No abstract

C. Pino, G. Silva, R. Hepp, and F. Venegas. 2007. Effi cacy of Peak Plus ® against Caliroa cerasi (Hymenoptera: Tenthredinidae). Cien. Inv. Agr. 34(1):23-29. i The pear slug (Caliroa cerasi L.) is an important pest of sweet cherries in Chile. It attacks during the harvest and can only be controlled by organosynthetic insecticides. The objective of this study was to evaluate the effect of fatty acids (Peak Plus ®) of low risk of toxicity on mammals. The mortality and median lethal concentration (LC 50) of Peak Plus ® against C. cerasi was determined under laboratory conditions using ten larvae fed on leaf disks in Petri dishes. The insecticide effi cacy and foliar damage were evaluated under fi eld conditions on sweet cherry cv. Bing. Treatments were arranged as randomized complete block design with six treatments replicated four times. The LC 50 obtained was 1.14 g•L-1 and LC 90 was 2.7 g•L-1 24 h after treatments. In the fi eld, Peak Plus ® at a concentration of 10 g•L-1 showed high effi cacy against C. cerasi, similar to the effects obtained with fenvalerate and methidathion. Peak Plus ® at the highest rate decreased foliar damage in a similar way to other insecticides currently used. Finally, we concluded that Peak Plus ® is an effi cient alternative to organosynthetic insecticides in the control of C. cerasi of sweet cherry.

The chemical and sorptive characteristics of mineral coals extracted from a mine in Lebu (Biobío Region, Chile) and its derivatives were studied. These derivatives were obtained by applying a thermal treatment in an environment with N 2 and CO 2 at different experimental conditions, in order to increase their specific surface. In addition, coals were characterized by using proximal analysis, elementary analysis and petrographic analysis. In order to know their structure and surface, Boehm titration analysis, FTIR infrared spectroscopy, X-ray diffraction and scanning electron microscopy were performed. The surface of the selected carbons was modified by selectively oxidizing it with (NH 4 ) 2 S 4 O 8 and with H 2 O 2 e impregnating with an iron solution for the study with H 2 O 2 In the oxidation of H 2 O 2 , the work was carried out at different pH. The results show a moderate homogeneity between different types of seams studied, whereas when coals are treated with heat or strong oxidants, increases its surface and can be used with analytical applications (v.g. electroanalytical sensors).