Experience has also shown us that aphid population growth begins to increase significantly once the weather warms up. Our local weather forecast suggests that temperatures will be in the upper 60’s with moderate nighttime lows in the upper 40’s for the next two weeks. Assuming the weather service is correct, these conditions may be ideal for aphid population growth. Similarly, with the rainfall we’ve experienced to date, I would definitely keep an eye for aphid pressure to start to picking up on your lettuce, celery, spinach and cole crops. Previous research has shown us that aphids tend to be more abundant during warm, wet winters. On our untreated lettuce plots at YAC, green peach aphids have begun colonizing small plants and we’ve seen an increase in winged green peach aphids on our yellow sticky traps over the last month. Consequently, PCAs should be extra vigilant in scouting for aphid colonies. Be on the lookout for foxglove aphid to become more abundant (they tend to be more biologically active under warmer temperatures that we’re experiencing now). If the field has been treated with imidacloprid at planting, then chances are you are in pretty good shape. But, continue to monitor as imidacloprid doesn’t generally last all season. Regardless of whether you find green peach or foxglove aphid the key to effective aphid management with foliar insecticide is to initiate sprays at the time apterous (wingless) aphids begin to colonize. Of course, this requires diligent scouting and sampling. On older lettuce, make sure you thoroughly examine developing heads/hearts. Fortunately, PCAs have many alternatives for aphid control. For more information on aphid management see: Keys to Aphid Management in Leafy Vegetables. So, keep your eyes open for new aphid colonies and treat early to keep ahead of the populations.

Can you Name the INSECT below?

Areawide Diamondback Moth Trapping Network

In response to the recent outbreaks of Diamondback moth (DBM) , Plutella xylostella in Yuma, we have established a pheromone trap network designed to monitor the activity and movement of adult populations of DBM. PCAs have had difficulty controlling DBM in cabbage, broccoli and cauliflower since October. Traps have been placed in Roll, Wellton, Dome Valley, Gila Valley and Yuma Valley in locations where cole crops are presently being grown or in areas where infestations were known to occur this fall.

Click here to see results of DBM pheromone trap network.

Remember, When in Doubt . . . . . “SCOUT”

To contact John Palumbo go to:jpalumbo@ag.arizona.edu

For questions or comments on any of the topics please contact Marco Pena at the Yuma Agricultural Center.
College of Agriculture, The University of Arizona, Tucson, AZ.