- Author: Ben Faber
Attend our training to become an invasive shothole borer monitor!
*Results from March 2023 ISHB Monitors Training*
Invasive shothole borers (ISHB) are wood boring beetles that attack many native and non-native trees in Southern California. These beetles bore tunnels into trunks and branches where they grow a fungus they use as food. The fungus causes a disease called Fusarium Dieback. Trees infected with Fusarium Dieback show branch dieback, canopy loss, and may eventually die. Infested trees become sources of beetles that can spread to surrounding hosts. This pest can also spread long distances through infested green waste and firewood, affecting new areas.
How you can help: Get trained, become an ISHB Monitor, and help us gather infestation data! In previous editions of the program, we learned that trained volunteers can identify ISHB-infested trees with 96% accuracy. This high accuracy of volunteer observations allows us to include the data collected through this program directly into the ISHB statewide distribution map. Knowing where beetles have spread will assist scientists, municipalities, and many other conservation agencies plan for management. Also, detecting infestations in their early stages allow for better chances of successful management. Your participation is needed to detect infestations throughout southern California.
Training for Monitors: You can become an ISHB monitor trained by scientists from UC Agriculture and Natural Resources. California Naturalists, Project Learning Tree Educators, and Master Gardeners are especially encouraged to attend, but curious minds of all ages are welcome.
Dates: Online training 7/7/2023. In person dates Ventura County 7/8/2023, Santa Barbara County 7/9/2023, San Diego County 7/14/2023, and Inland Empire (Riverside County or San Bernardino County) 7/15/2023 (specific locations to be determined).
Cost: Free.
Training Requirements:
- Registration is required.
- Attendance to online session is required.
- Attendance to one in-person session is required.
- Completion of the 1-hour free online eXtension Invasive Shothole Borer training is required.
- Monitors must create or already have a free account on iNaturalist.
- After the training, monitors must upload at least 5 observations to the UC ANR ISHB Monitoring Project on iNaturalist using the correct protocols ( UC ANR Invasive Shothole Borer Monitoring Project iNaturalist Guide ).
Note: Past participants of this program may choose not to attend the online session, but in-person session is required. Please make sure you contact us and let us know beforehand if you will not attend the online training.
AGENDA:
Pre-training assignments: before 7/7/2023 Complete 1-hour free online eXtension Invasive Shothole Borer training and make an account on iNaturalist. |
Online session: 7/7/2023 (12pm-2pm) Location: Virtual Zoom meeting. The meeting access information will be sent to registrants prior to training. Speakers will cover how this project fits into the big picture of efforts to manage emerging tree pests in California. There will be a short review of ISHB identification, look-alikes and tree species identification, and then an overview of how to use iNaturalist for this project. |
In person training: Participants may choose which field training to attend, all sessions cover the same material. Attendance at one of the sessions is mandatory. Ventura County 7/8/2023, Santa Barbara County 7/9/2023, San Diego County 7/14/2023, and Inland Empire (Riverside County or San Bernardino County) 7/15/2023 (specific locations to be determined). Speakers will review ISHB symptoms and iNaturalist collection protocols ( UC ANR Invasive Shothole Borer Monitoring Project iNaturalist Guide ), observation of infested trees and filed identification of signs and symptoms, and troubleshooting based on their experiences with the practice observation. |
Deadline for iNaturalist observations: 8/14/2023 After the training, monitors must upload at least 5 observations to the UC ANR ISHB Monitoring Project on iNaturalist using the correct protocols ( UC ANR Invasive Shothole Borer Monitoring Project iNaturalist Guide ) by 8/14/2023. |
Results: end of August 2023 After volunteer data has been evaluated, results will be shared will all participants. See results from March 2023 ISHB monitors training. |
Stay tuned for additional events! |
Registration
Please register here by 7/3/2023.
Contact
Questions or more information about the training can be directed to:
Hannah Vasilis - Statewide ISHB Survey and Trapping Coordinator
- Author: Ben Faber
Origin and evolution of fungus farming in wood-boring Coleoptera – a palaeontological perspective
David Peris, Xavier Delclòs, Bjarte Jordal https://doi.org/10.1111/brv.12763
A beetle bores a tree trunk to build a gallery in the wood in order to protect its lay. As it digs the tunnel, it spreads ambrosia fungal spores that will feed the larvae. When these bore another tree, the adult beetles will be the transmission vectors of the fungal spores in another habitat. This mutualism among insects and ambrosia fungi could be more than 100 years old --more than what was thought to date-- according to an article published in the journal Biological Reviews.
