Lettuce plants, cv. Vera, were grown under five salinity levels in a hydroponical experimental set-up using a 0.15 m deep sand growing bed. A standard nutrient solution was used, with the following composition, in mmol L-1: 16.9 NO3-; 2.0 H2PO4-; 1.0 SO4- 4.0 Ca++; 10.9 K+ e 1.0 Mg++, and, in mg L-1, 0.42 Mn; 0.26 Zn; 0,05 Cu; 0,50 B; 0,04 Mo, and 4.82 chelated Fe. The five salinity levels compared as treatments were obtained by varying the concentration of the standard nutrient solution, reaching average electrical conductivities (EC) of 0.80; 1.93; 2.81; 3.73 and 4.72 dS m-1, for T1, T2, T3, T4 and T5, respectively. The nutrient solution at each salinity level was supplied from a reservoir by means of a flooded-type electrical pump, for 15 minutes, at intervals of 90 minutes during the day and 420 minutes during the night. A completely randomised experimental design was used with four replications and 20 plants per plot. Four plants of each plot were harvested at 32 days after planting, to determine shoot and root dry mass, shoot fresh weight, leaf area and number of leaves per plant. Number of leaves was 18 per plant and was not affected by treatments. Dry mass of leaves increased 24,4% from T1 to T3. No relationships were found on data from stem and root dry mass. A positive effect of EC was recorded on shoot fresh mass, which increased 28.5% from T1 to T2, and decreased 16.5% from T2 to T5. Maximum LAI estimated value was 4.3 m² m-2 for an EC of 2.6 dS m-1. Salinity levels above 2.0 and 2.6 dS m-1 reduce fresh yield and plant growth, respectively.

The adoption of integrated pest management (IPM) in soybean is a great example of how this technology is essential to guarantee crop sustainability and productivity. In Brazil, up to 1970, soybean was cultivated with the use of pesticides applied without the adoption of any economic threshold to base this decision. As a consequence, a six-insecticide spraying per crop season used to be the average insecticide dosage. With the introduction of Soybean-IPM, the use of pesticides was reduced to approximately two applications per season. Comparing these two contrasting situations, the advantages of using IPM methods cannot be ignored, since they are economically and mostly environmentally feasible. Despite the benefits provided by Soybean- -IPM, this program was abandoned in Brazil, and its principles were almost forgotten, and, as a consequence, insecticide use increased. The success and failures of Soybean-IPM in Brazil will be further analyzed in this review in an attempt to point out how safe this technology is and whether there is any risk in fully adopting this approach.

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Egg parasitoid rearing on factitious hosts is an important step to reduce costs and increase availability of the biocontrol agent but it requires quality control to achieve success in field conditions. To this end, this study evaluated the quality of Telenomus remus (Hymenoptera: Platygastridae) reared on Corcyra cephalonica (Lepidoptera: Pyralidae) for until 45 generations. In the first bioassay, we evaluated the body size of the laboratory-produced parasitoids. In the second bioassay, flight activity was examined, measuring the percentage of 'flyers', 'walkers' and 'deformed' parasitoids. The third bioassay assessed parasitism on Spodoptera frugiperda (Lepidoptera: Noctuidae) eggs. Our data indicate that the laboratory-reared parasitoid neither lost its ability to fly nor to parasitize S. frugiperda eggs. In conclusion, quality did not decrease significantly during 45 generations, and therefore rearing of T. remus on C. cephalonica as factitious host promises to be successful.

The effects of intercropping aromatic plants (AP) on behavior and population development of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) were investigated in the field (adults) and in the greenhouse (nymphs). The responses of adults to the volatiles of tomato, Solanum lycopersicum L. (Solanaceae), plants plus AP [T + coriander (Co), rue (R), marigold (M), Greek basil (B), or citronella (Ci)] vs. humidified air or tomato volatiles only were assessed in laboratory Y-tube olfactometer assays. We found higher responses of adult B. tabaci to the humidified air than to the T + Co, T + B, and T + Ci treatments. The responses to T + R and T + M were similar to those to the humidified air. Responses to tomato volatiles were also greater than to T + Co, T + B, and T + Ci. In field assays, populations of adult insects were evaluated in tomato alone, in tomato intercropped with coriander or Greek basil, and in tomato mulched with citronella grass for 6 weeks. Adult whiteflies were generally found in greater numbers in the tomato-alone treatment compared to tomato intercropped with coriander or basil and tomato with citronella grass mulch. Reduction in adult whitefly populations compared to the population found in tomato alone was 84, 79, and 69% in intercrops of T + Co and T + B, and the tomato with citronella mulch treatment, respectively. Infestations of B. tabaci nymphs in plots of tomato plants cultivated alone or intercropped with reseeded coriander plants were also determined in a greenhouse. Nymph counts in the greenhouse assay were generally lower in tomato intercropped with coriander than in tomato alone for all six assessments. The mean reduction in nymphs in tomato intercropped with coriander was 37.7% compared with tomato alone. These results indicate that intercropping aromatic plants reduces infestations of B. tabaci.

This study aimed to evaluate the larval biology of Heliothis virescens in soybean MON 87701 x MON 89788 and its isogenic non-Bt. In general, the impact of soybean MON 87701 x MON 89788 on H. virescens was evidenced in all bioassays, 100% larval mortality, independent of the structure (leaf or pod) consumed by the pest. The small larvae (1 st and 3 rd instar) demonstrated that they were unable to damage fresh pods of soybean, regardless of whether Bt or not Bt. The large larvae (5 th instar) fed on soybean MON 87701 x MON 89788 soybeans consumed three times less compared to larvae fed on non-Bt soybeans, and resulted in reduced longevity and larval survival. When soybean plants were infested with 5 th instar larvae, H. virescens caused injuries in the steams of the conventional soybean. It was recorded that the insects moves quickly to this region of the plant. However the soybean MON 87701 x MON 89788 was an effective tool in controlling H. virescens.

Genetically modified crops with insect resistance genes from Bacillus thuringiensis Berliner (Bt-plants) are increasingly being cultivated worldwide. Therefore, it is critical to improve our knowledge of their direct or indirect impact not only on target pests but also on non-target arthropods. Hence, this study evaluates comparative leaf consumption and performance of Spodoptera eridania (Cramer), a species that is tolerant of the Cry1Ac protein, fed with Bt soybean, MON 87701×MON 89788 or its near [corrected] non-Bt isoline. Using this species as a model, we assessed [corrected] the comparative performance of the egg parasitoid Telenomus remus Nixon on eggs of S. eridania produced from individuals that fed on these two soybean genotypes [corrected] as larvae. Results showed that Bt soybean did not affect pest foliage consumption, but did reduce larvel duration by two days despite larvae in both treatments having six instars. Nevertheless, survival of S. eridania larvae, pupal weight, sex ratio, fecundity and longevity of female moths, and egg viability did not differ between Bt and non-Bt soybeans. Adult longevity of S. eridania males was increased when caterpillars were fed with Bt soybean versus the near isoline. No adverse effects of this technology were observed for the egg parasitoid T. remus. [corrected].

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