Boll Weevil

In 1892, near brownsville, texas, a small beetle, identified by local agricultural authorities as the Boll Weevil, or Anthonomus grandis, made its first appearance in the United States. For the next century, the tiny insect would radically alter the South's agricultural economy by attacking the region's major crop—cotton. Many believe that the weevil was one of the most important agents of social change in the South, second only to the Civil War. The beetle's destructive wrath, coupled with a backwards agricultural system known as sharecropping, impoverished the southern states and prompted Franklin D. Roosevelt during the 1930s to label the South as the “nation's number one economic problem.”

Although the boll weevil is indigenous to Mexico and Central America, it is an invasive species in the United States. At the time of its arrival, most of the South's agricultural lands were cultivated in cotton. Over the next 30 years, the ravenous beetle migrated eastward. By 1915, it was bearing down on Georgia. At the time of the beetle's entry into Georgia, approximately 5.2 million acres of the state's land was cultivated in cotton. The weevil's impact on the state could be observed eight years later when it was reported that only 2.6 million acres were devoted to cotton. The decline in cultivated acreage corresponded with a drastic reduction in yield. In 1914, for example, Georgia produced 2.8 million bales of cotton. By 1923, these numbers had been reduced to 600,000 bales, primarily due to the weevil. The story was the same across the Cotton Belt. In 1907, Mississippi produced 191,790 bales of cotton. Within only five years of the weevil's arrival, Mississippi farmers could barely generate 30,000 bales. During the height of the Great Depression in the 1930s, the South's estimates of damage due to the insect exceeded $200,000 annually. In 1950, the Cotton Belt set a historical record with losses topping over $750 million. By the end of the 20th century, the weevil had cost the region's cotton farmers an estimated $22 billion in losses and control efforts.

In order to survive, the boll weevil must have access to cotton. Adult weevils impact young cotton bolls (or squares) by feeding upon them and using them as a place to deposit their eggs. Actually, the damage done by feeding is minimal. It is the larval stage of the insect that is most devastating to cotton. Male weevils, after locating a cotton field, release a special pheromone to attract females. Thus, the presence of cotton is necessary to ensure the insect's propagation. Upon mating, females seek out a cotton boll in which to deposit an egg. Meanwhile, both males and females use their long snout to puncture the bolls and feed.

After mating, the female lays an egg (usually one per boll) in an abandoned feeding tube and covers it with a dark, sticky substance known as frass. Within the week, the egg hatches and a small, legless larva, or grub, emerges. For the next few days, the larva consumes the boll's internal tissues, after which it enters a pupation stage that lasts for about a week. At the end of the pupation period, an adult weevil emerges from the boll and immediately begins to seek out cotton and a mate.

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