''Dermolepida albohirtum'', the cane beetle, is a native

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

beetle Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

and a pest of

sugarcane Sugarcane or sugar cane is a species of tall, Perennial plant, perennial grass (in the genus ''Saccharum'', tribe Andropogoneae) that is used for sugar Sugar industry, production. The plants are 2–6 m (6–20 ft) tall with stout, jointed, fib ...

. Adult beetles eat the leaves of sugarcane, but greater damage is done by their

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e hatching underground and eating the roots, which either kills or stunts the growth of the plant. The beetles can also be found in the Philippines and are known there by the local name ''salagubang''.

Lifecycle

Adult cane beetles are white with speckles of black. Female cane beetles lay their eggs in the soil of sugarcane about deep, generally choosing the base of the tallest cane. A female beetle can lay up to three clutches with 20–30 eggs per clutch. Larvae, which are known as "greyback cane grubs", are small and white. The cane beetle grub feeds on the roots of the sugarcane during all three stages of its life. The crucial stage occurs during February to May, when it aggressively feeds on the sugarcane's roots, causing the most damage to the plant. Once it is fully fed, after 3–4 months, the grub burrows down to turn into a pupa. The pupa develops into an adult within a month, but does not emerge from the soil until the weather conditions are adequate.

Pest control efforts

Methods of control include applications of ''

Metarhizium anisopliae ''Metarhizium anisopliae'' is a fungus, the type species in the ''Metarhizium'' genus. It grows naturally in soils throughout the world and causes disease in various insects by acting as a parasitoid. Ilya Ilyich Mechnikov, Ilya I. Mechnikov nam ...

'', along with other biocontrol strategies, but pest control against cane beetles also damages a large variety of other insects and invertebrates that can be beneficial to the ecosystem, thus preventing their use. The introduction of the cane toad to Australia was a biocontrol attempt.

Cane toad introduction

The greyback cane beetle was, along with the Frenchi cane beetle, ''

Lepidiota frenchi ''Lepidiota'' is a genus of beetles belonging to the family Scarabaeidae. These beetles are large and cylindrical, measuring between 15-38mm in body length. Their body coloration varies and can be black, brown, dark brown or reddish brown, while ...

'', the reason that the

cane toad The cane toad (''Rhinella marina''), also known as the giant neotropical toad or marine toad, is a large, Terrestrial animal, terrestrial true toad native to South America, South and mainland Central America, but which has been Introduced spe ...

(''Rhinella marina'') was introduced to Australia. The toad was brought in as a biological control to protect sugarcane crops. While introduced cane toads did eat cane beetles, the toads preferred other insects, and ''R. marina'' itself became a major pest. The toad population rose exponentially. Native predators such as

quoll Quolls (; genus ''Dasyurus'') are carnivorous marsupials native to Australia and New Guinea. They are primarily nocturnal, and spend most of the day in a den. Of the six species of quoll, four are found in Australia and two in New Guinea. Anot ...

s ('' Dasyurus'', "marsupial cat") neither possess resistance to its toxins nor have learned avoidance; thus, these predators became locally extinct upon arrival of toads and suffered overall population declines – up to 97% for the northern quoll.

References

* * {{Taxonbar, from=Q2239580 Scarabaeidae Beetles of Australia Agricultural pest insects Beetles described in 1875