Aphid Alert 2000, No. 12, August 27

Update: Summary of virus vector situation through 27 August

Happily, the week ending 30 August saw another sharp decline in aphid flight activity. Captures of green peach aphid averaged 0.20 per trap compared to 0.58 the previous week. Captures of other aphid species that are potential virus vectors also declined to 6.63 per trap compared to 19.17 the previous week. Across all sampling dates, captures of both green peach aphid and other potential virus vectors in 2000 were only 1/5th of what they were in 1999. This should translate into fewer seed lot rejections for virus this winter. However, late season flights of green peach aphid are cause for particular concern. These aphids are mostly coming from commercial potato fields and are likely to be carrying virus. Most seed potato fields have already been killed, but any still remaining should be protected with an effective aphidicide until vine kill is accomplished.

Captures of winged aphids (mean number per trap), 1992-1994 & 1998-2000. Data for Minnesota and North Dakota locations in the Aphid Alert trapping network.

Fig. 1. Captures of winged green peach aphid per trap.

Fig. 2. Captures potential PVY vectors other than green peach aphid per trap.

Fig. 3. Captures of winged turnip aphid per trap.

Fig. 4. Captures of winged small grain aphids (i.e., bird cherry-oat aphid, English grain aphid and greenbug) per trap.

Fig. 5. Captures of sunflower aphid per trap.

Fig. 6. Captures of other potential PVY vectors (including potato aphid, corn leaf aphid, thistle aphid, and others) per trap.