| Life Cycle: | The adult green peach aphid does not usually overwinter in Atlantic Canada. It moves north from the southern United States following the prevailing winds. Its arrival in Atlantic Canada is generally early August. Generations can be very fast to develop, often in under two weeks. Aphids often reproduce without mating. The winged adult female has a black head and thorax. Winged females lay eggs on a large number of host plants, which results in rapid dispersion of the population. Eggs are oval shaped and are 0.5 mm long and 0.3 mm wide. They are greenish yellow when first laid but turn black prior to hatching. Non-winged females give birth to live nymphs at a rate of 1-2 per day. There can be four instar nymph stages. Young nymphs are green while later instars are yellow. Nymphs are 2 mm in length. |
| Host: | The green peach aphid attacks hundreds of agricultural crops in many different families. These include most of the major crops grown in Atlantic Canada. It is a particular threat to potatoes. Greenhouse crops are also at risk. In addition, stone fruit trees are often the host for overwintering. Bindweed, wild radish, redroot pigweed, wild mustard and lambsquarters are potential weed hosts for the green peach aphid. |
| Bio Region: | Throughout North America. The green peach aphid cannot overwinter in Atlantic Canada. |
| Damage: | The green peach aphid will retard the growth of plants and reduce yields by feeding on plant tissue. They do so by inserting their stylet through the leaf tissue into the phloem of the host. The aphid tends to feed on newer leaves. Crops are rarely destroyed by even significant infestations; however, the main damage caused by green peach aphids is the spread of disease. There are over 100 documented diseases that the green peach aphid spreads. The most significant of these diseases are the Potato Leafroll Virus, Potato Virus Y, and a number of mosaic viruses (cauliflower, cucumber, lettuce, turnip). Moulds can also develop on the leaf surface where the aphid leaves a reguritated substance referred to as honeydew. The mould shades the leaf surface and further weakens the plant. |
| Management: | Monitoring and identification is an important step in implementing control strategies. The green peach aphid can be distinguished from other aphids in its preference for new plant tissue. Yellow sticky cards can be used to trap winged aphids but are not as reliable as visual inspections. Plants should be randomly checked underneath the leaves, around the stem and on new growth. To aid in detection the plant should be shaken or gently struck over a white piece of paper. Removal of infested plants must be done carefully to minimize further spreading of the aphid population which can easily be transplanted to outdoor fields. In the field row covers can be used to inhibit populations of aphids in general. Always use clean transplant stock. |
| Controls: | Lacewings, aphid midges, and lady beetles all prey upon green peach aphids. Aphid midges and lady beetles provide better control in cooler climates. Parasitoids are a very effective control measure but develop more slowly than the aphid population in cold environments. Insecticidal soaps are effective if used before infestation become severe. Beauvaria bassiana is a fungus that will adhere to the aphid's body and then grow into it. It is very effective in controlling aphids in general. The use of horticultural oil on potential fruit tree hosts can help minimize future populations. |
