Anguina pacificae




Rev 01/30/2023

Pacific Shoot-gall Nematode Classification Hosts
Morphology and Anatomy Life Cycle
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Distribution Management
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              Anguina pacificae  Cid del Prado Vera & Maggenti, 1984


Anguina pacificae was synonymized with A. agropyri by Chizhov and Subbotin (1990) based on the identification af a nematode parasitizing Poa in Russia as A. agropyri (the documented host range of A. agropyri is in the grass genus Agropyron while that of A. pacificae is in the grass genus Poa).  However, the A. pacificae is still being used in some recent literature, e.g. McClure et al., 2008.

Recent molecular analyses of A. pacificae from California and A. agropyri from Europe indicate differences in the ITS region and suggest that A. pacificae is distributed in California and perhaps Russia while and A. agropyri is in Europe only (Sergei Subbotin, pers. comm.).. Note that A. pacificae has also been indentified in Ireland (Fleming, 2015).


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Morphology and Anatomy:



Anguina pacificae female  Females 

1.44-2.58 mm long. C-shaped when dead.  Four lines in lateral field.  Tail conical to a sharp point.

Stylet short (8.9-12.4 µm), esophageal glands do not appear to overlap intestine.

Vulva at 82-89%.  Monovarial, prodelphic ovary may have one or two flexures and extends to base of esophagus Post-uterine sac present. 


1.22-1.84 mm long.  

Caudal alae and gubernaculum present.

Anguina pacificae J2

Anguina pacificae male

Anguina pacificae: male tail, caudal alae, spicules

Photograph: I. Cid del Prado

Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:


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Anguina pacificae was found on grasses by Larry Costello (UC farm advisor) on Poa annua in 1978. It was described by Cid del Prado Vera and Maggenti in 1984.

It is reported from central coast golf courses in San Francisco, San Mateo and Monterey Counties.

As of 2001, golf course superintendents report that individual golf courses severely affected include Pebble Beach, Cypress Point, the Olympic Club, San Francisco Golf Club, and many other prominent courses.

  from McClure et al. (2008)

In 2015, Anguina pacificae was reported and confirmed infesting annual bluegrass (Poa annua) in County Dublin, Ireland (Fleming et al., 2015).

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Economic Importance:

C-rated pest in California, USA.

Damaging on golf courses, considered a serious problem by greens managers. Golf is a major recreational and sporting activity in California and many parts of the world. It supports hundreds of thousands of jobs and contributes billions annually to the economy. In Northern California, McClure et al. (2008) estimated there were over 1 million golfers who play on 400+ courses on which Poa annua accounts for more than 75% of the turf grass maintained on putting greens.

Anguina pacificae is a major threat to greens in cool, coastal golfing areas.


from McClure et al., 2008  
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Endoparasite in stem galls


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 Poa annua L., annual bluegrass.


For an extensive host range list for this species, click

 Several grass and cereal cultivars were tested for susceptibility to the A. pacificae, Dublin population. Of all the cultivars examined, only the P. annua and Velvet bentgrass (A. canina) had observable stem galls containing viable eggs. The other cultivars examined showed no galling; P. pratensis cv. Creon, Highland browntop bent (A. tenuis), F. rubra cv. Lucinda, Triticum aestivum var. Einstein, Triticum aestivum var. Alchemy, Hordeum vulgare var. Suzuka, and Hordeum vulgare var. Saffron. (Fleming et al., 2015).

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Life Cycle:

Ecophysiological Parameters:

For Ecophysiological Parameters for this species, click If species level data are not available, click for genus level parameters

The nematode induces green galls at stem bases. Galls may contain several adults and hundreds of juveniles and eggs. It does not attack the inflorescence (and presumably does not form seed galls, which might limit its spread). 

Mature galls may be filled with bacteria, which appears as a white cream. That is reminiscent of the association between Anguina spp. and Clavibacter spp. in wheat and ryegrass.


