Ação de produtos fitossanitários utilizados na agricultura orgânica sobre Ascia monuste orseis (Godart, 1818) Lepidoptera: Pieridae

Abstract

The kale (Brassica oleracea var. Acephala), is an important vegetable among the hardwoods, which is attacked by many pests, especially the cabbage leafworm Ascia monuste orseis (Godart, 1818) (Lepidoptera: Pieridae), whose damage occurring directly in the consumption product. Vegetables like cabbage, are important sources of income for family farming in Brazil and can be cultivated in a traditional way or through organic production thus the objective of this study was to evaluate the effects of pesticides used in organic production system on the A. monuste orseis. For this, we used the commercial products Azamax, DalNeem and Dipel, beyond grout sulfur and Bordeaux mixture at recommended concentrations by the manufacturer carrying out tests as the insecticidal activity. The applications were made in cabbage leaf sections (4 × 5 cm) with sprayer. For assessing the effect of treatments on the development of caterpillars offered the leaf sections to first instar larvae for 24 h, after which the larvae were fed leaf sections for free treatment. To check the action of neem-based products on A. monuste orseis in different instars were offered cabbage leaf sections 24 h to sprayed caterpillars of the first, second, third, fourth and fifth instar. A test was also performed to assess the systemic effects of neem on the insect, therefore, kale plant water stress presented received two irrigations, with products based on neem leaves were cut and offered to the caterpillars that received treated leaves throughout the development. In all trials were assessed daily, mortality, duration of instars, total duration of larval, pupal weight male and female pupal with four days of age, duration and pupal viability observing the percentage of adult emergence. Products Azamax, DalNeem and Dipel showed 100% mortality of the first instar, however the grout caused little influence on the development of A. monuste orseis. When tested in different instars Products Azamax, DalNeem presented mortality in all instars tested, and for Azamax did not observe significant difference in mortality between instars, referring to TL 50 and TL 80 is observed that there is increase in time according the age of the oldest caterpillar tracks which require more time to achieve the desired mortality. When applied to soil the product Azamax, presented higher translocation capacity of the plant causing higher mortality, and prolong the larval stage and pupal derail