- Pest Management: prevention, Early detection of invasive species
It is well established that early detection is the single-most effective strategy for control of invasive species. The brown marmorated stinkbug (BMSB, Halyomorpha halys), which has become a devastating pest to many northeastern farmers, was first detected in the US in 1996 and is currently still expanding across the continent. Current efforts at monitoring for the presence of BMSB on farms rely on capturing individuals using black light and pheromone traps, which are demonstrably inadequate at detecting BMSB presence while abundance is very low at the onset of infestations. Indeed, traps may be producing false negatives delaying management actions that could otherwise effectively control populations on agricultural fields. Environmental DNA (eDNA) is an emerging surveillance tool with a proven track record for determining presence of target species at abundances far below what direct monitoring can accomplish. However, this technique has so far been limited to aquatic systems. Our aim is to adapt and optimize eDNA techniques for terrestrial uses and develop a fine resolution detection protocol for agriculture pests, specifically BMSB. We propose to deliver a practical strategy for surveillance for BMSB implemented regionally and relevant to local farms allowing control measures to be started sooner and at a fine scale. Ultimately the use of eDNA and rapid-onset control will allow small produce farms to maintain their profitability by keeping costs low, due to reduced pesticide use, while experiencing fewer crop losses.
Project objectives from proposal:
1.Determine if BMSB eDNA can be detected on small produce farms. We will employ three sampling protocols and evaluate them in terms of their ability to detect BMSB DNA.
a.Can BMSB eDNA be detected on crop surfaces, or within suspected feeding sites on produce? BMSB tend to feed on the reproductive tissue of crops and do so by piercing the skin of the fruit and fruiting bodies, injecting digestive enzymes, then removing liquids. We will sample around, and within, the site of feeding damage in expectation that BMSB saliva or excreta will produce a positive test for their DNA.
b.Can BMSB eDNA be found in the top soil directly beneath crops? BMSB are highly mobile at most life stages and can occupy cultivated plants through several instars. Therefore water that washes through crops via rain and irrigation will possibly deposit excreta and exuviae in the topsoil just below occupied crops. Thus, sampling topsoil may produce a positive test for BMSB DNA.
c.Can BMSB eDNA be found within the water of crop wash stations? On the small produce farms like the ones we will study, farm staff harvest produce from fields and bring them to a central wash station where all dirt and other material are cleaned from the produce in preparation for customer purchase or consumption. We expect that the water rinsed off of such produce will contain BMSB DNA as it will contain their exuviae, excreta, saliva and dead bodies in a concentrated form.
2.Use eDNA to detect BMSB when they are so rare that direct monitoring fails to detect their presence. While simultaneously sampling for eDNA on a farm, we will also monitor their presence using (a) pheromone and (b) black light traps. This effort will allow us to compare the different methods in their ability to provide positive proof of BMSB presence on a farm. Successful detection of BMSB using eDNA when conventional traps are not showing detection will be considered evidence that our method has higher sensitivity.
3.Document and disseminate an eDNA surveillance protocol for detection of BMSB. We will compile all detection information and evaluate which sampling method(s) yielded the most cost effective approach for determining BMSB presence. If appropriate, we will then develop an eDNA surveillance protocol outlining best practices for farm-wide and crop-specific monitoring for BMSB presence.