Optimization of a phenotyping system in sugarcane to evaluate different strategies against Diatraea saccharalis (Fabricius)*

PERERA M.F; GASTAMINSZA G.; MICHAVILA M.G; CUENYA M.I.; BUDEGUER F.; RACEDO J.; CASTAGNARO, ATILIO P.

INTERNATIONAL SUGAR JOURNAL

INT SUGAR JOURNAL LTD

Año: 2020 vol. 122 p. 724 - 728

0020-8841

Sugarcane borer Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae) is the most important sugarcane pestin Tucumán, Argentina. Older larvae (L3, L4) bore into the stalks, disrupting the physiological integrity of the plant,facilitating fungi and bacteria colonization which indirectly reduce yield and quality of sugar. The aim of the present workwas to optimize a sugarcane plant-infestation method with D. saccharalis under controlled conditions to help to evaluatedifferent strategies to manage the pest. Different numbers of neonate larvae were placed in the leaf whorl of sugarcaneseedling (two-month-old) of cultivars TUC 95-10, TUC 03-12 and LCP 85-384. Ten larvae of several instars were added inthe ligule of second and third fully expanded leaves of single plants, six-month-old, of TUC 95-10. Trials were conductedunder controlled conditions (28-30oC; 50-70% RH). Each assay was repeated twice with 5-10 replicates per treatment.Several parameters were evaluated on 6-months-old plants: damaged sheath number, number of perforations in theinternodes, total tunnel length, and dead-heart symptom; whereas on sugarcane seedlings only the last parameter wasmeasured. Dead-heart symptoms were observed on sugarcane seedlings in all treatments with neonate larvae. Sugarcaneplants (six-month-old) showed damage in the sheath and stem when infested with L2, L3 and L4 instars, whereas neonatelarvae only produced sheath damage since they were unable to pierce and bore the sugarcane stem. Results suggested thatdifferent methods could be used to screen different strategies for sugarcane borer management.