ULV Malathion for Tarnished Plant Bug Control

The following is a very good report that Dr. Roger Leonard has recently put out on the use of ULV Malathion for late season control of tarnished plant bugs in cotton.  We have also been testing this the last several years with good results but I would like to point out a couple of minor differences between MS and LA with respect to using ULV.  First, Mississippi does not need any special exemptions for using ULV Malathion in cotton like LA.  Second, our crop is a couple of weeks later, so we should likely wait another couple weeks before widespread use due to late aphid and spider mites problems currently going on in our cotton.  Hopefully the aphid fungus will show up on a wide spread basis soon opening the window for use of this product.

By Dr. Rogers Leonard, LSU AgCenter

Generally, chemical control strategies used to manage tarnished plant bugs in cotton during 2011 have been successful.  The aggressive use of Diamond has reduced the impact of in-field reproduction and overall nymph infestations.   Diamond generally does not show immediate effects at 2-3 d after treatment, but at 7-14 d post-treatment tarnished plant bug nymphal development is suppressed.

Very little if any of our Louisiana crop has developed to a point where it is safe from this pest and some sprays likely will be needed in August.  Several of our products recommended for tarnished plant bug control in LA cotton have relatively low annual AI’s/acre/year.   We are about to complete our legal annual use limits for many products such as:

–          2 applications of Bidrin @ 0.5 lb AI/acre after flowering;

–          2 applications of Centric @ 2.5 oz [form]/acre;

–          Only 4 applications of Orthene (acephate) @ 1.0 lb [form]/acre can be used and I would not rely on it to finish the season.  

There are other insecticides (Carbine, Trimax, Lorsban, Vydate, Intruder, dimethoate) that can still be used, but I do not think we can finish the season successfully with these products.  In addition, some tarnished plant bug populations are expressing resistance to several of these products so it is very important to rotate whenever possible to reduce the risk of control failures.  

For the past two years during the month of August, we have had great success in managing tarnished plant bugs with a pyrethroid + Malathion ULV combination.  This treatment must be applied at 32 oz total volume / acre and a copy of the label should be in the hands of the applicator at the time of the application.  Louisiana’s Agricultural Commissioner, Dr. Mike Strain, and his staff have approved a multi-year exemption to use this treatment.  Prior to August, I am reluctant to recommend this treatment for fear of flaring cotton aphids, mites (or at least making them worse), or armyworms.

As we approach August, I believe now is the time to begin these applications. I have attached a three product use guides that summarize malathion (Fyfanon and FyfanonPlusULV) products by Cheminova.   Do not be confused by the similar names.  Fyfanon contains only malathion and a pyrethoid should be co-applied. Cheminova is recommending their pyrethroid (Declare), but others (Baythroid, Karate, Bifenthrin) may be substituted.  The second one, FyfanonPlusULV, is a pre-mix of malathion and a pyrethroid, Declare.  FyfanonPlusULV will only need the addition of vegetable oil because a pyrethroid is included in the pre-mix.

There are several important considerations to make this a successful treatment. 

 â€¢ The pyrethroid + Fyfanon (Malathion) or FyfanonPlusULV treatments for tarnished plant bugs must be applied at 32 oz total volume / acre.  Do not rely on Malathion alone, it has performed inconsistently without co-applying the pyrethroid.

ʉۢ Not all pyrethroids are labeled for use in ULV applications. Read the labels.

ʉۢ Do not add any other product Рall ratios change, the products may not mix, and efficacy may be compromised.

 â€¢ Warning : Do not substitute a crop oil  for the vegetable oil  â€“ Crop phytotoxicty  and poor control may occur.

• These are examples of  vegetable oils  AMIGO (CPS/LOVELAND), SOYDEX (HELENA) and SOYSURF (SANDERS).  An emulsifier is not needed nor recommended.

ʉۢ This treatment is approved for aerial application and applicators must use a boom approved for ULV work.

ʉۢ Do not add water or water-based additives.

 â€¢ Do not apply this treatment in the morning to we foliage, it will not stick and efficacy will be compromised.   

 â€¢ Target use rates – 16 oz malathion + pyrethroid (depends on which one, but Baythroid or Karate @ 2oz are standards) + vegetable oil (enough to bring total volume to 32 oz).

ʉۢ Example calculation when mixing a pyrethroid to the Fyfanon formulation (malathion alone) :

 16 oz Malathion +

  2 oz Baythroid +

14 oz vegetable oil

32 oz – total volume

ʉۢ Example calculation when using the FyfanonPlusULV formulation which already contains the pyrethroid:

16 oz FyfanonPlusULV (Pre-mix)

16 oz vegetable oil

32 oz – total volume

Both of these can provide similar performance. I would not use more than two applications on weekly interval; but it is likely that residual efficacy may extend beyond 7-10 days.  In many instances, a single application has provided sufficient control for > 14 days.   

Cheminova FACT SHEET Aerial Fyfanon + Declare ULV on cotton v2

Fyfanon PLUS ULV_label

FyfanonPlusULV_factsheet