Search
Blake E. Wilson and Stephen Baca, LSU AgCenter Department of Entomology
A new invasive insect, the pasture mealybug (Heliococcus summervillei, Figure 1), has been detected in Louisiana sugarcane fields in Vermilion and Iberia Parishes in 2025. The insect was also reported from cattle pastures in Texas and sugarcane fields in Mexico for the first time in 2025.
The insects were first observed by sugarcane crop consultants, Nick Daigle and Ryan Viator, from several commercial sugarcane varieties expressing a yellowing canopy symptom in late summer. Following their reports to the AgCenter, specimens were collected on September 3rd from Vermilion Parish sugarcane. The insects were observed in Iberia Parish sugarcane on the same day. The AgCenter’s initial identification efforts from DNA sequences did not match with available sequences of H. summervillei from India, but refined analysis showed a close association. Specimens were then sent to USDA Animal and Plant Health Inspection Service where scientists with the National Identification Services were able to confirm the species identification based on morphological characteristics and genetic comparison with specimens collected from Texas.
The pest status of H. summervillei in sugarcane is not well understood. Evidence from Australia has noted that both nymphs (immatures) and adults are found on the leaves and roots of sugarcane. Only the nymphs are thought to feed. This feeding maybe associated with yellow canopy syndrome, but the mealybug has not been identified as the direct cause of the symptoms. Fields in Louisiana where H. summervillei was observed expressed severe yellowing symptoms and suffered severe yield loss (Figure 2). Sugarcane fields in St. Landry Parish also expressed yellow canopy symptoms, but it is not known if the pasture mealybug was present there.
As the name suggests, the pasture mealybug has more often been associated with dieback of various species of pasture grass cultivated for livestock production. Early symptoms of infestations in pasture grasses cause discoloration ranging from yellowing to reddening. As the infestations persist, mealybug feeding and subsequent pathogen infections result in plant death. Pasture dieback was reported from 22 counties in southeastern Texas in 2025, but infestations in Louisiana pastures have not yet been detected.
Surveys will be initiated in 2026 to determine the current distribution of H. summervillei in Louisiana sugarcane and pasture grasses. Potential host plants include all species of pasture and turf grasses in addition to sugarcane. Suspected infestations of pasture mealybug should be reported to Blake Wilson (bwilson@agcenter.lsu.edu) for sugarcane and Ed Twidwell (etwidwell@agcenter.lsu.edu) for pasture. Extreme caution should be exercised before moving grass of any species around the state, but especially from Vermilion and Iberia Parishes.
Additional information, including identification and management guidance, is available in the Pasture Mealybug Factsheet.
Figure 1. Pasture mealybug, Heliococcus summervillei, colony on a sugarcane leaf (top) and close-up nymphs (bottom). Photos by B.E. Wilson.
Figure 2. Sugarcane yellow canopy syndrome field (left) and leaf (right). Photos by B.E. Wilson.
