Urucunzeiro, Bixa orellana Linnaeus 1753 (Bixaceae), em cultivo orgânico: fenologia, produção de sementes, furtadores de recursos florais e polinizadores (Arthropoda: Insecta)

Abstract

The annatto production chain and the efficiency of pollinating agents for seed production represent an important economic factor for family farming. Therefore, this research aimed to evaluate the phenological and seed production aspects of annatto in natural conditions, aiming to know the groups of floral visiting and pollinating insects, besides measuring the influence of body size of bees, seeking to correlate apid species with seed production rates. The study was carried out in annatto orchard at Estancia Biocenose (22 ° 20 '88 ”S; 54 ° 92 ’70” W, part of Fazenda Coqueiro, Dourados, Mato Grosso do Sul, under organic farming system. Ten samples were taken from February and April 2018, in plots composed of 20 annatto plants (Bixa orellana). It was found that the annatto flower has a daily cycle and the average time elapsed between plant bud and flower opening is 39 days. The 20 monitored plants accounted for 3,781 inflorescences (189.05 ± 40.74 per plant). In pre-anthesis state, before the floral opening, the number of 1,480 buds was obtained (on average 74 ± 48.02 per plant). For floral buds at the development stage, a total of 295 (mean of 14.75 ± 3.48) was estimated. The capture of floral visitors occurred in the first 20 minutes of each hour, between 06:00am and 18:20 pm, during 10 consecutive days in different plants of B. orellana, with an average evaluation time of 1 minute per plant in full bloom, until the 20 minutes set for each hour. In the other 40 minutes, the behavior of floral visitors in an indeterminate number of flowers was observed, totaling 130 hours between collections and observations. Floral visitors were collected from a nylon bag (entomological network) and placed in a lethal chamber containing absorbent paper numbed with ethyl acetate. The bees were separated by size and the pollination rate of bees classified morphologically with the aid of digital paquimeter, separated according to morphological size and grouped into categories of Large mass, medium robust, Average fine mass, Medium to small mass. Floral visitors were recorded from 6 orders of insects: Hemiptera, Diptera, Coleoptera, Neuroptera, Lepidoptera and Hymenoptera. In relation to the bees, four families visited the flowers of the urucuzeiro: Andrenidae, Apidae, Colletidae and Halictidade. Hymenoptera showed the highest abundance and number of individuals (60.35%), mainly Apidae family (46,22) followed by the following orders: Coleoptera (20.64%); Diptera (12.22%); Hemiptera (6.46%); Lepidoptera (0.22%) and Neuroptera (0.11%). Significant difference was found for fruit size, weight and number of seeds among bees of small, medium and large size.