Cigarrinhas-das-raízes (mahanarva fimbriolata): uma revisão narrativa acerca dos aspectos de interesse da espécie e perspectivas do controle biológico

Abstract

This work sought to collect data from the literature about the root leafhopper (Mahanarva fimbriolata) in the sugarcane crop. The objective was to identify the circumstances related to the elevating incidence of the species in the crop and, presenting aspects such as its biology, distribution and damages caused to sugarcane, as well as to discuss the management strategies already reported for the pest and to discuss the main perspectives of biological control. For this, a search for reports was carried out through research platforms, using relevant keywords to the topic and selecting works from 1996 to 2022. For the item 'biological control for leafhoppers', the works were chosen from 2015 up to now to understand the recent background of the biological management of this species. It was found that until the mid-1990s, leafhoppers were considered pests of economic importance only in some plantations in the Northeast and considered of minor importance in the state of São Paulo (SP). As a result of the increased incidence in sugarcane harvesting areas without burning (raw cane) in SP and other regions of the Center-South of the country, M. fimbriolata populations have been increasing and causing significant damage to the crop. The losses caused in the productivity of the sugarcane field and in the industrial performance occur by the reduction of the photosynthetic capacity and the quality of the raw material resulting from the way of feeding this species. Nymphs suck sap from the roots causing damage to xylem vessels and preventing the flow of water and nutrients, while adults feed by sucking sap from leaves and, injecting toxins during this process. Its occurrence is significantly influenced by climatic conditions, with higher populations being observed in the rainy season and egg diapause in dry conditions. Authors indicate that species control can reach efficient levels if different strategies are combined, such as chemical and biological control linked to the use of less susceptible varieties and straw management. Studies related to the response of sugarcane genotypes to the attack of leafhoppers showed that the cultivars RB925211, RB867515, IACSP01-5503, CTC 9004 and IM76-229 were more tolerant to the damage caused or less attractive to insects. Regarding the straw management, studies showed a reduction in root leafhopper infestation when straw was removed from the sugarcane field. Concerning the biological control of M. fimbriolata, in the last 7 years, scientific production has focused on elucidating the use of Metarhizium anisopliae and has shown excellent percentages of insect infection, as well as their mortality. Authors recommend that chemical insecticides be adopted in contexts of high population, while M. anisoplae should be used in populations within the level of biological control so that the root spittlebug can be controlled without causing economic damage to the crop.