Considering the similarities between the WHS list, it is somewhat surprising there does not seem to be many travel enthusiasts pursuing this list? Granted, some of the sites are more research/wilderness in focus and very difficult to visit (plenty biosphere reserves have limited to no access). Nevertheless, quite a few biosphere reserves are WHS. Moreover, plenty of these listed reserves have been mentioned as potential candidates for world heritage status. It is also fascinating to me to learn that the United States has the most biosphere reserves in the world (47), despite having no new nominations since 1991! It might be worth researching which countries are active in both programs or which state parties are only involved/active in one of them.

Total: 631 biosphere reserves in 119 countries

From what I can gather, my count is only 13.

KOREA (4)
Mount Sorak
Jeju Island*
Gwangneung Forest*
Gochang*

MEXICO (1)
Alto Golfo de California*

PHILIPPINES (1)
Palawan*

UNITED STATES (7)
Channel Islands
Everglades*
Organ Pipe Cactus
Sequoia-Kings Canyon
Mojave and Colorado Deserts
Golden Gate
Mammoth Cave Area*

* world heritage site

Sounds fun, always handy to have another list :)
I was trying to work out my own number, but a few of them aren't so obvious in terms of location without delving into it fully, so I may need a bit more time.

Though winterkjm have you not been to San Dimas Forrest? if not there is some low hanging fruit for you, with the additional bonus of a Bill and Ted themed day out!

Interesting you should mention this, I've been through many areas of the Angeles National Forest/San Gabriel Mountains National Monument, but never this small experimental forest. However, its actually fairly easy to visit, about 55 min. from where I live, so perhaps an upcoming weekend for a hike. This also brings up the point how different (MAB) Biosphere Reserves are in regards to boundaries. For one, some boundaries are only a small part of a massive habitat/park, sometimes the boundaries are over several parks, but rarely (or only sometimes) do they seem to match with WHS or National Park/National Monument boundaries, which makes me think why?

23 New UNESCO Biosphere Reserves

http://news.nationalgeographic.com/2017/06/unesco-new-biosphere-reserves-us-withdraws -reserves/

Perhaps the most surprising news is the United States has removed 17 Biosphere Reserves from the list.

U.S. sites removed from the biosphere reserve list this week:

Aleutian Islands National Wildlife Refuge - US Fish & Wildlife Service
Beaver Creek Experimental Watershed - US Forest Service
California Coast Ranges - University of California Natural Reserve System
Carolinian South-Atlantic - Non-Game and Heritage Trust (South Carolina)
Central Plains Experimental Range - USDA Agricultural Research Service
Coram Experimental Forest - US Forest Service
Desert Experimental Range - US Forest Service
Fraser Experimental Forest - US Forest Service
H.J. Andrews Experimental Forest - US Forest Service / Oregon State University
Hubbard Brook - US Forest Service
Konza Prairie Research Natural Area - Kansas State University
Land Between the Lakes - US Forest Service
Niwot Ridge Mountain Research Station - University of Colorado
Noatak National Preserve - National Park Service
Stanislas-Tuolumne Experimental Forest - US Forest Service
Three Sisters Wilderness - US Forest Service
Virgin Islands - National Park Service

At first glance, 3 criteria for removal.
1) Managed by the US Forest Service (Experimental Forest)
2) Current borders/name no longer relevant
3) Managed by a State University

Most remaining US Biosphere Reserves are National Parks or National Monuments

It is interesting how much attention Kansas is receiving with UNESCO this week. I have walked Konza many times, it is just a few miles from my home and is owned and managed by my university. I always thought it was nice having something on a UNESCO list close by, even if just a biosphere reserve.

I know there have been several budgetary constraints placed on Kansas State by the state government and have heard the prairie is becoming harder to manage, as well as harder to do research in general. I hope there is some logic behind this decision, but fear that the removal of Konza as well as the other sites could be for no longer being able to meet the requirements of protection that the Nat Geo article alludes.

Some information on the fourth Costa Rican biosphere reserve: the Savegre river watershed "the cleanest river in Central America" and includes seven protected areas, notably the Manuel Antonio National Parl on the coast and the Los Quetzales national park, Los Santos forest reserve and the Cerro Vueltas biological reserve in the Talamanca mountain range, ascending up to 3400 m. Additionally, it also includes the Portalón mixed wildlife refuge, the Hacienda Barú mixed wildlife refuge (in the lowlands) and the Cerro Nara protected area.

Savegre 

24 new biosphere reserves announced today. Undoubtably some sites to add to our connection.

https://news.un.org/en/story/2018/07/1015572

https://www.capital.cl/24-nuevos-sitios-ingresan-en-la-red-mundial-de-reservas-de-bio sfera-de-la-unesco/

http://www.arirang.com/News/News_View.asp?nseq=220961

Here you go with the list. Natural sites are a real weak point for me in terms of analysis so if anyone else know the details better jump in, descriptions of the sites can also be found here.

