6/2/2011 8:33:28 PM
Originally posted April 27, 2011, by Natalie Hummel on Louisiana Rice Insects
I lived in Texas for a couple of years before I moved over to Louisiana. Lately it seems that all my field calls have been pulling me back in that direction, but I haven’t managed to have a BBQ yet. Although I did have a delicious BLT with egg for breakfast. I never would have thought of that combination – Cajuns truly are the most creative and talented cooks I have ever known.
Today we started off with the Vermilion Parish Rice Growers mtg at Suire’s Grocery before heading out to scout rice fields in Calcasieu Parish. We had a great turnout at the meeting. Dr. Saichuk and I discussed observations we have made so far this season. Saichuk’s comments concentrated on herbicide drift problems, the dry conditions causing all sorts of trouble and some other general issues with some varieties. I discussed the seed treatments, trouble with chinch bugs, colaspis and what we have going for the rice water weevil demonstration this season.
After the meeting we headed over to Lacassine to meet Benet Augustine. Benet had called on Thursday to report some strange problems with rice – the heart of the mother tiller was dying in young rice, and the dead new leaf could be easily pulled out of the plant because it was severed at the base. There also appeared to be some chewing at the base. We tried to puzzle it out over the phone. Soon after, Dr. Saichuk and Barrett Courville visited the field and found rice levee bill bugs – an application of Karate was applied before the rain storm, and we could not find any living bill bugs – actually none at all – during our scouting visit today. The lack of insects caused me to be uncertain of whether the bill bugs had been responsible for the rice injury. A few fields later we found another bill bug infestation near Iowa and caught them “red-handed” causing the same injury as Benet had observed. So that mystery was solved. Following are some pictures of the bill bugs and the associated injury they can cause to seedling rice. This was my first time collecting them in a rice field. They have caused significant stand reduction at both sites (pictures 1 & 2) – both were treated with Dermacor X-100, and both were hybrids planted following a fallow season.
Here is where we observed a bill bug feeding (picture 3). You can see that he has his “snout” is embedded into the leaf sheath (pictures 4 & 5). Bill bugs belong to the beetle family Curculionidae (weevils) and are a relative of the rice water weevil (picture 8). Their chewing mouthparts are found at the end of a long “snout” (pictures 4 & 5). The bill bug feeding appears to be injuring the heart of the tiller, causing death of the new leaf. This explains the severed end when the dead leaf is pulled out of the leaf sheath. I saw this injury last season in Calcasieu Parish but was never able to catch the culprit.
We recommended treating with 2 oz of Karate to prevent further injury from the bill bug. This field is particularly vulnerable because of the low seeding rate. The stand is already marginal, and we hope some of the plants recover from the injury. Karate was used at another field location (as described above), and it appeared to be effective.