- VIEWPOINT -
New Insect Problems
I have been working as a research entomologist in Mississippi for a little over six years now. The beginnings of my career as an entomologist date back to when I was an undergraduate at Auburn University. I love to hunt and fish and my initial choice was to become a wildlife biologist. As part of the curriculum for wildlife biology, I was required to take a general entomology course, and I began working for the pecan Extension Entomologist, Dr. John McVay. I really enjoyed my time “checking” pecans for insect pests, and I began talking to some of the other entomology professors about the opportunities available for entomologists.
Auburn still had an undergraduate program in entomology, and I decided to change majors. During the summers, I spent most of my time on the road traveling to pecan orchards throughout south Alabama. As I mentioned, I love to hunt and fish, so I used that travel time to my advantage.
I also worked with other Extension specialists in the Auburn system, most notably Dr. Ron Smith, the cotton Extension entomology specialist. I remember being around Dr. Smith during the summer of 1995. His phone rang constantly during a large part of that summer because tobacco budworms were absolutely destroying the cotton crop despite numerous pyrethroid applications. That is where I got my first taste of what insecticide resistance really meant.
Fortunately, Bollgard cotton was released by Monsanto during the 1996 season. By that time, I was finishing my education at Auburn and had decided to go to graduate school at Louisiana State University to work for Dr. Roger Leonard on cotton insect problems.
It turns out that my decision was the correct one. One major difference with cotton compared to other crops is that there always seems to be another insect pest “waiting in the wings.” Tarnished plant bugs and bollworms have long been considered pests of cotton, but their status was never considered equal to that of the boll weevil or tobacco budworm.
For many years, we could effectively control boll weevils and tobacco budworms with synthetic insecticides. The organochlorines, including DDT, were the first synthetic insecticides introduced that effectively controlled all insect pests in a cotton field. Within a relatively short period of time, the first reports of control failures with these “miracle insecticides” began to be reported. During the 1960s, resistance to the organochlorines was documented and was widespread in several insect pests in multiple crops, including boll weevils and tobacco budworms.
During 1996, transgenic Bollgard cotton was released for commercial production. This technology provided a new delivery system for insecticides where the actual protein toxin is produced within the cotton plant’s tissue. We are now well into the second generation of transgenic cottons, including Bollgard II and WideStrike. Similarly, eradication has eliminated the boll weevil as a key pest in most areas of the United States.
The “new” insect problems that we currently face in Mississippi are not really different from the problems we faced in the past. When you consider the history of insecticide resistance in cotton, the industry has always responded with a better “mouse trap” that temporarily alleviated the problem. The chemical and technology industries are currently searching for the next “mouse trap.” A new in-plant trait or foliar insecticide that will provide control of tarnished plant bugs is the “Holy Grail” for the chemical industry right now. However, there does not appear to be anything coming in the near future for tarnished plant bug control. Because of that, the old standard insecticides such as acephate and dicrotophos will remain an important component of IPM in conjunction with some of the newer insecticides such as the neonicotinoids and Diamond.
Producers should not panic just yet when it comes to the tarnished plant bug. I am confident that the next innovation in insect control will come eventually. Until that time, we will must manage the available tools that we have to minimize the impact of plant bugs on cotton yields.
Contact Jeff Gore at Mississippi State University’s Delta Research & Extension Center at firstname.lastname@example.org or (662) 820-9969.