Effects of insecticides used in corn on immature stages of trichogramma atopovirilia (hymenoptera: trichogrammatidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Application of nanotechnology for the encapsulation of botanical insecticides for sustainable agriculture: Prospects and promises

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chronic motor neuron disease possibly related to intoxication with organochlorine insecticides

We report on two patients with a history of chronic exposure to organochlorine insecticides who developed clinical and electromyographic signs and symptoms of chronic motor neuron disease. Measurements of aldrin, lindane and heptachlor confirmed the intoxication. We emphasize the importance of searching for toxic and environmental factors in cases of motor neuron disease especially in Third World countries, where workers usually wear no adequate protective equipment.

Toxic heritage: maternal transfer of pyrethroid insecticides and sunscreen agents in dolphins from Brazil

Pyrethroids (PYR) and UV filters (UVF) were investigated in tissues of paired mother-fetus dolphins from Brazilian coast in order to investigate the possibility of maternal transfer of these emerging contaminants. Comparison of PYR and UVF concentrations in maternal and fetal blubber revealed Franciscana transferred efficiently both contaminants to fetuses (F/M > 1) and Guiana dolphin transferred efficiently PYR to fetuses (F/M > 1) different than UVF (F/M < 1). PYR and UVF concentrations in fetuses were the highest-ever reported in biota (up to 6640 and 11,530 ng/g lw, respectively). Muscle was the organ with the highest PYR and UVF concentrations (p < 0.001), suggesting that these two classes of emerging contaminants may have more affinity for proteins than for lipids. The high PYR and UVF concentrations found in fetuses demonstrate these compounds are efficiently transferred through placenta. This study is the first to report maternal transfer of pyrethroids and UV filters in marine mammals.

Compatibility of Beauveria bassiana commercial isolate with botanical insecticides utilized in organic crops in southern Brazil

Products based on botanical insecticides and entomopathogenic fungi have been widely used in organic farming, especially in southern Brazil. Thus, this study investigated, in vitro, the effect of aqueous extracts and commercial formulations of plants with insecticidal activity on Beauveria bassiana. The treatments comprised the botanical insecticides Neempro (azadiractin +3-tigloylazadirachtol), at the concentrations of 0.25, 0.5, 0.75, and 1.0% (v/v), and DalNeem (neem oil emulsifiable), at 0.5, 1.0, 1.5, and 2.0% (v/v) (both commercial formulations of Azadirachta indica (neem)), and the aqueous extracts, at the concentrations of 2.5, 5.0, 7.5, and 10.0% (w/v), of neem seeds, tobacco powder (Nicotiana tabacum), and catigua leaves (Trichilia clausenii). In potato, dextrose, and agar culture medium, the effects of each product on the mycelial growth and the production and viability of conidia of B. bassiana were estimated. According to the adopted compatibility index, the aqueous extracts of neem seeds and leaves catigua, depending on the concentration used, and the botanical insecticide Neempro, were classified as compatible with the entomopathogen, becoming important alternatives to integrate programmes of integrated pest management, especially in organic farming systems.

Effect of contact and systemic insecticides on the sharpshooter Bucephalogonia xanthophis (Hemiptera: cicadellidae), a vector of Xylella fastidiosa in citrus

The knockdown and toxic effects of insecticides of different chemical groups and modes of action registered for citrus in Brazil were investigated for effective control of Bucephalogonia xanthophis, a sharpshooter vector of Xylella fastidiosa in citrus. The active ingredients dimethoate (1.2 mL/1.2L), imidacloprid (0.24 mL/1.2L) and lambda-cyhalothrin (0.24 mL/1.2L), as well as a control (water), were sprayed onto branches of potted-citrus nursery trees to evaluate the effect of residual contact. The insects were confined on sprayed branches by using sleeve cages, in groups of 10 per branch (5 branches/treatment). Lambdacyhalothrin showed a knockdown effect on B. xanthophis (>70% mortality within 2 h of exposure), and the residues were effective for approximately one wk. Imidacloprid, lambdacyhalothrin and dimethoate suppressed the vector populations for up to 3 wk after application, when the insects were exposed to sprayed plants for at least 24 h. In another experiment, 2 neonicotinoid insecticides (thiamethoxam and imidacloprid) were applied by soil drench to potted nursery trees, in order to study their systemic effect, i.e., mortality by ingestion on sharpshooter adults. Thiamethoxam and imidacloprid effectively controlled the vectors at all concentrations tested, when the insects were exposed to treated plants for 24 h (>80% mortality) or 48 h (near 100% mortality). The knockdown effect of thiamethoxam and lambda-cyhalothrin might be particularly important to prevent vector transmission of X. fastidiosa in citrus groves.

