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A combination of pesticides and biological control agents is frequently necessary to achieve successful pest management requiring the assessment of their compatibility for the intended purpose. Aphidius flaviventris Kurdjumov is one of the parasitoids of the cotton aphid Aphis gossypii Glover, whose susceptibility to pesticides was not yet investigated. Accordingly, we investigated the lethal and sublethal effects of the commonly utilized insecticide mixture thiacloprid + deltamethrin on the cotton aphid and its parasitoid wasp Aphidius flaviventris. The estimated LC50 for the aphid was 14.1 mg ai/l; the effects of sublethal exposure at LC10 (2.80 mg ai/l) and LC30 (7.28 mg ai/l) on the aphid life-table parameters led to significantly increase on the development time of third- and fourth-instar nymphs and preadult. Sublethal exposure to the insecticide mixture compromised aphid longevity, fecundity, and life-table parameters (r, R0, and T). Moreover, population growth and parasitism rate of the parasitoid were significantly compromised at both concentrations of the insecticide mixture under sublethal exposure. These results not only indicate the efficacy of thiacloprid + deltamethrin against the cotton aphid, but also raise concerns regarding its negative impacts on the parasitoid Aphidius flaviventris and caution against its use in pest management programs.

Solenopsis invicta (Buren; Hymenoptera: Formicidae) is a species that has invaded China in recent years. Currently, S. invicta is mainly controlled by chemical treatment, though long-term use of chemical pesticides can cause serious environmental pollution. In this study, a microbial insecticide formulated for the control of S. invicta was screened for laboratory toxicity and field efficacy. The co-toxicity coefficients (CTCs) of the combination of Beauveria bassiana and thiacloprid at various mass ratios were 356.53, 251.20, 182.50, 215.03, and 143.19. When B. bassiana powder and thiacloprid were mixed at a mass ratio of 8:2, the CTC was 356.53, demonstrating a very significant synergistic effect. According to a field efficacy test, at 3 d after treatment, the efficacy of mound injection was significantly better than that of mound drenching. In this study, the insecticidal activity of pathogenic microorganisms against S. invicta was markedly enhanced by using a self-designed apparatus for mound injection of the tested preparation of a complex containing a pathogenic microbe. The results show that S. invicta can be sustainably controlled while ensuring the safety of the environment. The findings are a good reference for the promotion and application of safe control of S. invicta in the future.

In-field management of Bactrocera tryoni (Froggatt) and Zeugodacus cucumis (French) (Diptera: Tephritidae) in fruiting vegetable crops has relied almost exclusively on organophosphate cover sprays. Laboratory and semifield trials were performed to compare a number of alternative insecticides for efficacy against these species. A novel semifield method was used whereby the insecticides were applied to crops as cover sprays under field conditions, and treated plants bearing fruit were transferred to large cages and exposed to fruit flies. Efficacy was assessed in terms of numbers of pupae developing from treated fruit. A laboratory cage method was also used to assess effects on adult mortality and comparative effects of 1- and 3-d-aged residues. The neonicotinoids clothianidin and thiacloprid were very effective against B. tryoni and Z. cucumis. Clothianidin was the only insecticide other than dimethoate to affect adult mortality. The synthetic pyrethroid alpha-cypermethrin was also very effective, particularly in semifield trials, although higher incidence of aphid and whitefly infestation was observed in this treatment compared to others. Cyantraniliprole was effective against B. tryoni, but less effective against Z. cucumis. Imidacloprid, bifenthrin, spinetoram, and abamectin were all relatively less effective, although all demonstrated a suppressive effect.

The brown planthopper (BPH), Nilaparvata lugens (Stal) (Hemiptera: Delphacidae), is a serious pest of rice. At present, the application of chemical insecticides is the main control option for this pest. BPH has evolved resistance to various classes of insecticides. Cycloxaprid, a new oxabridged cis-configuration neonicotinoid insecticide, is a (nitromethylene) imidazole analog of imidacloprid. This study focused on the baseline susceptibility to cycloxaprid of 18 field samples of N. lugens collected from nine geographical locations in China, as well as possible cross-resistances between cycloxaprid and other important neonicotinoids in one laboratory-selected resistant strain of N. lugens to imidacloprid. The median lethal concentration (LC50) of cycloxaprid for the 18 samples ranged from 1.26 to 14.90 mg/liter. Furthermore, the cross-resistance studies showed that the imidacloprid-resistant strain exhibited a 27.63-fold resistance to imidacloprid and lower levels of cross-resistance to acetamiprid (16.64-fold), thiacloprid (12.64-fold), and nitenpyram (16.90-fold); however, there was no cross-resistance to cycloxaprid (1.92-fold). These results indicate that cycloxaprid could be an effective alternative insecticide for the management of N. lugens, which is urgently needed to prevent or delay further increases in insecticide resistance in N. lugens.

