Spatial distribution and sampling plan of the phytophagous stink bug complex in different soybean production systems

Abstract

Phytophagous stink bugs are major soybean pests, and knowledge of spatial distribution models of the pest in the crop is fundamental to establishing an appropriate sequential sampling plan, and thus, allowing the correct utilization of control strategies. This work aimed to study the spatial distribution of phytophagous stink bugs in soybean grown in different cropping systems and determine a sequential sampling plan. The experiment was conducted in Maracaju, MS, Brazil, during the agricultural year of 2012/2013. Soybean cultivars BRS 284 and SYN 1163 RR were placed in an experimental area comprising six fields (two soybean cultivars × three cropping systems). Sampling was performed weekly, using a beat cloth per plot and counting the number of stink bugs found, virtually throughout the soybean reproductive period. Concerning the statistical analyses, we used the dispersion indexes (variance‐to‐mean ratio, Morisita's index, exponent k of the negative binomial and Green's coefficient) and probabilistic methods of frequency adjustment (negative binomial and Poisson). Adult and nymph phytophagous stink bugs showed aggregate disposition in the field regardless of the cropping system, and their numbers were adjusted to the negative binomial probability distribution. There was no difference in the behaviour of adult and nymphs considering the tested cultivars. We elaborated a practical sequential sampling plan for phytophagous stink bug complexes, considering crops intended for the production of grains and seeds.

Temporal variation and spatial distribution of the pest insect Edessa meditabunda in cotton (Gossypium hirsutum) as an alternative host plant

“…On the other hand, according to the same authors, a movement of E. heros adults toward an aggregate distribution was observed based on the k index throughout its occurrence in cotton, corroborating this study on E. meditabunda. Fernandes et al, (2018) reported similar results for adults and the total population (nymphs + adults) of phytophagous stink bugs in soybean, where a strong aggregation of these insects was observed, regardless of the variety and system of soybean production. Also, based on the k index, the distribution of nymphs was aggregate in most evaluations.…”

“…The aggregation indices used to verify the degree of aggregation of the E. meditabunda were: variance/mean ratio and the Morisita and K indexes (Fernandes et al, 2018), while the theoretical frequency distributions used do evaluate the spatial distribution were: Poisson and negative binomial distributions, according to the methodology reported by Fonseca et al (2017).…”

“…We do not have studies examining the temporal and spatial distribution of E. meditabunda in cotton, with most of the available information on its distribution in soybean (Fonseca et al, 2017 andFernandes et al, 2018). Therefore, the present study aimed to examine the temporal variation and horizontal spatial distribution of E. meditabunda in cotton.…”

“…Reliable sampling is therefore needed to determine the population density of this pest as well as to assess damage intensity over time to improve sustainable pest management in cotton (Farias et al, 2001). Characterizing the spatial distribution of E. meditabunda is the first step to establish sampling plans, aimed at reducing sampling time, increasing the reliability of results (Grigolli et al, 2012), and accurately describing the occurrence of this pest in the field (Fernandes et al, 2018).…”

Assessment of Injury by Four Major Pests in Soybean Plants Using Hyperspectral Proximal Imaging

“…Outbreaks of the main soybean pests occur in nonuniform spatial distributions [20]. The spatial distribution is characterized as aggregating for species of the complex of defoliating caterpillars [37,38] and stink bugs [39,40]. In addition, pest inspection using beat-cloth is still currently being used as a traditional sampling method in soybean crops.…”