Lesser budworm and identification

Further to the last edition of PestFacts, Pulse development officer, Trevor Bray (Pulse Australia), has recently observed lesser budworm (Heliothis punctifera) moths near Griffith, in the Riverina district of New South Wales. The lesser budworm is closely related - and looks similar to - the native budworm (Helicoverpa punctigera), although they are rarely seen in the agricultural areas of south-eastern Australia. 

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. Lesser budworm can also be confused with the cotton bollworm (Helicoverpa armigera). Larvae of the corn earworm have white hairs on the collar, but typically have black to blackish-brown body hairs.

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 have wings that are lighter in colour and have less obvious patterns (although this is variable). Moths of the cotton bollworm have a distinct kidney-shaped spot in the middle of the forewing. The dark bands on the hind wings are also distinctive; the corn earworm has a pale patch in the middle of this band towards the edge of the wing, whereas the native budworm does not.

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. Native budworm is a widespread pest of many important crops in spring-summer. The cotton bollworm tends to be a pest later in the season, due to differences in life-cycle and breeding patterns. They are commonly found on cotton, wheat, sorghum and maize.

It is important to correctly identify species when considering control options. The level of damage caused by lesser budworm, native budworm and cotton bollworm can differ depending on crop type. Species also vary in their capacity to evolve insecticide resistance and may therefore respond differently to chemicals applications and/or other control attempts.

For more information and images of lesser budworm, click here. For information on cotton bollworm and native budworm, click here.