The study analyses for the first time the symbiotic associations and the coevolution between ambrosia fungi and beetles from a paleontological perspective using the Cretaceous fossil records of these biological groups. Among the authors of the study are the experts David Peris and Xavier Delclòs, from the Faculty of Earth Sciences and the Biodiversity Research Institute of the University of Barcelona (IRBio), and Bjarte Jordal, from the University of Bergen (Norway).
Beetles that grew fungi millions of years before human agriculture
Some termites, ants and beetles developed the ability to grow fungi in order to eat millions of years ago. This mutualism between insects and fungi --one of the top studied symbiosis in the natural field-- is an analogous evolutionary strategy in the farming activities of the human species since the Neolithic revolution.
Understanding the origins of the symbiosis between insects and fungi is a field of interest in several scientific disciplines. Nowadays, the mutualism between ambrosia symbiont beetles and fungi is the cause of forest and crop plagues that cause serious ecological and economic losses "it remains unclear which ecological factors facilitated the origin of fungus farming and how it transformed into a symbiotic relationship with obligate dependency", notes David Peris, first author of the study.
When did the lineage of farming insects begin?
Historically, phylogenetic studies suggest beetle fungiculture started more than 50 million years ago --before other insects-- and some studies dated it back to 86 million years ago. "The symbiotic relationship between fungus and beetles would have probably originated more than 100 million years ago, during the early Cretaceous, in groups of beetles that had gone unnoticed", reveals the expert David Peris.
As part of the study, the experts studied several specimens of worldwide distribution of the biological groups captured in amber from the Cretaceous. Therefore, the origin of ambrosia fungus is older than the main groups of beetles from the subfamilies Scolytinae and Platypodinae --Curculionidae family-- which now grow fungus in tree trunks, as stated by the authors.
"This suggests that these fungi used some other group of insects to spread millions of years ago", notes the researcher. Also, other beetle groups with a similar behaviour to ambrosia beetles --Bostrichidae and mostly Lymexylidae families-- present an older and abundant fossil record that would coincide with the emergence of ambrosia fungi, according to previous studies.
"The most interesting thing --he continues-- is that some studies note the ability to cultivate fungi in some of these current species".
Evolutionary convergence towards an obligate mutualism
The growing process of fungi starts when beetles colonize a new tree trunk or branch. During the Cretaceous, the abundance of fungi and wood-boring beetles facilitated a starting domestication of some groups of fungi. First, the fungal spores were accidentally transported from tree to tree by the wood-boring beetles "until this mutually beneficial association evolved towards a more intimate symbiosis in which fungi were inoculated into to a tree, the fungal mycelia grew and beetle larvae fed from the fungus", notes Bjarte Jordal.
This set of factors, together with the symbionts' high ability to adapt and change, eased the morphological and ecological adaptations of biological groups that converged in an obligated mutualism. That is, a symbiotic relationship between insects and fungi, beneficial for both, which still lasts.
"However, we need more studies on the knowledge of the ecology of the species from the Lymexylidae and Bostrichidae families to get more specific conclusions. Therefore, the discovery of new fossils in cretaceous amber of these groups will certainly help us to better understand the evolutionary history of this symbiotic relationship that still exists nowadays", concludes Professor Xavier Delclòs.
Read on: https://onlinelibrary.wiley.com/doi/full/10.1111/brv.12763
Photo: Invasive Shot Hole Borer tunnels in Box Elder trunk
/h1>- Author: Ben Faber
This is the most recent status report of theKuroshio Shot Hole Borer in the Tijuana River Valley of San Diego. For the full report go to: https://trnerr.org/kshb/
The Ecology and Management of the Kuroshio Shot Hole Borer
in the Tijuana River Valley
2019-20 (Year 5)
By
John Boland and Kellie Uyeda
This report presents the current status of the Kuroshio Shot Hole Borer (KSHB, Euwallacea kuroshio, Coleoptera: Scolytidae) in the Tijuana River Valley. It provides current rates of KSHB infestation; documents the current state of post-KSHB recovery in the most impacted forests in the valley; compares the current data with data collected over the past five years; and uses GIS technology for the first time to accurately map the spread of the KSHB in the valley.