The effects of repellency or irritancy in Galendromus occidentalis (Nesbitt) were studied for three rates of 16 pesticides commonly used in apple production. Adult female mites were exposed to residues in a series of choice bioassays (treated and untreated half of bean leaf disks). Novaluron, carbaryl, mancozeb+copper hydroxide, and sulfur were the most repellent materials to G. occidentalis, with females consistently avoiding the treated side of the leaf disk. Spirotetramat, flubendiamide, and cyantriniliprole caused an intermediate or inconsistent degree of repellency; azinphosmethyl, lambda-cyhalothrin, acetamiprid, thiacloprid, imidacloprid, spinetoram, spinosad, and chlorantriniliprole caused little to no repellency. Irritancy (running off of the disk, as opposed to resting on the untreated half) was the most pronounced in the acetamiprid and lambda-cyhalothrin treatments. Acute toxicity (within the 6 h test period) was highest in the lambda-cyhalothrin and spinetoram treatments; in the former case, the mortality at all rates tested was substantial enough to interfere with the measurement of behavioral effects. Although irritancy may be considered the more extreme form of repellency, there were several pesticides (carbaryl, cyantraniliprole, mancozeb+copper hydroxide, novaluron) where a moderate to high degree of repellency did not correspond to a high degree of irritancy. Similarly, repellency was not consistently related to acute toxicity; one of the most repellent materials (novaluron) was not acutely toxic. Behavioral effects may help explain instances where lethal or sublethal bioassays do not fully predict the effects of pesticides seen in orchard use.

Insecticides are the dominant pest management method in fruit and vegetable crops worldwide owing to their quick effect, low cost, and relatively easy application, but they bear negative effects on human health and the environment. Insecticide mode of action (MoA), target species, and sex are variables that could affect insecticide-induced mortality. We recorded the mortality caused by three neurotoxic insecticides with different modes of action (chlorpyrifos [organophosphate, acetylcholinesterase inhibitor], λ-cyhalothrin [pyrethroid, sodium channel modulator], and thiacloprid [neonicotinoid, nicotinic acetylcholinesterase receptor agonist]) applied topically to adult males and females of three economically important tortricid species [Cydia pomonella (L.), Grapholita molesta (Busck), and Lobesia botrana (Denis & Schiffermüller)] that strongly depend on insecticide use for their control. Concentration and dose-mortality curves were recorded at 24 and 48 h postapplication. Large mortality differences between insecticides (maximum 7,800-fold for LD50) were followed by much lower, yet important, differences between species (maximum 115-fold), and sexes (maximum 41.5-fold). Significant interactions between the three factors indicate that they are not independent from each other. Interestingly, with the organophosphate chlorpyrifos, males of the three species were less susceptible than females, which was unexpected, as females are larger than males. Higher female sensitivity to organophosphates has been reported previously but only in G. molesta, not in other moth species. Our results highlight the importance of taking into account sex in dose-mortality studies with adult moths. MAN-R was supported by a Ph.D. fellowship from the University of Lleida. This study was supported by research Grant AGL2013-49164-C2-1 MINECO, Spain.

Resistance levels in whitefly, Bemisia tabaci (Gennadius) collections from cotton and sunflower (up to four districts) for five neonicotinoids and two insect growth regulators (IGRs) were investigated for two consecutive years. Based on the LC50s, all collections showed slight to moderate levels of resistance for the tested insecticides compared with the laboratory susceptible population. The data also indicated that cotton and sunflower collections had similar resistance levels. In comparison (four collections), Vehari collections showed higher resistance for acetamiprid, thiacloprid, and nitenpyram compared with those of others. Average resistance ratios for acetamiprid, thiacloprid, and nitenpyram ranged from 5- to 13-, 4- to 8-, and 9- to 13-fold, respectively. Multan and Vehari collections also exhibited moderate levels (9- to 16-fold) of resistance to buprofezin. Furthermore, toxicity of neonicotinoids against immature stages was equal to that of insect growth regulators. The data also suggested that resistance in the field populations was stable. After selection for four generations with bifenthrin (G1 to G4), resistance to bifenthrin increased to 14-fold compared with the laboratory susceptible population. Selection also increased resistance to fenpropathrin, lambda-cyhalothrin, imidacloprid, acetamiprid, and diafenthuron. Cross-resistance and stability of resistance in the field populations is of some concern. Rotation of insecticides having no cross-resistance and targeting the control against immature stages may control the resistant insects, simultaneously reducing the selection pressure imposed.

