Field Assessment of Oryzophagus oryzae (Coleoptera: Curculionidae) Preference and Performance on Selected Rice Cultivars

Abstract

Plant resistance is a key strategy for the management of Oryzophagus oryzae (Costa Lima) (Coleoptera: Curculionidae), an important pest in South American rice paddies. The present study investigated the resistance of rice cultivars in terms of feeding and oviposition preference, growth, development, and biological performance of O. oryzae under natural conditions of field infestation during two consecutive rice seasons. There were no effects of the six cultivars on the feeding and oviposition preferences of O. oryzae as evaluated 5, 8, and 11 d After Flooding (DAF) of the plots, indicating the absence of antixenosis. Cultivars did not differ in terms of egg viability and larval density of first instars on the roots at 15 DAF. Significant differences were found 25 and 35 DAF when larval density per sample was high on ‘BRS Pampa CL’ (up to 24.5), intermediate on ‘BRS Querência’ and ‘BRS Ligeirinho’ (up to 16.1), and low on ‘BRS Atalanta’, ‘BRS Firmeza’, and ‘Dawn’ (up to 8.8). The cultivars ‘BRS Atalanta’, ‘BRS Firmeza’, and ‘Dawn’ caused malnutrition and inhibition of larval growth. These effects, typical of antibiosis, resulted in delayed pupation and emergence of adults; in addition, emerged females had body weight decreased strongly. The cultivars BRS Pampa CL, BRS Querência, and BRS Ligeirinho are susceptible, resulting in high larval populations and more suitable development of O. oryzae; antibiosis, as indicated for ‘BRS Atalanta’, ‘BRS Firmeza’, and ‘Dawn’, probably is the key mechanism of rice resistance to O. oryzae.

Differential response to the South American rice water weevil (Coleoptera: Curculionidae) damage of rice cultivars with contrasting levels of resistance: implications for field management

“…Levels of economic damage and control have been widely employed in IPM programs to instruct farmers on the most appropriate time to use control measures to prevent a growing arthropod population from causing significant yield losses 46,47 . From the consistent results of this direct field experiment study, rice plants of the cvs BRS Pampa CL, with RWW‐susceptible reaction, 26 and BRS Atalanta, with RWW‐resistant (antibiosis) reaction, 25,26 can tolerate ≤10.83 and 9.80 larvae per plant, respectively. These tolerance levels were determined according to Seinhorst's nonlinear regression model T parameter, 9 used in previous studies to assess the tolerance of plants to root pests 48–51 …”

“…26 Cultivar BRS Atalanta (Embrapa) was included in the present study, only in the 2018/19 season, as a standard of resistance to O. oryzae 19,25,34,35 of the antibiosis type on larvae. 26 BRS Atalanta is a conventional cultivar with 'modern' type plants, a very short cycle of <105 days, and yield potential of 9.3 t ha −1 (6.8 t ha −1 , on average); it was commercially released for flooded rice in southern Brazil in 1999. 35 However, it is an obsolete cultivar and is no longer planted in Brazil's commercial rice fields.…”

“…Nira, 23 and of O. oryzae in cvs BRS Atalanta and Dawn, with a consequent impact on adult fitness. [24][25][26] In rice, resistance-type tolerance to RWW injury (i.e. cultivars which exhibited low yield losses under high larval pressures) was associated with developing new roots and recovering the root system after root pruning by larvae.…”

“…Antibiosis affected larval growth of L. oryzophilus in cv. Nira, 23 and of O. oryzae in cvs BRS Atalanta and Dawn, with a consequent impact on adult fitness 24–26 . In rice, resistance‐type tolerance to RWW injury (i.e.…”

Monitoring soybean pests using remote sensing

“…Even though various specialists differentially define IPM, its strategies focus on sampling or monitoring procedures, knowing control and non-control levels, and selecting integrated control methods to be used (Kogan, 1998). For most field crops, chemical control through synthetic pesticides is the primary management tactic; however, there is a range of other tactics for pest control, such as biological control, pest-resistant and pest-tolerant cultivars, cultural control (crop rotation, intercropping, trap crops, manipulation of fertilizer and planting calendar, and elimination of crop residues), genetic control (sterile insect technique), and behavioral control (baits, traps, mating disruption techniques), alone or in combination with chemical control (attract-and-kill) (Govaerts et al, 2006;Huang et al, 2014;Padilha et al, 2017;Alphey and Bonsall, 2018;Neves et al, 2018;Blassioli-Moraes et al, 2019;Sharma et al, 2019;Nunes et al, 2020;Preti et al, 2020;Cardé, 2021, Jalli et al, 2021Kovaleski and Mastrangelo, 2021;Adomako et al, 2022;Parra et al, 2022;Pazini et al, 2022).…”