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Stem and leaf distortion, stem galls. On annual bluegrass, A. pacificae induces galls at the crown of the plant. The galls sequentially contain developing juveniles, adults, eggs and second-generation J2. Initial symptoms on turf consist of small yellow patches, 25 to 75mm in diameter, which enlarge and may coalesce as the nematodes spread. Young, infected plants may die and, when the infestation is severe, a rough, uneven putting surface results (McClure et al., 2008).

The nematode can be spread by any method that moves infected plant material or soil, or with irrigation water. It is not known to be seed borne (Schenck, 2022).

photograph: Ignacio Cid del Prado Vera

Nematode development in galls at stem bases at indicated days after infection (DAI) - from McClure et al. (2008)


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Chemical Control:

A single application of the nematicide fluopyram, applied at 0.22 lb/acre ,reduced the number of new shoot-galls and improved annual bluegrass appearance for several months. The efficacy was greater at increased rates and application frequency. Although the quality and appearance of  the treated turf was improved, and there were fewer new shoot galls, there was little apparent effect on individuals of A. pacficae in the soil, or on other plant-parasitic nematodes.  Researchers concluded that fluopyram did not move therough the thatch layer and into the soil although it clearly reduced the ability of pacific shoot-gall nematode juveniles to induce new shoot galls. Two applications of fluopyram provided season-long protection. A formulation of abamectin was similarly effective but required more frequent treatments to achieve the same result (Orlinski et al., 2021; Petelewicz et al, 2020).

Although one might speculate that reduction in numbers of shoot galls, feeding and reproduction sites for A, pacificae, would eventually lead to fewer nematodes, the researchers in the fluopyram study point out that the frequent use of pesticides can result in buildup of biodegrading microorganisms. The reliance on only one active ingredient against a pest like pacific shoot-gall nematode significantly increases the likelihood of developing resistance to the pesticide (Petelewicz et al, 2020).

Host Plant Resistance, Non-hosts and Crop Rotation alternatives:

For plants reported to have some level of resistance to this species, click
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Cid del Prado Vera, I. and A.R. Maggenti.  1984. A new gall-forming species of Anguina Scopoli, 1777 (Nemata Anguinidae) on bluegrass, Poa annua L., from the coast of California. J. Nematol. 16:386-392.

Chizhov, V.N. & Subbotin, S.A. 1990. [Phytoparasitic nematodes of subfamily Anguininae (Nematoda, Tylenchida). Morphology, trophic specialization, taxonomic]. Zoologichesky Zhurnal 69, 4: 15-26 (in Russian)

Fleming, T.R., A.G. Maule, T. Martin, M. Hainon-McDowell, K. Entwistle, M.A. McClure, C.C. Fleming. 2015. A First Report of Anguina pacificae in Ireland. Journal of Nematology 47:97-105.

McClure, M.A., Schmitt, M.E., McCullough, M.D. 2008. Distribution, Biology and Pathology of Anguina pacificae. J Nematol. 40: 226–239.

Orlinski, P.M., Petelewicz, P.,  Schiavon, M., Mundo-Ocampo, M., Becker, J.O. Baird, J.H. 2021. Pacific shoot-gall disease control in annual bluegrass putting greens using a new formulation of abamectin. International Turf Grass Soc. Res. J.

Petelewicz, P., Orlinski, P.M., Schiavon, M., Mundo-Ocampo, M., Becker, J.O., Baird, J.H.2020 .Fluopyram Controls Shoot-galling Caused by Pacific Shoot-gall Nematode and Improves Turf Quality in Annual Bluegrass Putting Greens  HortTechnology 30 :

Schenck, H.J. 2022.California Pest Rating Proposal for Anguina pacificae Cid del Prado Vera & Maggenti 1984 Pacific shoot-gall nematode. CDFA, Sacramento, California, USA.


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Copyright © 1999 by Howard Ferris.
Revised: January 30, 2023.