Syngenta Crop Protection recently announced EPA’s approval of their registration of five new insecticide products containing the active ingredient PLINAZOLIN technology (isocycloseram), which is a unique active ingredient that belongs to IRAC Group 30, offering broad-spectrum insect pest management.

https://www.syngenta-us.com/crop-protection/technology/plinazolin-technology/

Zivalgo^™: a foliar-applied insecticide for pome and stone fruit, citrus, potatoes and tree nuts that goes the distance in the race against codling moth, Colorado potato beetle and more with marathon-caliber residual control

Equento^®: this insecticide seed treatment for cereals and pulses offers a flexible and compatible option to terminate wireworms and suppress other below-ground pests, ultimately improving plant stand and helping growers’ bottom line
 

Opello^™: this soil-applied insecticide provides revolutionary control of corn rootworm, consistently helping corn yield up to 27 bu/A more than untreated¹, while its highly tank-mix compatible formulation allows growers to leave equipment clogs and slowdowns in the past
 

Vertento^®: a foliar-applied insecticide for cotton, onion, peanuts and soybeans that lands the knockout punch on tough-to-manage insect pests like plant bugs/lygus, stink bugs and mites, and offers champion-level residual control
 

Incipio^™: a foliar-applied insecticide for vegetables that’s tough on pests like diamondback moth and thrips but easy on growers, helping protect their time and peace of mind with long-lasting and reliable control
 

My lab has field-tested these insecticides against many pest groups on vegetables, potatoes, and other crops over the past several years. Plinazolin insecticide offers a wide pest spectrum including some hard-to manage pests such as: thrips, mites, lepidopteran larvae like diamondback moth and beet armyworm, Colorado potato beetle, alfalfa weevil etc. Because its mode of action is much different than other insecticides, it offers an excellent rotational tool for insecticide resistance management.

While presenting at a community garden meeting with growers and gardeners in Boydton, VA this morning (Sept 10), one of them talked about a pest that was creating holes in her sour gherkin cucumbers. I checked it out and it was pickleworm (see photos). Location was Clarksville, VA. This is not good news for our large pumpkin industry in Virginia. This means that at least some of these tropical moths have mead their way from the southern U.S. on storm fronts and are depositing eggs on blossoms of cucurbit host plants like cucumbers, squash, and pumpkins.

Larvae bore into fruit where they can cause the fruit to rot in addition to reducing marketability of the fruit. Growers should inspect their fruit and blossoms regularly until harvest. If pickleworm is found, there are many effective insecticides to control it, but the most affordable would probably be a pyrethroid.

Like every year, I get a lot of questions on late leaf spot fungicides the closer we get to digging. Since it’s near the end of the season, regardless if you’ve been on a rigorous, effective leaf spot program you’re going to see some leaf spot. I’ve heard some growers are having severe leaf spot and some significant defoliation. Below I’ll cover some points regarding late leaf spot management as we approach digging.

