By Ralph E. Mitchell
Did you ever walk by your favorite bougainvillea and notice the tips of the leafy branches chewed to pieces and the culprit apparently gone? I just had that experience the other day. My pink ‘Pixie’ bougainvillea had suffered from some chewing insect which had damaged the tips of each branch and shredded the leaves on down. I poked through the mess and teased out the problem – a small green, pudgy caterpillar which had folded up some leaves and fed inside causing loss of foliage and piles of droppings. What was I dealing with?
As it turned out this caterpillar is known as the bougainvillea leaftier. The caterpillar had actually tied up several leaves with silken threads and formed a foliar tube of sorts offering a safe place to hide from predators. The silken threads actually contract as they dry completing a tight, enclosed shelter. As the caterpillar grows it feeds on the surrounding leaves and excretes droppings that build up within the folded leaf. Before too long, the damage becomes apparent. While the damage may look horrible, it is often more of an eyesore under a normal infestation and will quickly grow back. Damage could be extensive, but, with vigilance, you can normally take control measures before it gets out of hand.
Control measures will include handpicking – which I choose – to suppress the outbreak. I simply examined each branch tip, unrolled the leaf shelter, and dispatched the caterpillar. In this way I became the “predator” and essentially groomed the plant until all offending caterpillars were gone. Interestingly enough, paper wasps were also present hunting for these fat caterpillars to feed their brood – a welcome natural predator. Certain spiders and other beneficial organisms would also take their share of these caterpillars. Earlier on when the leaftier caterpillars were small, I could also have applied Bacillus thuringiensis (Bt) as an insecticide which only kills caterpillars. Another least-toxic material to try is spinosad which is a microbial insecticide derived from a species of soil bacteria. If the infestation is large, you could step it up a bit and try something ”harder” like carbaryl. As with all pesticides, please make sure to read the label, as the label is the law!
Pests like the bougainvillea leaftier will likely pop up from time to time. As such, regular monitoring – which is a part of Integrated Pest Management or IPM – is a common-sense tool that will help you better manage pests in your yard. For more information on all types of pests infesting your landscape, please call our Master Gardener volunteers on the Plant Lifeline on Mondays, Wednesdays and Fridays from 1 to 4 pm at 764-4340 for gardening help and insight into their role as an Extension volunteer. Don’t forget to visit our other County Plant Clinics in the area. Please check this link for a complete list of site locations, dates and times – http://charlotte.ifas.ufl.edu/horticulture/Plant%20Clinics%20Schedule.pdf.
Caldwell, D. (2015) Bougainvillea Chewers. The University of Florida Extension Service, IFAS – Collier County.
Porchey, P. (2012) July Gardening Guide. The University of Florida Extension Service, IFAS – Sarasota County.
Buss, E. A. & Park Brown, S. G. (2014) Natural Products for Managing Landscape and Garden Pests in Florida. The University of Florida Extension Service, IFAS.