The Rio Negro and Neuquen Valley is the most important apple and pear growing region in Argentina. Cydia pomonella L. (Lepidoptera: Tortricidae), the main fruit-tree pest is being controlled by azinphosmethyl (AzMe), acetamiprid (Acet), and thiacloprid (Thia) among other insecticides. The objective of this study was to evaluate the response of neonate larvae of codling moth to these three insecticides and on the role of cytochrome P450 monooxygenase in their toxicity. All field populations presented significantly lower mortality to a discriminating concentration (DC) of Acet and AzMe. In addition, 13 of the 14 populations showed significantly lower mortality to DC of Thia. Most of the field populations (71%) showed significantly higher 7-ethoxycoumarine O-deethylase activity compared with the laboratory-susceptible strain. While positive significant correlation (r = 0.59) was found between Thia and AzMe mortalities at the DC level, no significant correlations were detected between Acet and Thia (...

The evolution of resistance to carbodiimide (a toxic metabolite of diafenthiuron) and four neonicotinoids imidacloprid, acetamiprid, thiamethoxam, and thiacloprid in the Pakistani populations of sweetpotato whitefly (Bemisia tabaci Gennadius) was monitored from 1996 to 2015 using a leaf-dip bioassay. Diafenthiuron, imidacloprid, and acetamiprid were introduced into Pakistani agriculture in mid-1990s and heavily used since then, because B. tabaci resistance and consequently control failures to conventional insecticides such as organophosphates, carbamates, and pyrethroids were widespread during the 1990s. According to the current studies, resistance to carbodiimide, imidacloprid, and acetamiprid during 1996-2010 and to thiamethoxam during 1999-2007 remained very low, but then it rose sharply, and by the year 2015, the B. tabaci resistance increased to very high levels. Among neonicotinoids, thiacloprid was the latest introduction in Pakistan in 2002. There was no thiacloprid resistance in 2002 and 2003, a low to moderate resistance during 2004-2006, and a very high resistance during 2007-2010 that even exceeded resistance to previous neonicotinoids. We may conclude that diafenthiuron and neonicotinoids remained effective against B. tabaci for 15 yr following their intensive use under field conditions, before a significant resistance, leading to their field failures, occurred in Pakistan.

The development of integrated pest management is hampered by lack of information on how insect pest abundances relate to yield losses, and how pests are affected by control measures. In this study, we develop integrated pest management tactics for Apion spp. weevils (Coleoptera: Brentidae) in seed production of red clover, Trifolium pratense L. We tested a method to forecast pest damage, quantified the relationship between pest abundance and yield, and evaluated chemical and biological pest control in 29 Swedish red clover fields in 2008 and 2011. Pest inflorescence abundance, which had a highly negative effect on yield, could be predicted with pan trap catches of adult pests. In 2008, chemical control with typically one application of pyrethroids was ineffective both in decreasing pest abundances and in increasing yields. In 2011, when chemical control included applications of the neonicotinoid thiacloprid, pest abundances decreased and yields increased considerably in treated field zones. A post hoc analysis indicated that using pyrethroids in addition to thiacloprid was largely redundant. Infestation rates by parasitoids was higher and reached average levels of around 40% in insecticide treated field zones in 2011, which is a level of interest for biological pest control. Based on the data presented, an economic threshold for chemical control is developed, and guidelines are provided on minimum effective chemical pest control.

