Lesser budworm

Lesser budworm (Heliothis punctifera) moths have been identified by Senior Technical Officer, Ken Henry (SARDI) in samples collected from Cootamundra, in the South West Slopes of New South Wales. Lesser budworm is closely related to the native budworm (Helicoverpa punctigera), although they are rarely seen in the agricultural areas of south-eastern Australia. 

The lesser budworm looks similar to the native budworm and the early larval instars are extremely difficult to tell apart. Lesser budworm larvae are usually dark in colour while native budworm varies from black to green to light brown in colour. Both have a light coloured strip down each side of the body. For older larvae (>20 mm in length), lesser budworm has white hairs on the collar (segment behind the head) and the body, while native budworm has black hairs on the collar and black to blackish-brown body hairs. A hand lens or microscope is required to observe the difference in hair colour.

Lesser budworm moths are generally darker in colour than the native budworm, which are light brown to reddish-brown. Adult moths also have a distinctive pattern on the forewing, whereas the native budworm typically has wings that are lighter (buff coloured) and have less obvious patterns (although this is variable). For more information and identification of moths, click here.

Outbreaks of lesser budworm are a rare event as a unique combination of biological and climatic conditions are required. The last outbreak occurred in spring 2005 where this species caused significant damage to a broad range of crops, with densities of 30-100 caterpillars per square meter reported in some paddocks. Crops most affected included lupins, lentils, medics, lucerne and vetch. Significant areas planted to these crops needed spraying during the outbreak. Field peas, faba beans, canola and cereals were also affected but to a lesser extent.

The potential level of damage that lesser budworm can cause is unclear due to the limited information and research conducted on this species. The lesser budworm usually occurs in outback Australia where it normally feeds on desert daisies.  It will be important to keep a look out for moth flights this spring and to regularly monitor using sweep nets and visual inspections for the presence of larvae in crops. Before any control decision is made, consider the target species, level of infestation, existing and potential damage and the effectiveness of control options. Always continue crop monitoring following any control procedure.