Top PDF The use of insecticides to control insect pests

Change in crops technology brought economic importance to pest control. Intensive fertilization of crops as well as protection efforts against weeds and diseases are factors contributing to the development of different insects. The latter can significantly reduce crop yields (Kaniuczak, 2013). In recent years, many pollinators have declined in abundance and diversity worldwide, presenting a potential threat to agricultural productivity, biodiversity and the functioning of natural ecosystems (Piiroinen et al., 2016). Unfortunately, all agrotechnical simplifications, new plants species, changes in agroclimate favor development of species of harmful insects that haven’t been observed in the area ever before. Changing climate- soil conditions, simplification of crop rotation (Bazok et al., 2012), and use of heavy equipment for field work affects oil. All of these mentioned factors can cause development of extra species which are harmful to crops. Insecticides are chemicals used for the protection of plants against harmful insects (Satyavani et al., 2012). Of course, only approved and registered insecticides should be applied. Additionally, for effective treatments, these substances should be properly selected, applied at the optimum for the insecticide temperature while maintaining grace period and prevention. The crops should include effective management of target pests, decreased use of conventional insecticides, and reduced harm to non-target organisms (Prischmann et al., 2007; Gassmann et al., 2014). Plant protection products should be used according to the label and with necessary precautions. The use of insecticides acting selectively on specific species allows for protecting the populations of beneficial insects such as bees, ladybugs, lacewings.  Bumble bees are important pollinators

For several reasons, P. tumifex is a good case study with which to illustrate our methods for assessing sampling strategies. First, despite the pest’s importance, no practical monitoring program has been available for P. tumifex. Giese & Benjamin’s [24] recommended sampling schemes were labour-intensive and impractical for application by growers. Only recently has a functional sampling unit been determined at the tree level [2], and no formal analysis has been available to guide site-level density estimation or decision making with respect to pesticide-application thresholds. Second, the development of comprehensive pest management strategies for P. tumifex (and for other Christmas tree pests) is further hampered by a high diversity of agricultural practices in the industry. Farms can range in size from ,1 ha to .100 ha and are derived from reclaimed agricultural fields, forest clearcuts, and even disused military compounds. Farms can be bordered by pastures, row crops, water, or forests. Seedlings for tree stock can come from natural regeneration, sowing of purchased seed stock, out-planting of seedlings or combinations of the three. Pest management practices, including willingness to use insecticidal sprays and methods used to assess pest density, are highly variable among farmers. This diversity means that any monitoring strategy must be robust enough to deal with substantial variation in attributes of sites, crop, and farming techniques. Finally, we suspected (based on previous observations) that P. tumifex, like many other insects, would possess complex distribu- tions that could make conventional sequential sampling inefficient or ineffective.

In the present study, another species frequently observed was F. schultzei (> 83%) (Table 1). It was observed mainly in the regions with large commercial cotton cultivation areas, such as Alcinópolis, Chapadão do Sul, Costa Rica, and Sidrolândia. Furthermore, F. schultzei was overabundant in the municipalities of Sidrolândia and Costa Rica. A common feature of these two municipalities was the use of insecticides creating a shock effect on the cotton crop residue, and no physical methods were followed. Therefore, insect pests with a high fertility rate and short life cycle were able to recover rapidly in this environment, as observed in A. gossypii, B. tabaci, and F. schultzei. These insects exhibited the highest faunal index values in the municipalities studied (Gallo et al., 2002; Campos et al., 2009; Funichello et al., 2012).

Plants used to collect volatiles were treated similar to methods described by Wei et al. [23]. In most cases, healthy plants were exposed to 150–200 adult pea leafminers for 2 h so that they obtained a cohort of second instars larvae after 4 to 5 days. In order to mimic the damage caused by pea leafminer in non-host plants, we used a method similar to the one described by Dicke et al. [21]. One Chinese rose shoot plant with 4–6 sets of leaves or a Boston ivy shoot plant with 15–20 leaves was placed with stems into vials containing 6 mL of an aqueous jasmonic acid (JA) (Sigma-Aldrich Co., St. Louis, Missouri, USA) solution (1 mM) for 36 h [42]. JA has been dissolved in 0.5% ethanol (Beijing Huateng Chemical Co., Ltd., Beijing). The vials were sealed with parafilm. The control plants were placed in vials with 6 mL of 0.5% alcohol for 36 h. Before volatile collections, the JA-treated plants and the controls were transferred from their vials to individual glass tubes filled with 50 mL of tap water. Half of the control shoots were used for collection as the treatment for undamaged leaves, and the other half of the leaves were cut with a blade as treatment for mechanically damaged leaves (200 cuts per plant). All were subjected to the volatile collection system.

