Government of New Brunswick

The potato aphid is worldwide in distribution. In Canada, it is transcontinental and occurs in all potato-producing areas. It is also the most abundant aphid on potato in Eastern Canada. In Atlantic Canada, this is the first aphid to appear on potato. It can usually be found in June in most fields. It shows a preference for the middle and upper part of the plant, which is where the winged forms usually settle. High numbers can weaken the crop and reduce yields.

Overwintering hosts are Rosaceae, such as shining rose, swamp rose and rough rose.

Summer hosts include a variety of vegetable crops and various other plants. Potato is one of the potato aphid's preferred summer hosts.



Wingless potato aphid adults are 1.7 to 3.6 mm in length, which makes them the largest of the potato-colonizing aphids in Atlantic Canada. The body is elongate, wedge-shaped, yellowish-green to pink and darker along the middle of the back. The head has prominent antennal tubercles which are directed outwardly. Winged adults have a pale yellow-brown, green-brown or dark brown head and thorax.

The potato aphid is quite restless and will drop when disturbed.

Life History

The potato aphid overwinters as nymph-producing females in sheltered sites, such as greenhouses and as eggs on rosaceous plants. The eggs hatch in the spring as the buds begin to swell. Two to six generations of females are produced on the overwintering host, during which time winged females mature and migrate to various weeds and to potato plants. Population build-up occurs at temperatures between 5 and 25EC. Aphid numbers continue to increase in July and winged forms are produced. By early or mid-August, the number of potato aphids on potato declines because winged males and females start to move to their overwintering hosts.

Crop Injury

Wilting of the plants and honeydew on the leaves may be an indication of high numbers of potato aphids on the crop. Mainly flowers and shoots are attacked.

The potato aphid transmits potato virus Y on tobacco, but almost never on potato. It is also considered to be a poor vector of potato virus A and potato leafroll.

Pest Management

Monitoring - Abundance of the potato aphid is estimated by counting aphid numbers on leaves (see green peach aphid). In Eastern Canada, management is not necessary unless the potato aphid becomes sufficiently abundant to affect yields, which is why the empirical threshold is set fairly high. For example, in New Brunswick the threshold is 50 aphids per 3 compound leaves per plant and 40 to 60% of plants infested.

Chemical Control - Any recommended insecticide can be applied whenever sudden, rapid and significant increases in abundance of the potato aphid occur. However, chemical control of the potato aphid is only needed occasionally in Eastern Canada.