Insect Resistance

AR37 endophyte has been shown to provide superior resistance against a wider range of insects than ryegrass containing either standard endophyte1 (SE) or AR1 endophyte. It provides strong resistance to Argentine stem weevil, porina*, pasture mealy bug, root aphid, and black beetle.

AR37 provides protection from major pasture pests

Black BeetleBlack beetle
Found in Northland, Waikato, Bay of Plenty 
Pastures with AR37 have much better resistance to black beetle relative to AR1.

Argentine Stem WeevilArgentine stem weevil
New Zealand wide    
AR37 provides excellent resistance against the Argentine stem weevil larvae which is responsible for most of the damage caused by Argentine stem weevil.

New Zealand wide    
Almost all porina Caterpillars die when placed on AR37 ryegrass, whereas almost all survive on AR1 and half die on standard endophyte ryegrass*.

Root AphidRoot aphid
New Zealand wide    
Virtually all root aphids die when placed on ryegrass inoculated with AR37, whereas most survive when on pasture with standard endophyte or AR1.

Pasture Mealy BugPasture mealy bug
New Zealand wide, especially areas with moist and cloudy summers    Pastures with AR37 provide excellent resistance against pasture mealy bug.

In early field trials when an insecticide was applied to a cultivar in various endophyte strains, the insecticide did not increase above or below-ground growth of the plants with AR37. This indicates that AR37 appears to naturally gives similar protection as chemical insecticides.

Because AR37 reduces insect damage, pasture is more persistent and produces an average 12% more drymatter nationally than the same cultivar containing standard endophyte. The average results of the four regional trials are available by clicking here. The better quantity and quality (as a result of the improved persistence) of pasture can have considerable benefits for your stock and overall production on your farm.

Note: In pastures with AR37 ryegrass, porina can be present and feed on the other pasture mix components.

Endophyte Insect Control (Perennial and Long-Rotation Ryegrass)

These ratings are indicative and may vary slightly between cultivars. If Argentine stem weevil or black beetle are present at sowing, an appropriate seed treatment is recommended, to improve insect resistance during establishment. These tables were compiled by AgResearch, Dairy NZ and NZPBRA.

Table 1 - Diploid perennial ryegrass

Table 1 2017

Table 2 - Tetraploid perennial ryegrass

Table 2 2017

Table 3 - Italian and short term (hybrid) ryegrass

Table 3 2017

Key to Tables 1 - 3

- No control
diam.png Low level control: Endophyte may provide a measurable effect, but is unlikely to give any practical control.
diam.pngdiam.png Moderate control: Endophyte may provide some practical protection, with a low to moderate reaction in insect population.
diam.pngdiam.pngdiam.png Good control: Endophyte markedly reduces insect damage under low to moderate insect pressure. Damage may still occur when insect pressure is high.
diam.pngdiam.pngdiam.pngdiam.png Very good control: Endophyte consistently reduces insect populations and keeps pasture damage to low levels, even under high insect pressure.
( ) Provisional result: Further results needed to support the rating. Testing is ongoing.

Notes to Tables 1 - 3

  1. AR37 endophyte controls Argentine Stem Weevil larvae, but not adults. While larvae cause most damage to pastures, adults can damage emerging grass seedlings. In Argentine Stem Weevil prone areas it is recommended to use treated seed for all cultivars with novel endophyte.
  2. AR1 plants are more susceptible to Root Aphid than plants without endophyte.
  3. Also active against Black Beetle larvae