinensis outside of the treatment zone. Surprisingly, unlike reports for other ant species, we achieved nearly complete P. chinensis population reductions 1 d after treatments were applied. Significant ant reductions were achieved until the end of our study at 28 d. No difference was recorded between clumped and scattered application methods. We found no overall difference in ant reductions from the edge out to 5 m beyond the treatment zone. Other local ant species appeared to be unaffected by the bait and foraging activity increased slightly after P. chinensis removal from treated areas. We suggest that Maxforce Complete Granular Insect Bait can be effective in an Asian needle ant treatment program.

Integration of Fly Baits, Traps, and Cords to Kill House Flies (Diptera: Muscidae) and Reduce Annoyance

Combinations of commercial fly baits, traps, and cords were evaluated for integration into a fly management system. Imidacloprid granular and sprayable baits caused house fly, Musca domestica L., mortality at a faster rate than methomyl granular fly bait; however, the methomyl granular bait had the highest overall mortality at 24 h. Commercial fly traps had a variety of designs that resulted in differences in efficiency for retaining house flies. Among 6 commercial traps tested, the Trap n' Toss™ (Farnam Companies, Inc., Phoenix, AZ) captured the most flies, and the design was selected for our field cage studies. These cage studies with flies (~300) determined that without treated cord or attractant, fly traps captured and killed 5% of the fly population; whereas, fly traps with attractant captured and killed only 14% of the population in the first 24 h. A 46-cm cord (6 mm diam.) dipped in 2.5% imidacloprid was looped around a fly trap (identical to the Trap n' Toss), and the trap was baited with commercial fly attractant. The addition of the bait-treated cord killed 60 - 70% of flies at 24 h and 84 - 90% at 48 h. However, bait-treated fly cords used alone killed 70% of flies at 24 h and 94% at 48 h and demonstrated the relatively poor efficiency of commercial fly traps. Fly annoyance was eliminated by the high fly mortality resulting from the use of bait-treated cords. Bait-treated cords can be used to improve the efficiency of fly management programs, either in conjunction with commercial fly traps or alone.