Growth by sugarcane plants in response to lesser cornstalk borer Elasmopalpus lignosellus (Zeller) (Lepidoptera: Pyralidae) damage during early growth stages

Lesser cornstalk borer, Elasmopalpus lignosellus (Zeller) (Lepidoptera: Pyralidae) feeds on sugarcane shoots and causes dead hearts and symmetrical rows of feeding holes in emerging leaves. To determine plant compensation capability for this damage, an experiment was conducted using three sugarcane varieties (CP 78-1628, CP 89-2143, and CP 88-1762) having different growth habits (fast, medium, and slow emergence, respectively). Experimental units consisted of 18.9 L (5 gal) buckets filled with mineral soil planted with two single-eyed seed pieces. Four third instar E. lignosellus larvae were added to each bucket when plants reached the 3, 5, or 7-leaf growth stages. Feeding damage in the form of dead hearts, completely dead plants, and symmetrical rows of holes in the leaves was observed. The number of secondary shoots and the height of 3-mo-old plants also was recorded. Results showed the varietal dependence of sugarcane ability to survive feeding damage as well as the plant response to damage. CP 78-1628 shoots survived feeding damage the best followed by CP 88-1762. The number of secondary shoots produced by CP 78-1628 and CP 88-1762 was greater in damaged than undamaged plants, but damaged CP 89-2143 plants produced fewer secondary shoots than undamaged plants. A delay in the growth (less plant height) of damaged compared to undamaged plants of all three varieties was also observed.