Arly (Burkina Faso)
Mount Huangshan (China)
Mount Kumgang (Democratic People's Republic of Korea)
Chocó Andino de Pichincha (Ecuador)
Khangchendzonga (India)
Berbak-Sembilang (Indonesia)
Betung Kerihun Danau Sentarum Kapuas Hulu (Indonesia)
Rinjani-Lombok (Indonesia)
Kopet-Dag (Islamic Republic of Iran)
Mont Peglia (Italy)
Val Camonica – Alto Sebino (Italy)
Tsimanampesotse – Nosy Ve Androka (Madagascar)
Lower Prut (Republic of Moldova)
Quirimbas (Mozambique)
Maasheggen (Netherlands) –
Charyn Biosphere Reserve (Republic of Kazakhstan)
Zhongar Biosphere Reserve (Republic of Kazakhstan)
Suncheon Biosphere Reserve (Republic of Korea)
Mountainous Urals (Russian Federation)
The Mura River (Slovenia)
Marico (South Africa)
Ponga (Spain)
Wadi Wurayah (United Arab Emirates)
Gombe Masito Ugalla (United Republic of Tanzania)
Extensions:
Thuringian Forest Biosphere Reserve ­ [extension and renaming, former Vessertal-Thuringe Biosphere Reserve] (Germany)
Ticino, Val Grande Verbano Biosphere Reserve [extension and renaming of the former Valle del Ticino Biosphere Reserve] (Italy)

Certainly these 3 are also WHS:
Arly (Burkina Faso)
Mount Huangshan (China)
Khangchendzonga (India)

Seonamsa Temple, which is one of the components of the Sansa, Buddhist Mountain Monasteries in Korea WHS is located within the Suncheon Biosphere Reserve (Republic of Korea)

https://en.unesco.org/biosphere-reserves/republic-korea/suncheon

18 New sites join UNESCO's World Network of Biosphere Reserves

https://en.unesco.org/news/18-new-sites-join-unescos-world-network-biosphere-reserves

2 new biosphere reserves connecting with the DMZ
- Gangwon Eco-Peace Biosphere Reserve (Republic of Korea)
- Yeoncheon Imjin River Biosphere Reserve (Republic of Korea)

Huge extension added for Jeju Island:

Republic of Korea—Jeju Island Biosphere Reserve. Extension from 83,094 hectares to 387,194 hectares to improve integrated and effective conservation of biodiversity. Jeju Island is one of the few sites in the world to have a triple designation as a UNESCO biosphere reserve (2002), a World Heritage site (2007, expanded in 2018) and a UNESCO Global Geopark (2010).

No new connections for us I believe? Komodo was already one, Ferrara (Po-delta) and Jeju as well.

Valle del Cabriel Biosphere Reserve (Spain): "Rich cultural heritage remains the area include Villar del Humo, part of the Rock Art of the Mediterranean Basin on the Iberian Peninsula World Heritage site."

The Isle of Wight isn't one, but is essentially a continuation of the Devon and Dorset Jurassic Coast.

Also I think it moves to the top of the list of first places on a UNESCO list I visited.

https://en.unesco.org/news/twenty-five-sites-join-unescos-world-network-biosphere-reserves

Withdrawn: 11 Sites
- Uluru Ayers Rock-Mount Olga (Australia)
- Croajingalong (Australia)
- Riverland (Australia)
- Kosciuszko (Australia)
- Mamungari (Australia)
- Ali Botouch (Bulgaria)
- Doupki-Djindjiritza (Bulgaria)
- Mantaritza (Bulgaria)
- Parangalitsa (Bulgaria)
- Lufira (DRC)
- Islas del Golfo de California (Mexico) *Double Listed (deletion of smaller version)

New Biosphere Reserves: 25 Sites
Ordino Biosphere Reserve (Andorra)
Complex W-Arly-Pendjari (WAP) Biosphere Reserve (Benin, Burkina-Faso, Niger)
Oueme Lower Valley Biosphere Reserve (Benin)
Fogo Biosphere Reserve (Cabo Verde)
Maio Biosphere Reserve (Cabo Verde)
Mwali Biosphere Reserve (Comoros)
Asterousia Mountain Range Biosphere Reserve (Greece)
Panna Biosphere Reserve (India)
Bunaken Tangkoko Minahasa Biosphere Reserve (Indonesia)
Karimunjawa-Jepara-Muria Biosphere Reserve (Indonesia)
Merapi Merbabu Menoreh Biosphere Reserve (Indonesia)
Almaty Biosphere Reserve (Kazakhstan)
West Altai Biosphere Reserve (Kazakhstan)
Minett Biosphere Reserve (Luxembourg)
Addu Atoll Biosphere Reserve (Maldives)
Fuvahmulah Biosphere Reserve (Maldives)
Toson-Khulstai Biosphere Reserve (Mongolia)
Hadejia Nguru Bade Biosphere Reserve (Nigeria)
Oban Biosphere Reserve (Nigeria)
Okangwo Biosphere Reserve (Nigeria)
Bosques de Neblina – Selva Central Biosphere Reserve (Peru)
Island of Porto Santo Biosphere Reserve (Portugal)
Kologrivsky Forest Biosphere Reserve (Russian Federation)
Gishwati Mukura Landscape Biosphere Reserve (Rwanda)
North-East Tobago Biosphere Reserve (Trinidad and Tobago)