Posts Tagged: scale
Citricola Scale in the Big Valley
Sandipa Gautam, Area Citrus IPM Advisor serving Kern, Tulare, Fresno, and Madera counties has been maintaining a web page on the Lindcove Website Citrus IPM - Lindcove Research and Extension Center (ucanr.edu). Within this page, she writes a blog on pest issues that are problem for growers in the SJV region. For subscribing, click https://ucanr.edu/blogs/IPMBlog/ and enter your email address. You will receive an email to confirm subscription, follow the instructions to complete subscription. Every time a post is made you will receive and email notification. This page also hosts pest memos of this season and archives from the previous season along with links to Citrus related extension posts, newsletters.
Within the Citrus IPM tab, you will also find Degree Days, which is regularly updated for California red scale for four counties in the SJV. If you are in Ventura county or other citrus growing counties (not in the valley) and California red scale is a pest you manage and are interested in Degree Day calculation and predictions, please contact sangautam@Ucanr.edu .
If you would like to receive emails on pest memos/other events, please send an email to sangautam@ucanr.edu to be added to her email list.
citricola scale blog
Californina Red Scale News
Read all about Sandipa Gautam's Central Valley research and what chemicals are working. There was trouble loading the file,but you go to the bottom and click on "Attached File" You'll the wonderful work she is doing.
LinkstoPesticidetrialsonCRS
- CRStrial 2015
- CRStrial 2016
- CRStrial 2017
- CRStrial 2018
- CRStrial 2019
- CRSTrial2022
- CRSTrial2023Trial-1
- CRSTrial2023Trial-2
red scale feeding on grapefruit
CRS July Memo Page 1
CRS July Memo Page 2
CRS July Memo Page 3
CA Red Scale
From
Sandipa Gautam in the Central Valley
Hello everyone,
Please find first California red scale memo for 2024 season. CRS degree days for four counties, Kern, Tulare, Fresno, and Madera are updated on the LREC website. Please visit link for biweekly DD updates using the CIMIS station data https://lrec.ucanr.edu/Citrus_IPM/Degree_Days/.
Management choices for CRS – Mating disruption (CheckMate CRS), Biological control Aphytis melinus release; insecticides (Check UCIPM guidelines)
How can we better manage CRS – three key points to remember
- Spray applications are most effective when populations consist of immatures and are synchronized. Spray as crawlers of the first or second generation are emerging. Expect first generation crawlers in 1-3 weeks depending on your location.
- Monitor for CRS
- Pheromone cards for monitoring males, weekly or per flight.
- Leaf/twig sampling – sample the edge, interior or top of the tree. Determine if the scale is live or dead by rubbing your thumb.
- Use high gpa (750-1000) and drive <1.5 mph for a thorough coverage, except for Movento – apply at 250 GPA.
Attached is the first CRS memo of 2024 season with links to field trials conducted on CRS in the last decade.
Have a great season!
sandipa California Red Scale May 2024 Page 1
sandipa California Red Scale May 2024 Page 2
sandipa California Red Scale May 2024 Page 3
Red Scale Alert
California red scale season has started in the SJV
Sandipa Gautam - Citrus IPM Advisor
Based on traps placed at LREC citrus blocks, California red scale season began with Biofix on March 10. Pest Control Advisors in Kern, Tulare, and Fresno County reported that they have seen activity in the week of March 10.
Figure 1. California red scale male. Note: feathery antennae and brown band through the waist.
What is CRS Biofix?
CRS Biofix is the start of California red scale activity for this season. As weather warms up and heat units are accumulated above the lower developmental threshold of this insects, overwintering females start producing crawlers which develop. Males' complete development and fly to find third instar females to mate. Mated females then produce crawlers which is the First Generation of Crawlers, observed 550-degree days after the biofix.
What do males on the trap cards mean for management?
Pest control advisors have long used pheromone cards to monitor males and degree days to predict successive life event (crawler emergence) for timely management of CRS. Trap numbers may be different depending on the management choice.
Figure 2. Trap with pheromone placed within an arm's length inside the tree canopy. For assessment, count number of males within square box and multiply by 5.
- IGRs and Mating Disruption – few male scales may be on the cards as these two options affect males more than it does females. You may have lower males on card but have high CRS populations.
- Aphytis and Movento – Aphytis targets third instar females, thus affecting females more than it does males. Also, Movento controls CRS on twigs but not on wood. If Aphytis or Movento or both are used, you may see higher male numbers. If Movento was used, check the inner canopy branches, top of the tree for CRS patches.
Citrus entomology group will monitor degree days for four counties and update it biweekly on ucanr website https://lrec.ucanr.edu/Citrus_IPM/Degree_Days/.
Management is targeted at 1st and 2nd generations as the crawlers are emerging. Based on previous years, first generation crawler emergence occurs around 2nd/3rd week of May. As the degree day accumulation is temperature dependent, monitoring is critical to predict accurately.
Stay tuned for updates.
Treatment Options for Management of Walnut Scale and Frosted Scale
Walnut scale (Figure 1) is an important economic pest of walnuts in California. High populations of...
Figure 1. The covering of a group of walnut scales forms a daisy shape. Removing the cover reveals the yellow adult females
Table1
Figure 2. Ten weeks after the delayed-dormant application of IGRs, frosted scale populations were observed on untreated (A) and IGR-treated (B) trees. Photo B is from an excised branch of a CentaurĀ® (34.5 oz/acre)-treated tree, illustrating the lack of maturation of frosted scale resulting from the delayed-dormant IGR treatment.
Figure 3
Figure 4. The average total number of crawlers emerged over the season was evaluated across treatments. P?0.01