June beetle larvae are described as which shape, and what is the population threshold?

• A. Small straight larvae; 10 per square inch
• B. Large C-shaped larvae; 3 per cubic square inch
• C. Curved larvae; 1 per cubic foot
• D. Plump larvae; 5 per square foot

Answer: (B)

The key idea is identifying the grub and using an action threshold based on how many grubs are in a given soil volume. June beetle larvae are among the larger white grubs and have a pronounced large, C-shaped body when viewed from the side. That distinctive shape signals a substantial root feeder, which is why it matters for management decisions. The threshold used to justify control is about three grubs per unit of soil volume (per cubic inch). When you find roughly three of these large C-shaped grubs in a cubic inch of soil, the potential for root damage is high enough to warrant management actions. If you encounter smaller, differently shaped larvae, they belong to other pest groups and typically have different thresholds, so the combination of a large C-shaped form with a density around three per cubic inch best matches the given option.