Plant Bug | Rubrocuneocoris calvertae

California Pest Rating  for
Plant Bug | Rubrocuneocoris calvertae Henry
Hemiptera: Miridae
Pest Rating: A


Initiating Event:

Rubrocuneocoris calvertae was reported to be established on Hawaii and Oahu islands, Hawaii (Henry, 2017; J. Matsunaga, pers. comm.).  It is currently Q-rated, and a permanent pest rating proposal is required to support an official pest rating.

History & Status:

Background:  Rubrocuneocoris calvertae is a small plant bug (approximately 2.5 millimeters in length) that is dull brown in color except for distinctive red markings on the posterior portion of the forewings (a character shared with other members of the genus).  This species is only known from Hawaii, but it is presumed to have been introduced from somewhere in Asia or the Pacific, because the other species in the genus are native to these areas.  In Hawaii, R. calvertae is reported to feed on Macaranga tanarius (Euphorbiaceae) and Pipturus sp. (Urticaceae) (Henry, 2017; J. Matsunaga, pers. comm.), but no information is available on the extent of damage inflicted on these plants by this bug.  Very little information was found on the biology of this genus.  Most collections of Rubrocuneocoris appear to have been made with light or malaise traps, which provides little biological information.

Worldwide Distribution:  Rubrocuneocoris calvertae is only known from Hawaii (Hawaii and Oahu islands), and it was presumably introduced there from an unknown location in east Asia or the Pacific (Henry, 2017; J. Matsunaga, pers. comm.).

Official Control: Rubrocuneocoris calvertae is not known to be under official control anywhere.

California Distribution:  Rubrocuneocoris calvertae is not known to be present in California (Symbiota Collections of Arthropods Network).

California Interceptions:  Rubrocuneocoris calvertae has not been intercepted in California.

The risk Rubrocuneocoris calvertae would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Rubrocuneocoris calvertae has been reported to feed on plants in the families Euphorbiaceae and Urticaceae. There are plants in these families present throughout California.  This insect is only known to be present in Hawaii, although it is presumed to be native to somewhere in east Asia or the Pacific.  At least one species in the genus Rubrocuneocoris occurs in the Primorye region of the Russian Federation, which suggests it may be tolerant of a more temperate climate (Vinokurov et al., 1988).  Therefore, even though it is likely that calvertae originated in a tropical or subtropical area and is limited to such climates, it is also possible that this species is native to an area with a temperate climate, and thus could survive in much of California.  Therefore, R. calvertae receives a High (3) in this category.

– 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: This species has been reported to feed on two families of plants, the Euphorbiaceae and Urticaceae. Its native distribution is unknown, but this species may feed on other plants there.  The unknown feeding habits in the (also unknown) native range are considered here.  Therefore, calvertae receives a Medium (2) in this category.

– 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: Rubrocuneocoris calvertae presumably flies, because other species in the genus are caught at light traps (Schuh, 1984).  Therefore, it receives a Medium (2) in this category.

– 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: This species feeds on plants.  It is not known to be present in California, and it is possible that it has a very limited distribution and may not have been exposed to some economically-significant plants that are present in California.  Therefore, even though there is no evidence that calvertae is a pest elsewhere, there is still the possibility that it could become a pest in California if it became established here.  If it became a pest in California, it could lower crop yield and increase crop production costs, for example, through increased pesticide use.  Therefore, it receives a Medium (2) in this category.

Economic Impact: A, B

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

The pest could trigger the loss of markets (includes quarantines).

The pest could negatively change normal cultural practices.

The pest can vector, or is vectored, by another pestiferous organism.

The organism is injurious or poisonous to agriculturally important animals.

The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 2

– 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: As explained above, under Economic Impacts, there is the possibility that calvertae could become a pest if it was established in California. This could trigger treatment programs, for example, in agriculture or ornamental plantings.  There is a rare Euphorbia species in California, E. hooveri, which could be attacked by R. calvertae if it became established in California.  Therefore, R. calvertae receives a High (3) in this category.

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

Environmental Impact: B, D

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.

Environmental Impact Score: 3

– 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 Rubrocuneocoris calvertae: Medium (12)

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: Rubrocuneocoris calvertae is not known to be present in California.  It receives a Not established (0) in this category.

–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:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (12)


The full extent (including native range) of the distribution of R. calvertae are presumably not known.  This means that the climatic tolerances and feeding habits of this insect are also unknown, which makes it challenging to determine its potential for impact in California.  No information was found suggesting that any species in the genus Rubrocuneocoris is a pest.  This suggests that the genus may have a low potential for economic or environmental impact.

Conclusion and Rating Justification:

Rubrocuneocoris calvertae is only known from Hawaii, but it is presumed to be native somewhere in Asia or the Pacific.  It is possible that it could have economic and environmental impacts if it became established in California.  For these reasons, an “A” rating is justified.


Henry, T.  2017.  A new species of the plant bug genus Rubrocuneocoris Schuh (Heteroptera: Miridae: Phylinae) from Hawaii.  Proceedings of the Entomological Society of Washington.  119(1): 63-69.

Lin, C-S.  2006.  Genus Rubrocuneocoris Schuh (Hemiptera: Miridae) of Taiwan.  Formosan Entomologist.  26: 295-302.

Schuh, R.T.  1984.  Revision of the Phylinae (Hemiptera, Miridae) of the Indo-Pacific.  Bulletin of the American Museum of Natural History.  177: 1-476.

Symbiota Collections of Arthropods Network.  Accessed November 20, 2017.

Vinokurov, N.N., Golub, V.B., Kanyukova, E.V., Kerzhner, I.M., and G.P. Tshernova.  1988.  Volume II: Homoptera and Heteroptera.  In (P.A. Lehr, ed.) Keys to the Insects of the Far East of Russia.  Nauka Publishing House, Leningrad.  972 pp.


Kyle Beucke, 1220 N Street, Room 221, Sacramento, CA, 95814, 916-403-6741,[@]

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Pest Rating: A

Posted by ls