Neonicotinoid insecticides severely affect honey bee queens

Queen health is crucial to colony survival of social bees. Recently, queen failure has been proposed to be a major driver of managed honey bee colony losses, yet few data exist concerning effects of environmental stressors on queens. Here we demonstrate for the first time that exposure to field realistic concentrations of neonicotinoid pesticides during development can severely affect queens of western honey bees (Apis mellifera). In pesticide-exposed queens, reproductive anatomy (ovaries) and physiology (spermathecal-stored sperm quality and quantity), rather than flight behaviour, were compromised and likely corresponded to reduced queen success (alive and producing worker offspring). This study highlights the detriments of neonicotinoids to queens of environmentally and economically important social bees, and further strengthens the need for stringent risk assessments to safeguard biodiversity and ecosystem services that are vulnerable to these substances.

A DERMATOLOGICAL EVALUATION OF SYNTHETIC PYRETHROID INSECTICIDES (PARESTHESIA, FENVALERATE, PERMETHRIN)

In this investigation, differences in parasthesia were detected by human participants between synthetic pyrethroids with a cyano group in the (S)-configuration of the 3-phenoxybenzyl alcohol of their molecular structure (fenvalerate) and those that do not (permethrin). A strong relationship was noted between insecticidal potency and degree of induced cutaneous sensation for the alpha-cyano and non-cyano pyrethroids, with a prominent difference between the two. A linear correlation between concentration and degree of induced dysesthesia was observed for both pyrethroids. Regressing the cutaneous sensation on the common logarithm of concentration resulted in a regression equation of Y = 84.0 + 31.0X(,1) for fenvalerate and Y = 27.5 + 15.8X(,1) for permethrin. An evaluation for dermal cytotoxicity in albino rabbits yielded a slight increase in cutaneous perfusion as indicated both visually and by laser Doppler velocimetry. However, no significant difference was detected in edema or thermal variation. Histopathological alterations were minimal after repeated daily applications with the majority of changes involving acanthosis. A highly efficacious therapeutic agent for pyrethroid exposure was noted to be dl-alpha tocopherol acetate. An impressive degree of inhibition of parasthesia resulted from the topical application of vitamin E acetate, with a therapeutic index of almost 100%. ^

Evaluation of Bt and Non-Bt Corn with and without Soil Insecticides for Control of Corn Rootworm

The purpose of this study was to evaluate the effectiveness of Bt corn and soil insecticides, either alone or in combination, for the control of corn rootworm. Evaluation of Bt hybrids included SmartStax, SmartStax with refuge in a bag, and Herculex XTRA. Soil insecticides evaluated were SmartChoice-SB, Counter-SB, Aztec, and Force.

Evaluation of Foliar Fungicides and Insecticides on Soybean

Use of foliar fungicides and insecticides are an effective strategy for managing foliar diseases on soybean. There are many different fungicides and insecticides available for use currently in Iowa. Iowa State University personnel assessed the success of fungicides and insecticides across Iowa. This study was conducted at six locations: Sutherland (NW), Kanawha (NC), Nashua (NE), Ames (central), Crawfordsville (SE), and Lewis (SW) research farms (Figure 1).

Evaluation of Foliar Fungicides and Insecticides on Soybeans

Use of foliar fungicides and insecticides are an effective strategy for managing foliar diseases of soybean. There are many different fungicides and insecticides available for use currently in Iowa. Iowa State University personnel assessed the success of fungicides and insecticides across Iowa. This study was conducted at six locations: Sutherland (NW), Kanawha (NC), Nashua (NE), Ames (central), Crawfordsville (SE), and Lewis (SW) research farms (Figure 1).

Evaluation of Bt and Non-Bt Corn with and without Soil Insecticides for Control of Corn Rootworm

The purpose of this study was to evaluate the effectiveness of Bt corn and soil insecticides, either alone or in combination, for the control of corn rootworm. Evaluation of Bt hybrids included SmartStax, SmartStax with a blended refuge (refuge in the bag), and Herculex XTRA. Soil insecticides evaluated were SmartChoice-SB, Counter-SB, Aztec, and Force.

Evaluation of Foliar Fungicides and Insecticides on Soybeans

Use of foliar fungicides and insecticides are an effective strategy for managing foliar diseases of soybean. There are many different fungicides and insecticides available for use currently in Iowa. Iowa State University personnel assessed the success of fungicides and insecticides across Iowa. This study was conducted at six locations: Sutherland (NW), Kanawha (NC), Nashua (NE), Ames (central), Crawfordsville (SE), and Lewis (SW) research farms (Figure 1).

Evaluation of Foliar Fungicides and Insecticides on Soybeans

Use of foliar fungicides and insecticides are an effective strategy for managing foliar diseases of soybean. There are many different fungicides and insecticides available for use currently in Iowa. Iowa State University personnel assessed the success of fungicides and insecticides across Iowa. This study was conducted at six locations: Sutherland (NW), Kanawha (NC), Nashua (NE), Ames (central), Crawfordsville (SE), and Lewis (SW) research farms (Figure 1).