This report is the fifth in a series of annual reports about the KSHB in the valley. It adds to and further develops four main storylines about the KSHB in the valley:
1. The KSHB in the valley went through a rapid boom-and-bust cycle. Annual surveys of infestation rates in the field and annual calculations of canopy damage from satellite images show that the KSHB population went through a rapid outbreak and a rapid decline over a five-year period. The infestation rates peaked in Fall 2016 and the canopy damage was greatest between 2016 and 2017. The early increase in population was characterized by the KSHB's presence in the Wet Forests and the swift damage to these forests (see frontispiece). The later decrease in population was characterized by the KSHB's presence in the Dry Forests and the slower damage to those forests. The KSHB population decline appears to be due to the KSHB depleting their preferred host trees and not reinvading the recovering host trees in the Wet Forests. This boom-and-bust cycle occurred naturally, with no management interventions to control the spread or severity of the outbreak.
2. The willow forests that were extensively damaged by the KSHB are responding with vigorous regrowth. Since the KSHB heavily damaged the Wet Forests in 2015-17, there has been extensive willow forest recovery in three ways: by the survival of a few, scattered mature infested trees (‘Big Trees'); by the resprouting of mature KSHB-damaged trees (‘resprouts'); and by the seeding of new trees (‘seedlings'). The frontispiece shows the striking recovery of one of the Wet Forests. Some of the forests have recovered so much in just four years that they are now similar to their pre-KSHB stature.
3. The KSHB has not substantially reinfested the recovering willow forests. Even though others predicted that all of the trees in the recovering Wet Forests would be quickly reinfested, only 3% of the Big Trees, 2% of the resprouting trees, 1% of the young trees, and 0% of the seedlings were infested with KSHB in 2019. This unexpected result begs the question: Why are the recovering willows not being attacked by the KSHB? In this report we suggest three possible reasons.
4. The invasive plant, Arundo donax, is now a major problem. Willow trees are arundo's only competitors in the valley, and when the KSHB attacked and heavily damaged the willows it allowed arundo to flourish more than ever before. Our main recommendation for the park managers in the valley is to control the arundo on their property. To assist them we provide a map of the current distribution of arundo using satellite images and object-based imagery analysis (OBIA) software.
The research reported here is unique among KSHB studies. It involves detailed and long-term field surveys of the KSHB invasion in one valley, documents an entire boom-and-bust outbreak of the KSHB and describes the damage to and recovery of the forests. This report also discusses the six most important ecological findings and suggests that incorporating these findings into the existing predictive numerical model would make the model more accurate. Finally the report presents several recommendations for needed future research and for immediate management actions.
Further Project Summary and Comments about Invasive Species: http://nivemnic.us/
- Author: Ben Faber
What Are the UC Ag Experts Talking About?
Invasive shot hole borers in avocado
May 20, 2020, Wednesday, 3-4 PM
Upcoming topics:
- Vertebrate pests by Roger Baldwin (June 2020)
- Ants in citrus by Mark Hoddle (July 2020)
- Use of plant growth regulators on citrus by Ashraf El-kereamy (August 2020)
Check out previous talks and listen to their recordings
- Author: Ben Faber
Ambrosia beetles, which are a large group of several thousand species worldwide, belong to the bark beetles. All species are characterized by the ability to cultivate fungi. Invasive Shot Hole Borers that attack avocado and a range of native and landscape trees in California and the Laurel Wilt Disease that hammers avocado in Florida are ambrosia beetles. These beetles cultivate fungi in living trees and over time, the fungus is what kills the tree.
Beetles share the work of cultivating their fungal gardens: some clean the tunnel systems that are being eaten into the wood; others clear the dirt from the nest and clean their fellow workers -- always with the aim of optimizing the symbiosis of beetle and fungus.
It's been long known that alcohol is produced by weakened trees and that these trees are recognized and colonized by the beetles. Traps baited with alcohol are used to catch the insects when they fly. Alcohol is very attractive to the beetles in large part because the fungi they feed on performs best in an alcohol-rich environment. Alcohol is normally used as a preservative to impede other fungi, such as molds from growing, and this is the case for the fungi associated with these beetles. They prefer to grow in an environment where other fungi don't grow.
Here's an interesting article showing how this preference by disease-causing fungi allows them to thrive in a normally harsh environment. Maybe it can be exploited.
Christopher M. Ranger el al., "Symbiont selection via alcohol benefits fungus farming by ambrosia beetles," PNAS (2018). www.pnas.org/cgi/doi/10.1073/pnas.1716852115
Photo: Party Beetles
Credit: Gernot Kunz