Student Research Spotlight - Anna Busch
Posted: March 27, 2015
Lions and Tigers and Slugs, oh my!
by Alex McMenamin
Younger siblings everywhere may have the right idea when they scream in fear as that slug you threw hit them in the forehead. Slugs are not just slimy, but they are actually a real concern for farmers. Indeed, it is scary how much damage slugs can pose to a farmer’s crop. Anna Busch, a Master’s student in Penn State’s Entomology Department is investigating just how big a problem they can be, and also how to control them by striking fear in their hearts.
“Slugs tend to eat seeds and seedlings, before they even have a chance to become productive plants,” said Busch.
Busch is working with Penn State researchers to monitor slug populations and the populations of their predators on Pennsylvania farms. Slugs pose the largest threat to farmers very early in the season when they subsist primarily on seeds and seedlings, which can seriously reduce the number of plants that go on to produce sellable field-crops, namely corn and soybeans, Busch says. In small operations, this can result in a devastating hit to a farmer’s income.
In the wild, slugs are preyed upon by other critters like beetles. In an on-going field experiment, Busch and her colleagues are trying to figure out what kind of farms beetles like in order to encourage the beetles to live in their crop fields. It is in the farmer’s interest to support a healthy predator population so that slugs don’t overrun their crop. Ideally, the beetles would police the slugs and reduce the damage the slugs might cause to plants.
In another ongoing experiment, Busch is interested in determining whether the slugs are afraid of these beetles. The hope is that a scared slug might be less likely to stick around, similar to how you might run the other way if you encounter a bear or a wolf.
“If it turns out that slugs can detect their beetle-predators and ‘hide’, releasing beetles might be a control option in the future,” said Busch.
This kind of pest control method, in which another organism is used to control a pest species, is called “biocontrol.” Traditionally, biocontrol methods rely on a predator or a pathogen to directly kill the pest. Busch is coming at this problem from a new angle and trying to determine whether the presence of the beetle alone might be enough to paralyze the slugs with fear, thereby reducing the damage a slug might cause. Currently no biocontrol methods are approved against slugs in the U.S. But, using their fears against them could be one avenue for control.