INVASIVE SPECIES UPDATE
David Headrick Horticulture and Crop Science Department Cal Poly State University, San Luis Obispo INVASIVE SPECIES UPDATE
Some who, what, where, when, why and how…
Focusing on ID, damage, spread and some controls WHO? WHEN?
Invasions in California are constant and the rate is alarming
Plants
Insects
Plant pathogens PLANT INVASIONS
www.sccgov.org PLANT SPECIES IN CALIFORNIA (JEPSON 1993)
1023 (17%) 1416 (24%)
Native Species 3423 (59%) Endemic to CA
Alien Species INVASIONS 1993 - 2003
315 exotic plant species discovered new to California between 1993 - 2003 = 1 every 12 days
Of these, 18 (5.7%) were considered noxious weeds INSECT INVASIONS
Photo courtesy of UC IPM Arthropod Species Exotic to California 1955-1988 (Dowell & Gill 1989) 18 16 14 12 10 8 6 4
Species New Annual 2 0 1950 1960 1970 1980 1990 YEAR PLANT PATHOGEN INVASIONS
Tomato Yellow Leaf Curl Virus PATHOGENS
Rate of fungal diseases reported
Fisher, et al. 2012, Nature 484: 186-194 WHY? HOW?
Increasing volume of global trade increases frequency of introductions
Movement of infested plant materials
Plenty of blame to go around FOCUS ON INSECTS
WHERE?
Introductions originate from all over the globe
CA has a distinct south to north trend, but many species also introduced into northern CA INSECTS:
Heteroptera: Red Bug, Brown Marmorated Stinkbug, Bagrada bug
Homoptera: Sternorrhyncha: Asian Citrus Psyllid
Lepidoptera: Light Brown Apple Moth
Update: Polyphagous Shot Hole Borer HETEROPTERA: TRUE BUGS
Red Bug, Scantius aegyptius (Hemiptera: Pyrrhocoridae)
© Peter J. Bryant RED BUG
Old World species widespread throughout Europe and Asia
Observed in OC in 2009, expanding northward
Not causing issues here, but many reports on finding large aggregations
Alarming red color RED BUG CLUSTERS
Aggregations will disperse in the spring SIMILAR RED BUGS
Seed bug White-crossed seed bug
© Peter J. Bryant © Ron Hemberger Small milkweed bug Large Milkweed Bug
© Ron Hemberger © Peter J. Bryant BROWN MARMORATED STINK BUG BROWN MARMORATED STINK BUG
Accidental introduction from Asia in the late 1990s
First sighted in Pennsylvania, spread quickly
Trapped in CA starting in 2005
Moving southward from Pacific NW SIMILAR BUGS
Rough stink bug Eustichus stink bug
© Peter J. Bryant
© Ron Hemberger
Consperse stink bug BMSB ID DAMAGE - AGRICULTURE
Primarily damaging fruit – huge host range; tree fruits plus vegetables
Prefer ripe fruit
Toxic saliva creates Steve Jacobs, Penn State wounds at feeding site DAMAGE - URBAN
Nuisance Pest – aggregations in the late summer and fall for overwintering
Homes and other sheltered locations NUISANCE PEST
usatoday.com 2011
http://flickriver.com/photos/tanyagin/5029863353/ BMSB AGGREGATIONS
On Chinese pistache in Sacramento
http://www.stopbmsb.org Baldo Villegas USDA-NIFA SCRI Coordinated Agricultural Project,
BIOLOGICAL CONTROL
New egg parasitoids may eventually be released, one showed up on its own in WA
Trissolcus & Telenomus spp.
© 2007 David E. Reed BAGRADA BUG
© 2012 Ryan Johnson BACKGROUND
African origins (also India, Pakistan, SE Asia, parts of Italy)
Discovered in SoCal 2008
Wide host plant range (mainly crucifers, but also grasses and grains, potatoes, some legumes…) IDENTIFICATION ISSUES
© 2008 John R. Maxwell Harlequin bug Bagrada bug EARLY FALL AGGREGATIONS
J. Taylor, OC Parks AROUND THE HOME
Darcy Reed, UC Riverside CROP DAMAGE
Multi-crowned broccoli BLIND CAULIFLOWER
MULTI-HEADED CABBAGE
DIRECT DAMAGE TO FRUIT CONTROLS
Cultural
Chemical
Biological – limited so far
CULTURAL
Adjust plantings in fall to avoid Bagrada at highest populations
Must get beyond the 6 leaf stage – use transplants over direct seeding
Host free periods and sanitation around fields not proven . Sweet Alyssum issues
CHEMICAL
Early season – pyrethroids – Asana
Later season – neonicotinoids, avoiding these if possible due to bee issues
Organic production challenging . Pyganic the most effective registered option for chemical control ASIAN CITRUS PSYLLID
© Lyle Buss, U of Florida ACP
2008 ACP expanded range from Mexico into San Diego County
Detections now as far north as Bay Area and Lodi
Two approaches – eradication strategy and management strategy BIOLOGICAL CONTROL
Tamarixia radiata – from Pakistan
Mike Lewis, CISR
Diaphorencyrtus aligarhensis – from Pakistan Mark Hoddle, CISR LIGHT BROWN APPLE MOTH
Ksby.com LBAM
Originally from Australia
Detected in Bay Area in 2007
October: detection in SLO, has been on the coast since 2011
ID RESOURCES
http://www.ipm.ucanr.edu/PDF/PMG/LBAMinCAnurseries.pdf LBAM QUARANTINES
Quarantines restrict movement of certain plants/green waste
Exempted Host List https://www.aphis.usda.gov/plant_health/plant_pest_info/lba_moth/downloads/exempted_host_list. pdf
Slows research for California conditions . Limited chemical and biological controls . Bt and Spinosads targeting larvae NEWS FLASH!
Polyphagous Shot Hole Borer moving into the central coast
Trapping and then beetle activity in avocado groves in Santa Paula, Ventura Co. (early Nov.) ANOTHER VECTOR
Two species of PSHB, each with different species of Fusarium Dieback
Reproductive hosts: Avocado, Box elder, California sycamore, Coast live oak, White alder, Japanese maple, and Red willow (http://eskalenlab.ucr.edu/) PSHB
Photo credit: Gevork Arakelian FUSARIUM DIEBACK SYMPTOMS
Photo credit: A Eskalen, M. Dimson RESOURCES
Basic info for PSHB and Fusarium in English and Spanish
harvesting best practices
shot hole borer symptoms on non- avocado host trees
Suspect Tree Report AVOCADO COMMISSION
Grower Information Mtg: Tuesday December 1st at the Ventura County Ag Museum, 926 Railroad Avenue, Santa Paula from 10:00am to 12:00pm APPROPRIATE RESPONSES
Invasions are a process, not just an event…
Address anything that looks out of place – early detection is best
Make the effort to get ID from County Ag QUESTIONS