Thrips are small insects that feed on many plants including roses. They cause no harm to humans or pets, but they do pose a threat to most garden plants because they suck up water from the soil and make it available for other organisms. You may have seen them crawling around your flowers or even inside your roses!
The best way to kill these little pests is with natural methods such as spraying pesticides or using natural predators like ladybugs and lacewings.
However, there are other ways to control thrips that don’t involve chemicals. One of those methods is to use natural enemies like ladybirds and lacewing larvae. These creatures will eat the adult thrips before they can lay eggs.
The larva will then consume the egg cases once hatched into adults.
Lacewing larvae are tiny little critters that live all over the world. They are very common in ponds and streams, where they feed on aquatic plants. They’re also found in some deserts and grasslands.
Their life cycle lasts only about three months, during which time they’ll pupate out of sight until spring when they emerge again ready to start feeding again. Ladybird larvae are smaller than ladybugs, but much larger than aphids. They are all predatory and will dine on various pest insects.
In addition, rose growers can also use companion planting to thwart the thrips. They can pair off plants that don’t get along well with the thrips and experiment with different combinations until they find ones that seem to work well. They can also employ this method as a preventative measure before their roses even get infested.
Unfortunately, none of these methods are foolproof. Thrips can be very stubborn and difficult to kill, but if you’re vigilant and pay close attention, you should be able to keep them away from your roses.
The best time to spray against most bugs is in the evening just as the sun is setting. This gives the plants time to dry off but still keeps the chemical from burning the plant (some chemicals can burn plant leaves).
The most important time to spray your plants, including roses, is just before bloom when the petals start to open and after they bloom; this will prevent disease and many insects. If you have the resources and live in an area that allows it, you can also make your own plant spray.
Sources & references used in this article:
Ecological studies on Thrips imaginis Bagnall (Thysanoptera) in flowers of Echium plantagineum L. in Australia by WDJ Kirk – Australian journal of ecology, 1984 – Wiley Online Library
Irradiation as a quarantine treatment of cut flowers, ginger and turmeric against mites, thrips and nematodes by AD Bhuiya, MZR Majumder, G Hahar, RM Shahjahan… – 1999 – inis.iaea.org
Insecticide resistance in European and African strains of western flower thrips (Thysanoptera: Thripidae) tested in a new residue-on-glass test by HF Brødsgaard – Journal of economic entomology, 1994 – academic.oup.com
The chilli thrips, Scirtothrips dorsalis: current status in the Greater Caribbean Region by W Klassen, DR Seal, MA Ciomperlik, DA Fieslemann – 2008 – ageconsearch.umn.edu