What federal authorities dubbed Operation Spiderman began last March, when a routine search of an international package revealed about 300 live tarantulas being shipped to Los Angeles, according to the U.S. Attorney's Office.
U.S. Fish and Wildlife agents intercepted a second package that contained 22 Mexican red-kneed tarantulas, a species that is protected under an international treaty.
Agents ordered more tarantulas from Koppler, who allegedly sent a package that included about 70 live tarantulas and one dead spider.
Koppler received about $300,000 as a result of tarantula sales to spider fanciers in dozens of countries, including nine people in the United States, according to the criminal complaint.
Koppler plans to plead guilty to an animal importation charge, which carries a potential sentence of 20 years in federal prison and a fine of $250,000, according to court papers.
The plea agreement is not binding until Koppler appears before a judge for sentencing on April 11, prosecutors said.