Since the discovery of the white-fringed weevil (Pantomorus leucoloma) in New South Wales, near Scone in 1932, this South American weevil has spread throughout the State.

Although it has a very wide range of host plants, including most, if not all, legumes and many non-leguminous ornamentals and weeds, it is most troublesome as a pest of lucerne. The soil-dwelling larvae chew into the taproot, seldom severing it, but most commonly working for some distance along its length, causing a furrowing sometimes several inches long. In young plants, the death rate would he very high, but in older, well established plants. it is sometimes found that the wounds heal over and the plants survive, but not without a considerable loss of vigour.

Infestations are often patchy, with all plants within a small area being killed. However. damage is frequently such that a lucerne stand is no longer productive and must he ploughed out prematurely.

The adults, which are all females, first appear about December and emergence continues until April. Each one is capable of laying 1,000 or more eggs. Eggs are laid in hatches of 10 to 20 on the surface of the soil, usually affixed to a piece of dead leaf or twig where it is in contact with the soil, and hatch in 10 to 14 days. The newly-hatched larvae immediately make their way into the soil where they feed through autumn, winter and spring.

The population to be found in October and November consists mostly of final instar larvae, prepupae and pupae.

The pupae are formed within an oval-shaped earthen cell, and often fully formed adults are found in such cells awaiting a good fall of rain (or irrigation) to soften the soil so that they can make their way to the surface. This is the annual cycle for most individuals but sometimes one or more of all stages of the pest may he found during any month of the year.

The adults, which are unable to fly, do not burrow hack into the soil, but crawl about on the surface. They feed on foliage, but such damage is unimportant.