Tag Archives: Coleoptera: Oedemeridae

Ananca bicolor (Fairmaire): Red-Black False Blister Beetle

California Pest Rating for
Ananca bicolor (Fairmaire): Red-Black False Blister Beetle
Coleoptera: Oedemeridae
Pest Rating:  B

Initiating Event:

The false blister beetle Ananca bicolor was recently intercepted by CDFA’s high risk programs on a shipment of Plumeria cut flowers from Hawaii.  The beetle is presently assigned a temporary rating of “Q”.  A pest rating proposal is required to support a permanent pest rating.

History & Status:

Background Ananca bicolor adults are nocturnal and highly attracted to lights1,2.  They are considered a nuisance pest and may enter dwellings in large numbers.  The adult beetles feed on pollen.  The larvae are not well documented but similar beetle grubs feed on rootlets and rhizomes3Ananca bicolor may be transported long distances when infested cut flowers are moved or as a contaminating pest.

Worldwide Distribution: Ananca bicolor is Polynesian in origin4.  It is known to be established in Samoa, Tahiti, Marquesas, Tonga, Ellice Island, and New Hebrides4.  It invaded Hawaii sometime before 18854.

Official Control: Ananca bicolor is not listed on any nations’ harmful organisms lists5 and is not known to be under official control anywhere.

California Distribution:  Ananca bicolor has never been found in the environment of California.

California Interceptions:  Ananca bicolor has been intercepted by CDFA four times. Three interceptions were on cut Plumeria flowers from Hawaii and one was on green vegetables.

The risk Ananca bicolor (Red-black false blister beetle) would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Ananca bicolor is only known to be established on tropical islands.  Almost all oedemerid larvae are limited to wet/moist environments.  This indicates that if the beetle were to establish in California it is likely to be limited to warm coastal areas.  It receives a Low (1) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California.  Score:

Low (1) Not likely to establish in California; or likely to establish in very limited areas.

Medium (2) may be able to establish in a larger but limited part of California.

High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Ananca bicolor adults are polyphagous on a wide variety of pollen.  Grubs are presumed to be equally polyphagous on organic matter in soil.  The beetle receives a High (3) in this category.

Evaluate the host range of the pest. Score:

Low (1) has a very limited host range.

Medium (2) has a moderate host range.

High (3) has a wide host range.

3) Pest Dispersal Potential: In Hawaii Ananca bicolor occurs in large numbers indicating that it likely has a high reproductive rate.  Despite its abundance and more than a century of transoceanic commerce, Ananca bicolor has not spread beyond Polynesia, indicating that it does not often spread via trade.  Ananca bicolor receives a Medium (2) in this category.

Evaluate the natural and artificial dispersal potential of the pest. Score:

Low (1) does not have high reproductive or dispersal potential.

Medium (2) has either high reproductive or dispersal potential.

High (3) has both high reproduction and dispersal potential.

4) Economic Impact: If Ananca bicolor were to establish in California it is not expected to lower any crop yields.  It may lower the value of cut flowers and flowering nursery stock by contaminating plants with its presence.  It is not likely to trigger lost markets, change cultural practices, vector other organisms, injure animals, or interfere with water supplies.  Ananca bicolor receives a Low (1) in this category.

Evaluate the economic impact of the pest to California using the criteria below. Score:

A. The pest could lower crop yield.
B. The pest could lower crop value (includes increasing crop production costs).
C. The pest could trigger the loss of markets (includes quarantines).
D. The pest could negatively change normal cultural practices.
E. The pest can vector, or is vectored, by another pestiferous organism.
F. The organism is injurious or poisonous to agriculturally important animals.
G. The organism can interfere with the delivery or supply of water for agricultural uses.

Low (1) causes 0 or 1 of these impacts.

Medium (2) causes 2 of these impacts.

High (3) causes 3 or more of these impacts.

5) Environmental Impact: If Ananca bicolor were to establish in California it is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes.  It is not likely to directly affect threatened or endangered species or disrupt critical habitats.  Since adult beetles are attracted to lights in large numbers, they may trigger new private treatment programs by residents who find them to be a nuisance.  The beetles are not likely to have significant impacts on cultural practices, home/urban gardening, or ornamental plantings.  Ananca bicolor receives a Medium (2) in this category.

Evaluate the environmental impact of the pest on California using the criteria below.

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.
B. The pest could directly affect threatened or endangered species.
C. The pest could impact threatened or endangered species by disrupting critical habitats.
D. The pest could trigger additional official or private treatment programs.
E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Score the pest for Environmental Impact. Score:

Low (1) causes none of the above to occur.
Medium (2) causes one of the above to occur.
High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Ananca bicolor (Red-Black False Blister Beetle):  Medium (9)

Add up the total score and include it here.

-Low = 5-8 points
-Medium = 9-12 points
-High = 13-15 points

6) Post Entry Distribution and Survey Information: Ananca bicolor has not been found in California and receives a Not established (0) in this category.

Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included.

Not established (0) Pest never detected in California, or known only from incursions.
Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).
Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.
High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (9)


California does have a rich oedemerid and melyrid fauna, which would be the direct competitors of Ananca bicolor.  If this new beetle were to establish in California it might outcompete and displace these native beetles.  It is possible that Ananca bicolor may be able to adapt to wider variety of climates and colonize a larger part of California.

Conclusion and Rating Justification:

Ananca bicolor has never been found in California and is likely to have impacts on the cut-flower and nursery industries and become a nuisance to residents if it were to establish in the state.  A “B” rating is justified.


1 Kinsey, Beth T. 2015. Red-black False Blister Beetle.  The Firefly Forest.  http://fireflyforest.net/firefly/2009/07/08/red-black-false-blister-beetle/

2 Tenorio, JoAnn M. and Gordon M. Nishida. 1995. What’s Bugging Me?: Identifying and Controlling Household Pests in Hawaii. University of Hawaii Press. 184pp.  https://books.google.com/books?id=2ehBWyagf2gC&pg=PA69&lpg=PA69&dq=Ananca+bicolor&source=bl&ots=ROFVnohzQs&sig=K-jbQylsU-8-EjiOcwGtf-8ARV8&hl=en&sa=X&ei=-HaMVdjENIvooAS00r24Dw&ved=0CEAQ6AEwBzgK#v=onepage&q=Ananca%20bicolor&f=false

3 Arnett, Ross H. Jr. 2014. Common Name: False Blister Beetles. University of Florida Featured Creatures. http://entnemdept.ufl.edu/creatures/urban/medical/false_blister_beetles.htm#top

4 Swezey, O.H. 1939. Notes on Oedemeridae in Hawaii and Palmyra. Proc. Haw. Ent. Soc. 10(2):263-264.  http://scholarspace.manoa.hawaii.edu/bitstream/handle/10125/15990/PHES10_263-264.pdf?sequence=1

5 USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD).  https://pcit.aphis.usda.gov/pcit/

Responsible Party:

Jason Leathers, 1220 N Street, Sacramento, CA, 95814, (916) 654-1211, plant.health[@]cdfa.ca.gov.

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Pest Rating:  B

Posted by ls