Caterpillars can cause significant economic damage in both greenhouse and field crops due to their aggressive feeding habits. Most species target leaves and young shoots, and their high consumption rate can quickly weaken or destroy plants. When caterpillars are very small, they are unable to chew through entire leaves and instead graze the undersides, creating a distinctive "windowing" effect where only the upper epidermis remains intact. These early instars are often found in groups and gradually spread across the plant as they grow.

As caterpillars increase in size, the damage becomes more extensive. Leaves are often skeletonized, with only the midribs remaining, and larger caterpillars may also feed on flowers, fruits, and growing tips, further reducing crop quality and yield. Some species are more discreet in their feeding habits, tunneling into leaves, fruit, or stems, which makes them harder to detect and control. In addition to the direct damage caused by feeding, caterpillars also contaminate plants with frass (insect droppings), which can reduce the aesthetic and market value of ornamental and edible crops.

Common culprits include Tomato Looper (Chrysodeixis chalcites), Tomato Moth (Lacanobia oleracea), Cabbage Moth (Mamestra brassicae), Beet Armyworm (Spodoptera exigua), Tomato Fruitworm (Helicoverpa zea), Cabbage Leafroller (Clepsis spectrana), and Box Tree Moth (Cydalima perspectalis), among many others. Despite their different names and target crops, these caterpillar pests share similar feeding habits, typically chewing holes in leaves, boring into fruit, or mining plant tissues, all of which reduce yield and marketability.

If you know the exact caterpillar pest affecting your crop, feel free to reach out to us directly. We may be able to recommend a specific pheromone lure to pair with a trap, improving monitoring and even enabling mass trapping in some cases. Identifying the species is key—all pheromones are highly targeted and only attract one pest type. Whether you're dealing with leafy greens, ornamentals, tomatoes, or boxwoods, we’re happy to help tailor a solution to your situation.

The life cycle of butterflies and moths begins with the egg stage. These eggs are very small and can vary in shape, colour, and texture depending on the species. They are usually laid on host plants that the caterpillar will feed on after hatching, as many caterpillars are selective about what they eat. This careful placement ensures the newly hatched larvae have immediate access to food.

Once the egg hatches, the insect enters the caterpillar stage, also known as the larva. The primary role of the caterpillar is to eat and grow. Because caterpillars have exoskeletons, they cannot grow continuously and must shed their skin as they expand in size. Most caterpillars go through five moults, or skin sheds, during this stage.

After completing its growth, the caterpillar enters the pupal stage, often referred to as the chrysalis. At this point, the caterpillar seeks a safe place to undergo metamorphosis. Some species attach themselves to the host plant, others burrow into the soil, or spin a silk cocoon around themselves before forming a pupa. Inside the chrysalis, the caterpillar’s body breaks down and reorganizes into the adult form—a remarkable transformation.

The final stage is the adult butterfly or moth. Depending on the species, the pupal stage can last from a week to over a year. When the adult emerges, its wings are initially soft and crumpled. The insect will pump fluid into the wings to expand and strengthen them, preparing for its first flight. As adults, butterflies and moths are typically focused on reproduction and, in many species, feeding on nectar.

Preventing moths from laying eggs on your plants is an important step in avoiding the damage caused by their caterpillars. One of the most effective strategies is regular monitoring. Carefully inspect plants, particularly the undersides of leaves, for small eggs or newly hatched caterpillars. Manually removing and destroying these early stages can significantly reduce infestations before they become a problem.

Another effective method is to use physical barriers like floating row covers or fine insect netting. These materials physically block moths from reaching your plants to lay eggs. Row covers are especially useful in vegetable gardens and should be secured tightly to the ground to prevent moths from slipping underneath. Since many moths are nocturnal, applying these covers in the late afternoon or evening can provide added protection.

Limiting artificial light around your garden at night is another helpful tactic. Moths are attracted to light, and bright nighttime lighting can draw them toward your plants. Reducing or eliminating outdoor lighting near garden beds in the evening can help make your plants less inviting to egg-laying adults.

Timing your planting can also be useful. If possible, avoid planting highly susceptible crops during periods of peak moth activity, particularly in areas where specific species are known to be problematic. This reduces the window of opportunity for moths to lay eggs on vulnerable young plants.

Pheromone traps can also be used to monitor and reduce moth populations. These traps lure in male moths using species-specific scents, helping to interrupt mating and providing early warning signs of pest activity. While not a complete solution, they are a valuable tool in integrated pest management.

By combining these preventive strategies, gardeners and growers can significantly reduce the chances of moths laying eggs and keep caterpillar damage to a minimum.

For caterpillar control, we use Capsanem, a biological product that contains the entomopathogenic nematode Steinernema carpocapsae. These microscopic roundworms are natural parasites of many insect pests, including caterpillars. When applied to infested plants leaves, the nematodes actively seek out caterpillars, entering their bodies through natural openings. Once inside, they release symbiotic bacteria that quickly kill the host. The nematodes then reproduce inside the dead caterpillar before moving on to find new targets.

Capsanem is most effective against young caterpillars and is best applied in the early morning or late afternoon when humidity is higher and UV exposure is lower. It works well in both greenhouse and outdoor environments, especially when used as part of an integrated pest management (IPM) program.

To ensure effectiveness, good coverage is essential. As Capsanem is a living organism, it should be stored and handled according to the label instructions to maintain viability. While not a contact insecticide, its targeted action offers a sustainable and environmentally friendly option for managing caterpillar populations without harming beneficial insects, pollinators, or plants.