D3179: Testing DNA recovery in sticky trap insects treated with Histo-Clear

To investigate the plant diets of honeydew insects, we are analyzing their consumed DNA. When collecting insects with sticky traps, the surfaces of specimens can be covered in adhesive and DNA from surrounding plants. Solvents used to free trapped insects, plus any residual glue, may possibly interfere with DNA recovery. Effective and safe insect removal is required to avoid these problems. We tested two batches of aphids collected by hand from the same plants. Some insects were placed on a sticky trap, while control insects were stored in ethanol. Sections of sticky traps containing insects were soaked in Histo-Clear to remove the glue. We used 4% bleach to sterilize insect surfaces. The DNA was extracted and amplified with ITS2 primers, and then amplicons were sent to a commercial lab for Sanger sequencing. The Sanger results were inconclusive after original and repeated DNA work. Moving forward we are using two identical batches of flatid insects that were collected from separate location to repeat the experiment with out bleaching. We are using flatid insects because they are larger than aphids which makes DNA recovery easier. We will determine if using Histo-Clear to remove insects from sticky traps compromises the DNA by comparing the Sanger sequencing results of Histo-Clear and control samples. This study is important for its application as a part of standardizing sample preparation methods.