Non-target Beneficial Insects Research Articles

Control efficacy of azadirachtin on the fall armyworm, Spodoptera frugiperda (J. E. Smith) by soil drenching.

The fall armyworm (FAW), Spodoptera frugiperda, is an important agricultural pest species native to the Western Hemisphere and has recently invaded to Africa and Asia. Owing to the development of pesticide resistance and environmental contamination, ecofriendly pesticides are desirable for FAW control. Azadirachtin is a plant-derived natural pesticide with low toxicity to humans and the natural environment. Azadirachtin is primarily applied by foliar spraying; however, this approach lowers the efficacy of controlling target insects owing to photodegradation and might give a harmful effect on nontarget beneficial insects. Thus, we investigated whether applying azadirachtin to soil improves FAW control and its toxicity to corn plants. Soil drainage of azadirachtin exhibited no phytotoxic effects on corn plants but significantly reduced the larval body weight and delayed the developmental period of each larval instar of FAW. Applying 10, 15, and 20 ppm azadirachtin to soil inhibited larval growth by 68%, 76%, and 91%, respectively. Furthermore, the survival rate of FAW gradually decreased when larvae were fed azadirachtin-treated corn leaves. Collectively, this is the first study suggesting the systemic efficacy of azadirachtin by soil drenching against FAW.

Direct and Indirect Infection Effects of Four Potent Fungal Isolates on the Survival and Performance of Fall Armyworm Larval Parasitoid Cotesia icipe

Fall armyworm (FAW), Spodoptera frugiperda, has recently invaded Africa where it is seriously threatening food security. Current management methods rely heavily on synthetic insecticides which are harmful to humans, the environment, and non-target beneficial insects. Cotesia icipe was recently identified as a major FAW-associated indigenous parasitoid causing a high parasitism rate on the pest in Kenya. Previous studies have demonstrated the efficacy of Metarhizium anisopliae ICIPE 7, ICIPE 41, ICIPE 78, and Beauveria bassiana ICIPE 621 against FAW. However, limited information is available on the interactions between these potent isolates and C. icipe. This study therefore assessed direct and indirect infection effects of these fungal isolates on C. icipe, induced 2nd instar FAW mortality, and parasitism rates of the infected C. icipe. Results showed that when C. icipe were directly exposed to dry conidia of the fungal isolates, ICIPE 7 and ICIPE 41 caused the highest (100%) C. icipe adult mortality seven days post-exposure. Both isolates also induced the highest FAW larval mortality of 55% and 53%, respectively. ICIPE 78 recorded the highest parasitism rates after direct infection. In the indirect exposure (fungal-infected FAW larvae exposed to the parasitoid), 1 × 109 conidia mL−1 recorded high C. icipe adult and FAW 2nd instar mortalities for all fungal isolates. This study provides an important baseline for effective fungal-based biopesticides development that could also be used in augmentative biological control. However, further studies are warranted to assess the performance of C. icipe in combination with these potent biopesticides in the field.

Field and Cage Studies Show No Effects of Exposure to Flonicamid on Honey Bees at Field-Relevant Concentrations.

Simple SummaryThe effects of pesticides on honey bees are of great concern to beekeepers and the general public. In particular, a class of pesticides called neonicotinoids has been found in some studies to affect bee learning and colony function. A pesticide classified as a neonicotinoid, flonicamid, has been detected in the residue analyses of honey and pollen samples for a published study, and that compound was tested at three concentrations (0, 50, and 250 parts per billion (ppb)) in sugar syrup in a field study with bee colonies and in two cage studies. Colony population levels, hive weight changes, thermoregulation, and CO2 concentrations were measured in the field study, and syrup consumption, thermoregulation, and survivorship by worker bees were measured in the cage studies. No significant treatment effects of the pesticide exposure were observed in either the field or the cage studies. These results support the idea that flonicamid is safe for honey bees at these concentrations. Publishing such results when they occur is important, so people use safe pesticides when they need them.The extent to which insecticides harm non-target beneficial insects is controversial. The effects of long-term exposure on honey bees to sublethal concentrations of flonicamid, a pyridinecarboxamide compound used as a systemic insecticide against sucking insects, were examined in a field study and two cage studies. The field study involved the continuous weight, temperature, and CO2 monitoring of 18 honey bee colonies, 6 of which were exposed over six weeks to 50 ppb flonicamid in sugar syrup, 6 exposed to 250 ppb flonicamid in syrup, and 6 exposed to unadulterated syrup (control). Treatments were derived from concentrations observed in honey samples in a published study. No effects were observed on foraging activity, hive weight gain, thermoregulation, or average CO2 concentrations. However, Varroa mite infestations may have also contributed to experimental variability. The two cage studies, in which cages (200 newly-emerged bees in each) were exposed to the same flonicamid concentrations as the field study and kept in a variable-temperature incubator, likewise did not show any experiment-wide effects on survivorship, thermoregulation, or syrup consumption. These results suggest that field applications of flonicamid that result in concentrations as high as 250 ppb in honey may be largely safe for honey bees.

