Identification of Two Additional Behaviorally Active Gland Constituents of Female Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae)

Maycon Da Silva,Angela Cortes,Christer Löfstedt,Paulo Zarbin,Eraldo Lima,Glenn Svensson

doi:10.21577/0103-5053.20200171

Abstract

The sugarcane borer, Diatraea saccharalis (Fabricius), is the major pest insect attacking sugarcane crops in Brazil. Population control by insecticide treatment is not efficient due to simultaneous presence of all developmental stages of the insect throughout the year, and alternative control methods are needed. Two female-produced sex pheromone components, (Z,E)-hexadeca-9,11-dienal and (Z)- hexadec-11-enal, have previously been reported to elicit antennal activity and behavioral response of males in flight tunnel experiments. However, the attractiveness of these compounds in field tests has been very low. In this study, two additional female-produced compounds in D. saccharalis eliciting consistent antennal response in males were identified as (Z)-hexadec-9-enal and hexadecanal. In flight tunnel assays, the behavioral response to a quaternary blend was significantly higher when compared with the previously identified binary blend. Subtracting (Z)-hexadec-9-enal or hexadecanal from the full blend did not reduce attraction, indicating redundancy in the communication channel. We conclude that additional compounds are part of the sex pheromone of D. saccharalis, which may improve the efficiency of trap lures for monitoring of this pest.

Highlights

The sugarcane borer, Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae), is the major pest in sugarcane plantations in Brazil
In subsequent chemical analyses by Gas chromatography-mass spectrometry (GC-MS), the most abundant compound with strongest antennal activity was identified as Z9,E11-16:Ald based on Kováts retention index, fragmentation pattern, and comparison with synthetic standard
The first eluting compound in the extract was a compound not previously reported in the pheromonal blend, and it was identified as Z9-16:Ald based on the following features: tR 12.56; Kováts index (KI) of 1800; and fragment ions at m/z (%): 238 (M+, 3), 220 (8), 135 (7.5), 121 (15), 98 (29), 81 (42), 69 (50), 55 (100), 41 (59)

Summary

Introduction

The sugarcane borer, Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae), is the major pest in sugarcane plantations in Brazil. For this insect, population control using pesticides is inefficient due to simultaneous presence of all developmental stages of the insect throughout the year. Larval and pupal stages are protected inside the plant.[1,2] Many strategies have been developed in order to decrease the damage caused by D. saccharalis in sugar cane crops, including biological control with the braconid larval parasitoid Cotesia flavipes (Cameron) (Hymenoptera: Braconidae), manual collection of the larvae and cultivation of genetically modified varieties of sugarcane.[3] Pheromone-based methods for population monitoring and control have been successfully applied to manage important agricultural pests,[4,5] and such methods may be implemented in integrated pest management (IPM) programs for D. saccharalis in sugarcane plantations. The goal of this work was to reinvestigate the sex pheromone of D. saccharalis using electrophysiological and behavioral analyses, in order to identify additional female-produced compounds that might be important for the attraction of males of this species

Objectives

Results

Conclusion