Intensive Application Of Insecticides Research Articles

Is Integrated Management of Gymnandrosoma aurantianum Possible with Trichogramma atopovirilia and Novel Products Used in Citrus Orchards in Brazil?

In Brazil, the citrus fruit borer, Gymnandrosoma aurantianum Lima, 1927, is a serious pest in orange orchards, causing an annual loss of 80 million US dollars, and is managed with multiple insecticide applications, often 56 in a single season. On the other hand, the parasitoid wasp Trichogramma atopovirilia Oatman & Platner, 1983 has the potential for controlling G. aurantianum by attacking its eggs. Considering the intensive insecticide applications in citrus orchards in Brazil to control the large complex of pests, especially Diaphorina citri Kuwayama, 1908, evaluation of the harmful effects of insecticides on T. atopovirilia is important to maximize efficiency in managing G. aurantianum. Here, we tested the effects of new products used in citrus orchards (cyantraniliprole, cyantraniliprole + abamectin, abamectin, sulfoxaflor, spinetoram, flupyradifure, and Cordyceps fumosorosea (Wize) Kepler, B. Shrestha & Spatafora) on adults and pupae of T. atopovirilia. Of the insecticides tested, spinetoram caused the highest impacts on T. atopovirilia parasitism, longevity, emergence, and mortality. The other products caused more sublethal than lethal effects and were classified as 1 and/or 2 in the IOBC/WPRS classification. Abamectin, cyantraniliprole, cyantraniliprole + abamectin, and the entomopathogenic fungus C. fumosorosea were classified as short-lived. Except for spinetoram, these products were classified as selective. In this study, spinetoram was considered harmful to T. atopovirilia and, therefore, should be managed carefully in IPM programs combining this parasitoid. In order to safely use this insecticide, one should respect the interval of release of the parasitoid, which is 21 days after its spraying. The novel products tested, cyantraniliprole, cyantraniliprole + abamectin, abamectin, sulfoxaflor, and the entomopathogenic fungi C. fumosorosea were selective and non-persistent to T. atopovirilia. These products are possible replacements for non-selective insecticides to achieve higher control from both chemical and biological tools.

Energetic costs of resistance in the Agonoscena pistaciae Burckhardt & Lauterer, 1989 (Hemiptera: Aphalaridae), against spirotetramat, acetamiprid and hexaflumuron

Abstract: The common pistachio psylla, Agonoscena pistaciae Burckhardt & Lauterer, 1989 (Hemiptera: Aphalaridae), is a key pest found in pistachio orchards in Iran. This pest has a high potential for developing resistance to insecticides due to its short life cycle and high reproductive potential. Intensive application of insecticides leads to excessive selection pressure followed by resistance to synthetic insecticides in some psylla populations. In this research, effects of four concentrations of three extensively used insecticides (spirotetramat, acetamiprid, and hexaflumuron) on energy resources (like sugar, lipid, glycogen, and protein contents), energy consumption, and cellular energy allocation were investigated in resistant and susceptible populations of the common pistachio psylla in the Kerman province of Iran. Energy resource contents in the susceptible population (133 331.2 mj/insect) were significantly more than in the resistant population (96 253.5 mj/insect), whereas energy consumption in the resistant population (38 630.4 mj energy/h/insect) was higher than in the susceptible population (31 276.8 mj energy/h/insect). Additionally, cellular energy allocation in the resistant population (2 400.9 mj energy/h/insect) was higher than in the susceptible population (2 126.13 mj energy/h/insect). Therefore, stress (especially toxicants) causes variations in metabolism, which influences the growth and reproduction of the pest.

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.

Host Plant Resistance to Bemisia tabaci to Control Damage Caused in Tomato Plants by the Emerging Crinivirus Tomato Chlorosis Virus.

Tomato chlorosis virus (genus Crinivirus, family Closteroviridae) (ToCV) is rapidly emerging, causing increased damage to tomato production worldwide. The virus is transmitted in a semipersistent manner by several whitefly (Hemiptera: Aleyrodidae) species and is expanding its geographical and host ranges associated with the emergence of whiteflies of the Bemisia tabaci complex. Control is based essentially on intensive insecticide applications against the insect vector but is largely ineffective. No virus-resistant or tolerant commercial tomato cultivars are available. Recently, a B. tabaci-resistant tomato line based on the introgression of type IV leaf glandular trichomes and secretion of acylsucroses from the wild tomato Solanum pimpinellifolium was shown to effectively control the spread of tomato yellow leaf curl virus, a begomovirus (genus Begomovirus, family Geminiviridae) persistently transmitted by B. tabaci. As short acquisition and transmission periods are associated to the semipersistent transmission of ToCV, its possible control by means of the B. tabaci-resistant tomato could be compromised. Moreover, if the antixenosis effect of the resistance trait present in those tomato plants results in increased B. tabaci mobility, an increased ToCV spread might even occur. We demonstrated, however, that the use of acylsugar-producing B. tabaci-resistant tomatoes effectively controls ToCV spread compared to a near-isogenic line without type IV trichomes and acylsugar secretion. No increase in the primary ToCV spread is observed, and secondary spread could be reduced significantly decreasing the incidence of this virus. The possible use of host plant resistance to whiteflies to limit spread of ToCV opens up new alternatives for a more effective control of this virus to reduce the damage caused in tomato crops.