The aim of the research was to identify efficacious and less environmentally harmful treatments than the standard chlorpyrifos sprays used for the control light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), eggs on nursery stock. A series of dip experiments showed a range of responses when comparing the efficacy of insecticides on egg hatch of E. postvittana. The insecticides that compared most favorably with chlorpyrifos were lamda-cyhalothrin and gamma-cyhalothrin, and thiacloprid. Indoxacarb, novaluron, and spinosad caused significant mortality only when combined with All Seasons mineral oil. All Seasons, showed ovicidal properties when evaluated alone and demonstrated adjuvant properties when combined with the above-mentioned insecticides, except gamma-cyhalothrin and thiacloprid. Several other horticultural mineral oils performed similarly, except the efficacy of spinosad varied with the oil product used, suggesting that the oil type selected is important for some insecticide and oil combinations. Several insecticides evaluated in this study are likely candidates for further work to develop treatments against E. postvittana eggs on nursery plants. Mineral oils are ovicidal and combinations with insecticides are likely to be advantageous.

Plum curculio, Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae), adults were exposed to field-aged residues of thiamethoxam, acetamiprid, thiacloprid, indoxacarb, or azinphos-methyl on tart cherry, Prunus cerasus L. variety Montmorency. At 1, 3, 7, and 14 d postapplication, fruit were sampled for chemical residues, and bioassays were used to assess beetle mortality and plant tissue injury. Azinphos-methyl had lethal activity within 1 d of exposure at all postapplication intervals and significant fruit protection extended to 14 d postapplication. All of the neonicotinoids had lethal activity at 3 d posttreatment, with acetamiprid activity extending to 7 d. Antifeedant and oviposition deterrent effects were seen with thiamethoxam and thiacloprid; damage incidence was significantly reduced in the absence of significant beetle mortality or intoxication. Thiamethoxam and acetamiprid penetrated into leaf and fruit tissue and were detected in the interior tissues at 14 d postapplication, but interior thiacloprid residues were not detected after day 1. Indoxacarb provided some fruit protection out to 7 d postapplication, and 14-d-old residues intoxicated beetles, but the slow action of this compound allowed significant damage to occur before beetles were incapacitated. Indoxacarb was only detected as a surface residue after the first day postapplication. These data on the plant-insect-chemistry interactions will support use and management decisions as compounds with acute contact activity are phased out.

Field-based experiments were used to determine the lethal activity of insecticides on apple maggot, Rhagoletis pomonella (Walsh) (Diptera: Tephritidae), eggs and larvae in apple (Malis spp.) fruit. The organophosphates azinphosmethyl and phosmet and the neonicotinoids thiacloprid, acetamiprid, clothianidin, and thiamethoxam showed significant curative activity on the apple maggot postinfestation, when applied topically to apple fruit 24 h postharvest. Of the compounds tested, only phosmet showed significant curative activity on apple maggot when applied 14 d postharvest. The pyrethroid esfenvalerate, oxadiazine indoxacarb, anthranilic diamide chlorantraniliprole, and spinosyns spinosad and spinetoram did not show activity on apple maggot eggs and larvae in fruit. Residue profiles showed that for most compounds, the majority (>85%) of residues were found in the skin and the outside 2 mm of the apple flesh. For the neonicotinoid compounds, however, substantial portions of residues were found to penetrate in and beyond the outer flesh regions, and the total flesh residue recoveries were generally greater than those from the skin. Residues of azinphosmethyl and phosmet were detected in all three flesh regions, with the largest proportions recovered from the skin.

Insecticide bioassays were used to investigate resistance of Cydia pomonella (L.) (Lepidoptera: Tortricidae) to insecticides with various types of active ingredients. The efficacy baselines of selected insect growth regulators (fenoxycarb), insect growth inhibitors (diflubenzuron and teflubenzuron), organophoshorous insecticides (phosalone), and neonicotinoids (thiacloprid) against the eggs and first and fifth instars of sensitive laboratory strains of codling moth were determined. According to concentration-mortality baseline, 50% lethality concentration values and 90% lethality concentration values were determined for all the tested insecticides. The lethal concentration ratio quantified the relation between the efficacy of selected insecticides against fifth instars found by topical application and against first instars found by diet-treated bioassay. No difference was detected when the efficacy of technical grade diflubenzuron diluted in tetrahydrofuran and diflubenzuron in the formulated product Dimilin 48 SC diluted in water was compared. However, just before the application of insecticide, the integument of larvae must be treated with acetone. Two bioassays were used to monitor the resistance of codling moths collected in 2003-2005 in two apple (Malus spp.) orchards with different intensities of chemical control. Resistance ratios (RRs) to the tested insecticides were determined for both field populations of codling moth. For the population of codling moth from a commercial apple orchard in Velke Bilovice, cross-resistance to fenoxycarb, teflubenzuron, and phosalone was detected after the topical application of insecticides to fifth instars. The population of codling moth from Prague-Ruzyne was slightly resistant to phosalone and teflubenzuron. No resistance to diflubenzuron was detected in either tested population.

