Spring Break! Unwelcome Guests

Editor’s Note: The following article was adapted from Techletter, with permission from Pinto & Associates.

Hotels, resorts and commercial accounts with large, landscaped grounds often don’t consider that what’s going on outside could be contributing to pest problems inside. The lush, heavily watered and heavily mulched flowering plants found throughout a hotel’s grounds invite guests to relax in a tropical oasis. Grounds and maintenance staff don’t know they provide pests with everything they need: food, water and shelter.

Most of our serious structural and ground pests originated in the tropics, so anything that recreates that warm, humid setting allows them to thrive. When it comes to hospitality settings and exterior landscaping, if the pest management professional has any influence with the management at all, he or she should stress that less is more. Here are some examples of how too much of a good thing outdoors can result in indoor pest problems:

Mulch is kept too wet. Automatic watering systems run at night and wet the mulch around the foundation, creating ideal conditions right up against the building for termites, ants, millipedes, pillbugs, oriental cockroaches, springtails, earwigs, crickets and others. It is not difficult for these pests to then enter the hotel from the mulch through weep holes, gaps in the masonry, holes under siding, expansion joints, or simply under doors or around windows without screens or weather stripping.

Susceptible plants are too close. When certain plants and shrubs are placed too close to the foundation, and when they are not pruned back, ants can trail from the plants directly onto the building. Certain plants (like azaleas) are prone to infestations from aphids, scales or other bugs that suck plant juices and excrete sugary “honeydew.” Ants will tend these bugs to feed on the honeydew secretions. Some fly and wasp species, including yellowjackets, also are attracted to the honeydew. Fewer plantings placed farther away from the building are best. Poor plant choices encourage rodents. Vines, like English ivy, and ground cover plants, like Pachysandra, are much too pest-friendly for hospitality settings. They attract burrowing rats and mice and other pests. Thick ground cover plantings, thorny shrubs and shrubs with dense lower branches are difficult to inspect and treat for pests. They also trap food trash. Vines on walls provide nest sites for birds and become natural bridges that allow pests to move into the facility. Rodents, especally rats, will burrow among juniper shrub roots and in planters placed on patios and balconies, particularly if there are also food sources like trash cans nearby.

Editor’s note: This article originally appeared in the 10/21/2014 Techletter and it was based on a chapter in the PCT Commercial Pest Management, which can be purchased at www.pctonline.com/store.