Molting regulative neuropeptides in Dalbulus maidis, the corn leafhopper

NICOLAS ANDRADA; MARCOS STERKEL; INES CATALANO

La Plata

Congreso; II Congress of the Latin American Society for Vector Ecology; 2022

Latin American Society for Vector Ecology

Insect growth involves a series of molts during which the old cuticle is got rid of, while a new, larger cuticle is formed. Failures in molting might be lethal, so it has been proposed as a target for new strategies for pest control. This event is regulated by enzymes and hormones from different origins. Two of the hormones that regulate molting are Bursicon-α (Burs-α) and Ecdysis Triggering hormone (ETH). This work aimed to identify and characterize the function of Burs-α and ETH in the leafhopper Dalbulus maidis, an insect with agronomical relevance because is an important corn pest in the Americas. We identified the related transcripts of these two hormones using the transcriptome of this insect obtained in our lab. To perform RNA interference experiments, we obtained double-stranded RNA (dsRNA). dsRNA was diluted to a specific concentration (1 µg/µl) and 0.25 l were injected into 5th stage nymphs. The injected insects with dsRNABurs-α presented a lethal phenotype because of the inability to expand their wings and defected sclerotization. Insects injected with dsRNAETH couldn’t fully shed their cuticle and die. A few insects survived briefly, although they could barely come out of the cuticle which still attached to them. Surviving insects were able to move, but they couldn’t fly or jump and finally died. In addition, gene silencing of both genes resulted in significant molting impairment and mortality compared to the control group (dsRNAβlac). These results show that the strategy of RNA interference is a promising tool to control D. maidis.