Projects We're Working On: GSOB Confirmed in the Hodges Watershed

GSOB has now been found in Del Dios Park, on Laurel, Kalmia, and Juniper Lanes. It is also on Mount Israel near Detwieler Road. We can assume in the next several years our large Coast Live Oak trees will see GSOB. The adult beetles emerge from mid-May through August, so presence of the beetle in healthy trees may not be detectable yet.

Residents and the City of San Diego are being urged by the Del Dios Habitat Protection League to protect high value oaks from this deadly invasive beetle. We are putting together a community plan to treat trees together to reduce the individual tree cost.

We are asking for people who are interested in being part of the solution to step up and contact Stacy McCline stacy@DDHPL.org right away.

The gold spotted oak borer is a tiny beetle causing huge damage in Southern California. It infests the region's towering oak species - coast live oak and canyon live oak - and can kill a centuries-old tree in just a year or two.

Read more about GSOB from Western IPM Center

GSOB Update: May 2017

GSOB Confirmed in Del Dios and Mt. Israel

This beetle - the Gold Spotted Oak Borer, is a highly invasive, non-native flathead borer that kills oak trees.

San Diego County Ag has confirmed the presence of GSOB based on pictures submitted to them on Thursday May 11, 2017. So far, Clark Mahrdt and I have identified the oak killing beetle in two locations on the north end of Del Dios, as well the confirmed location on Mt Israel near Detwieler Road. Additionally, Conor Lenehan, RSF Fire, announced its presence on Mt. Israel at the Elfin Forest/Harmony Grove Town Council meeting last month. According to neighbors, GSOB may have arrived in Mt. Israel a few years ago, but we believe this to be a new problem in Del Dios, based on my examination the trunks of failing and dead oak trees for the last 3 years.

Please review the GSOB Identification Guide, especially page 5. When you first start looking at the trunk of a mature oak tree you will notice there are a lot of different shapes and sizes of holes in it. GSOB has a characteristic D-shaped hole in the bark, about the size of the lead of a #2 pencil. 

Evidence of GSOB

GSOB has a characteristic D-shaped hole in the bark, about the size of the lead of a #2 pencil.

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The first steps for limiting the spread of this infestation are 1: Alert the community that no oak wood should be moved in or out of our area and 2: Determine the extent of the problem – how many trees are effected and how they are grouped. According to the resources below, activities to contain the extent of the damage by GSOB include removing dead and dying trees effected with the beetle and using preventative treatment of unaffected or slightly affected trees in the vicinity.

We will need to work together and coordinate our efforts to be effective in stopping the spread of this pest in our area.

I will post again as I have more information to share.

Stacy McCline

President

Del Dios Habitat Protection League

Resources

Additional links, resources and video can be found in our original GSOB post.

Project Update - December

Oak Woodland Restoration and Fire Fuel Reduction Project Update

December 2016

Invasive removal is focused on tamarisk and pampas grass. These invasive plants are being sprayed or removed, around the lake perimeter. December work will include eucalyptus removal. Roadside weeds were sprayed in November to help with next year’s fire season.

Planting has begun - 250 plants were planted by volunteers on 12/3 and a good time was had by all. Locally harvested mulefat and willow were planted, and more pole planting is happening thru January. Its a great way to actively connect with nature, so kids absolutely love it. 

Stinkwort- Update: 9 locations were found and removed in our community of Del Dios. Volunteers cruised the streets, and we think we found all weed populations and removed them. We will be monitoring in July 2017 to where this new invasive shows up in town.

Volunteer days start with the promise of cooler weather,  I Love a Clean San Diego brought 80 volunteers, removing 40 pounds of garbage and 2 full dumpster loads of tamarisk.   (See Photos Here) 

The natives plantings are coming in strong in our restoration areas, however , please stay out of the Restoration Areas except for volunteering at Del Dios Habitat Protection League events.  

Project Update: September

Phase 3 of the Hodges Watershed Restoration has begun

Target Species: Eucalyptus, Pampas Grass and Tamarisk.

Plantings with the winter rains: Sycamore, Oaks, Mulefat, Willow.

Invasive non-native plants are threatening the ability of the San Dieguito River and watershed to function properly. Many non-native plants contribute to flood damage, are a fire risk and degrade native habitats. The Del Dios Habitat Protection League is working in partnership with the San Dieguito River Park to help restore the natural functions of the river. An action that enhances watershed health is the control of non-native plants.  The seasonal watercourses and lakeshore of Hodges reservior provide valuable habitat for native flora and fauna that is a cornerstone for our incredible biodiversity of the region.

Along the new lower level of Hodges reservior, cat tails and bulrushes have established as well as willows directly above this level. This is much the same as what these species do along a natural river. Several locals have expressed concern to the League about the invasion of Pampas grass and Tamarisk that is also moving into these same areas.

Phase 3 of the Oak Woodland Restoration and Fire Fuel Reduction Project will include the establishment of native plants as well has removal of non-native invasives, such as Tamarisk, Pampas grass and Eucalytpus.

This work is sponsored by the NRCS and is the result of partnerships with numerous local agencies, including the City of San Diego Public Utilities Department, the San Dieguito River Park and the Del Dios Mutual Water Company.

Establishment of native species is scheduled to start with the first rains in areas where eucalyptus has been removed.  We look forward to working with weekend volunteers planting acorns, pole cuttings and potted native plants.

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Pampas Grass

According to the California Invasive Plant Council, pampas grass creates a fire hazard with excessive build-up of dry leaves, leaf bases, and flowering stalks. In addition, pampas grass out-competes native vegetation, by propagating easily and growing rapidly. 

Cal-IPC Plant Assessment Form

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Tamarisk (Salt Cedar)

Tamarisk is the other species of high concern that is taking over a large swath of the 'bathtub ring" below the high waterline of Lake Hodges. Tamarisk that has a long history in the west for out competing native willow habitat and poisoning the soil to keep other plants from growing in the same areas with it. The plant is also called Salt Cedar.

Phase 3 will include removing tamarisk and pampas grass and planting willows at Green Lagoon (second parking lot from the gates at Lake Dr) and other prime locations to encourage the Southwestern Willow Flycatcher (endangered, federally listed songbird) to come live and breed here at Lake Hodges.

Make sure to look for volunteer opportunities with the winter rains to help with the planting. Become a member of the Del Dios Habitat Protection League.