North Carolina may have a beetle problem in blueberry fields. For the first time, state scientists have documented the beetle's presence. Prionus imbricornus , eating blueberry bushes . This longhorned beetle and its larvae are capable of devastating the state's valuable blueberry fields. The research findings are described in a paper published this week in Journal of Integrated Pest Management .
Blueberries are native to North Carolina, but they weren't cultivated until 1935. The state ranks sixth in the United States for blueberry production, with production valued at approximately $70 million. Protecting the plants from pests is crucial, as blueberries are considered one of North Carolina's most valuable and sought-after agricultural crops.
Several species, including the blueberry fly ( Rhagoletis mendax ), plum weevil ( Conotrachelus nenuphar ) and cranberry moth ( Acrobasis vaccinii Riley ), can pose a threat to blueberry crops. They may now be joined by the longhorned beetle. P. imbricornus . P. imbricornus Known for its long antennae, the woodworm is considered a wood-boring insect. Adult females typically lay eggs in the soil near the roots of deciduous trees. The larvae then feed on and destroy the roots. These larvae can grow up to five inches long and can potentially kill trees, as the adults do not feed.
Larva P. Imbricornis . This larva, which can grow up to five inches long, feeds on the roots of blueberry bushes. Image: Matt Bertone/NC State.
North Carolina became the first state to report active feeding of the weevil beetle. P. imbricornus on blueberry bushes. However, reports of unidentified larvae of beetles of the genus Prionus , Reports of weevil larvae feeding on and damaging the roots of blueberry bushes have been reported since 2010. Over the past 16 years, identifying the specific species responsible has been difficult, as the larvae live near the plant roots. Different species of weevil larvae also closely resemble each other, and uncertainty about the species could hinder pest control efforts.
«Previously, researchers often simply identified the species Prionus "on their products based on the identification of adult individuals," said Kenneth Geisert, a co-author of the study and a graduate student at North Carolina State University, in a statement. "If this assumption turned out to be incorrect, it could indicate the use of a treatment strategy inappropriate to the problem and the incorrect matching of species and their hosts.".
For example, P. imbricornus attacks the roots, while another species of longhorn beetle may attack dead branches or the trunk of a tree.
«"Without knowing the beetle species and its ecology, improper control methods can harm non-target insects," Gaisert added.
For this study, the team used a series of black panel traps impregnated with sex pheromones to attract and collect adult beetles. The traps were placed on six farms in Pender, Sampson, Bladen, and New Hanover counties. The team then used genetic barcoding to analyze small, standardized DNA segments from the larvae to identify the species. They then compared the unknown larval DNA sequences to the same genetic segments from known adults. Prionus .
They managed to identify the species P. imbricornus with an accuracy of 98 to 99 percent. According to the researchers, this result is both good and bad news for farmers.
«"On the one hand, it's crucial to know exactly which species we're dealing with," said Lorena Lopez, a co-author of the study and an entomologist at North Carolina State University. "On the other hand, North Carolina was the first state to report blueberry infestation with Prionus fungi, and there are currently no insecticides approved for this blueberry pest.".
To address this problem, Lopez began testing insecticides. Identifying effective insecticides and determining the optimal timing of their application during reproductive cycles P. imbricornis This could potentially limit larval development. Fewer larval numbers could help prevent serious root damage and provide blueberry farmers with an effective crop protection tool.