2020-08-09
Silva, Roberto Balbino da, Souza Junior, Silvio Lisboa de, Silva, Allef de Souza, Salustino, Angélica da Silva, Batista, Jacinto de Luna, Oliveira, Robério de, Malaquias, José Bruno
Silva, Roberto Balbino Da ; Souza Junior, Silvio Lisboa De ; Silva, Allef De Souza ; Salustino, Angélica Da Silva ; Batista, Jacinto De Luna ; Oliveira, Robério De ; Malaquias, José Bruno ; ABSTRACT Diatraea impersonatella (Walker, 1863) (Lepidoptera: Crambidae) is a key pest of sugarcane in Northeastern Brazil, yet information on its relationship with plant age and varietal traits remains scarce. This study evaluated the interaction among D. impersonatella infestation, sugarcane varieties (RB 92-579, RB 04-1443, and RB 86-7515), and plant age (45, 70, 130, and 200 days after planting) on agroindustrial characteristics. The experiment was conducted under field conditions in six municipalities of Paraíba State, with 144 plots selected for uniform soil and planting conditions. Infestation levels were assessed through visual diagnosis of bored stalks, while agroindustrial analyses (BRIX, POL, PURITY, FIBER, ATR, and PBU) followed standardized methodologies. Data were analyzed using generalized linear mixed models, principal component analysis, and non-parametric bootstrap. All tested varieties were infested, with RB 92-579 showing the highest susceptibility, especially as plant age increased, and exhibiting elevated Brix, purity, and POL levels. Conversely, RB 86-7515 showed a decreasing trend in infestation with plant age, lower Brix, higher PBU and fiber content, and POL, purity, and fiber values similar to RB 04-1443 but lower than RB 92-579. This study concludes that RB 92-579 is the most susceptible to D. impersonatella, with infestation clearly related to plant age and varietal traits. These findings provide reliable field-based insights for improving integrated pest management strategies in Northeastern Brazil’s sugarcane cultivation.
2020-08-09
Sorensen, Sofia, Urso, Maria Virginia
Sorensen, Sofia ; Urso, Maria Virginia ; ABSTRACT Studies on entomogenous galls in the Brazilian savannah of the State of São Paulo are very scarce, and the diversity of gall-forming insects in these areas is barely known. The Ecological Station of Jataí (ESJataí), located in Luiz Antônio, is the largest protect area of Cerrado in the state of São Paulo, Brazil, covering 9,074 hectares. This study builds on the 2012 survey of entomogenous galls, extending it to new areas and phytophysiognomies within the ESJataí. A total of 103 gall morphotypes were identified on 47 plant species belonging to 22 families in these new samples. The results showed that only ten host plant species and ten morphotypes were present in both surveys. Another difference from the previous study are that Fabaceae (N=33), rather than Annonaceae (N=10), presented the highest richness of gall morphotypes and the super-host plant species is Copaifera langsdorffii Desf. (Fabaceae) (N=15) instead of Byrsonima cf intermedia A. Juss. (Malpighiaceae) (N=6). Duguetia furfuracea (A. St.-Hil.) Saff. (Annonaceae) was found to be a super-host species in both surveys (N=5 in 2012 and N=9 in 2024). The associated fauna is composed of four guilds, inducers (N=17), parasitoids (N=25), inquilines (N=4), and successors (N=17). Most of the gall-inducing insects belonged to the Cecidomyiidae family (Diptera) (N=17), with Clinodiplosis bellum Urso-Guimarães and Carmo-Neto, 2015, Alycaulus hexadentatus Urso-Guimarães, 2018, and Lopesia curupirae Urso-Guimarães, Garcia and Ospina, 2024 reported for the first time to this area.
2020-08-09
Avellar, Guilherme Souza de, Marriel, Ivanildo Evódio, Santos, Nathan Moreira dos, Ferreira, Alef Vilela, Santos, Douglas Graciel dos, Mendes, Simone Martins
Avellar, Guilherme Souza De ; Marriel, Ivanildo Evódio ; Santos, Nathan Moreira Dos ; Ferreira, Alef Vilela ; Santos, Douglas Graciel Dos ; Mendes, Simone Martins ; ABSTRACT Forage sorghum, valued for its high protein content and resilience to abiotic stress, is key component in livestock feed production. However, it faces challenges from various insect pests such as aphids, fall armyworms, and sugarcane borers. This study investigated insect dynamics, focusing on Melanaphis sorghi, and their interactions with natural enemies, weather patterns, and other pests in forage sorghum cultivation. Conducted over two seasons crop in Brazil, the research compared plots with and without insecticide treatment, employing weekly insect sampling and climate monitoring. Our findings revealed M. sorghi as the predominant pest, with populations peaking during the vegetative stage. Correlation analysis showed a positive relationship between M. sorghi and Syrphidae predators, with weaker associations observed for Spodoptera frugiperda. The prevalence of Rhophalosiphum maidis increases in the second season, influenced by rainfall. Predatory insects like Coccinellidae and Syrphidae contribute to pest population control. Untreated areas exhibit higher diversity and equitability, indicating a balanced pest-predator ecosystem. Principal component analysis (PCA) suggested that the climate and specific pests exert an influence on treated areas, suggesting potential resistance or the need for more refined control strategies. This study underscores the importance of understanding pest dynamics for sustainable agriculture, providing valuable insights for the integrated pest management strategies to mitigate economic losses.