Insecticide-contaminated honeydew: risks for beneficial insects.

ABSTRACTHoneydew is the sugar‐rich excretion of phloem‐feeding hemipteran insects such as aphids, mealybugs, whiteflies, and psyllids, and can be a main carbohydrate source for beneficial insects in some ecosystems. Recent research has revealed that water‐soluble, systemic insecticides contaminate honeydew excreted by hemipterans that feed on plants treated with these insecticides. This contaminated honeydew can be toxic to beneficial insects, such as pollinators, parasitic wasps and generalist predators that feed on it. This route of exposure has now been demonstrated in three plant species, for five systemic insecticides and four hemipteran species; therefore, we expect this route to be widely available in some ecosystems. In this perspective paper, we highlight the importance of this route of exposure by exploring: (i) potential pathways through which honeydew might be contaminated with insecticides; (ii) hemipteran families that are more likely to excrete contaminated honeydew; and (iii) systemic insecticides with different modes of action that might contaminate honeydew through the plant. Furthermore, we analyse several model scenarios in Europe and/or the USA where contaminated honeydew could be problematic for beneficial organisms that feed on this ubiquitous carbohydrate source. Finally, we explain why this route of exposure might be important when exotic, invasive, honeydew‐producing species are treated with systemic insecticides. Overall, this review opens a new area of research in the field of ecotoxicology to understand how insecticides can reach non‐target beneficial insects. In addition, we aim to shed light on potential undescribed causes of insect declines in ecosystems where honeydew is an important carbohydrate source for insects, and advocate for this route of exposure to be included in future environmental risk assessments.

Lethal and sub-lethal activity of Brevibacillus laterosporus on the mosquito Aedes albopictus and side effects on non-target water-dwelling invertebrates

The biocidal potential of Brevibacillus laterosporus against mosquitoes of major medical importance has been widely documented, but its effects on non-target invertebrates are still poorly known. In this study, we determined the lethal and sub-lethal effects of B. laterosporus strain UNISS 18, an entomopathogenic bacterium known for its effectiveness against synanthropic Diptera, on the larvae of the Asian tiger mosquito Aedes albopictus, a vector of several pathogens to humans. Moreover, we compared the larvicidal activity with the lethal action on the invasive snail Physella acuta and on two non-target water-dwelling species: the mayfly Cloeon dipterum, and the harlequin fly Chironomus riparius. B. laterosporus exhibited significant lethal effects on all the tested species with a concentration-dependent activity. However, the susceptibility varied among species, with a higher susceptibility of Ae. albopictus (LC50 = 0.16 × 107 spores mL−1) than the other species (LC50 = 0.31, 0.33, and 0.30 × 107 spores mL−1 for C. dipterum, C. riparius, and P. acuta, respectively). While 1st instar mosquito larvae were very susceptible to the bacterial infection, no effects on preimaginal development stages and adult emergence were observed at sub-lethal spores’ concentrations. Even if the efficacy of B. laterosporus against Ae. albopictus and the invasive freshwater snail P. acuta is promising for their control, the susceptibility of non-target beneficial aquatic insects, highlights the need of accurate evaluations before applying B. laterosporus for pest management in water environments.

Neonicotinoid Pesticides Cause Mass Fatalities of Native Bumble Bees: A Case Study From Wilsonville, Oregon, United States.