When used for the control of pests, fungi are also part of the poultry management system, as well as chemical disinfectants and insecticides (Bellaver et al., 2003). However, such chemicals must be rationally applied, i.e., the preservation of natural pest enemies and the health of poultry and humans must be taken into account. Although many studies on the impact organic-synthetic pesticides on natural pest enemies were published, no such articles were found in the context of poultry production, nor specifically on the fungus B. bassiana. Therefore, the objective of, this experiment was to evaluated the effects of disinfectants and insecticides commonly used in poultry houses on the fungus B. bassiana strain Unioeste 4 in order make recommendations for their application.

ABSTRACT – Eucalyptus species are originally from Australia and its plantations is the major forestry activity in Brazil. The Myrtaceae family is widely represented in Brazil, enabling native insects to migrate to Eucalyptus plants. Native herbivorous insects may adapt to the species planted in monoculture with low availability of their natural host plants and natural enemies. Within this context, the differential occurrence pattern of eleven insect pests of Lepidoptera, Coleoptera and Hemiptera orders, from 450 Eucalyptus stands of different ages recorded in 2002 to 2010 in eastern State of Minas Gerais, Brazil was evaluated. Bayesian inference was used for data analyses in hypothesis testing. The probability of occurrence of pest species was estimated using a linear multinomial model, relating their occurrence with the Eucalyptus stand age. Pest occurrence in Eucalyptus stands were linked to plant age, with younger ones being more susceptible to phytophagous insects. That association with chronological plant age may be associated with the resource exploration strategy of each group of pest insects. Thus, Eucalyptus forest management should be adapted to the temporally differential use of the stands by pest species, providing more efficient control strategies.

PALAVRAS-CHAVE: Biopesticida, controle biológico, fermentação, formulação, estabilização ABSTRACT - Thousands of potential microbial biocontrol agents have been isolated from agricultural fields and crops during research over the last 80 years, yet only a few are in commercial use. Recently, public health and safety concerns about the environmental impact of chemical pesticides have led to consideration of biological control as a natural approach to maintaining crop health. Despite environmental incentives and strong research efforts, commercialization of biocontrol agents has been slow to evolve. The momentum of the chemical industry is difficult to shift, and fermentation processes tend to be more expensive to operate than synthetic chemical processes.Yet there is a demand for biological control products, especially in agricultural niche markets, where there is no chemical competitor. However, given this market demand, the fundamental methods of economical large-scale production and application of biological control agents are lacking. Many aspects of biocontrol agent production and development represent untrodden territory in the progression of industrial fermentation technology beyond its well-established food and pharmaceuticals niche. Distinguishing them from traditional fermentation products, biocontrol agents must not only be produced in high yield but must also meet the following quality criteria: high (near 100%) retention of cell viability with maintenance of crop compatibility and consistent bioefficacy during several months of storage. Research examples will be reviewed to illustrate the challenges and strategies of developing processes to manufacture and deliver biological agents for insect, weed, and plant disease control.

