Blueberry maggot flight begins in southeastern North Carolina

Oneal blueberries ripening at The Bush & Vine, York, SC.  Photo: HJB

We captured our first blueberry maggot (Rhagoletis mendax) adult, a female, at the Ideal Track of the Horticultural Crops Research Station, Castle Hayne, NC.  This marks the beginning of the blueberry maggot flight, right on schedule for the historic average flight time, 25 May.

We are monitoring blueberry maggot flies and other insects at 15 locations in southeastern NC.  We not caught flies at any of the commercial blueberry farms, nearly all of which are following the calendar-based management program for blueberry maggot and began treating at least 2 weeks ago.

View blueberry maggot, sharpnosed leafhopper, and SWD captures from NC blueberry country here.  Ideal Track is Site 14 in the blueberry maggot trapping list.

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Blueberry maggot and sharpnosed leafhopper monitoring data now available UPDATE: SWD data now added

Wake County cooperative extension cut

Cooperative extension has been disproportionately cut throughout the country at both the university and county levels but this week the cuts came close to home.  The Wake County Commission has eliminated funding for the horticultural extension agent for the county.  Although Wake County is home to Raleigh (the 2nd largest city in NC), Cary, Gardner, and other urban areas, it is also the 4th largest nursery & floriculture producing county, the 12th largest sweet potato producing county, and the 17th largest tobacco producing county.  This production occurs on 827 farms that cover 84,956 acres.  (Source: NCDA & CS)

The economic value of agriculture to the county isn't the whole story, however.  City dwellers in Wake County benefits from the growing local food movement, spearheaded by cooperative extension's 10% Campaign, and the NC Master Gardener program.

Cutting extension is a short sighted solution to a budget problem.  The modest investment in extension personnel and programs ($22,000 per year, in the case of the Wake County horticulture agent position) has real and tangible benefits.  Adding salt to the wound is the fact that the rest of the Wake County employees will receive a 2% raise this fiscal year.  With cuts like this, extension will come out of the recession a much weakened institution but still tasked with helping America's farms feed, clothe, and support the world.

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Wake County Board of Commissioners

Insect activity beginning in the research hop yard

Caterpillars feeding on a hops leaf at the Lake Wheeler Field Laboratory. Photo: HJB

Yesterday, undergraduate intern Mandi Harding and I visited the research hop yard at the NC State Lake Wheeler Field Laboratory to check the traps we placed last week, collect mite & aphid samples, and observe any insect activity. The plants are just starting to reach to the top of the trellis, so I didn't necessarily expect large insect populations. I was correct in that there was minimal activity, but we did see some notable insects eating hops or eating other insects that were eating hops. Several plants had recently hatched caterpillars (see above) present, and they all appeared to be the same species. Rather than collecting these larvae and rearing them in lab, we are going to keep an eye on them in the field and collect them when they are closer to pupation.

There were also plenty of beneficial arthropods (insects and mites) present, including lady beetles, predatory mites, minute pirate bugs, and lightning bugs (which are actually beetles and are one of my favorite things about living east of the Mississippi). Thrips were clearly visible crawling on leaves and inside cones. Thrips are potential pests of hops in the southeast, and I am always amazed at the sheer number of thrips present in the early summer in North Carolina. I am even more impressed when I talk to cooperators on research projects in the Pacific Northwest who catch on the order of 10-15 thrips per trap, and we catch 0ver 300 in the same time period. Thrips seem to thrive here, for better or worse. Also thriving are thrips predators, like the lightning bug (beetle) below.

A lighting bug feeding on thrips on a hop leaf. Click here to enlarge this image for a better view of the distinctively striped soybean thrips highlighted. Photo: HJB

We'll be collecting samples and observing insect populations in the hops yard throughout the summer and will post updates when interesting insects appear.

What to watch for: Raspberry cane borer

Damaged blackberry primocane at the Sandhills Research Station, May 23, 2011.  Photo: HJB

While checking our virus vector monitoring plots today at the Sandhills Research Station, near Jackson Springs, NC, I noticed a few plants with classic raspberry cane borer injury.  Female raspberry cane borer beetles lay their eggs near the tip of primocanes causing the end to wilt and creating a distinctive, paired girdling of the cane.

Raspberry cane borers are one the many exciting "boring" insects that feed on caneberries in the southeast.  If left unchecked, the larvae can kill the cane they feed on over the course of 1-2 years, depending on where in the US they are.  In North Carolina, these insects probably have a 1 year larval life cycle.

