We are happy to announce that the diamondback moth capture data, presented as maps, is now housed in our own University of California Cooperative Extension Monterey website.
To access to these maps, simply click on the link below:
These maps use the closest town or landmark where the traps are located to show moths per trap per day. Moth captures are presented as yellow bubbles. The bigger the bubble, the larger the population of moths is.
On the same page, you will also find the overall population fluctuations of these moths in the Valley, as a series chart.
We also stored the overall fluctuation of aphids and thrips numbers, captured in yellow sticky cards in our UCCE Monterey website. To access to these bar charts, click on the link below:
If you would like to learn more about these three monitoring programs happening in the Salinas Valley, do not hesitate to contact Alejandro Del-Pozo at email@example.com or 831-759-7359.
We continue the effort of monitoring diamondback moth (DBM) across the Salinas Valley using sex pheromone baited traps, as shown in the picture above. We have been adding additional traps to cover a larger area along Highway 101. We have daily moth capture data from Castroville to Greenfield. The chart below summarizes these daily captures from our pheromone traps.
As stated in a previous blog post, higher numbers of DBM have been usually recorded in Castroville. It seems like we just passed a generation of adults during late March to early April. Currently, DBM capture numbers are going down. Lower adults in the system could be paired with more caterpillars feeding on several host plants.
We have set up yellow sticky cards to track the overall population of winged aphids and thrips. These sticky cards are in the same locations as the pheromone traps. At this point, data for aphids and thrips is not broken down at the species level.
From the chart above, there was a flight of aphids during late March to early April. Some PCAs mentioned to me that foxglove aphid started to show up in their fields during that time period. It seems now that winged aphid numbers are going down. However, it does not mean that numbers of aphids in our crops are decreasing. We might be facing higher population of wingless aphids in our crops right now.
We need to keep an eye on population dynamics of thrips in the Valley. The ultimate goal is to be better prepared this season to manage those creatures and reduce the incidence of INSV virus. The chart below shows captures of thrips in our sticky cards.
It seems like thrips populations had a spike two weeks ago. Currently, thrips numbers are going down. I believe that keeping track of the fluctuation of thrips numbers in our Valley would help us detect large populations of this pest. There is a need to alert PCAs when the front of a 'thrips wave' would happen.
If you are interested in getting more information on this monitoring effort, please do not hesitate in contacting Alejandro Del-Pozo at 831-759-7359 or firstname.lastname@example.org.
There are sex pheromone traps for Diamondback moth set up across the Salinas Valley. This pheromone only attracts males of this pest. These traps were first put out on February 20th, 2019. Traps are located in Castroville, Marina, Buena Vista, Chualar, Gonzales, by the Prison (near Soledad), and Soledad. Thanks to the PCAs who are helping me with this project.
Basically, numbers of moths per day per trap have been zeros, with the exception of the trap located in Castroville. Interestingly, moths were captured in all traps last week. The actual values of those captures are presented in the below figure as yellow dots. The bigger the dot represents a larger moth capture.
It seems like a new flight for the diamondback moth is about to begin across the Salinas Valley. Additionally, there has not been a break on the life cycle of this pest in the Castroville area. Population of this moth are persistent throughout the year in that area. The trap in Castroville has always captured moths since it was set up. Populations of this moth are residents of brassica weeds, as noted in previous scouting trips.
But, what does it mean to have less than one moth per trap per day, compared to 5 moths per trap per day? Is 5 moths a high value? How is that translated to caterpillars in the field? The next step will be to pair moth trap captures with actual scout data for caterpillars found in the surrounding areas of the traps. In the meantime, the information from these traps could help us to potentially predict when caterpillars might be present in the system in larger numbers. It is more likely that we will be able to see an increase of diamondback moth caterpillars in the next two weeks. It may be good to pay attention to cole crop fields, with the goal to early detect potential damaging populations of this pest in scouted fields.
I will be updating this map with moth captures at least every other week. Stay tune!
If you would like to learn more about this project, do not hesitate in contacting Alejandro Del-Pozo at email@example.com or 831-759-7359.
Diamondback moth (DBM) is a persistent pest in the Salinas-Castroville area. We were able to find late instar caterpillars in several spots along Blackie road on Tuesday January 22nd. Basically, these caterpillars were feeding on brassica weeds, located along the side of the road (Fig. 1). This is an example of how insects exploit weeds as alternative hosts when there is a lack of a preferred and abundant host plant in the landscape. DBM will continue feeding on these weeds, while increasing their numbers. These DBM adults, originated from weeds, have the potential to infest any commercial cole crop during the upcoming weeks and months. Based on our observations, most of these caterpillars were close to pupate. Within the next two weeks, we might see an influx of DBM adults flying around fields and weed patches. A new generation of caterpillars may be present around mid-February in our system, depending on temperature fluctuations.
It seems like not all of these caterpillars will become adults. Approximately, 10% of the caterpillars collected from Blackie road were parasitized by Diadegma wasp. We took these caterpillars to the UCCE Entomology lab to refresh and re-introduce DBM into our colony; and we were able to spot the parasitic wasp pupae inside our rearing containers (Fig. 2).
Ideally, controlling weeds outside our fields and along the roads could be part of our strategies to manage resident pest populations. Control of these weeds will allow to reduce population of these pests cycling through the winter here in the Salinas-Castroville area. Managing these weeds could be challenging too, due to accessibility and other issues. Please, keep in mind that cole crop fields surrounded by weedy patches will have a higher chance to be infested with DBM. You could prioritize the scouting of those fields to timely detect any economically damaging DBM population in your crop.
If you would like to learn more about DBM and the research conducted by the UCCE Entomology team, please contact Alejandro Del-Pozo at firstname.lastname@example.org or 831-759-7359.
It has been a couple of “rough” weeks managing the diamondback moth (DBM), Plutella xylostella (Lepidoptera: Plutellidae), in the Central Coast. Based on my conversations with some PCAs, we are managing large populations of this moth, resulting in high infestations in cole crops like broccoli and Brussel sprouts. Larvae of this insect will typically feed on the underside of the leaves, rasping the epidermis and generating this characteristic “window panning” that results on perforations later on (Fig. 1). Diamondback larvae will also feed on the plant's growing points, floral stalks, and even on flower buds.
It seems like populations have been building up during early summer in our area, resulting in enough individuals, at this point, generating significant injury in cole crops. PCAs have been recommending spraying several different insecticides to reduce the infesting populations in affected fields, since damage has been beyond tolerable. For instance, after one of my field visits, I was able to spot affected larvae in treated fields (Fig. 2). Treatments are working, I believe we need to continue being ahead of future DMB infestations.
Some information to consider:
- Scout early. If you have transplants or direct seeded seedlings, pay a visit more often. We are dealing with a large DBM population right now. There will be a high chance that those fields may ended having DMB earlier than expected during this time of the year.
- Use of adjuvants. The waxy nature of cole crop leaves represents a challenge for insecticide deposition in the canopy. Make sure that you are using a spreader/sticker adjuvant to potentially reduce any pesticide “sliding off” from the waxy leaves.
- Rotate pesticides. Consider using different classes of insecticides, before using different active ingredients within the same class. For instance, using an avermectin and then a diamide, instead of using chlorantraniliprole and cyantraniliprole (two different active ingredients within the diamide class) back to back. Using different modes of actions will help to delay potential issues of developing insecticide resistance in our DBM populations.