Rice Husk Bio-Char Improves Brinjal Growth, Decreases Insect Infestation by Enhancing Silicon Uptake

To meet the food demand of the increasing world population, use of insecticides is increasing day by day. However, intensive application of insecticides has increased the health risks to the human. Therefore, sustainable alternatives with a limited or no harm to the human and environment are always preferable. A study was conducted to determine the effect of rice husk biochar (RHB) on brinjal growth, mineral nutrients and insect infestations. The soil filled pots (7 kg pot−1) were amended with various levels of rice husk biochar (Control, RHB 3.5, RHB 7, RHB 14, RHB 21 and RHB 28 g pot−1) and its effects were determined on brinjal plant. Rice biochar (RHB 28 g pot−1) amended plant produced maximum biomass. Further, results also showed that higher doses of RHB significantly lower the insect infestation. Biochar treatment has also improved the plant mineral nutrients especially silicon (Si) concentration in the leaves. Hence, it is concluded that RHB tends to reduce insect infestation on brinjal plants by improving Si uptake and it may provide a strategy to sustain brinjal production. However, further studies must be carried out for comparative efficacy of the RHB with insecticide in deterring insect infestation for its widespread recommendations.

Invasion Biology, Ecology, and Management of Western Flower Thrips.

Western flower thrips, Frankliniella occidentalis, first arose as an important invasive pest of many crops during the 1970s-1980s. The tremendous growth in international agricultural trade that developed then fostered the invasiveness of western flower thrips. We examine current knowledge regarding the biology of western flower thrips, with an emphasis on characteristics that contribute to its invasiveness and pest status. Efforts to control this pest and the tospoviruses that it vectors with intensive insecticide applications have been unsuccessful and have created significant problems because of the development of resistance to numerous insecticides and associated outbreaks of secondary pests. We synthesize information on effective integrated management approaches for western flower thrips that have developed through research on its biology, behavior, and ecology. We further highlight emerging topics regarding the species status of western flower thrips, as well as its genetics, biology, and ecology that facilitate its use as a model study organism and will guide development of appropriate management practices.

Use of Systemic Acquired Resistance and Whitefly Optical Barriers to Reduce Tomato Yellow Leaf Curl Disease Damage to Tomato Crops.

Epidemics of tomato yellow leaf curl disease (TYLCD) caused by tomato yellow leaf curl-like begomoviruses (genus Begomovirus, family Geminiviridae) severely damage open field and protected tomato crops worldwide. Intensive application of insecticides against the whitefly vector Bemisia tabaci is generally used as control strategy to reduce TYLCD impact. This practice, however, is frequently ineffective and has a negative impact on the environment and human health. TYLCD-resistant varieties are commercially available, but cultivation of susceptible traditional tasting ones is also requested if possible. For susceptible tomatoes, here we show that using whitefly optical barriers by means of UV-blocking plastics in protected crops can contribute to reducing TYLCD damage and increasing commercial fruit yield. Moreover, induction of systemic acquired resistance by application of the elicitor of plant defense acibenzolar-S-methyl was effective to reduce yield losses when viral pressure was moderate. Interestingly, combining both practices in protected tomato crops can result in a significant TYLCD control. Therefore, these control practices are proposed to be used commercially as management alternatives to include in integrated management of TYLCD.