In June of 2013 an application of dinotefuran on an ornamental planting of European linden trees (Tilia cordata Mill. [Malvales: Malvalceae]) in a shopping mall parking lot in Wilsonville, Oregon provoked the largest documented pesticide kill of bumble bees in North America. Based on geographic information systems and population genetic analysis, we estimate that between 45,830 and 107,470 bumble bees originating from between 289 and 596 colonies were killed during this event. Dinotefuran is a neonicotinoid that is highly effective in exterminating and/or harming target pest insects and non-target beneficial insects. Analysis to detect the concentration of pesticides in flowers that received foliar application revealed that the minimum reported dinotefuran concentration of a sampled T. cordata flower was 7.4 ppm, or in excess of 737% above the LC50 of the beneficial pollinator, the honey bee (Apis mellifera Linnaeus, 1758 [Hymenoptera: Apidae]). Furthermore, sampled Vosnesensky bumble bees (Bombus vosnesenskii Radoskowski, 1862 [Hymenoptera: Apidae]) were found to have an average dinotefuran concentration of 0.92 ppm at the time of death, which exceeds the maximum LC50 of A. mellifera (0.884 ppm). Our study underscores the lethal impact of the neonicotinoid pesticide dinotefuran on pollinating insect populations in a suburban environment. To our knowledge, the documentation and impact of pesticide kills on wild populations of beneficial insects has not been widely reported in the scientific literature. It is likely that the vast majority of mass pesticide kills of beneficial insects across other environments go unnoticed and unreported.

Sublethal exposure to deltamethrin stimulates reproduction and has limited effects on post-hatching maternal care in the European earwig.

Although pesticides are typically used to limit pest population, the diversity and nature of their unintentional effects on non-target organisms remain unclear. Better understanding these effects requires to carry out risk assessments on key physiological and behavioral processes specific to beneficial insects. In this study, we addressed this question by exposing mothers of the European earwig (a beneficial insect) to two sublethal doses of deltamethrin (a common pesticide in agriculture) during family life and measured the short- and long-term effects on a series of behavioral, physiological, and reproductive traits. Somewhat surprisingly, our results first revealed that high and low doses of deltamethrin enhanced mothers' future reproduction by augmenting their likelihood to produce a second clutch, shortening the number of days until its production, and increasing the resulting number of eggs and their hatching rate. Conversely, the high dose of deltamethrin was detrimental, as it limited maternal brood defence, and reduced food consumption and expression of self-grooming. Finally, other traits were independent of deltamethrin exposure, such as three proxies of family interactions (i.e., distance to the brood, occurrence, and duration of mother-offspring contacts), mothers' walking distance, and mother weight gain during family life. Our study overall demonstrates that sublethal exposure to a pesticide such as deltamethrin can have both positive and negative effects on non-target beneficial insects. It thus emphasizes that focusing on narrow parameters can lead to misleading conclusions about the unintended impacts of pesticides in treated agro-ecosystems and call for better considering this parameters diversity in integrated pest management programs.

Reproductive toxicity of Novaluron in Bombyx mori (Lepidoptera: Bombycidae) and its impact on egg production

Bombyx mori was used as a model to evaluate the reproductive toxicity of Novaluron in insects. Morphological analyses of the testes and ovaries of B. mori throughout their life cycle revealed important alterations in the germ and somatic cells involved in spermatogenesis and oogenesis. We observed in all testicular developmental phases that Novaluron affected not only the organization, distribution and development of the cysts containing male germ cells, but also the morphological features of cell death. Similar cellular characteristics were found in the treated B. mori ovaries, suggesting the occurrence of cell death in both organs, in addition to a significant reduction in oviposition of eggs by female moths. We demonstrated reproductive toxicity of Novaluron to the nontarget beneficial insect silkworm, thus providing a theoretical basis for revealing the reproductive toxicity of this insecticide to other nontarget beneficial insects.

Aedes Albopictus (Diptera: Culicidae) Susceptibility Status to Agrochemical Insecticides Used in Durian Planting Systems in Southern Thailand

High rates of dengue morbidity occur in southern Thailand. The intensive application of insecticides in orchards could affect not only agricultural insect pests, but also nontarget mosquitoes or beneficial insects. In this study, the type and quantity of insecticides commonly used across durian plantations in southern Thailand were characterized, along with the population density of Aedes albopictus (Skuse) (Diptera: Culicidae). Our primary aim was to determine the susceptibility status of field-derived Ae. albopictus to typical application concentrations of four agrochemical insecticides; cypermethrin, chlorpyrifos, carbaryl, and imidacloprid. Mosquito eggs were collected from durian cultivation sites in five provinces in southern Thailand and used to generate adults for susceptibility tests. The cultivation sites were categorized into three groups based on insecticide application: intensive application of insecticides, low application of insecticides, and no application of insecticides. Twenty ovitraps were deployed for at least three consecutive days at each study site to collect mosquito eggs and to determine Ae. albopictus population density. WHO tube assays were used to determine the susceptibility of adult mosquitoes derived from field-collected eggs to selected insecticides. This represents the first report of the susceptibility status of Ae. albopictus from durian orchards in southern Thailand to agrochemical insecticides. Results showed complete susceptibility of these Ae. albopictus to chlorpyrifos, but reduced mortality following exposure to λ-cyhalothrin, carbaryl, and imidacloprid, which is suggestive of the development of resistance. These findings provide new insights into the status of insecticide susceptibility in Ae. albopictus populations, with important implications for mosquito and mosquito-borne disease control in Thailand.

