J. M. Beuzelin, M. O. Way, T. E. Reagan, M. J. Stout, N. A. Hummel, and J. K. Saichuk
August 22, 2011
1. Learn to identify the Mexican rice borer (MRB)MRB Identification card
Field Notes by Johnny Saichuk - June 24, 2011
Field Notes by Johnny Saichuk - July 14, 2011
Louisiana rice insects blog by Natalie Hummel - July 19, 2011 - MRB larvae confirmed in Calcasieu Parish
Field Notes by Johnny Saichuk - July 22, 2011
2. Population monitoring
- Use pheromone traps (Picture 3) to assist with adult monitoring.
- Hummel, Saichuk, Stout, Reagan and LDAF (Hardy) will be coordinating a monitoring program. If you’d like to participate please contact Hummel (email@example.com)
- Become adept at visual scouting for larvae in rice.
- Starting at the panicle differentiation stage - scout for characteristic feeding signs (Picture 4).
- During heading - scout for the presence of whiteheads (Picture 5). Whiteheads are panicles that contain unfilled grains, resulting in a reduction in yield. You should not put out an insecticide based on the appearance of whiteheads. This is because whiteheads are a symptom of injury that has already been inflicted by insect feeding. The only exception would be in a field with un-even maturity where a large portion of the crop is delayed and still susceptible to injury.
2. Cultivar selection
- All cultivars of rice are susceptible to infestation and injury from MRB.
- It is wise to be aware if the variety you are growing is more or less susceptible. Refer to Way et al. (2006), Reay-Jones et al. (2007), Way and Espino (2011), see Table 1.
- The relative susceptibility of rice to sugarcane borers is currently being studied by the LSU AgCenter entomology research program [Sidhu, Stout, and Hummel (unpublished)]
3. Insecticide control considerations
Consider using Dermacor X-100 seed treatment – if field is in a region where both rice water weevil (RWW) and MRB are present and problems are anticipated. If you click here you will see a Map of MRB Finds as of July 2011. (This map was provided by Mr. Tad Hardy of LDAF.)
- RWWs are worse in: Late planted rice, thin rice, weedy rice, deeper water, isolated fields surrounded by woods, fields flooded early in relation to rice emergence, medium grain rice (as compared to long grain rice)
- Stem borers are worse in: Late planted rice, certain cultivars are more susceptible – as described above.
- Foliar applications of pyrethroids (Karate Z, Mustang Max, Prolex) are labeled for stem borer control – it is important to scout aggressively in areas that are currently infested with MRB or on the fringe. Scouting begins at PD and continues through boot. Treatments must be applied when borers are feeding in the leaf sheath, before penetrating the stem.
- The ratoon crop will benefit from both RWW and stem borer control on the main crop (Way)
- Neo-nicotinoid seed treatments used for RWW management (CruiserMaxx, NipsIt INSIDE) will not control stem borers.
4. Stubble management
- Reduce harvest cutting height (Picture 6).
- Timely stubble destruction
- Destroy stubble in the fall if it is compatible with farm management program –don’t allow it to remain in field over the winter. Stubble can serve as an overwintering host for MRB larvae (Picture 7).
- Ensure that stubble destruction will not contradict with environmental regulations for duck habitat management.
- A variety of means of stubble destruction can be deployed:
5. Non-crop habitat management
- Manage large perennial grasses along field margins and ditch banks, primarily johnsongrass and Vaseygrass (Picture 8).
- Mow ditch banks in the fall and early spring to prevent overwintering populations from multiplying on the borders of fields .
Table 1. Relative susceptibility of selected rice varieties to sugarcane borer and Mexican rice borer
Adapted from Way and Espino, 2011. Insect management, pp. 38-53. In 2011 Texas Rice Production Guidelines. Texas A&M AgriLife Extension Service Pub. B-6131, College Station, TX.
Beuzelin, J. M., A. Mészáros, M. O. Way, and T. E. Reagan. Rice harvest cutting height and ratoon crop effects on late season and overwintering stem borer (Lepidoptera: Crambidae) infestations. Crop Prot. (submitted, 7/14/2011, CROPRO-D-11-00513).
Beuzelin, J.M., A. Mészáros, T. E. Reagan, L. T. Wilson, M. O. Way, D. C. Blouin, A. T. Showler. 2011. Seasonal infestations of two stem borers (Lepidoptera: Crambidae) in non-crop grasses of Gulf Coast rice agroecosystems. Environ. Entomol. (in press).
Reay-Jones, F. P. F., M. O. Way, and T. E. Reagan. 2007. Economic assessment of controlling stem borers (Lepidoptera: Crambidae) with insecticides in Texas rice. Crop Prot. 26: 963-970.
Reay-Jones, F. P. F., L. T. Wilson, T. E. Reagan, B. L. Legendre, and M. O. Way. 2008. Predicting economic losses from the continued spread of the Mexican rice borer (Lepidoptera: Crambidae). J. Econ. Entomol. 101: 237-250.
Reay-Jones, F. P. F., L. T. Wilson, A. T. Showler, T. E. Reagan, and M. O. Way. 2007. Role of oviposition preference in an invasive Crambid impacting two graminaceous host crops. Environ. Entomol. 36: 938-951.
Way, M. O., F. P. F. Reay-Jones, and T. E. Reagan. 2006. Resistance to stem borers (Lepidoptera: Crambidae) among Texas rice cultivars. J. Econ. Entomol. 99: 1867-1876.