Cacti, with their spiny structure and waxy surface, seem like an unlikely food source. However, while grasshoppers are typically generalist herbivores consuming soft grasses in moist habitats, resource scarcity in dry ecosystems forces certain species to adapt. Specific desert grasshoppers have evolved the means to successfully consume the tough exterior and water-rich interior of cacti.
The Primary Answer: Grasshoppers as Cactus Feeders
The answer is definitively yes, particularly in regions where alternative food sources are scarce. Desert-dwelling species feed on the fleshy pads and fruits of cacti, treating them as a survival food during dry summer months when the plant’s stored moisture is an attractive resource.
The genus Opuntia, or prickly pear, is the most frequent target due to its flat pads and softer new growth. Grasshoppers often target the newest pads, tender developing fruit, or the plant’s soft base near the soil. Damage appears as chewed-out holes or superficial scoring marks across the epidermis. Large species like the Horse Lubber Grasshopper readily turn to cacti when other greenery is unavailable. Damage can be significant, causing cosmetic injury or, in severe infestations, compromising the plant’s structural integrity and ability to photosynthesize.
Specialized Feeding Mechanisms and Adaptations
Grasshoppers possess robust, highly sclerotized mandibles, which are well-suited for processing difficult plant material. These chewing mouthparts operate horizontally, like a pair of shears, enabling them to bite off and grind tough plant fibers and the waxy skin of a cactus.
The insect’s feeding strategy helps them navigate the physical structure of the plant. They often avoid large, sharp spines by targeting relatively spine-free areas, such as the base or the edges of the pads. Some desert grasshoppers scrape the surface, focusing on the nutrient-rich layers just beneath the waxy cuticle rather than chewing through the entire mass. This technique minimizes contact with the inner mucilage, the gooey substance inside the cactus, which can be difficult to ingest.
Mitigation and Protection Strategies
Protecting cacti requires a multi-pronged approach focused on physical exclusion and targeted control.
Physical and Manual Control
For small or highly prized cacti, using fine-mesh screen cages or floating row covers is an effective physical barrier to prevent the insects from landing and feeding. This method reliably separates the pest from the plant without chemicals.
Manual removal is a practical strategy, especially when dealing with smaller infestations or larger, slow-moving species like Lubber grasshoppers. Hand-picking the grasshoppers early in the morning when they are sluggish and placing them into a container of soapy water can reduce pest numbers quickly. This method is best used on individual plants or in small garden settings.
Broader Control Measures
For broader control, gardeners can employ biological and chemical measures.
- The naturally occurring microbe Nosema locustae can be applied as a bait to infect and reduce grasshopper populations over time, though it is most effective on younger nymphs.
- Insecticidal soaps or neem oil can be sprayed directly onto the pests, but test a small area of the cactus first, as some succulents are sensitive to oil-based applications.
- Managing surrounding weeds and tall grasses is also helpful, as these areas serve as breeding grounds and temporary shelters for grasshopper nymphs before they move to more valuable plants.