Hello, Thank you for coming to my defense. I am going to talk about the research I conducted in primocane-bearing caneberries 2007-2009.
The main pest of interest for this study has been the Japanese beetle. In brambles, adult Japanese beetles chew small holes in the fruit and skeletonize the leaves of the plants. Ripened berries exposed to sunlight are favored. Not only does this damage make the fruit unmarketable, it also makes the plants susceptible to diseases.
Here is the Japanese beetle’s life cycle. As you can see as generalization adults are present June through August. In southwest Virginia, we start seeing adults the third week of June throughout AugustThey are therefore present early in the primocane-bearing caneberry harvest.
Another, group of pests of caneberries are the complex of stink bugs. Stink bugs overwinter as inactive adults beneath ground debris and emerge in the spring to begin feeding on multiple hosts. The most common stink bugs in Virginia have 2 generations per year.They are present during caneberry harvest. This pest family’s impact on bramble production is not completely clear; however, they have been observed feeding on caneberries. Both Adults and nymphs use their piercing-sucking mouthparts to extract plant fluids.Immature fruiting structures are preferred and injury can be major.Also, the offensive odor that stink bugs produce has been known to make the berries distasteful.
The study was conducted at Kentland Farm in southwest VA. I considered 8 cultivars of raspberries including Anne, Autumn Bliss, Caroline, Dinkum, Fall Gold, Heritage, Himbo Top and Prelude. All the varieties at listed here are primocane-bearing which also sparked interests in the research.
I counted the number of JB present within the treated plots.We also harvested the fruit within each plot and separated the marketable from unmarketable berries.A berry was considered unmarketable if it had any injury/ it wasn’t something you’d find at the grocery store.Also, I looked at the amount of defoliations within each plot.
The decrease in JB populations can be seen on these y-axis
Autumn bliss is desirable: greater marketable yield and less injured fruitYellow raspberry cultivars less overall fruit but Fall gold was less suseptibility to injury than AnnePrelude less overall yield and also had less injured fruit in 2009
Geraniums are toxic to JB so I wondered if they could be used to reduce JB activity on raspberries
I conducted field experiments in 2007 to see if previous exposure to geraniums reduced JB defoliationBeetles were either caged with a potted raspberry or geranium plant for 48 hoursThey were then removed and bagged onto raspberry canes.5 beetles were in each bag.After 24 hours, the beetles were removed and defoliation was estimated.
In 2009, I conducted laboratory tests exploring geraniums effeicacy as Japanese beetle controlIn the first experiment, two JB were placed in with a ‘Prelude’ raspberry leaf an a zonal geranium flower. Had 25 reps.After 24 and 48 hours the location of the JB was noted. After 48 hours, the defoliation of the raspberry leaf was measured and compared to th defoliation of prelude raspberry leaves that did not have geranium flowers in with them. In the second experiment, JB were either contained with a raspberry leaf or a geranium flower. After 24 hours, the JB were removed and put in fresh containers that contained fresh prelude leaves.After another 24 hours, the defoliations were measured and compared.
Since prelude is preferred cultivar, choice tests with other cultivars JB might choose to be on geranium.
E. Servus made up almost half
When they fed on leaves, they were feeding on the veins.
Here we see them feeding on the sepals
Anytime the I saw the stink bugs feeding on the raspberries, they were feeding in between the droplets. Therefore, any resulting injury would be in between the droplets.
I then went back to images I took in 2008 I found the holes between the drupelets that can be identified as stink bug injury.This first image shows small holes around the drupelet which probably caused the dupuplet to cave in. The second image shows what I consider to be the main injury caused by stink bugs, their feces. People have reported popping a berry in their mouth and tasting stink bugs..which is from their feces..yum.
Pest Management of Japanese Beetle and a Study of Stink Bug Injury on Primocane-Bearing Caneberries in Southwest Virginia
Department of Entomology<br />Virginia Tech<br />Blacksburg, VA<br />PEST MANAGEMENT OF JAPANESE BEETLE (COLEOPTERA: SCARaBaEIDAE) AND A STUDY OF STINK BUG (HEMIPTERA: PENTATOMIDAE) INJURY ON PRIMOCANE-BEARING CANEBERRIES IN SOUTHWEST VIRGINIA<br />Laura Maxey <br />
Japanese Beetle (Popillia japonica Newman) <br /><ul><li>Chew holes in fruit
Injured berries are more susceptible to diseases
Skeletonize the leaves</li></li></ul><li>Japanese Beetle Life Cycle <br />University of Nebraska Lincoln: http://elkhorn.unl.edu/epublic/pages/publicationD.jsp?publicationId=532<br />
Stink Bugs (Hemiptera: Pentatomidae)<br /><ul><li> Adults emerge from ground debris in spring
Autumn Bliss, Caroline, Dinkum, Heritage, Himbo Top, and Prelude</li></li></ul><li>Measured Responses<br />Number of JB on each raspberry cultivar<br />Marketable, Unmarketable, Percent Unmarketable, and Overall Yield of each cultivar <br />Defoliation of each cultivar<br />
Groups of 5 beetles were bagged on Autumn Bliss raspberry canes for 24 hours
Estimated Percent Defoliation</li></li></ul><li>Geranium Toxicity to JB<br />Geranium and Raspberries <br />Two JB were contained with: <br />Geranium petal<br />‘Prelude’ raspberry leaf<br />Geranium or Raspberries<br />One JB was contained with either Geranium petal or ‘Prelude’ raspberry leaf<br />After 24 hours, each JB placed in container with just ‘Prelude’ leaf<br />Defoliation <br />The last leaf exposed in both experiments<br />
Results<br />Caged Experiments<br />Previous Exposure to Geraniums Significantly Reduced Estimated Defoliation to ‘Autumn Bliss’ (7.0 to 4.4 %)<br />Bioassay Geranium and Raspberry<br />Significantly reduced defoliation (8.7 to 3.3 %) but JB preferred to be on ‘Prelude’ raspberry leaf <br />Bioassay Geranium or Raspberry<br />Reduced defoliation (8.4 to 4.9 %) but not significantly<br />
Study of Stink bugs and Their Injury to Raspberry<br />
Stink Bug Conclusions<br />Brown stink bug, twicestabbed stink bug, green stink bug, and dusky stink bug were the main species present 2008-2009<br />Stink bugs feed on multiple parts of raspberry plants <br />Injury to ripening and ripened berries is identified as holes between the drupelets and ill tasting droppings<br />BMSB threat<br />Polyphagous<br />Nymphs and adults can cause injury<br />Increasing populations in Virginia<br />
Overall Conclusions <br />‘Prelude’ raspberries were preferred by JB<br />‘Autumn Bliss’ produced greatest yields with less injury<br />Previous exposure to geraniums reduced raspberry defoliation<br />Stink bug feeding injury is identified as holes between drupelets<br />
THANK YOU!!!<br /><ul><li>IR-4 and the Small Fruit Consortium $$</li></ul>Faculty and Staff at VT<br /><ul><li>Kentland Farm Crew