Population Trends of the Sugarcane Borer (Lepidoptera: Crambidae) in Louisiana Sugarcane

Abstract

The sugarcane borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), is the primary pest of sugarcane, Saccharum spp., in Louisiana. Spring populations are not considered economically damaging, but quantifying infestations can provide an indication of the spatial and temporal character of the damaging summer populations. Statewide surveys quantified the density of sugarcane tillers killed by D. saccharalis (deadhearts) from sugarcane fields across the state in spring from 2003 to 2020. Deadheart density varied greatly among years with a high of 1,318/ha in 2003 to a low of 0/ha in 2018. Linear regressions of the 3-yr rolling average showed declines in spring D. saccharalis populations and the percentage of acreage treated with insecticides over 17 yr. Weather factors including minimum winter temperatures and average spring temperatures were poor predictors of D. saccharalis populations. Only total precipitation in the month of April was positively correlated with numbers of deadhearts per hectare. Results suggest overwintering mortality is not a key factor influencing populations of the first generation of D. saccharalis in Louisiana. Total precipitation in the month of July was positively associated with percentage of treated acreage. Spring deadheart density was directly related to percentage of acreage treated with insecticides during the summer. Quantifying first-generation D. saccharalis populations by recording deadheart density can aid in predicting pest pressure later in the growing season.

Registration of ‘L 12‐201’ sugarcane

“…The resistance/susceptibility rating of L 12-201 to sugarcane borer [Diatraea saccharalis (F.) (Lepidoptera: Crambidae] was assessed in plant-cane crops at the Sugarcane Research Station. The rating was established by comparing borer infestation on L 12-201 relative to those of sugarcane cultivars with known levels of susceptibility/resistance according to Wilson et al (2020). Trials were conducted under enhanced pest pressure, and bored internode data collection followed the methods of White et al (2008) and Wilson et al (2020).…”

Registration of ‘L 11‐183’ sugarcane

“…The resistance/susceptibility rating of L 11-183 to sugarcane borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), was assessed in the plant cane (2018) and first ratoon cane (2019) crops at the Iberia Research Station. The rating was established by comparing borer infestation on L 11-183 relative to sugarcane cultivars with known levels of susceptibility or resistance according to Wilson et al (2020). Trials were conducted under enhanced pest pressure, and data collection followed the methods of White et al (2008) and Wilson et al (2020).…”

“…The rating was established by comparing borer infestation on L 11-183 relative to sugarcane cultivars with known levels of susceptibility or resistance according to Wilson et al (2020). Trials were conducted under enhanced pest pressure, and data collection followed the methods of White et al (2008) and Wilson et al (2020). Data from both trials were analyzed together using generalized linear mixed models in SAS.…”

Characterization of Resistance to the Mexican Rice Borer (Lepidoptera: Crambidae) among Sugarcane Cultivars

“…The most important insect pests of sugarcane in Louisiana and Texas (USA) are the stem borer complex [ 2 , 3 ], which is formed by two species of the family Crambidae (Lepidoptera). The primary pest historically has been the sugarcane borer ( Diatraea saccharalis (F.)), which is decreasing in importance [ 4 ].The emerging threat is the invasive Mexican rice borer, Eoreuma loftini (Dyar) [ 3 , 5 ], which is expected to increase economic losses caused by insects significantly once it has become established throughout Louisiana [ 5 , 6 , 7 ]. Since 2008, E. loftini has been spreading northward and eastward into Louisiana’s sugarcane and rice production regions, with infestations becoming more frequent in recent years [ 8 , 9 ].…”

“…One of the most promising management tactics for E. loftini is cultivar resistance. Cultivars with documented resistance to D. saccharalis have greatly improved IPM success and reduced reliance on chemical controls methods in Louisiana sugarcane [ 4 , 5 , 16 , 17 ]. Cultivar resistance is particularly compatible with stem borer IPM because resistant cultivars that delay stalk entry enhance larval exposure to insecticides and natural enemies [ 14 ].…”