Faunistic analysis and seasonal fluctuation of ladybeetles in an agro-ecological system installed for organic vegetable production

Plans for an agro-ecological system for agricultural production must consider vegetal diversification in agricultural properties because, among other advantages, it can help the biological control of pests when it focuses on such an end. Predator ladybeetles (Coleoptera: Coccinellidae) can be found in different environments; they play an important role in biological control. The aims of the present study were to feature ladybeetle populations through faunistic analysis and determine their fluctuations in an agro-ecological system comprising seven sub-systems subjected to different cultivation systems in Seropédica County, RJ. The experiment was conducted from December/2018 to December/2019 at Módulo de Cultivo Orgânico Intensivo de Hortaliças (MCOIH), which is located at Sistema Integrado de Produção Agroecológica (SIPA). In total, 1,231 adult ladybeetles were captured, distributed into 13 species, 3 genera and 2 tribes of Coccinellidae, which resulted in S (taxon richness) = 19, Shannon-Wiener diversity index (H') = 0.65 (at 0 to 1 scale) and Margalef diversity index (α) = 2.53 (values lower than 2.0 represent low diversity sites). Equitability was low (E = 0.22), since one of the ladybeetle species has prevailed: Cycloneda sanguinea (most frequent, dominating and constant) in MCOIH, as well as in each of the sub-systems. However, the simplest sub-systems installed for vegetable production (monoculture gardens) were not favorable for ladybeetle diversity, whereas sub-systems installed for polyculture of leafy vegetables recorded the greatest taxa diversity of ladybeetles, including species that predate in aphids that attack vegetables [Coleomegilla maculata, Coleomegilla quadrifasciata, Cycloneda sanguinea, Eriopis connexa, Harmonia axyridis, Hippodamia convergens and Hyperaspis (Hyperaspis) festiva]. The sub-system comprising gliricidia was used to produce fertilization biomass and favored the predominance of C. sanguinea in comparison to the other ladybeetle species in MCOIH. Spring was the season mostly favoring the occurrence of C. sanguinea and H. convergens adults; which were dominant species in ladybeetle assemblage in MCOIH; however, C. sanguinea was constant and H. convergens was accessory.

Propuesta de unos principios generales para la ciencia de la agroecología: una reflexión / Proposal of some general principles for the science of agroecology: a reflection / Proposta de princípios gerais para a ciência da agroecologia: uma reflexão

Resumen Diversos autores han presentado a la agroecología como una ciencia que se funda en principios. No obstante, no existe un consenso alrededor de cuáles son y algunos de los que son formulados no se corresponden con lo que es un principio científico, mientras otros no están redactados de manera adecuada impidiendo determinar de manera clara cuáles son los presupuestos básicos a partir de los cuales se estructura toda la teoría agroecología. Por este motivo, se realizó una revisión crítica de los diversos principios que se han planteado en la teoría y se formularon siete principios generales que pueden operar como un centro firme que permita avanzar en la consolidación de la agroecología.

Palabras clave: Sostenibilidad agraria, biomímesis, principios agroecológicos, biodiversidad

Abstract Several authors have presented agroecology as a science based on principles. However, there is not agreement on what are the basic principles of agroecology. Also, some of the principles have been formulated in a way that does not correspond to what a scientific principle is. For this reason, a critical review of theoretical literature was conducted in order to establish the basic principles of agroecology. Seven principles that can work as hard core of theory of agroecology.

Resumo Vários autores apresentaram agroecologia como uma ciência baseada em princípios. No entanto, não há consenso em torno do que são e alguns dos que são formulados não correspondem ao que é um princípio científico, enquanto outros não são elaborados de forma adequada, evitando a determinação clara dos orçamentos básicos com base em que é estruturada toda a teoria da agroecologia. Por esta razão, foi feita uma revisão crítica dos vários princípios que foram levantados na teoria e foram formulados sete princípios gerais que podem funcionar como um centro firme que permite o progresso na consolidação da agroecologia.