Dealing with destructive little ones doesn’t require a scorched-earth approach
Spotting pests making homes on your cacti, succulents, and shrubbery is never a delightful discovery. The more those little buggers thrive and multiply, the likelier it portends not-swell effects for your precious leaf babies plants. As much as we gardeners want to evict those gluttonous trespassers like yesterday, ideally the solution doesn’t lie in harsh, chemical-heavy measures. No. 1, it starts with ecologically minded gardening (namely, approximating your plants’ natural habitat as best as possible).
This motley cast of plant-mangling characters includes aphids, mealybugs, spider mites, aphids, scale, and thrips, as well as larger players such as snails and slugs. Those with agaves may have to contend with the rot-causing agave snout weevil.
Aphids: Tiny sap-sucking, pear-shaped, sometimes-winged bugs that come in a range of colors, including green, yellow and black. Ants fancy the apparently delectable honeydew secreted by aphids as they feed on plant material.
Mealybugs: Resembling bits of cotton, mealybugs spell potential, distorting trouble to succulents much in the same way as aphids, and also attract hungry ants in the process. Adult females can lay hundreds of eggs. The secretions can build up as a sooty, photosynthesis-disrupting film.
Root mealybugs: These guys specialize in, yep, root consumption. As their numbers increase, the surrounding soil may take on a bluish tint courtesy of their waxy secretions. Root mealybugs make plants more prone to rot from bacterial and fungal infections.
Spider mites: These little, colony-forming ones do spin webs, but are far smaller and much more harmful to plants than their larger relatives.
Scale: These grayish-white, tissue-consuming insects live inside dome-shaped hard shells, are about 1/8 inch long, and can be difficult to eradicate.
Thrips: Often yellow or black, these slender fellers can damage leaves, fruit, and shoots. One particular type of thrip attacks the buds of prickly pear cactus, undermining fruit development.
First of all, try not to panic. Your blowtorch at best will provide fleeting satisfaction. Pest management starts with practicing good cultural techniques. This means growing plants in recommended conditions pertaining to fundamentals like sunlight, water, drainage, and ventilation.
Pest control solutions vary depending on plant species and the particular distress or offender. As many wee humans learn from Eric Carle’s The Grouchy Ladybug, ladybugs love to make meals out of aphids. Mealybugs, mites, and scale too. They are available at many garden centers and nurseries. There are other predators available for pest consumption work as well.
Aside from such biological controls, it may be possible to simply blast away most pests with a garden hose. If that proves no better than temporarily effective, consider spraying with a bottle of soapy water or isopropyl alcohol diluted 50-50 with water. Spot application via alcohol-solution-dipped cotton swab, as opposed to drenching the entire plant, may be appreciated by sensitive plants at risk of damage to the epidermis. As such, test a small area of the infested plant before applying store-bought insecticidal soap everywhere.
Mealybugs cause enough problems that it may be necessary to remove an injured plant to spare its neighbors. Root mealybugs, especially when infesting a landscape specimen, can be a bigger headache, possibly requiring a pesticide soil treatment. It’s a little easier if they’re colonizing in a container. In that scenario, dump the affected soil, thoroughly wash the container, and repot clean cuttings in fresh soil.
An interesting if frustrating note about thrips: By the time you notice the damage caused, these insects may have split, and no amount of chemical application will restore the appearance of damaged tissue.
Scale may require more drastic measures. You can start by scraping off those itty-bitty aggravators with a plastic knife. Severe infestation may require quarantining the plant, permanently removing pieces, and giving the whole specimen a bath before repotting or replanting it.
A comprehensive overview is tough to pull off in 600 words, so we’ll conclude with this tidy list of online resources.