Bahia is the Brazilian state with the largest production of sugar apple fruits (Annona squamosa L.), and fruit borer (Cerconota anonella, Sepp. 1830) is a key crop pest. Insecticides are the main strategy for pest control even though there are no pesticides registered for this crop. This study aimed to assess the efficacy of insecticides to control fruit borer and determine the levels of insecticide residues in sugar apple fruits aiming at requesting the extension of authorization to use insecticide products in this crop. The experiment was conducted in an eight-year-old irrigated orchard (2 × 4 m) located in Anagé, Bahia, Brazil. The experimental design was a randomized block design with 10 treatments (three insecticides with three doses and a control with water) and 5 replications. Each plot was composed of four plants but only the two central ones were assessed. Insecticides and doses (g a.i. 100 L -1 water) were Bacillus

In addition to the economic losses related to reduced produc- tion, pest control requires measures that contribute to increased spending, which increases the damage that these organisms cause to the economy, to the environment, and to human and animal health. Brazil is one of the largest consumers of pesticides, including insecticides, miticides, fungicides, and herbicides, and the sales of these products reached US$ 8.5 billion in 2011 (SINDAG, 2013). Although successful control strategies of pests are used in Brazil that enables the control of key pests with reduced environ- mental impacts, based, for example, on biological control agents, such as in sugarcane for stem borers (Botelho, 1992), and the use of genetically modified plants in crops like soybean, corn and cotton (Sousa Ramalho et al., 2011; Bernardi et al., 2013; Okumura et al., 2013), the application of synthetic insecticides has been the main

Room temperature nitrogen gas was used in the experiment. It is much less expensive than liquid nitrogen and widely avail- able. A standard vacuum cleaner with a hose (Figure 1A) was used to remove air through the bags’ one-way valves. A stan- dard gas regulator is needed for the nitrogen tank. Most institu- tions already have such regulators or they can be purchased for around $100.00. Nitrogen tanks cost about $2.00 per month per tank to keep full. There can also be a irst time fee of about $75.00 when service is started. One tank was suficient to treat the contents of an herbarium case, with 20 of its 22 shelves illed with specimens. The amount of gas used included enough to re- ill bags that were improperly sealed or leaked. Bags must be monitored for potential leaks, especially for the irst two days to make sure they are not delating. The inlation or delation of each bag provided an indicator for successful removal of air and illing with nitrogen. Suficient table or other space was needed to leave the bags undisturbed for at least one week (Figure 1D). Air was collected from the valve positioned at the

Entomopathogenic fungi could also be an alternative for the control of the lesser mealworm, provided care is taken when treating the poultry house facilities to preserve the fungi in the environment, such as using selective products for poultry house disinfection. However, specific studies on these disinfectants are required. The disinfectants applied during downtime, together with high ammonia concentrations in the litter prevent the survival of entomopathogenic fungi in the poultry house environment. The direct contact with the litter is extremely harmful to those fungi (Geden et al., 1998; Alves et al., 2008). The use of oil formulations was shown to be more efficient to protect fungi from abiotic factors (McClatchie et al., 1994; Hedimbi et al., 2008; Lopes et al., 2011), and their application on the soil during downtime showed better results, as observed with other lesser mealworm control practices (Santos et al., 2009).

ABSTRACT - A technique for rearing Elasmopalpus lignosellus (Zeller),larvae in laboratory, infesting plants in the field and evaluating treatments was described and tested in rice. In addition, the performance of insecticides as seed treatments to control larvae, under artificial and natural infestations, was evaluated on three planting dates. The experimental design was a Latin 6x6 square and the experimental unit consisted of seven 4 m long rows and 0.4 m spacing between rows. Treatments consisted of the following insecticides and doses: thiamethoxam (52.5, 70, and 105 g a.i./100 kg seeds), furathiocarb (320 g a.i./ 100kg seeds), carbofuran (525 g a.i./100kg seeds), and an untreated control. Artificial infestations were made, in two groups of three selected tillers at the border rows in each plot and confined in PVC cylinders on three dates of each planting. Tillers were infested with three 7-day old E. lignosellus larvae. Immediately after infestation, cylinders containing three rice tillers were protected to avoid the effect of rain on the larvae. Damage was evaluated 20 days after the infestations. Artificial infestations increased the damage 32 fold, in relation to natural infestations in the untreated control. Insecticides reduced larval survival significantly for 60 days after planting compared to the untreated control. KEY WORDS: Insect, lesser cornstalk borer insect rearing, seed dressing

