Tillage Reduces Survival of Grape Berry Moth (Lepidoptera: Tortricidae), via Burial Rather Than Mechanical Injury

Abstract

The grape berry moth, Paralobesia viteana (Clemens), is a key pest of vineyards in eastern North America that overwinters as pupae in leaf litter on the vineyard floor. This presents an opportunity for tillage to disturb and bury the pupae, providing a potential nonchemical approach to control of this pest. Using a Lilleston-style rotary cultivator, we determined the distribution of pupae within the soil profile after single tillage passes, measured the type and severity of damage inflicted on pupae, and investigated how these effects on pupae influenced their survival. Survivorship of pupae recovered from the vineyard immediately after tillage and held until emergence was not significantly different from those recovered from an untilled control area, indicating little effect of mechanical damage on this pest. However, a single pass of the tillage implement buried three-quarters of pupae under at least 1 cm of soil. A laboratory experiment to recreate these conditions resulted in significant increase in mortality when pupae were buried in more than 1 cm of sand. We conclude that 1) interference with adult emergence of diapausing pupae via burial is the primary mechanism by which tillage controls grape berry moth, and 2) efforts to optimize the impact of tillage on grape berry moth populations should focus on maximizing the number of pupae buried. We discuss the potential integration of tillage into different vineyard management systems to enhance pest management.

Cultural Control of Giant Sugarcane Borer, Telchin licus (Lepidoptera: Castniidae), by Soil Mounding to Impede Adult Emergence

“…Thus, a layer of soil 10 cm in depth around the base of plants was sufficient to prevent T. licus adult moths from reaching the soil surface, likely because they lack either tarsi or mouthparts that would enable digging behavior. Thus, control by burial is likely to be less affected by soil properties such as texture, moisture content, temperature, or degree of compaction than it is for other insects that naturally pupate in litter or soil (Chen & Shelton 2007;Renkena et al 2012;Matlock et al 2017;Hooper & Grieshop 2020). Similarly, mounding of soil around the base of apple rootstocks can provide 76 to 99% control of dogwood borer, Synanthedon scitula (Harris) (Lepidoptera: Sesiidae) (Gut et al 2005).…”

“…Burial via tillage also can provide effective control of pests that pupate in litter on the soil surface, such as the grape berry moth, Paralobesia viteana Clemens (Lepidoptera: Tortricidae) (Matlock et al 2017). Burial of mature larvae of the codling moth, C. pomonella, below a depth of 1 cm resulted in complete mortality of all insects (Baughman et al 2015).…”

Routine On-farm Soil Tillage Helps Control Asparagus Fly (Plioreocepta Poeciloptera)

“…The effects of different soil cultivation methods on insects may vary between species, time of cultivation, soil type and insect life stage (Johnson et al 1984;Stinner and House 1990;Seal et al 1992;Chu et al 1996;Holland and Luff 2000;Holland and Reynolds 2003;Baughman et al 2015;Matlock et al 2017;Alyokhin et al 2020) and cannot be generalised. Since the soil samples were mixed before the boxes were filled, the depth position of the individual pupae within the boxes can be expected to be random.…”