|Boyd Jr, David|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/17/2006
Publication Date: 12/1/2006
Citation: Rinehart, T.A., Boyd Jr, D.W. 2006. Rapid, High-Throughput Detection of Azalea Lace Bug, Stephanitis pyrioides (Scott) (Hemiptera: tingidae) Predation by Lacewing Larvae, Chrysoperla. Journal of Economic Entomology. 99(6):2136-2141. Interpretive Summary: Azalea lace bugs feed on azalea leaves and create unsightly damage to ornamental azalea plants in the nursery and the landscape. While damage does not usually kill the plant, consumers do not buy plants with brown leaves so growers are obligated to spray pesticides to lace bugs. Pesticide use increases the costs of producing azaleas and this increase is passed to consumers. An alternative to pesticide use is insect biocontrol which involves the release or encouragement of living organisms that attack plant pests, both in the nursery and landscape. Lacewings are general insect predators that appear to consume lace bugs in laboratory studies. However, documenting lacewing predation in real-world nursery environments is difficult, especially by direct observation. Here we developed a PCR assay specific to lace bug DNA that can detect the digested remains of lace bugs in the gut contents of lacewing predators up to 32 hours after being eaten. This new method is rapid and inexpensive allowing us to estimate lace bug biocontrol in the field on a large scale.
Technical Abstract: Azalea lace bugs feed on the leaves of azaleas during nursery production and in the landscape. Pesticides are the most commonly used form of control but biocontrol strategies include the introduction and/or encouragement of predatory insects. While not a specific predator of lace bugs, lacewings are natural enemies and easily consume them in laboratory studies. Field studies on lacewing biocontrol of azalea lace bugs are underway; however, monitoring the rate of lacewing predation in a nursery environment by direct observation is impractical. Here we describe a fluorescent-PCR method to estimate Stephanitis pyrioides (Scott) consumption based on the gut contents of lacewing predators. Lace bug DNA was detected in fed lacewings up to 32 hours after ingestion. More than 80% of the ingested lace bugs were detected using our method with only one false positive result. The assay is both high-throughput and inexpensive making it a practical approach to documenting control of lace bugs in the field.