California Pest Rating for
Hypogeococcus pungens Granara de Willink | Harrisia cactus mealybug
Pest Rating: A
PEST RATING PROFILE
An infestation of Hypogeococcus pungens was discovered on cacti in a recreation area in Orange County in September 2018. This mealybug currently has a Q-rating. A permanent pest rating proposal is required to support an official pest rating.
History & Status:
Background: Hypogeococcus pungens is a mealybug that has been reported to attack at least six genera of cacti as well as plants in the families Amaranthaceae, Polygonaceae, and Portulaceae (Hodges, 2009; Zimmermann et al., 2010). Cactus feeding is concentrated on portions of the plant that are actively growing. This results in distorted growth, including curling branches and growth of new, deformed branches that are sometimes referred to as galls (Le Quay-Velázquez et al., 2015). Death can take years, especially in older plants, but feeding has an immediate impact of fruit production because the mealybugs are concentrated on developing flowers. Therefore, this mealybug can have a severe impact on cactus reproduction (Patterson et al., 2011).
Natural dispersal appears to be limited but may include wind dispersal in the first instar (Zimmermann et al., 2010). Movement of plants is probably the most effective means of spread of this mealybug.
In the 1970s and 1980s, this mealybug was introduced to Australia and South Africa as part of biological control programs targeting introduced cacti, including Harrisia spp. This mealybug was credited as an effective biological control agent, helping to clear cacti from thousands of hectares.
Aguirre et al. (2016) provided evidence that more than one species may be currently identified as H. pungens. Specimens collected from the type host plant (Amaranthaceae) did not produce viable offspring or did not survive at all on cacti. The cactus-feeding H. pungens introduced to Australia for biological control of cacti had been collected from cacti in Argentina. Significantly, the H. pungens in Australia have not been found on Amaranthaceae, even though this family of plants is common in Australia. The mealybug in Florida rarely attacks cacti but it is common on Alternanthera (Polygonaceae) and Portulaca (Portulaceae) species. In addition, the Amaranthaceae-feeding H. pungens are reported to be parthenogenetic, whereas the cactus-feeding mealybug is not. This evidence suggests there are likely at least two species currently recognized as H. pungens; one that feeds on cacti (native to South America and introduced to Australia, South Africa, the Caribbean, and possibly California) and one that feeds on Amaranthaceae and other plant families (also native to South America and introduced to Florida).
In addition, H. pungens has been misidentified as H. festerianus in the past (CABI, 2018).
In areas with native cacti but where H. pungens is not native to, there is concern that the mealybug could have an impact on native cacti. Hypogeococcus pungens was reported to cause severe damage to native cacti in Puerto Rico, including reducing the density of cactus stems (Weaver, 2011).
Worldwide Distribution: Hypogeococcus pungens is native to South America (northern Argentina, western Brazil, Paraguay, and Peru). It has been introduced to Australia, the Caribbean (including the Dominican Republic and Puerto Rico), Europe (France, Greece, and Italy), South Africa, and the United States (Florida and Hawaii) (German-Ramirez et al., 2014; Hodges, 2009; Milonas et al., 2008; Pellizzari and Sacco, 2010; Segarra-Carmona et al., 2010). As of 2009, it was reported from 26 counties in Florida (Hodges, 2009).
Official Control: Hypogeococcus pungens is considered Reportable by the USDA (USDA-APHIS).
California Distribution: Hypogeococcus pungens was found in California in Beverly Hills in 2010, 2012, 2014, and 2018 and in a recreation area in Orange County in 2018. Both of these infestations are now under eradication, and this species is not known to be present anywhere else in the state.
California Interceptions: Hypogeococcus pungens was found on cacti at one residence in Beverly Hills (in 2010, 2012, 2014, and 2018), in a recreation area in Orange County in 2018, and in nurseries in Riverside, Orange, San Diego, and San Mateo County in 2004, 2011, 2012, and 2018. It was intercepted on alternanthera and ludwigia plants from Florida in 2002 and 2004 (see comment on host breadth and taxonomic uncertainty, above).
The risk Hypogeococcus pungens would pose to California is evaluated below.
Consequences of Introduction:
1) Climate/Host Interaction: Hypogeococcus pungens has been reported from areas that vary in climate from temperate to semi-arid to tropical. It has been reported to feed on plants in four families. It could possibly establish a widespread distribution in California. Therefore, pungens 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: Four plant families are reported to be attacked by mealybugs that were identified as pungens. Although it is possible that multiple species with different feeding habits are being lumped together in this PRP (see Background, above, and Uncertainty, below), it is necessary to consider characteristics of what has been (and are likely to be) identified as H. pungens. Therefore, H. pungens 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 Reproductive and Dispersal Potential: Some pungens are reported to be parthenogenetic, but see Background, above. Natural dispersal ability appears to be limited, with wind-dispersal of first instar nymphs being reported as likely. Movement of infested cactus plants is another likely mode of dispersal. 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: Hypogeococcus pungens is likely to infest cacti in nurseries if it became established in California. This could lead to higher costs of production. Additionally, the presence of this mealybug could lead to a loss in cactus markets, as this pest threatens native cacti in other countries, including Mexico. Therefore, it receives a Medium (2) in this category.