Microorganisms as bioinsecticides; short review

Hundred thousand tons of chemical insecticides are used annually in Nigeria to combat insect disease vectors especially agricultural pests, but this sort of vector control method is gradually being substituted due to their environmental effects on non-target beneficial insects especially vertebrates through contamination of food and water. To counteract this contamination, attention, efforts and researches were directed to the use of biological control agents including insect pathogens. As a result, the use of bio insecticide, as a component of integrated pest management (IPM), has been gaining acceptance over the world. Microbial pathogens comprise of organisms which cause disease, these organisms are disseminated in the pest population in large quantity in a manner similar to application of chemical pesticides. Insects like other organisms are susceptible to a variety of diseases caused by different groups of microorganisms including virus, bacteria, fungi, protozoa and nematodes. Microbial pathogens of insects are intensively investigated to develop environment friendly pest management strategies in agriculture. Microbial insecticides represent today the best alternative to chemical insecticides in controlling insect pests, they are safe for non-target species and human health are believed to show low persistence in the environment. This short review indicates that microbial insecticides are the safe alternative way possessing all the requirements to replace chemical insecticides hence, they can be utilized in pest management and control.
 Keywords: Bio-insecticides, Microorganisms, biological control, pest, chemical insecticides

Glyphosate tolerant and insect resistant transgenic Bt maize efficacy against shoot borer, cob borer and non-target insect pests

Introducing Bt insect resistance genes into hybrid maize seems to be the most feasible and effective technique accessible to control the pest. Transgenic stack hybrid maize (MON 89034X NK 603) was developed by Monsanto for checking yield losses of maize crop to increase productivity. Transgenic stack hybrid maize was claimed to have both insect protection and herbicide tolerant traits to provide protection to the crop from target pests and also provide effective weed management. MON 89034X NK 603 is 2nd generation glyphosate tolerant with Bt maize technology effective against lepidopteron insect pests with “dual mode of action”. A field experiment was carried out at ICAR-Directorate of Weed Research, Jabalpur for two years during Kharif (rainy season) 2009 and 2010 to evaluate the efficacy of transgenic stack hybrid maize (MON 89034X NK 603) against shoot borer (Chilo partellus), cob borer (Helicoverpa armigera), non-target insect pests and beneficial insects. Treatments consisted of two transgenic stacked hybrids named ‘Hishell’ and ‘‘900M Gold’’ with two conventional hybrids namely ‘Proagro-4640’ and ‘‘HQPM-1’’. Artificial infestation of Chilo partelus revealed complete absence of stem borer infestation in all the transgenic entries of ‘Hishell’ and ‘900M Gold’ with less than one leaf injury score (LIS), while in other conventional entries, stem borer infestation was observed and LIS was more than one. Hlicovepa armigera infestation was also not observed on transgenic hybrids whereas in the remaining non-transgenic maize treatment, significant attack of Helicoverpa armigera was observed in the range of 37 to 56%. These transgenic entries were not found resistant to aphids and grass hoppers. Beneficial insects were observed to visit transgenic Bt maize and conventional maize entries with no significant difference.

Impact of Terminalia chebula Retz. against Aedes aegypti L. and non-target aquatic predatory insects

