Chile: Recommendations and control for potato aphids

For a favorable harvest, it is necessary to follow a series of recommendations and steps to prevent aphid infestations from damaging the crop. On this occasion, Patricia Navarro, researcher and entomologist at INIA Carillanca, spoke with Mundoagro, where she offered a series of recommendations and discussed the current situation and how a potential aphid infestation could impact potato crops.

In potato crops, there is a complex of aphids that transmit viruses and affect crop yield and production. Globally and nationally, the species Myzus persicae (commonly known as the green peach aphid) is the most important in terms of virus transmission, as it has a high transmission efficiency. However, in studies conducted by Navarro and Monje in 2020 in the southern region of Chile, La Araucanía, the species Myzus persicae, Aulacortum solani (also known as the potato aphid), and Brevicoryne brassicae (crucifer aphid) were found to be the most present in potato crops, being the most relevant species as virus vectors.

The cruciferous aphid is one of the species that could be most impacting potato crops in recent years in terms of viral diseases and yield losses. According to studies carried out by Rosales and Acuña (2016), this species transmits potato virus Y (known by its acronym in English PVY, Potato Virus Y). Although B. brassicae is not very efficient as a vector at transmitting PVY, its population level in crops in southern Chile is 200 times higher than that of other aphids (Navarro and Monje, 2020), due to the large areas of rapeseed and other cruciferous crops grown around potato areas. Thus, the cruciferous aphid, while not being as efficient as a virus transmitter, could be the species most responsible for the viral diseases observed in recent years in the potato zone of southern Chile.

Considerations for proper integrated pest management

To combat this situation, producers are advised to implement integrated pest management techniques. This includes the use of virus-resistant varieties, the elimination of crop debris and weeds that can serve as refuges for aphids from one generation to the next, and crop rotation practices. Caution is also advised when using insecticides, especially neonicotinoids, which have negative effects on pollinating fauna, such as bees.

“In a potato crop, especially for seed production, the most important thing is to detect the early presence of non-colonizing aphid species such as B. brassicae and prevent the establishment of colonizing species such as M. persicae, A. solani, and Macrosiphum euphorbiae (the latter being the primary colonizers in potato crops). If the crop already has colonies and the potato producer has identified their presence once they are established, applying an insecticide control agent is recommended to reduce damage. However, it is most likely that the virus has already been transmitted from diseased to healthy plants. This is why monitoring the first 20% of potato plants from the emergence of the plant is critical, as is the use of certified seed, thus avoiding sources of virus inoculum,” stated the entomologist and expert in the field regarding recommendations and steps to follow.

It is essential that producers remain alert and monitor their crops so they can respond promptly to the presence of this pest. Collaboration between farmers and agricultural support organizations is crucial to implementing effective strategies and minimizing the impact on production.