Non-destructive DNA extraction methods for entomophagous insects with emphasis on biological control.

Abstract

One of the major challenges in molecular analysis of arthropods, especially for natural enemies of insect pests, is the intact preservation of the specimens to be integrated into entomological collections. However, most of the DNA extraction protocols involve maceration of the tissue, avoiding the preservation of the original specimen. Two general methods were adapted into non-destructive DNA extraction protocols, DNeasy® Blood & Tissue Kit (A) and the CaCl2 lysis buffer method (B), while the potential of the method with the alkaline lysis buffer (HotSHOT; C) was evaluated for the first time on insect specimens. These protocols were assessed for the recovery of DNA from Ceraeochrysa valida, Tamarixia radiata, and Hippodamia convergens. Photographical records showed that morphological features of the specimens were preserved after the DNA extraction process. COI fragments were successfully amplified with method A (100%), B (77%), and C (88%), respectively. We conclude that these non-destructive DNA extraction methods avoid the destruction of tissue and preserve the original insects and their morphological characteristics for future reference.