The San Jose scale Diaspidiotus perniciosus Comstock is one of the most important pests of deciduous fruit trees. The major cause of recent outbreaks in apple orchards is thought to be the development of insecticide resistance, specifically organophosphates. The first report was given in North America, and now, in Chile. In the present study, San Jose scale populations collected from two central regions of Chile were checked for their susceptibility to different mode of action insecticides in order to establish alternatives to manage this pest. No evidence of cross resistance between organophosphates insecticides and acetamiprid, buprofezin, pyriproxyfen, spirotetramat, sulfoxaflor, or thiacloprid was found. Baselines of LC50-LC95 for different life stages of San Jose scale are given, as reference to future studies of resistance monitoring. The systemic activity of acetamiprid, spirotetramat, and thiacloprid was higher than the contact residue effect of these compounds. For sulfoxaflor, both values were similar. Program treatments including one or more of these compounds are compared in efficacy and impact on resistance ratio values. In order to preserve new insecticides as an important tool to control San Jose scale, resistance management programs should be implemented, considering insecticide mode of action classes alternated or mixed.

Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), a pest native to China and Korea, was discovered in North America in 1996. Currently, the only reliable strategy available for eradication and control is to cut and chip all infested trees. We evaluated various doses of the systemic insecticides azadirachtin, emamectin benzoate, imidacloprid, and thiacloprid for control of A. glabripennis in naturally infested elms (Ulmus spp.), poplars (Populus spp.), and willows (Salix spp.) in China between 2000 and 2002. Significantly more dead A. glabripennis adults were found beneath elm and poplar trees treated with imidacloprid (in 2000 and 2001) or thiacloprid (in 2001) and beneath willow trees injected with imidacloprid or thiacloprid (in 2002) compared with control trees. In 2000, 4 mo after injection, the density of live A. glabripennis was significantly reduced in poplar trees treated with imidacloprid (90%) and in willow trees treated with imidacloprid (83%) or emamectin benzoate (71%) compared with controls. In 2001, 9 mo after injection, the density of live A. glabripennis was significantly reduced in poplar (76%) and willow (45%) trees treated with imidacloprid compared with control trees. Similarly, percentage mortality of all life stages of A. glabripennis feeding within trees was significantly higher on poplar trees 4 mo after injection with imidacloprid (64%) in 2000 and on elms (55%) and poplars (63%) 9 mo after injection with imidacloprid in 2001 compared with control trees. Imidacloprid residue levels in leaves and twigs collected at various times from 1 d to 9 mo after injection ranged from 0.27 to 0.46 ppm. Injecting A. glabripennis-infested trees with imidacloprid can result in significant mortality of adults during maturation feeding on leaves and twigs and of all life stages feeding within infested trees. Imidacloprid is translocated rapidly in infested trees and is persistent at lethal levels for several months. Although, injection with imidacloprid does not provide complete control of A. glabripennis, systemic insecticides may prove useful as part of an integrated eradication or management program.

Eight reduced-risk insecticides (acetamiprid, thiamethoxam, imidacloprid, thiacloprid, methoxyfenozide, pyriproxyfen, indoxacarb, and spinosad) and three conventional insecticides (azinphosmethyl, fenpropathrin, and esfenvalerate) were tested against Neoseiulus fallacis (Garman) (Acari: Phytoseiidae), the most abundant predacious mite in North Carolina apple (Malus spp.) orchards. To assess the effect of insecticides on development and mortality of N. fallacis immatures, 12-h-old eggs were individually placed on bean leaf disks previously dipped in insecticide solutions. Tetranychus urticae Koch (Acari: Tetranychidae) females were added as a food source. None of the reduced-risk insecticides significantly affected immature N. fallacis compared with the control; however, the pyrethroids esfenvalerate and fenpropathrin were highly toxic to immatures. To evaluate the effect of insecticides on mortality and oviposition of adult N. fallacis, 7- to 8-d-old females were confined on insecticide-treated bean leaves with Malephora crocea (Aizoaceae) pollen added as a food source. Spinosad resulted in the highest mortality, whereas azinphosmethyl, acetamiprid, fenpropathrin, and imidacloprid were moderately toxic, and mortality from esfenvalerate, indoxacarb, thiacloprid, methoxyfenozide, pyriproxyfen, and thiamethoxam did not differ significantly from the control. Oviposition was affected in a similar manner, with the exception of acetamiprid that did not affect oviposition, and thiamethoxam that reduced oviposition.

