Beneficial Insects in Tobacco
Last week while scouting my plots at Kinston and Rocky Mount, I spotted two predatory insects: big-eyed bugs and spined stilt bugs. Big-eyed bugs (Geocoris puntipes) are common predators found in many cropping systems.
The spined stilt bug (Jalysus wickhami) is an important predator in tobacco and several other crops.
The stilt bugs feed on smaller, slower insects including aphids and tobacco budworm and hornworm eggs. A single stilt bug can consume 80 tobacco budworm eggs during its development to adulthood, and adults consume 25 eggs per day during an 80-day lifetime. Therefore, a single stilt bug can prevent the development of over 2000 budworm larvae throughout its life.
Because the spined stilt bug is an important predator, it is essential to understand how pest management practices may impact it. Previous research has linked applications of older, infrequently used insecticides to significantly lower numbers of stilt bugs in flue-cured tobacco. While these insecticides are rarely used any more, the impact of their replacements on the spined stilt bug have not been assessed. Thus, a major effort in my research is determining the impact of both systemic and foliar insecticides on the spined stilt bug, with the goal of recommending compatible insecticides that will conserve the predators. Preserving predators through the modification of pesticide usage is referred to as conservation biological control and is a simple, cost-effective form of biological control. Future updates will discuss this research in more detail.