The parasitic mite A. lacunatus is an important biological control agent because besides having showed tolerance to the insecticides and high rates of parasitism on R. dominica eggs, its presence inhibits oviposition by this insect-pest. Deltamethrin was the most effective insecticide for reducing R. dominica populations resulting in reduced grain loss and for maintaining the mite population at low but effective levels (90.6 ± 9.38% egg parasitism). Although the efficacy of bifenthrin, fenitrothion and pirimiphos-methyl was low in reducing R. dominica adult populations, it resulted in greater availability of the host eggs and allowed faster mite population growth. The mite population growth is not likely to compromise grain quality because these arthropods are easily removed from the grain mass in their regular cleaning process before processing (Scholler & Flinn 2000). Flinn & Hagstrum (2001) showed that augmentative releases of the Theocolax elegans wasp in wheat decreased in 89% the damage caused by R. dominica besides reducing in 92% the insect fragments in the final product (flour).

Another pest associated with potato culture is the beetle Diabrotica speciosa (Germar, 1824) (Coleoptera, Chrysomelidae), which is widespread in Brazil and other South American countries (MACHADO et al., 2007). The adult beetles cause indirect damage by consuming the leaves of the potato plant, while during the larval stage direct damage reduces the value of the tubers (AZEREDO et al., 2004). In order to control the larvae, either liquid or granulated insecticide is normally applied during the cultivation cycle or incorporated into the potato mounds. Such procedures demand relatively large amounts of active ingredient per cropping area thereby increasing the cost of production and causing environmental contamination, particularly in sandy soils (PEREIRA et al., 2005).

P. aduncum (0.65) was the only species to transform the bean grains to be repellent to the weevil in the sachet application form (Figure 1). It is well known that the Piperaceae family generally possesses promising secondary compounds with insecticide activity. The effect of these phytochemicals is related mostly to the concentration of piperamides (e.g., piperine) and can show uncounted modes of action, including repellent, contact, and antifeeding effects (SCOTT et al., 2008). This suggests the effect of P. aduncum is due to the existence of these volatile compounds on its tested structures. Even though a promising result was demonstrated by using sachet, it was expected that the powder form could cause a similar repellent effect to the insect; however this was not observed in this study.

Although the Amazon region is one of the main centers of biodiversity, the reports of the plants with insecticidal properties are becoming more frequent from the 2000s (COITINHO et al, 2006; SILVA et al., 2007; SARRIA et al. 2011; ALVES et al., 2012; FAZOLIN et al., 2016; SANTOS et al., 2015, 2016). In general, botanical insecticides are less toxic than the synthetic ones and they degrade faster (ABBASSY; ABDELGALEIL; RABIE, 2009). Another advantage of botanical insecticides is the chemo-biodiversity of plants, which provides a variety of bioactive compounds against pests and significantly reduces the selection of resistant ones (PAVELA, 2009; PINO; SÁNCHEZ; ROJAS, 2013). The insecticidal activity of COR can be attributed to several identified chemical constituents, which belong to monoterpene, sesquiterpene, and diterpene classes (GERIS et al., 2008; LEANDRO et al., 2012).

*XDYDZHHYLOConotrachelus psidii Marshall (Coleopera: Curculionidae). This is a major pest of guava in certain areas in Brazil. Females lay eggs in immature fruit (3-4 cm diameter) and larvae progress through four instars as the fruit develops. Infestation leads to acceleration in fruit maturation and fruit drop when ripe. At this moment, larvae crawl into the soil where they develop into prepupae. Individuals may remain in this stage for up to six months before pupation and development into the adult (Boscán de Martinez & Cásares 1982, Bailez et al. 2003). Control methods involve weekly applications of insecticides to suppress adults, but most of those currently in use for guava weevil control will be discontinued soon (Souza et al. 2003, Agência Nacional de Vigilância Sanitária 2004). Without chemical control, the percentage of damaged fruit in heavily infested orchards can reach 100% (Bóscan de Martinez & Cásares 1980). The amount of fruit attacked has been increasing over the past three years possibly due to the development of insecticide resistance (reference?). Poorly timed chemical applications and the tendency for adult weevils to hide in the litter around trees and avoid contact with the chemicals could also be involved (Denholm & Rolland 1992).