Aedes aegypti Linn is one of the most important mosquito species. The vectors are responsible for causing deadly diseases like dengue and dengue hemorrhagic fever. Several chemical pesticides used to control these dengue vectors caused severe toxic significances on human health and other non-target beneficial insects. Therefore the current investigation has been made to access the bio-efficacy of the crude seed extracts of T. chebula against the dengue vector Ae. aegypti. The GC-MS analysis of crude seed extracts of T. chebula identified nine chemical compounds with major peak area in the 1,2,3-Benzenetriol (61.96%), followed by Tridecanoic acid (09.55%). Ae. aegypti larvae showed dose dependent mortality rate was observed between the treatments. Prominent protection rate at greater concentrations of 100ppm and moderate protection at 75 and 50ppm was observed in the repellent assay. Lethal concentration (LC50 and LC90) of fourth instar larvae of Ae. aegypti was observed in 138 and 220ppm concentration respectively. Similarly, the seed extracts showed 100% adulticidal activity at the concentration of 400ppm at 30min of exposure time. Phytochemicals present in the seed extracts of T. chebula significantly affects the major portions of the midgut tissues of Ae. aegypti at the concentration of 100ppm. The toxicological evaluation of seed extracts also proved non-toxic towards the A. bouvieri and Tx. splendens aquatic predatory insects. Hence, the present result suggest that bio-rational plant derived T. chebula could be incorporated in the dengue vector control and have no adverse effects on non-target beneficial insects.

Achieving bilinearity in non-bilinear augmented first order kinetic data applying calibration transfer

In this paper a calibration transfer method is used to achieve bilinearity for augmented first order kinetic data. First, the proposed method is investigated using simulated data and next the concept is applied to experimental data. The experimental data consists of spectroscopic monitoring of the first order degradation reaction of carbaryl. This component is used for control of pests in fruits, vegetables, forages, cotton and other crops. It is highly toxic and likely human carcinogen, and is lethal to many non-target beneficial insects. The kinetic experiment is performed at different pH-values and emission wavelengths using an excitation wavelength equal to 275nm. Rate constants of different data matrices at different pH values were calculated based on a hard modeling method. Analysis of simulated and experimental data shows that if there is a deviation from bilinearity, applying the model based methods to augmented datasets leads to inaccurate results. The application of a calibration transfer method as an additional step in the hard modeling procedure improves the results, and accurate estimation of reaction rate constants are obtained. The proposed method was compared to Local Spectra Mode of Analysis (LSMA) which was proposed by Puxty et al. A comparison of the results shows that the proposed method is more efficient than LSMA and leads to less uncertainty in estimated rate constants and less percent error in the relative residuals.

EPA's Proposed Biotech Policy Turns a Deaf Ear to Science

Nina Fedoroff,* Robert Haselkorn, and Bruce M. Chassy *Huck Institutes of the Life Sciences, Penn State University, University Park, Pennsylvania, USA; King Abdullah, University of Science and Technology (KAUST), Thuwal, Saudi Arabia; Dept of Molecular Genetics & Cell Biology, The University of Chicago, Chicago, Illinois, USA; and Department of Food Science and Human Nutrition University of Illinois at Urbana-Champaign, Urbana, Illinois, USA

Attractant-baited traps for the sugar-beet weevil Bothynoderes ( Cleonus) punctiventris: Preliminary study of application potential for mass trapping

The sugar-beet weevil ( Bothynoderes punctiventris Germar) (Coleoptera: Curculionidae) is one of the most important insect pests of sugar-beet throughout central, eastern and southeastern parts of Europe. The damage by the overwintering adult beetles is caused by feeding on sugar-beet seedlings in early spring. As a possible alternative to insecticides, the present research was aimed at studying the potential of traps baited with a synthetic aggregation attractant in decreasing the population of the sugar-beet weevil through mass trapping at the overwintering sites. It was demonstrated that by setting out traps baited with a blend of synthetic ( Z)- and ( E)-2-ochtodenal [ = Grandlure III–IV; ( Z)- and ( E)-(3,3-dimethyl)cyclohexylidene)acetaldehyde; the aggregation attractant] at 10 and 30 trap/ha densities, 30–100% of the sugar-beet weevil population was mass-trapped at the overwintering sites. Traps caught non-target beneficial insects in very low numbers. Application of the traps shows good potential as a control method especially at population densities of 30 000 insect/ha or below, and may be capable of decreasing the population pressure of immigrating beetles to sites where sugar-beet is planted in the spring.