The codling moth, Cydia pomonella (L.), is the key pest of apple production worldwide. Insecticide resistance has been reported in all producing countries, based on five different mechanisms. Codling moth in Chile has resistance to azinphos-methyl and tebufenozide in post-diapausing larvae. However, there are no studies about the susceptibility of these populations to insecticides from other chemical groups. Therefore, the efficacy of azinphos-methyl, chlorpyrifos-ethyl, esfenvalerate, methoxyfenozide, tebufenozide, and thiacloprid on neonate and post-diapausing larvae from six field populations was investigated, and identified resistance mechanisms in this species were evaluated. Neonate larvae were susceptible to all insecticides studied, but post-diapausing larvae from four populations were resistant to chlorpyrifos, one of them was also resistant to azinphos-methyl, and another one was resistant to tebufenozide. The acetylcholinesterase insensitivity mutation was not detected, and the sodium channel knockdown resistance mutation was present in a low frequency in one population. Detoxifying enzymatic activity of glutathione S-transferases, esterases, and cytochrome P-450 monooxygenases in adults differed among populations, but chlorpyrifos resistance was associated only with a decreased esterase activity as shown by a significant negative correlation between chlorpyrifos mortality and esterase activity.

Both chemical and biological methods are essential for control of insects, for example, lepidopterans, on rice. Thus, it is important to know the effect of chemicals on the biological control agents. In this study, we assessed the toxicity of commonly used insecticides on a biological control agent, Trichogramma japonicum Ahmead (an egg parasitoid of rice lepidopterans) by using a dry film residue method. Results showed that thirty insecticides from seven chemical classes exhibited various degree of toxicity to this parasitoid. Among the seven classes of chemicals tested, organophosphates (chlorpyrifos, fenitrothion, phoxim, profenofos, and triazophos) and carbamates (carbaryl, carbsulfan, isoprocarb, metolcarb, and promecarb) exhibited the highest intrinsic toxicity to T. japponicum, with an LC50 of 0.035 (0.029-0.044) to 0.49 (0.34-0.87) mg active ingredient (a.i.) L(-1), followed by antibiotics (abamectin, emamectin benzoate, and ivermectin), phenylpyrazoles (butane-fipronil, ethiprole, and fipronil), pyrethroids (cyhalthrin, cypermethrin, fenpropathrin, and lambda-cyhaothrin), and neonicotinoids (acetamiprid, imidacloprid, imidaclothiz, nitenpyram, thiacloprid, and thiamethoxam). Moreover, the insect growth regulator insecticides (chlorfluazuron, fufenozide, hexaflumuron and tebufenozide) exhibited the lowest toxicity to the wasps with an LC50 of 3,383 (2406-5499) to 30206 (23107-41008) mg ai. L(-1). Risk quotient analysis showed that phenylpyrazoles, pyrethroids, insect growth regulators, neonicotinoids (with the exception of thiamethoxam), and antibiotics (with the exception of abamectin) are classified as safe agents to the parasitoid, while organophosphates and carbamates are classified as slightly, moderately, or highly toxic agents to the parasitoid. The data presented in this paper provided useful information on the selection of compatible insecticides with T. japonicum.

Laboratory and semifield bioassays were conducted to determine the life-stage activity of insecticides for controlling cranberry fruitworm, Acrobasis vaccinii Riley (Lepidoptera: Pyralidae), a key lepidopteran pest of highbush blueberry, Vaccinium corymbosum L. The organophosphates azinphosmethyl and phosmet, the pyrethroid esfenvalerate, and the carbamate methomyl were lethal to all life stages. The neonicotinoids thiacloprid and acetamiprid demonstrated strong larvicidal and ovicidal activity but were somewhat weaker adulticides than the conventional broad-spectrum compounds. Bacillus thuringiensis, indoxacarb, and emamectin benzoate were shown to control A. vacinii primarily through their larvicidal activity. Spinosad was toxic to all life stages, including eggs laid on top of residues and those that were treated topically, but larvicidal activity was short lived. The growth regulators pyriproxyfen and novaluron had strong ovicidal activity when eggs were laid on top of residues but had limited larvicidal activity. Tebufenozide was not directly toxic to eggs, but demonstrated larvicidal activity, and ovilarvicidal activity when topically applied to eggs. Azinphosmethyl, phosmet, indoxacarb, thiacloprid, and acetamiprid were all toxic to the egg parasitoid Trichogramma minutum Riley. In contrast pyriproxyfen, emamectin benzoate, methomyl, novaluron, and spinosad did not negatively affect the survival of T. minutum within Acrobasis vacinii eggs. These results help inform the ongoing development of integrated strategies for insect management in blueberry.

