Spotted Wing Drosophila Monitoring Report July 1, 2016

— Written By Grant Palmer

As the month of July has come to an end, so has the growing season for many of the varieties of blueberries at our research sites. Due to this, many of our participating growers have hedged portions of their fields to reduce the area of hospitable resources for pest species, including spotted wing drosophila (SWD). This reduction of available resources, combined with stormy weather the week of 6/15/2016 may have led to the spike in trap capture numbers seen below in both blueberry YSW and blueberry Scentry baited traps.

This increase in trap captures may also have been the impetus for predators like spiders and dragonflies to lurk around our traps. The spider in the picture below was doing just that before we deposited it on one of the surrounding blueberry plants so we could collect the trap’s contents without incident.

spider on plant

Spiders are fairly common at our research sites. This one here was found on one of our YSW trap posts. Photo: Grant Palmer

The average number of total (male and female) SWD captured per site per day are presented in the figures below. Trapping began at six blueberry fields on May 11, 2016. Scentry lures were not available until May 17th, so these were deployed at blueberry locations during the second week of monitoring.

YSW refers to traps baited with “yeast/sugar water”, and Scentry refers to traps with Scentry lures.

2016 blueberry YSW data

2016 blueberry scentry data

We are monitoring a total of five blackberry fields, and first checked traps on May 17, 2016. SWD trap captures are generally higher in blackberry fields as compared to blueberry fields.

2016 blackberry YSW data

2016 blackberry scentry data

Data is continually processed and will be updated weekly as it becomes available.

6/15/2016 was also the first collection day after new Scentry bait traps were deployed at our research sites. This is an additional reason why we may have seen sharp rises in our trap capture numbers. The scentry bait traps are rated for eight weeks, but they do not appear to last this long in North Carolina conditions. Our first set of Scentry bait traps were changed out after four weeks.

More information

Past insect monitoring reportsEntomology Portal