Biological control or biocontrol is a method of controlling pests, whether pest animals such as insects and mites, weeds, or pathogens affecting animals or plants by using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also involves an active human management role. It can be an important component of integrated pest management (IPM) programs.
Mealybugs are insects in the family Pseudococcidae, unarmored scale insects found in moist, warm habitats. Of the more than 2000 described species, many are considered pests as they feed on plant juices of greenhouse plants, house plants and subtropical trees and also act as a vector for several plant diseases. Some ants live in symbiotic relationships with them, protecting them from predators and feeding off the honeydew which they excrete.
Scale insects are small insects of the order Hemiptera, suborder Sternorrhyncha. Of dramatically variable appearance and extreme sexual dimorphism, they comprise the infraorder Coccomorpha which is considered a more convenient grouping than the superfamily Coccoidea due to taxonomic uncertainties. Adult females typically have soft bodies and no limbs, and are concealed underneath domed scales, extruding quantities of wax for protection. Some species are hermaphroditic, with a combined ovotestis instead of separate ovaries and testes. Males, in the species where they occur, have legs and sometimes wings, and resemble small flies. Scale insects are herbivores, piercing plant tissues with their mouthparts and remaining in one place, feeding on sap. The excess fluid they imbibe is secreted as honeydew on which sooty mold tends to grow. The insects often have a mutualistic relationship with ants, which feed on the honeydew and protect them from predators. There are about 8,000 described species.
Aonidiella aurantii or red scale is an armored scale insect and a major pest of citrus. It is thought to be a native of South China but has been widely dispersed by the agency of man through the movement of infected plant material. In the United States it is known as California red scale. It was first found in California between 1868 and 1875, apparently brought there on planting material imported from Australia.
Icerya is a genus of scale insects in the family Monophlebidae. It is named after physician-naturalist Dr. Edmond Icery of British Mauritius.
Pseudococcus viburni is a close relative of the grape mealybug and a pest of the vineyards around the world.
William Miles Maskell was a New Zealand farmer, politician and entomologist.
Albert Koebele was an economic entomologist and a pioneer in the use of biological controls to manage insect pests.
Novius cardinalis is a species of ladybird beetle native to Australia. It was formerly placed in the genus Rodolia, but that genus was synonymized under the genus Novius in 2020.
Aleurocanthus woglumi is a species of whitefly in the family Aleyrodidae. It is a pest of citrus crops, and is commonly known as the citrus blackfly because of its slate-blue colour. It originated in Asia, but has spread to other parts of the world. The parasitic wasps, Encarsia perplexa and Amitus hesperidum can help control the pest.
Coccus viridis is a soft scale insect in the family Coccidae with a wide host range. It is commonly known as green scale or sometimes coffee green scale because it is a major pest of coffee crops throughout the world.
Monophlebidae is a family of scale insects commonly known as the giant scales or monophlebids. They occur in most parts of the world but more genera are found in the tropics than elsewhere.
Charles Pugsley Lounsbury was an American-born South African entomologist, widely regarded as having laid the foundations of economic entomology in Southern Africa.
Planococcus citri, commonly known as the citrus mealybug, is a species of mealybugs native to Asia. It has been introduced to the rest of the world, including Europe, the Americas, and Oceania, as an agricultural pest. It is associated with citrus, but it attacks a wide range of crop plants, ornamental plants, and wild flora.
Tamarixia radiata, the Asian citrus psyllid parasitoid, is a parasitoid wasp from the family Eulophidae which was discovered in the 1920s in the area of northwestern India (Punjab), now Pakistan. It is a parasitoid of the Asian citrus psyllid, an economically important pest of citrus crops around the world and a vector for Citrus greening disease.
Frazer Smith Crawford was a photographer in the colony of South Australia, founding manager of the Adelaide Photographic Company, then photolithographer for the Government of South Australia. In a seemingly unrelated sphere, Crawford came to be recognised as an authority on agricultural pests and diseases, particularly known for identifying and exploiting naturally occurring predators of plant pests.
Aonidiella citrina or yellow scale is an armored scale insect from the family Diaspididae. It feeds by sucking sap from plants in a number of plant families, but is mostly known for being a pest of citrus.
Cryptochetum iceryae, the cottony cushion scale parasite, is a species of scale parasite fly in the family Cryptochetidae. Originating in Australia, it was deliberately introduced to California in the 1880s in an attempt to control cottony cushion scale, and has also been introduced to Israel and South America. In 2019, the species was discovered in the United Kingdom for the first time, having been identified in the wildlife garden at the Natural History Museum.
Novius iceryae is a species of ladybird beetle native to Afrotropical realm, and was described from South Africa. It is also found in Senegal. In 1880, Novius iceryae was used to successfully control cottony cushion scale, Icerya purchasi in South Africa. It was later introduced in New Zealand for the management of cottony cushion scale. This and related species were formerly classified in the genus Rodolia.
Pesticide induced resurgence, often shortened to resurgence in pest management contexts, can be described as a constraint of pesticide use, by which they fail to control pests such as insects and spider mites: instead ‘flaring up’ populations that may have been of minor importance. Although there are more than one mechanisms by which this takes place, mortality of natural enemies following the use of broad-spectrum insecticides and acaricides is often implicated. This is sometimes called the “pesticide treadmill”: a term coined by Robert van den Bosch to describe a self-reinforcing over-dependence on agrochemicals and inimical to natural biological controls. Notable examples include the flare-up of rice brown planthopper populations, following over-use of broad-spectrum inscticides.
