Fuller rose beetles are a primarily a problem because they lay eggs under the calyx of fruit and those fruit can be rejected when exported, because some export countries don't want this pest to establish in their region. Fuller rose beetle can also cause significant leaf damage to newly topworked orchards. We have been sampling an orchard near Lindcove and, while a few beetles emerge year round, we are seeing heavier numbers emerging as of the first week of August. You can find Fuller rose beetles first by looking for notched leaves (edges chewed) and frass (insect feces), then look for the adult beetles inside curled leaves. They love new flush and leaves rolled by leafminer damage. They tend to be on the lowest branches of the tree. You can also survey for them by putting a beating sheet or tray under the trees and shaking the adults out onto the tray.
The Kearney and Lindcove Entomology research teams are studying the impact of earwigs on mature and young citrus trees this year. We have evaluated damage of young trees, conducted both field and laboratory pesticide screening and are beginning to study earwig lifecycles in mature citrus. We invite you to join us at Lindcove on July 27 at 9 am to hear about the results of the work we have conducted so far. See the event calendar page for more information.
Degree days indicate that the 3rd flight of citrus peelminer will occur the last week of June. The Lindcove entomology crew has been monitoring pummelos this week and found a few small mines confirming that the 3rd flight is starting. If you have pummelo or grapefruit varieties that have had infestations of citrus peelminer, you should treat now to prevent moths from depositing eggs and/or eggs from hatching into larvae.
Citricola scale crawlers have been hatching and emerging for several weeks. Now the California red scale crawlers are joining them. Red scale crawlers begin to emerge at 550 degree days. Our degree day web site http://ucanr.org/sites/KACCitrusEntomology/Home/California_Red_Scale/Degree_Days_885/
indicates that Tulare county has accumulated 571 degree day units. We use double sticky tape wrapped around twigs with female red scales to catch crawlers and confirm that emergence is matching up with the degree day units.
Now is a good time to apply insecticides, as the crawlers will settle down and become 1st instar nymphs and that is the stage that is most susceptible to insecticides.
The San Joaquin Valley is about 80 degree days behind the 30 year average. For California red scale, we expect to see crawler activity when degree days reach 550 (with a lower developmental threshold of 53oF). Even Kern County, where the temperatures are warmest, has only accumulated 460 DD. Depending on weather, it will be about another 7-10 days before the crawlers begin to emerge in that region and even later as you move northward towards Madera. Double sticky tape around a twig next to a female scale will most accurately pinpoint crawler emergence.