- Author: Steven A. Tjosvold
Soon after LBAM was discovered in Alameda County in 2007, officials started recording the nursery and fruit crops it was detected on. A 2008 CDFA list included 152 species. Many of these were new hosts, not recognized or recorded earlier. Clearly, LBAM was taking advantage of the California flora and nursery crops smorgasbord.
In a scientific review article on the host range of Light Brown Apple Moth (LBAM) in 2011, the authors summarized that there are “At least 545 plant species in 363 genera from 121 families that have been reported as hosts.” Further they stated that “Light brown apple moth is one of the most polyphagous insects known.” (See Attached files at the bottom of page.)
Although we knew something about common hosts within nurseries, we did not know a lot about the hosts that often surrounded these nurseries. We surveyed the native hosts and weeds that surrounded these sites for more than 2 years, and found that there were many common native hosts and weeds that LBAM could colonize ( See figure above).
This has important implications since these closely associated hosts could be launching pads for the migration of moths into nursery or fruit crops. LBAM adults have been shown to migrate at least 100 meters from their original sources. (See figure above.)
It is important to scout and perhaps control weeds that are outside the nursery and crop perimeters to minimize impact on LBAM migration into production areas.
Brockerhoff - 2011 - Worldwide Host Plants
- Author: Steven A. Tjosvold
The Light Brown Apple Moth (LBAM) is an important invasive pest for California, and is established in much of California's coastal and some inland areas where nursery products are produced. It is a federally and state regulated pest in many ornamental and fruit crops.
Although the LBAM life cycle (egg to adult) progresses and develops through the entire year, our monitoring around the Monterey Bay Area production areas showed that there were peaks in LBAM flights consistently in the Fall (see red arrows).
These adults produce a focused generation of young larvae (see red circles), if detected early enough, could be targeted with a softer pesticide such at Bacillus thuringiensis (B.t., e.g. Dipel), which is active mainly on young larvae. B.t. is selective to moth larvae such as LBAM, therefore not interfering with parasitoids of LBAM, and it is relatively inexpensive.
A pesticide application, particularly with a short residual pesticide such as B.t., should be made when young larvae are detected through scouting. However, identifying larvae of LBAM has always been difficult. There are many look-alike leafrollers , especially when they are younger. We produced a LBAM identification guide and training video that helps identify adults, eggs, pupae, and most importantly, the targeted larvae.
LBAM ID Guide and Video at LBAM identification
- Author: Mark Bolda
I had several growers drop by my office early this morning regarding the management and regulatory regime for light brown apple moth (LBAM). I really enjoyed give and take of our little charla in the parking lot and thought this might be beneficial to the some of you, so I write a summary of our conversation below:
How is it that there is so much LBAM around right now, especially in the organic strawberries? Although we can't say for sure when exactly the last flight of moths and subsequent mating occurred, but it's usually been in March that we have one, another in June and then another in September. Figuring on egg laying in late March, and subsequent hatch and growth, doesn't make it surprising that we are seeing a lot of larvae now. Too, as the growers pointed out, it was difficult to get in and spray because of all the rain so a pretty sizable cohort of larvae came through safe and sound.
How is it that the USDA and CDFA people find the larvae so easily in my field when my field crews can't? The USDA and CDFA people are professionals, and are number of them are very good. I heard of one inspector, who upon arriving at a suspect field and casting a glance around at the surroundings, declared that he'd find something there and within minutes lo and behold, had found a larva. If you want to be a good angler, you need to fish where the fish are, and that's what the inspectors are doing. They check the edges of the field very close, especially when next to wooded areas, and when they find one larva, they slow down and look around there real close because there are sure to be others. Make sure your crews know WHAT they are looking for and HOW to look for them to best utilize their time.
How about the twist ties for pheromone based mating disruption? Twist ties for sure are the first leg of a sound LBAM control strategy. We all need to understand however that these take time to work, since they are disrupting mating and therefore reducing total volume of eggs laid sometime in the future. No moths, eggs, larvae or pupae are being killed here, and it's just that the numbers of those future generations will be reduced. So those people who did not put twist ties out in March let LBAM adults mate freely and are seeing the consequences currently. It's not too late though, since putting the twist ties out now will serve to disrupt the upcoming moth flight in late May or June. Raise them up a bit on flags, lines or sticks over the canopy, and make sure to spread them out EVENLY over the field – no “barriers”, big blobs of twist ties in the middle of the field or any other funny business. Configurations like every 10-15 feet every third bed should get you to the requisite 300 ties per acre.
What should I be spraying in organic to control this – in strawberries I only have 3 sprays of Entrust and don't want to use them all now. Managing LBAM is a lot more difficult in organic than conventional to be sure. Any formulation of Bt doesn't seem to work all that well, and the material that works well, Entrust is limited to three applications max. I agree, I would not panic and blow out all of my Entrust applications this early in the game because I may need one in a pinch later on, so would pursue a strategy of regular Bt sprays to keep down populations. It's understood that Bt's, while able to kill smaller larvae outright, tends to just make the bigger larvae sick, they stop feeding for a while, and when they start feeding again the Bt is worn out. Therefore on occasion it might be a good idea to closely space the applications, to have fresh material on the plant for our survivors to feed on. It's worth noting too, that spraying in the evenings is better than in the morning, since UV radiation can break down Bt.
Don't forget about your surfactants either, they are pretty important when it comes to enhancing the physical and in some cases chemical efficacy of a pesticide.
Always bear in mind to read the label of the pesticide you are using and hew closely to the instructions therein.
Really great having the guys come by this morning and hope I was able to help some. My time is your time, so please let me know if you need more information.
- Author: Mark Bolda
Farm Advisor de la Extension Cooperativa de la Universidad de California Mark Bolda brindará un entrenamiento de la palomilla marrón de manzana (“LBAM” en sus siglas en ingles) para certificar participantes a ser un “scout aprobado” en relación del Acuerdo de Conformidad para mando de fresas y moras a Canadá. A cumplir en entrenamiento, asistentes recibirán un Certificado como un record de su participación.
Este entrenamiento tomará lugar una vez en inglés y una vez en español.
Lugar: UCCE Auditorium, 1430 Freedom Boulevard, Suite E, Watsonville, CA
Cuando: 24 de abril – 8:00- 9:00 am en inglés
25 de abril – 8:00- 9:00 am en español
No hay necesidad de registrarse. Se invita a todos con la necesidad de esta información, aunque no tienen intento de mandar fruta al exterior.
No se ofrece horas de educación continuada en esta reunión.
Favor llámense a Mark Bolda en (831)-763-8025 si tiene pregunta cualquiera.
- Author: Mark Bolda
UCCE Farm Advisor Mark Bolda will be providing a training on light brown apple moth (LBAM) that qualifies attendees to be an “approved scout” relating to the Compliance Agreement for shipment of berries to Canada. On completion of the brief training, attendees will receive a Certificate as a record of their participation.
This training will be held once in English and once in Spanish.
Where: UCCE Auditorium, 1430 Freedom Boulevard, Suite E, Watsonville, CA
When: April 24 – 8:00-9:00 AM in English
April 25 – 8:00-9:00 AM in Spanish
No pre-registration necessary. All are welcome to attend, even if they do not intend to ship berries to Canada.
No continuing education hours will be offered at this meeting.
Please call Mark at (831) 763 8025 if you have any questions.