Early season insect pests represent a consistent threat in Louisiana which can hurt the rice crop right from the onset of the growing season. Fortunately, farmers have several insecticidal seed treatments available which can help to mitigate pest damage.
In fact, economic analysis of seed treatment trials in Louisiana and Mississippi indicate seed treatments provide economic benefits in over 70 percent of fields where they are applied. However, each of the available products have different attributes, and choosing which one fits best with your situation isn’t always easy.
The primary early season insect pest of rice throughout Louisiana is the rice water weevil (Lissorhoptrus oryzophilus) which begins attacking rice roots shortly after permanent flood. Additional early- and mid-season pests include the grape colaspis, chinch bugs, thrips, South American rice miner, fall armyworm, and a complex of stem borers.
Insecticidal seed treatments available for rice have different spectra of pests which they control. All insecticidal seed treatments provide satisfactory control of the rice water weevil, but data indicate that the highest level of control can be achieved with Dermacor X100.
Dermacor also provides exceptional control of fall armyworms and stem borers, and may be a good option for rice producers in more western regions where the Mexican rice borer (Eoreuma loftini) is becoming an increasingly damaging pest.
The neonicotinoid seed treatments, Cruiser and NipsIt Inside, control a broader spectrum of pests including aphids, chinch bugs, grape colaspis, and thrips. These treatments may be a good fit for fields which typically have low to moderate weevil pressure and have not previously had high numbers of whiteheads caused by stem borers.
None of the available seed treatments provide control of late season pests such as the rice stink bug.
Selection of the best treatment to control the most damaging pest complex in your fields will maximize the benefits of these important tools. Additionally, seed treatments should be rotated whenever possible to reduce the risk of insecticide resistance development.
Other considerations when selecting a seed treatment include input costs and seeding rates. The label rate of Dermacor X100 varies according to the seeding rate to achieve a constant amount of insecticide per acre, while the neonicotinoids are applied to seed on a per-pound basis. In fields which are planted with low seeding rates such as in hybrid rice cultivars, neonicotinoids may be substantially less expensive.
The availability of fungicidal seed treatments is another factor which should be considered. CruiserMaxx and NipsitSuite include fungicides, but no Dermacor/fungicide mixes are available. Refer to the table below for information on pests controlled, economic considerations, and availability of fungicidal-insecticide combinations.