Economic Impact: B, C
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.
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: There are 38 native cacti in California, including 8 endemic species (Jepson Herbarium, 2018), that could be threatened by this mealybug, including the rare golden-spined cereus (Bergerocactus emoryi (Engelm.) Britton & Rose) and the San Diego barrel cactus (Ferocactus viridescens (Torr. & A. Gray) Britton & Rose). Infestations of this mealybug could trigger treatments and could impact ornamental cactus plantings. Therefore, it receives a High (3) in this category.
Evaluate the environmental impact of the pest on California using the criteria below.
Environmental Impact: B, D, E
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 Hypogeococcus pungens: 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: Hypogeococcus pungens is not known to be established 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.
7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (12)
There is significant uncertainty regarding the identity of the mealybugs identified as H. pungens. As described in the Background (above), there may be at least two species that are currently identified as H. pungens; one that feeds on cacti and one that feeds on other plants, including Amaranthaceae. This makes it difficult to extrapolate impacts of H. pungens observed in other places to California. For example, H. pungens is reported to be widely distributed in Florida, but this does not appear to be the cactus-feeding form. In this PRP, characteristics and possible impacts of the mealybugs identified as H. pungens were considered because, in the absence of further systematic work on these mealybugs, they are likely to be similarly identified as H. pungens if intercepted in California.
Conclusion and Rating Justification:
Hypogeococcus pungens or a cryptic species that is currently identified as H. pungens attacks cacti and poses a threat to cacti in California, both rare, native species as well as those cultivated as ornamentals in nurseries. Besides the infestations that are under eradication, this mealybug is not known to be established in California. For these reasons, an “A” rating is justified.
Aguirre, M. B., Diaz-Soltero, H., Claps, L. E., Saracho Bottero, A., Triapitsyn, S., Hasson, E., and Logarzo, G. A. 2016. Studies on the biology of Hypogeococcus pungens (sensu stricto) (Hemiptera: Pseudococcidae) in Argentina to aid the identification of the mealybug pest of Cactaceae in Puerto Rico. Journal of Insect Science 16:1-7.
California Department of Food and Agriculture. Pest and damage record database. Accessed October 5, 2018: https://pdr.cdfa.ca.gov/PDR/pdrmainmenu.aspx
CABI. 2018. Invasive Species Compendium. Hypogeococcus pungens (cactus mealybug) datasheet. Accessed October 5, 2018: https://www.cabi.org/isc/datasheet/110614
German-Ramirez, E., Kairo, M. T. K., Stocks, I., Haseeb, M., and Serra, C. A. 2014. New record of Hypogeococcus pungens (Hemiptera: Pseudococcidae) in the Dominican Republic with comments on specific characters. Florida Entomologist 97:320-321.
Hodges, A. 2009. Hypogeococcus pungens Granara de Willink (Insects: Hemiptera: Pseudococcidae). Accessed September 24, 2018: http://entnemdept.ufl.edu/creatures/orn/mealybug/hypogeococcus_pungens.htm
Jepson Herbarium. 2018. Jepson eFLora. Accessed October 5, 2018:
Le Quay-Velázquez, G., Ciomperlik, M., and Rodrigues, J. C. V. 2015. Gall formation on the endangered cactus, Leptocereus quadricostatus caused by the invasive mealybug, Hypogeococcus pungens (Hemiptera: Pseudococcidae). Proceedings of the Caribbean Food Crops Society 51:174-180.
Milonas, P. G., Kozár, F., and Kontodimas, D. C. 2008. List of scale insects of Greece. pp. 143-147 in Branco M., Franco J.C., and Hodgson C. (eds.), Proceedings of the XI International Symposium on Scale Insect Studies. ISA Press, Lisbon, Portugal.
Paterson, I. D., Hoffmann, J. H., Klein, H., Mathenge, C. W., Neser, S., and Zimmermann, H. G. 2011. Biological control of Cactaceae in South Africa 19:230-246.
Pellizzari, G., and Sacco, M. 2010. Le cocciniglie delle piante ornamentali in Liguria. Protezione delle Colture 4:27-36.
Segarra-Carmona, A. E., Ramírez-Lluch, A., Cabrera-Asencio, I., and Jiménez-López, A. N. 2010. First report of a new invasive mealybug, the Harrisia cactus Hypogeococcus pungens (Hemiptera: Pseudococcidae). The Journal of Agriculture of the University of Puerto Rico 94:183-187.
USDA-APHIS. U.S. regulated plant pest table. Accessed September 26, 2018:
Weaver, P. L. 2011. Early recovery of subtropical dry forest in south-western Puerto Rico. Bois et Forêts de Tropiques 310:12-23.
Zimmermann, H. G., Pérez, M., Cuen, S., Mandujano, M. C., and Golubov, J. 2010. The South American mealybug that threatens North American cacti. Cactus and Succulent Journal 82:105-107.
Kyle Beucke, 1220 N Street, Room 221, Sacramento, CA, 95814, 916-403-6741, plant.health[@]cdfa.ca.gov
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12/6/2018 – 1/20/2019
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Pest Rating: A
Posted by ls