Tart cherry, Prunus cerasus L. variety Montmorency, fruit were infested with plum curculio, Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae), and treated with insecticides to target late instars, neonates, and eggs. The organophosphates azinphos-methyl and phosmet and the neonicotinoid thiamethoxam reduced larval emergence rates by >90% for all life stage targets; after >30 d, few surviving larvae were found inside fruit. Acetamiprid and thiacloprid also had curative activity and yielded >75% reductions in emergence and few surviving larvae in the fruit after >30 d. The juvenile hormone analog pyriproxyfen reduced larval emergence, but 66% of fruit that was treated to target late-instars still had live larvae inside of them after >30 d. Novaluron, chlorantraniliprole, and esfenvalerate had no curative activity. Indoxacarb had limited curative activity, and all targeted life stages had larval emergence. Internal and external residues were analyzed and are discussed in relation to their penetration and curative potential. The curative activity of azinphos-methyl has played an important role in meeting federal standards for infestation-free tart cherries at processing. Regulatory changes are eliminating the use of this compound, and new integrated pest management programs for plum curculio will need to address the loss of azinphos-methyl's curative activity.

Previous reports indicate that applications of imidacloprid, a neonicotinoid insecticide, can lead to population buildups of twospotted spider mite, Tetranychus urticae Koch, in the field. Moreover, laboratory studies showed enhanced fecundity of T. urticae after an imidacloprid treatment. In this study, experiments were conducted in the greenhouse to investigate the potential effects of imidacloprid and several other neonicotinoid insecticides on fecundity, egg viability, preimaginal survivorship, and sex ratio of T. urticae (German strain WI) on French beans, Phaseolus vulgaris L. Four insecticides, i.e., imidacloprid (Confidor 200SL), thiacloprid (Calypso 480 SC), acetamiprid (Mospilan 70 WP), and thiamethoxam (Actara 25 WG), were tested at field-relevant (100, 120, 125, and 95 ppm) and sublethal doses (10, 12, 12.5, and 9.5 ppm), respectively. Both spray and drench applications were tested. At field-relevant doses, fecundity of T. urticae decreased and was lower in the treatments compared with the untreated control, whereas preimaginal survivorship and proportion of female offspring (i.e., sex ratio) were lower compared with the control. At sublethal doses, no significant differences were found among the treatments. Data on egg viability, preimaginal survivorship, and sex ratio at sublethal doses followed the same trends as at field-relevant doses. In an additional experiment, the metabolism of imidacloprid into monohydroxy-imidacloprid, olefine, guanidine, and 6-chloronicotinic acid was compared with the oviposition pattern of T. urticae. These findings are discussed with regard to previous laboratory and field observations of imidacloprid-induced fertility increases in T. urticae.

Laboratory bioassays and field tests were conducted to compare the effectiveness of the new insecticides, imidacloprid, indoxacarb, pyriproxyfen, spinosad, thiacloprid, and thiamethoxam, against apple maggot. The activity ranking of the compounds in reducing oviposition in laboratory bioassays was: imidacloprid, 95% reduction at 11 ppm > thiamethoxam, 91% and thiacloprid, 89% reduction at 100 ppm > spinosad, 98% reduction at 316 ppm > indoxacarb, 80% reduction at 1000 ppm > pyriproxyfen, 0% reduction at 38 ppm. In laboratory bioassays, the only insecticides that were toxic to flies at concentrations equal to or below the recommended field rates were imidacloprid, (50% of flies at 11 ppm), spinosad (90% of flies at rates >10 ppm), and thiamethoxam (≈50% of flies at 32 ppm). In field trials, thiacloprid was the only material that consistently controlled apple maggot fruit infestation that was comparable to standard treatments of organophosphate insecticides. Spinosad applied at weekly intervals, and indoxacarb applied as biweekly sprays provided adequate control of apple maggot damage when infestation levels in the field were low, but were not effective in preventing damage in small plots when apple maggot pressure was high.