An ecological assessment of transgenic crops

Since the first commercial release of a transgenic crop in 1994, the land area planted to these crops has expanded to over 90 million ha worldwide, with approximately 8.5 million farmers in 21 countries cultivating transgenic crops. Public apprehension has mounted apace. Concerns include: (i) the potential for gene flow into wild plant populations or soil organisms; (ii) adverse effects on non-target organisms; (iii) gene products or crop residues persisting in the environment with deleterious effects and, for insecticidal crops; (iv) resistance developing in target pest populations. Numerous studies on the environmental risks of transgenic crops are published. Gene flow to a crop's wild relatives has been demonstrated in the field; hence, the use of these crops is restricted to regions where wild relatives are not endemic. Gene flow to soil organisms is yet to be demonstrated under field conditions and is unlikely given the safeguards employed, but not impossible. The weight of the evidence suggests that there is little risk to non-target soil organisms, but reduced numbers of non-target beneficial insects have been reported with the use of insecticidal crops in some systems. Population effects on non-target insects associated with the use of insecticidal crops are significantly less extensive than those experienced using chemical pesticides, and it has yet to be determined if observed population changes are ecologically significant in these cropping systems. Resistance of target pests to insecticidal crops is possible and eventually likely, but after nearly a decade of use has yet to be detected under field conditions. Several strategies to reduce potential ecological impacts are either under development or near release. Ecological risks posed by new technologies under development and the need for in-country risk assessment and post-release monitoring are discussed.

Monitoring the Seasonal Flight Activity of <I>Cydia pomonella</I> and <I>Argyrotaenia velutinana</I> (Lepidoptera: Tortricidae) in Apple Orchards by Using Pheromone-Baited Traps

Abstract Codling moth, Cydia pomonella (L.), and redbanded leafroller, Argyrotaenia velutinana (Walker), are two key tortricid orchard pests in Minnesota. Field trials were conducted during 2001 and 2002 in Minnesota apple orchards to determine seasonal phenology of C. pomonella and A. velutinana and to evaluate two popular trap designs (Pherocon 1CP or 1C “Wing” trap versus Pherocon VI “delta” trap) for monitoring both species. Trap performance was determined by comparing the number of males captured, date of first moth capture, and the capture of nontarget beneficial insects. For C. pomonella, two distinct flight periods were recorded, suggesting two generations per year in Minnesota. Emergence and flight activity of first generation C. pomonella began at ≈110 degree-days (DD) base 10°F. This corresponded to apple bloom in southern Minnesota. The delta trap captured significantly more C. pomonella males than the wing trap (Pherocon 1CP version). For A. velutinana, three flight periods were recorded at a...

Direct and indirect sublethal effects of Galanthus nivalis agglutinin (GNA) on the development of a potato-aphid parasitoid, Aphelinus abdominalis (Hymenoptera: Aphelinidae)

Snowdrop lectin ( Galanthus nivalis agglutinin, GNA), has been shown to confer partial resistance to two potato aphids Myzus persicae and Aulacorthum solani, when incorporated in artificial diet and/or expressed in transgenic potato. First-tier laboratory-scale experiments were conducted to assess the potential effect of GNA on the aphid parasitoid Aphelinus abdominalis. GNA (0.1% w/v) was successfully delivered to Macrosiphum euphorbiae via artificial diet and induced a reduced growth rate and increased mortality compared to aphids fed a control diet. As aphid parasitoid larvae are endophagous, they may be exposed to GNA during their larval development and potential “chronic toxicity” on A. abdominalis was investigated. The amounts of GNA present in aphid and parasitoid tissues were estimated by western blotting. Results suggest that parasitoids excrete most of the GNA ingested. Sublethal effects of GNA on several parasitoid fitness parameters (parasitism success, parasitoid development and size, emergence success, progeny survival and sex ratio) were studied. No direct detrimental effect of GNA on A. abdominalis was observed. However, GNA had an indirect host-size-mediated effect on the sex ratio and the size of parasitoids developing in GNA-fed aphids. This work highlights the need to determine the exact “causes and effects” when assessing the ecological impact of transgenic plants on non-target beneficial insects. Such bioassays form the basis of a tiered risk assessment moving from laboratory studies assessing individuals towards field-scale experiments assessing populations.

Insecticide Control of Plant Bugs and Effect on Beneficial SPP., 1982

Abstract An insecticide test was conducted in a farmer cooperator’s field near Conran, MO, to evaluate 4 insecticides for the control of plant bugs and their effect on non-target beneficial insects. Eight-row plots, 200 ft long were replicated 4 times according to a randomized complete block design. Insecticides were applied Jul 21 at the rate of 5 gpa at 30 psi directed over the row through 1 nozzle/row with an air-pressurized system mounted on an 8-row Hahn 300 Hi-boy high clearance sprayer. Pretreatment counts were taken over the entire plot Jul 21 by shaking ten 3-row-ft samples over a drop sheet. Post-treatment counts were made by sampling 3-row-ft at 4 sites in each plot. Pretreatment counts of the mean number of insects and beneficials per plot were as follows: total plant bugs (15.6) and total beneficials (32.8).