The injury at Sandhills was very recent, as evidenced by the fact that the end of the cane was just wilted and not dead.  In addition, no larvae were readily found in the cane when I tore it open, suggesting that the eggs have not yet hatched.

Cultural control, via removal of infested canes, is the recommended management strategy for both raspberry and rednecked caneborers, and this is the perfect time to remove raspberry cane borer infested tissue!  Infested primocanes can be tipped, and will continue to grow over the course of the summer.  If left until fall, during the typical pruning period, the entire damaged cane must be removed to ensure the raspberry cane borer larva is destroyed.  Neither raspberry or rednecked cane borer injury typically damages more canes that would be removed through typical fall/winter pruning in North Carolina.  We generally only see significant raspberry or rednecked crown borer injury at locations where pruning has been minimal.  Now is a good time to scout for borers are remove the damaged plant parts before they can get a foothold.

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Blackberry borers can mean big problems

Tobacco budworm update

Calls about tobacco budworm have begun in earnest this week, and the main questions I am hearing are "What is the difference between Belt^TM(Bayer CropScience) and Coragen® (DuPont)?" and "I used Belt^TM/Coragen®, how long should I wait before I decide if I need to treat again?"

First instar tobacco budworm larva in eastern North Carolina tobacco. Photo via Loren Fisher.

What is the difference between Belt^TM and Coragen®?

Belt^TM and Coragen® are two recently registered insecticides for use in tobacco against Lepidopteran (caterpillar) pests. Both these insecticides share a common, and novel, mode of action. They act on ryanodine receptors, which form calcium channels in muscle cells, and inhibit muscle contraction. The Insecticide Resistance Action Committee (IRAC) places both of these materials in Group 28 (ryanodine receptor modulators). In other words, Belt^TM and Coragen® kill insects in the same way and using one following the other does not represent a rotation.

In our research trials over the last 3 years, Belt^TM and Coragen® perform similarly to one another when applied as foliar treatments. They also perform similarly to the standard insecticide used for tobacco budworm control, Tracer (spinosad, Dow AgroSciences). The key difference between Belt^TM and Coragen® is the potential in-plant movement of the latter. Coragen® is xylem mobile, which means that it moves in the plants water channels when applied to the soil. Coragen® has a transplant water label in tobacco, but our data on the efficacy of this application method is limited.

I used Belt^TM/Coragen®, how long should I wait before I decide if I need to treat again?

Both Belt^TM and Coragen® slow or stop feeding quickly. However, larvae may appear alive, but sickly (or moribund) for up to 4 days after treatment. Another insecticide application should not be made until sufficient time has passed to allow for the insecticide to work. If another treatment is considered necessary, growers should be sure to rotate to another mode of action.

As always, when I discuss treatment thresholds (10% infestation) for tobacco budworm, it is important to understand that these thresholds are very conservative, meaning that yield loss has rarely been documented due to budworm feeding, even at much higher infestation rates than 10%.

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A note about pesticide recommendations

Strawberry season coming to a close

After another short picking season, we are pulling the plug on our strawberry research plots at the Central Crops Research Station near Clayton, NC this week. The spring of 2010 was also a quick, short growing season, and I am curious how many other strawberry farms are wrapping up harvest in the next few weeks. I am also curious if this pattern is related to our cold winters, and if short seasons are the norm under these conditions. We will maintain our planting for the next few week to monitor for spotted wing drosophila, but our two mite trials have ended because the plants are growing more foliage than fruit at this point.

SWD trap in strawberry plots at the Central Crops Research Station, 2011. Photo: HJB

It's always a little bittersweet to end a field project, so I read the latest post from Berry Girl, a relatively new strawberry grower near Goldsboro, NC with interest. They, too, are ending their field season for the year and looking towards next year. I've enjoyed reading their blog this spring and hope they keep it up!

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Bowing out - The True Adventures of Berry Girl

Blackberry field visits, May 26th

Green June beetle feeding on ripe blackberries at the Lower Coastal Plain Research Station, Kinston, NC in 2009. Photo: HJB

I will be in southwestern North Carolina this Wednesday and Thursday for a Southern Region Small Fruit Consortium sponsored agent training. Following the training on the 26th, I will be visiting several blackberry growers to discuss SWD monitoring and management. SWD have been detected in several counties in southwestern NC and northwestern SC, and large populations were present in a non commerical planting in 2010. Blackberry & raspberry growers should be aware of their management tools and be prepared to both monitor and treat in 2011.

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Insecticides registered for use in caneberries & their potential use against SWD