Keanekaragaman Dan Kemerataan Serangga Pada Areal Tanaman Kentang (Solanum tuberosum L) Setelah Berbagai Metode Aplikasi Insektisida

Pest is one of the biological limiting factors that led to low production of potatoes. The use of pesticides is a solution in controlling pests. The objective of this study was to determine the diversity and evenness of insect; and potato yield losses due to insecticide applications methods. The treatment was controlled and intensive insecticide application which were compared with no insecticide application. The experiment was set up in completely randomized design with five replications. The results showed that the insects are dominated by Empoasca sp, Liriomyza sp and Miridae. The highest insect population was Empoasca sp. i.e 80.83 Empoasca sp. which was found in control treatment. Controlled and intensive application of insecticides decreased insect population up to 56.50 and 26.17. Evenness index of insect and economic value of lost results unaffected by differences in pesticide application methods

Effect of pirimicarb application on field ppulations of Myzus persicae (Sulz.) (Homoptera: Aphididae) with different esterase levels

The frequency and intensity of Myzus persicae (Sulz.) resistance were studied using bioassays and biochemical tests in two potato crops in Ibicoara, Bahia. Both areas received several insecticide applications which failed to control M. persicae. By the end of the crop season, one of the areas received two applications of pirimicarb and the other was not sprayed. Six samples of 700 aphids each were randomly collected before and after the pirimicarb applications, with an interval of four days. Specimens of M. persicae were also collected from isolated potato plants. At the laboratory, the samples were characterized by the CL50 based on insecticide bioassays and by total esterase activity using colorimetric assays. After the pirimicarb applications, the susceptible (S), the moderate resistant (R1) and mixed S/R1populations presented decreasing resistance frequencies (from 36.6 to 9.9; 12,0 to 7.5 and 11.4 to 5.9%, respectively). On the other hand, high resistant individuals (R2), extremely resistant (R3), and mixed populations of R1/R2 had increasing frequencies (from 17.7 to 36.7%; 2.3 to 9.1%, and 20.0 to 30.8%, respectively). The survival of S individuals was probably due to their wandering behavior on the plants to avoid sprayed areas. All changes in frequency were reflected in the LC50 and in the resistance ratio (rr). In the pirimicarb untreated area, high frequencies of R2, R3 and R1/R2 were observed. High frequency and resistance intensity of M. persicae in areas under intensive insecticide applications can be related to the selection of resistant populations and due to the entrance of winged migrants from spontaneous plants, where the frequency of R2+R3 was 81.4%.

Economic Impact of Integrated Pest Management Strategies for Cotton Production in the Coastal Bend Region of Texas

A long-season (160–180 days) cotton variety with a conventional production system was formerly grown in the Texas Coastal Bend Region. Cotton producers in the region used intensive insecticide applications throughout the growing season and harvested in August or September, and occasionally in October. In general, intensive insecticide applications for boll weevil and fleahopper control destroyed the beneficial insects and spiders. Late-season tobacco budworm infestations were thereby aggravated. These late-season insect infestations were a result of the relatively high rainfall during August and September. Moreover, high rainfall during this time not only interfered with harvest, but also reduced both the yield and quality of cotton (Lacewell et al.).

Comparative Studies of Urban Fly Populations in Arizona, Kansas, Michigan, New York, and West Virginia

For the purpose of determining the possible relationship of flies to the transmission of poliomyelitis, an investigative program was initiated in 1948 at 5 cities: Phoenix, Arizona; Topeka, Kansas; Charleston, West Virginia; Muskegon, Michigan; and Troy, New York. To measure the effectiveness of the control operations in the aforementioned cities, 5 nearby towns were selected to serve as comparison areas. These untreated cities were: Mesa-Tempe,[1][1] Arizona; Lawrence, Kansas; Dunbar-St. Albans,[1][1] West Virginia; Grand Haven, Michigan; and Cohoes, New York (Figure 1). As an essential part of the fly appraisal studies at each project, fly trapping surveys were conducted in both treated and untreated cities. However, since the effect of the intensive application of insecticides in the treated cities upon the fly population varied in the different municipalities, this paper will describe only the trap data procured in the untreated cities during 1949 and 1950. Because of the voluminous amount of material available, further reduction will be effected by confining the discussion to the 10 related species of major importance: Musca domestica, Phaenicia sericata, Phaenicia pallescens, Phaenicia caeruleiviridis, Phormia regina, Ophyra leucostoma, Ophyra aenescens, Muscina stabulans, Muscina assimilis , and Callitroga macellaria . The findings from the treated cities and with reference to the other species will be treated in a subsequent paper. Most of the trap data which are available on adult fly populations and the seasonal prevalence of individual species have been related to those blow flies which produce parasitic myiasis in domestic animals. As the majority of this work has been limited to rural areas, relatively little information is available on the abundance, distribution, and seasonal incidence of those species which commonly form fly populations of urban areas. The principal studies of this nature are those reported by Power et al. (1943) and Power and Melnick (1945), which describe work in New Haven, Connecticut, and the 2-year survey conducted at Madison, Wisconsin, by Dicke and Eastwood (1952).[2][2] [1]: #fn-1 [2]: #fn-2