The efficacy of Entrust ® to control S. exigua by contact (glass-vial) or ingestion (diet incorporation) agrees with the fact that it reduced infestations of lepidopteran pests of cole crops Plutella xylostella (L.), Pieris rapae (L.), and Trichoplusia ni (Hübner) in Alabama (Maxwell and Fadamiro, 2006). The Entrust ® has broad-spectrum activity, multiple modes of entry and residual effect and its active ingredient, spinosad, is a contact and stomach poison (Liu et al., 1999; Balusu and Fadamiro, 2012). However, the selectivity of Entrust ® to non- target species is arguable because it showed higher toxicity to P. maculiventris by ingestion in contaminated water than by contact to its residues on the glass- vial. The effect of spinosad on predators has been reported and 71% of the studies reviewed indicated lethal effect under laboratory conditions (Biondi et al., 2012). In addition, predatory stinkbugs can present insecticide irritability (i.e., avoidance after contact) to spinosad, what can increase its survival (De Castro et al., 2013).

Santa Catarina, Paraíba, Pernambuco and Minas Gerais). Studies on Trichogramma have to focus on collection, identification and maintenance of Trichogramma strains; selection of factitious hosts for mass rearing of parasitoids; biological and behavioral aspects of trichogramma spp.; egg dynamics of target pests, parasitoid release; numbers, places, seasons and ways; selectivity of agrochemicals; efficiency evaluation and pest/parasitoid simulation model (Parra & Zucchi, 2004). However, except for some cases, like the use of T. pretiosum to control Tuta absoluta (Lepidoptera: Gelechiidae), the releases on cotton by Embrapa Algo- dão, in Paraíba State, the sporadic use of T. atopovirilia and T. pretiosum to control Spodoptera frugiperda (Lepidoptera: Noctuidae) in corn and Plutella xylostella (Lepidoptera: Plutellidae) in cabbage, the project has not reached large areas, due to the difficulty in transferring the technology, and particularly the lack of good quality insects available for the farmer. The volume of information and results are very interesting and liable to be used in crops such as cotton, soybean, sugarcane, tomato and other vegetables, corn, stored grain pests, etc. In addition, Garcia (1998) and Molina (2003) demonstrated the potential of use of T. pretiosum in citrus to control Ecdytolopha aurantiana (Lepidoptera: Tortricidae), the citrus fruit borer; in avocado, the parasitoid is being studied to control (Lepidoptera: Elachistidae) (Hohmann & Meneguim 1993); in agricultural crops, T. pretiosum, T. atopovirilia, and T. galloi have shown the greatest potential for use in Brazil (Parra & Zucchi, 2004).

The screening of Bacillus thuringiensis (Bt) Cry proteins with high potential to control insect pests has been the goal of numerous research groups. In this study, we evaluated six monogenic Bt strains (Bt dendrolimus HD-37, Bt kurstaki HD-1, Bt kurstaki HD-73, Bt thuringiensis 4412, Bt kurstaki NRD-12 and Bt entomocidus 60.5, which codify the cry1Aa, cry1Ab, cry1Ac, cry1Ba, cry1C, cry2A genes respectively) as potential insecticides for the most important insect pests of irrigated rice: Spodoptera frugiperda, Diatraea saccharalis, Oryzophagus oryzae, Oebalus poecilus and Tibraca limbativentris. We also analyzed their compatibility with chemical insecticides (thiamethoxam, labdacyhalothrin, malathion and fipronil), which are extensively used in rice crops. The bioassay results showed that Bt thuringiensis 4412 and Bt entomocidus 60.5 were the most toxic for the lepidopterans, with a 93% and 82% mortality rate for S. frugiperda and D. saccharalis, respectively. For O. oryzae, the Bt kurstaki NRD-12 (64%) and Bt dendrolimus HD-37 (62%) strains were the most toxic. The Bt dendrolimus HD-37 strain also caused high mortality (82%) to O. poecilus, however the strains assessed to T. limbativentris caused a maximum rate of 5%. The assays for the Bt strains interaction with insecticides revealed the compatibility of the six strains with the four insecticides tested. The results from this study showed the high potential of cry1Aa and cry1Ba genes for genetic engineering of rice plants or the strains to biopesticide formulations.