1. Leaf spot has a greater affect on yield the earlier it occurs.  If the onset of disease begins near harvest we often don’t observe much loss.  I’d be more concerned about yield loss in fields where leaf spot was significantly spreading in early to mid-August compared to just seeing it get worse since labor day weekend.  However, if you see up to 40% or more defoliation, a fungicide application at that point isn’t going to help and you may consider digging early to help preserve yield.
2. The cooler it gets leaf spot takes longer to spread.  Cooler weather coupled with the extremely dry weather we’re experiencing really slows disease development.  The big increases in leaf spot you’re seeing now are the result of infections that took place 2-3 weeks ago or more.  That would mean the fungicide applications you made (or not) early to mid-August are impacting what you’re seeing now more than sprays you applied within the past 2 weeks.  Applying a fungicide now won’t have a major impact on leaf spot or yield.
3. Just because I just said spraying leaf spot now won’t have a big effect on yield doesn’t mean spraying for leaf spot is a terrible idea right now.  A lot of that depends on how close you are to digging based on peanut maturity.  If you’re over 2 weeks away from digging I can see where a fungicide application may help leaves stay on longer and prevent yield loss compared to peanuts that are within 2-weeks of digging.  Everyone’s maturity situation is different, and it can vary from field to field.  The situation is very different between dryland and irrigated peanuts.  In talking to Jacob Forehand in Virginia and David Jordan in NC this morning, according to pod blasting results, peanuts are not maturing very quickly due to cool, dry conditions and peanuts may be mature a little later than “normal”.  Plus, although the forecast isn’t calling for much rain, if it becomes warmer and we get some unexpected rain that can change things so far as maturity and diseases are concerned.  Lots to consider…
4. If you’re going to use a fungicide this late, make sure it’s a fungicide that’s going to be effective (kinda intuitive I know).  I hear about a lot of people making fungicide recommendations that are questionable.  If you ask me about a fungicide to use right now I’m going to tell you to use Provost Silver or chlorothalonil (Bravo, Echo, Equus etc) with or without micronized sulfur.  Why those?  They are the only fungicides that I am confident in providing some control.  The efficacy and curative activity of Provost Silver is well established, chlorothalonil works as well as it did when it was first used back in the 70’s because it has multiple modes of action and carries practically no risk of resistance development, and micronized sulfur has been shown by several researchers in several states to enhance the efficacy of leaf spot applications when mixed with an effective fungicide.  Each product has some downsides which may be a cause for pause. 
5. We use FRAC Group 3 fungicides in almost every application we make on peanuts, and the actives in Provost Silver are both groups 3’s.  Provost Silver is probably the most used FRAC Group 3 fungicide.  The more we use the same MOA (mode of action) over and over again we put more pressure on them for resistance development.  Couple that with spraying when higher inoculum levels are present during the late season adds more to the resistance risk. 
6. Chlorothalonil has been shown to increase the risk of spider mite development, and to a lesser degree it can enhance the development of Sclerotinia blight.  As dry as it is I can see growers being resistant to use chlorothalonil because of spider mites.  But since sulfur has some activity against spider mites, I’ve been suggesting tank-mixing it with chlorothalonil to provide some control of spider mites.  Spider mites are favored by hot, dry conditions.  We have the “dry” but don’t have the “hot” right now and looking forward.  I’m not saying there’s no risk of spider mite infestations right now, but conditions are less favorable for them to occur.
7. The main issue with sulfur are problems with mixing and it’s potential to leave residues in spraying equipment that can cause clogging.  I recommend trying different formulations of micronized sulfur.  The one’s I’m familiar with are Microthiol Disperss® (dry), Kolla® (liquid), and Suffa® (liquid).  I keep using the word “micronized” for a reason.  That is that all the positive efficacy data I talked about earlier was with micronized formulations only.  Non-micronized sulfur does not show the same positive effects on leaf spot control.

Corn earworm larvae have been found well in excess of economic thresholds in several counties throughout Virginia the past two weeks. In Prince George, we sampled a field with 50+ larvae per 15 sweeps (see below photo). There are a few key things to remember for managing corn earworm in soybeans.

1. It pays to scout. Use the economic threshold.
   For corn earworm in soybeans, we have what’s called a “dynamic threshold”. The benefit of using a dynamic threshold is that it shifts with commodity prices, production practices, and the cost of control and you can be certain that you will get economic return on a spray under current conditions. You can find the calculator here. At an estimated soybean price of $10/bu, and $15 cost of control using a sweep net to sample 15 inch soybean rows you get an economic threhsold of 2.2 larvae per 15 sweeps.
   
   We have expanded our corn earworm moth monitoring in 2025. While these traps do not indicate the need to spray alone, they can guide your scouting efforts and help make decisions. The monitoring tool is updated in real time and can be found here.
2. Select the right insecticide
   Pyrethroids alone will have limited efficacy for corn earworm, particularly for large larvae. Our most recent efficacy data can be found in the figure below. These numbers are total number of corn earworm larvae per 15 sweeps at 2 days post application. If targeting stink bugs as well as corn earworm a product containing both a pyrethroid and a diamide (I.e. Besiege or Elevest) would be a good option. If you are also reaching defoliation thresholds (15% during reproductive stages) and have mostly soybean loopers, Besiege has offered limited control for soybean loopers in recent years. Intrepid Edge or Steward are good options to manage both corn earworm and soybean loopers.

As always, please contact me if you have any questions or concerns. Tim Bryant (btim2@vt.edu).