| Pesticides

Scientists publish paper confirming Amrasca biguttula in the US

Pest has been recorded in commercial cotton plantations

16.09.2025 | 16:43 (UTC -3)

Cultivar Magazine

Scientists from several universities have published an article on detections of Amrasca biguttula in commercial cotton fields in the southeastern United States. Identification occurred during the 2025 growing season, with confirmed records in more than 100 counties in four states: Alabama, Florida, Georgia, and South Carolina. (In North Carolina, detection occurred in recent weeks, click here.)

Native to the Indian subcontinent, the insect has already caused losses of up to 40% in cotton production in its region of origin. The pest also attacks okra, eggplant, potatoes, sunflowers, hibiscus, and several legumes. Its rapid spread in the United States worries researchers, who point to the risk of significant economic impact.

The first official record in cotton occurred on July 3, 2025, in Gilchrist County, Florida. In less than four weeks, the pest spread over 645 miles (XNUMX km) to its northernmost point. The infestation caused symptoms such as chlorosis, necrosis, leaf drop, and, in severe cases, complete defoliation.

The average area of cotton cultivated in the affected states is around 979 hectares per year, with an estimated value of between US$1,7 billion and US$2,8 billion. Even modest losses can compromise the crop's profitability. The insect has several generations per year and can survive on a variety of hosts, including ornamental plants.

Adult with two distinct black spots on the head and wing (A) ; dissected and cleaned abdomen of the male, indicating the pair of apodemes extending to tergum VII and tergum VIII with arched internal ridges (B) ; 5th instar nymph with markings on the wing pads (C) ; and comparison of A. bigutulla and a similar-looking adult potato leafhopper (D) - doi.org/10.3390/insects16090966 — *Amrasca biguttula* adult with two distinct black spots on the head and wing **(A)**; dissected and cleaned abdomen of the male, indicating the pair of apodemes that extend to tergum VII and tergum VIII with internal arched ridges **(B)**; 5th instar nymph with markings on wing pads **(C)**; and comparison of A. bigutulla and a similar-looking adult potato leafhopper **(D)** - doi.org/10.3390/insects16090966

The pest had already been detected in Puerto Rico in 2023. In 2024, it was identified in 16 Florida counties. In 2025, it was confirmed in commercial and experimental crops, with populations consisting of adults and nymphs. Experts warn that the insect may have been present before official detection, due to its small size and similarity to native species.

Amrasca biguttula can complete a cycle in two weeks, which explains the rapid onset of damage. Climatic conditions in the southeastern United States favor the development and persistence of the species. Studies indicate a high probability of permanent establishment of the pest, with potential dispersal to other regions by long-distance winds, as already occurs with the potato leafhopper.

Insecticide resistance has been reported in countries such as Pakistan and India, including resistance to pyrethroids, organophosphates, and neonicotinoids. There are still no defined control strategies in the United States.

Further information at doi.org/10.3390/insects16090966