Ocorrência de coccinelídeos (COLEOPTERA: COCCINELLIDAE) em pomares citrícolas (Citrus sp.), orgânico e convencional, no centro-oeste de Santa Catarina

Abstract

Coccinellids are round- to oval-bodied insects with a body length ranging from 0.8 to 18mm. They have elytra that cover the whole extension of their body with the presence or absence of fine hair. These insects belong to the family Coccinellidae and are considered one of the more important families within this Order due to their high predatory feeding habit, which is based on the consumption of aphids, scales, aunts, extrafloral nectaries, leaves, among others, raising the importance of their use as biological control agents. In Brazil, and all over the world, citrus production has been suffering with pest attacks, which cause great economic losses, decreasing the productivity of the culture and exacerbating the unconscious usage of pesticides. The objective with this work was to identify and assess the species of coccinellids present in orchards, organic and conventional, located in the Central-west region of Santa Catarina, Brazil, aiming at understanding the feeding habits, the diversity, richness, evenness of theses species as well as their similarity in abundance. Samplings were carried out between march 13th, and june 18th, 2016 in Chapecó – SC (conventional orchard) and Xaxim – SC (organic orchard). Both groves had a similar altitude (~580 m) and area (4.0 and 4.3 hectares for the conventional and organic orchards, respectively) and were separated by a linear distance of ~25 km. Yellow sticky-cards containing entomological glue in both sides were used for the samplings. A sampling pressure of 1:570m2 was used in this work. The cards were placed 1.5 meters high using the branches of the trees for their positioning. Exchange of cards happened every 14 days. The specimens collected were prepared and sent to the Federal University of Paraná to be identified up to the taxon of species, when possible. A total of 291 specimens were collected, 48.80%, 14.13% and 36.77% were identified up to their taxon, genus and tribe, respectively. Of all the identified specimens 61.17% had feeding habits based on the consumption of aphids and scales. The organic orchard presented 54.29% of all the sampled coccinellids, had a richness and diversity 20.0% and 18.86% greater than that found in the conventional orchard, respectively. The organic orchard tends to present a greater richness, abundance, evenness and diversity of species when compared to the conventional one, however, they present themselves statistically similar according to ANOVA (P = 0.5694)