Pink bollworm moth
The pink bollworm moth, scientifically known as Pectinophora gossypiella, is an insect originally native to Asia that became an invasive pest in the United States during the 1920s. This species was particularly detrimental to cotton growers, causing significant crop damage, including a reported $32 million loss in Arizona in 1992 alone. The damaging phase occurs during the larval stage when the caterpillars bore into cotton bolls, consuming both the cotton fibers and seeds. The adult moths are dark brown with black markings, measuring slightly less than one inch in wingspan, and do not feed; instead, they reproduce rapidly, leading to multiple generations each year.
Efforts to control the pink bollworm included the use of man-made pheromones for trapping and the development of faster-growing cotton varieties. In the late 1990s, a sterilization program was initiated, releasing sterilized moths to disrupt reproduction. By 2018, these measures led to the successful eradication of the pink bollworm moth from the United States, marking a significant achievement in agricultural pest management.
On this Page
Subject Terms
Pink bollworm moth
The pink bollworm moth is an insect species originally native to Asia, but became an invasive species in the United States in the 1920s. This species was a terrible pest to cotton growers and many other plants. It was eradicated in the United States around 2019.
Kingdom: Animalia
Phylum: Uniramia
Class: Insecta
Order: Lepidoptera
Family: Gelechiidae
Genus: Pectinophora
Species: Gossypiella
Cotton growers and those who raise a number of other plants in the southern United States had long been familiar with the pink bollworm moth. This incect species was the cause of severe damage to cotton crops and the flowers and fruits of up to thiry-nine other types of plants in tropical regions. As an example, cotton growers in Arizona sustained losses of $32 million to the Pink bollworm in 1992.
The pink bollworm moth was not a problem as an adult in its matured moth form. It was the moth larvae, or young, which caused damage to crops. The problem with the adult moth was that it mated and reproduced. After mating, the female would lay her eggs on the outside of the cotton bolls. A cotton boll is the round, brown pod which contains the soft cotton and the cotton seeds. The larvae hatched as caterpillars, then bored into the boll and ate the cotton and the seeds. This is the source of their name, bollworm. They are called pink bollworms because they turned pink while they are growing. The bollworms grow quickly, splitting and molting, or shedding, their skins and growing new ones. This process is sometimes called ecdysis.
When the bollworms grow to 1/2 inch (one centimeter), they are fully grown and ready to pupate. Pupation is the process of transforming into adults and occurs inside cocoons. They pupated inside the cotton bolls or in the ground. They emerge as adult moths during the summer after only a few days.
The adult pink bollworm moth's body and forewings are dark brown with black markings. Its hind wings are silver gray. The wingspan is a little less than one inch (about 1 1/2 to 2 centimeters). This moth does not eat as an adult, but it reproduces quickly so that several generations of pink bollworm moths may be born each year.
The pink bollworm moth probably first appeared in the southern United States, and spread to other tropical regions around the world in cotton shipments. It is a difficult insect to control or kill with insecticides since it reproduces quickly. Because of this, many attempts were made to save cotton crops from the pink bollworm moth, including growing types of cotton that grew more quickly so they could be harvested before bollworms infected the bolls. Another method involved using man-made pheromones to attract moths into traps where they were killed. Pheromones are special chemicals used by female moths and other insects to attract males for mating.
Other related species of moths which cause similar problems are some of the members of the family Nocturidae. Heliothes armigera and Heliothes zea are two species of moths which are called cotton bollworms, corn earworms, or tomato fruit worms, depending on the plants they attack. These species occur nearly worldwide in tropical regions. These caterpillars are larger than the pink bollworm and are up to 1 1/2 inches (about four centimeters) long.
In the late 1990s, the U.S. Environmental Protection Agency began a program where adult moths were collected and sterilized. This meant they would not be able to reproduce. The sterilized moths were released back in the wild in large numbers. Pink boll worm moths were unable to find a fertile mate. Not only could they not produce the larvae, but their numbers began to decrease. After several decades, it was assessed that there were few, if any, unsterilized moths living in the wild. In 2018, the U.S. Department of Agriculture announced that the species had officially been eradicated, or removed, from the United States.
Bibliography
“Pink Bollworm.” A-Z Animals, 28 Feb. 2023, a-z-animals.com/animals/pink-bollworm. Accessed 16 Apr. 2024.
“Cotton Pests.” U.S. Department of Agriculture, 29 Mar. 2024, www.aphis.usda.gov/plant-pests-diseases/cotton-pests. Accessed 16 Apr. 2024.
“How Science Wiped Out the Invasive Pink Bollworm in the U.S.” Entomology Today, 16 Feb. 2021, entomologytoday.org/2021/02/16/how-science-wiped-out-invasive-pink-bollworm-united-states. Accessed 16 Apr. 2024.