Predictive models based on diagrammatic scales of damage have been developed to estimate the population density of Aceria guerreronis, an important coconut pest. Steneotarsonemus concavuscutum colonizes the same habitat as A. guerreronis and causes similar lesions on fruits. The present study aims to evaluate the possibility of using predictive models developed for A. guerreronis to estimate S. concavuscutum populations. Fruits infested by S. concavuscutum were collected and evaluated according to the diagrammatic scales developed by Galvão et al. (2008) and by Sousa et al. (2017). All active forms of S. concavuscutum were accounted for. Graphical and statistical analyzes were performed to evaluate the adequacy of the predictive models. Both the models proved to be inadequate to estimate the population of S. concavuscutum, both statistically and graphically. New predictive models were proposed using the grades of the diagrammatic scales and the mean numbers of S. concavuscutum/fruit. To validate the models, new fruits were collected and evaluated by 10 examiners with both the diagrammatic scales. All active forms of S. concavuscutum were accounted for. The new predictive model based on the grades of Galvão et al. (2008) underestimated the populations of S. concavuscutum, while the model obtained from the grades of Sousa et al. (2017) generated values close to the expected, proving itself to be adequate statistically and graphically, to estimate the populations of S. concavuscutum.
Tarsonemids are mites that can damage coconut fruits, leading to losses in crop yield and quality. In this study, a survey of tarsonemid species and associated predatory mites underneath the perianth of coconut was carried out on palms cultivated along the coast of northeastern Brazil, and their spatial distribution was studied in one of the cultivations, on fruits of different ages, to subsidize monitoring and management of pest species. Samples of fruits of different ages were collected from cultivation sites of 9 states, with sites ranging from a few km to a maximum of 100 km apart from one another. Three coconut palms were selected from each site, collecting 10 fruits with necrotic lesions similar to those caused by Steneotarsonemus species from each palm. The mites were collected, mounted and identified. For the analysis, a re-evaluation was done of the tarsonemids collected in similar surveys for mites in general on coconut fruits, as reported previously in the literature. Subsequently, a field in Igarassu (Pernambuco, Brazil) bearing fruits with symptoms caused by Steneotarsonemus species was selected, and a total of 943 fruits from 2–8-month-old bunches were collected for mite quantification and identification. Consequently, Steneotarsonemus concavuscutum Lofego and Gondim Jr., Steneotarsonemus furcatus De Leon, and four morphospecies of Tarsonemus were found under the perianths of coconut fruits growing along the coast of northeastern Brazil. In Igarassu, the most abundant tarsonemid was S. concavuscutum, representing 98.4% of all quantified mites. Populations of S. concavuscutum were observed in all fruit bunches, regardless of age (ranging from 19 to 167 mites/fruit), with the highest numbers occurring in the 6-month-old bunches. In this same geographic location, Neoseiulus baraki (Athias-Henriot) represented 99.0% of the predaceous phytoseiid mites, with a population ranging from 0.04 to 5.3 mites/fruit that attained the highest population levels on 7-month-old fruit bunches. The N. baraki population densities were positively correlated with the mean S. concavuscutum numbers.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.