Beneficial Bugs

Who let the bugs out? The zoo’s horticulture team did!

When asked to think about garden insects, most people would land on the term ‘pest’ before ‘beneficial.’ Although insects typically receive a bad reputation, certain species can help control plant pests. Inside Lincoln Park Zoo’s buildings, like McCormick Bird House and Regenstein Small Mammal-Reptile House, the Horticulture team releases insects, known as beneficials, to help keep the plants healthy. The introduced insects act as natural predators for the harmful pests that stress and often damage the zoo’s indoor plants.

Lacewing (Chrysoperla rufilabris)

Since late 2018, the Horticulture team has released three species of beneficials: mealybug destroyers (Cryptolaemus montrouzieri), spider mite predators (Neoseiulus cailfornicus), and lacewings (Chrysoperla rufilabris). There’s a science and art behind releasing beneficials, as the team has to work to create an environment where the released insects will stay in the targeted area. This includes monitoring both humidity and temperature and creating a livable space for the beneficials. The Horticulture team also partners with Veterinary staff to ensure the insects are safe for zoo animals to ingest—just in case.

Spider Mite Predator (Neoseiulus cailfornicus)

Beneficials are delivered to the zoo every two to three months and arrive in varying life stages. The Horticulture team releases lacewings in their larvae stage, when they are their hungriest, and mealybug destroyers as mated adults in the hopes that the released population will continue to grow. The goal is for the beneficials to sustain their own population, as well as control harmful pests.

Mealybug Destroyers (Cryptolaemus montrouzieri)

The insects are slowly dispersed across the foliage of the zoo’s tropical plants in designated areas. Spraying the leaves of the plants with water helps the bugs stick better. The process is far from simple, though. If the Horticulture team adds too many beneficials to any given area, they could over-consume their food source, the pests, and die off. Balance is key. These beneficial bugs support the zoo’s efforts to live wildlife friendly by acting as a natural pest control alternative to pesticide use.