<p><strong>Background.</strong> Plant powders are ecological agents for pest management in grains stored by small-scale farmers. <strong>Objective.</strong> This study was conducted to evaluate the effects of plant powders of leaves of basil (<em>Ocimum</em> <em>basilicum</em>), spearmint (<em>Mentha spicata</em>), wormseed (<em>Chenopodium ambrosioides</em>) and rue (<em>Ruta graveolens</em>) on the mortality, repellency and infestation of <em>Zabrotes subfasciatus</em> in stored grains of <em>Phaseolus lunatus</em>. <strong>Methodology. </strong>The plant powders were applied at concentration of 1% (weight/weight) to grain samples stored in plastic containers and subsequently the grains were infested with <em>Z. subfasciatus</em> adults. <strong>Results.</strong> The powder of <em>C. ambrosioides</em> caused 96% and 100% mortality in <em>Z. subfaciatus</em> adults at 2 and 4 days after exposure, respectively. The powder of <em>C. ambrosioides</em> caused a decrease in oviposition and progeny production.  The powder of <em>C. ambrosioides</em> completely prevented the damage to the grain. Plant powders of the other species had minimal repellent effects.<strong> Implication.</strong> Plant powders represent a feasible alternative to manage pest insects of stored grain. <strong>Conclusion.</strong> The powder of <em>C. ambrosioides</em> prevents damage by <em>Z. subfasciatus</em> in stored grains of<em> P. lunatus</em>.</p>

<p><strong>Background.</strong> The use of biostimulants is an alternative to improve the growth and productivity of horticultural crops. <strong>Objective.</strong> To evaluate the effect of three biostimulants (seaweed extracts, humic acids and amino acids) on the plant growth, foliar characteristics, and population density of <em>Bemisia tabaci</em> in habanero pepper plants (<em>Capsicum chinense</em>). <strong>Methodology.</strong> The biostimulants were applied to the plant growth substrate in seedling and in pot plants. The response variables were plant growth, leaf thickness and toughness, leaf area and population density of <em>B. tabaci</em>. <strong>Results.</strong> Humic acids promoted the number of leaves and stem thickness in seedlings. The thickness of the leaves was stimulated by seaweed extract and humic acids and the leaf area by amino acids. The biostimulants had no effect on the response of the plants to the population density of <em>B. tabaci</em>. <strong>Implication.</strong> The use of biostimulants in habanero pepper plants could enhance plant growth in specific growth phases. <strong>Conclusion.</strong> The use of biostimulants in habanero pepper plants did not show consistent effects on plant growth promotion in habanero pepper. There were no effects of the biostimulants on the induction of plant defense to <em>B. tabaci</em> in habanero pepper. </p>

Insecticides used in agricultural pest management pose survival risks to the stingless bees that forage on crops in tropical and subtropical regions. In the present study, we evaluated, under laboratory conditions, the acute oral toxicity of five selected insecticides (dinotefuran, imidacloprid, flupyradifurone, spirotetramat, and cyantraniliprole) to two species of neotropical stingless bees: Nannotrigona perilampoides and Frieseomelitta nigra. At field recommended doses, dinotefuran, imidacloprid, and flupyradifurone caused the highest mortality in both bee species. These insecticides also caused the largest decrease in the survival rate when exposed to a 10-fold dilution of the field recommended doses. Notably, dinotefuran exerted a high effect even at 100-fold dilution (100% mortality). In contrast, cyantraniliprole had a low effect and spirotetramat was virtually nontoxic. These results suggest that some insecticides used to control sap-sucking insects may have a significant negative impact on the communities of stingless bees.

<p><strong>Background.</strong> The whitefly <em>Bemisia tabaci</em> (Gennadius, 1889) (Hemiptera: Aleyrodidae) is a pest that causes significant losses in field and greenhouse crops worldwide. <strong>Objective.</strong> To evaluate the incorporation of biorational and chemical insecticides on the population density of whitefly <em>Bemisia tabaci</em>, fruit yield and fruit quality in tomato. <strong>Methodology. </strong>Three pest management treatments were included: Biorational (botanical insecticides and insect growth regulators), Biorational-Intermediate (botanical insecticide and chemical insecticides) and Conventional (conventional chemical insecticides). <strong>Results. </strong>Overall, the population density of <em>B. tabaci</em> was low from the time when the pest-exclusion floating net was removed to the sampling periods 61 to 78 days after transplant (dat). However from 92 to 108 dat, the population density of inmature and adults increased dramatically. The treatment Conventional was the most effective to supress the population density of <em>B. tabaci</em> when they were low, but when an increase in population density of <em>B. tabaci</em> ocurred, the treatment Biorational-Intermediate was the most effective. The population density of eggs and nymphs on plant leaves were similar among treatments. The fruit yield and overall the bromatologic characteristics of fruits were not significantly different among treatments. <strong>Conclusion. </strong>The treatment Biorational-Intermediate would represent a feasible strategy to manage <em>Bemisia tabaci</em> in tomato crops.</p>