''Macrolophus caliginosus'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

true bug Hemiptera (; ) is an order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from to around ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Miridae The Miridae are a large and diverse insect family at one time known by the taxonomic synonym Capsidae. Species in the family may be referred to as capsid bugs or "mirid bugs". Common names include plant bugs, leaf bugs, and grass bugs. It is the ...

. It is

omnivorous An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutri ...

and both preys on insects and feeds on plant tissues. It is used in Europe in the

biological control Biological control or biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also invo ...

whitefly Whiteflies are Hemipterans that typically feed on the undersides of plant leaves. They comprise the family Aleyrodidae, the only family in the superfamily Aleyrodoidea. More than 1550 species have been described. Description and taxonomy The A ...

tomato The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word ...

es grown under glass.

Description

''M. caliginosus'' is a slender pale-green insect some in length. Its eyes are red, its antennae are green with a black base and its legs are long, enabling it to move rapidly. The

nymphs A nymph ( grc, νύμφη, nýmphē, el, script=Latn, nímfi, label=Modern Greek; , ) in ancient Greek folklore is a minor female nature deity. Different from Greek goddesses, nymphs are generally regarded as personifications of nature, are typ ...

are yellowish-green.

Ecology

The eggs of ''M. caliginosus'' take about eleven days to hatch at and thirty-seven days at . The nymphs pass through five stages, completing their development in about nineteen days at . They and the adults are inconspicuous as they keep to the underside of leaves. The adult female may live for about forty days, during which time she will lay between one hundred and two hundred and fifty eggs, the number depending on the temperature and the availability of prey. The preferred prey of ''M. caliginosus'' is whitefly but it also feeds on

aphid Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...

mite Mites are small arachnids (eight-legged arthropods). Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari, but genetic analysis does not show clear evid ...

s and the eggs of

moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

s. An adult can consume upward of thirty whitefly eggs each day. When offered the greenhouse whitefly (''

Trialeurodes vaporariorum ''Trialeurodes vaporariorum'', commonly known as the glasshouse whitefly or greenhouse whitefly, is an insect that inhabits the world's temperate regions. Like various other whiteflies, it is a primary insect pest of many fruit, vegetable and or ...

'') and the silverleaf whitefly (''

Bemisia tabaci The silverleaf whitefly (''Bemisia tabaci'', also informally referred to as the sweet potato whitefly) is one of several species of whitefly that are currently important agricultural pests. A review in 2011 concluded that the silverleaf whitefly ...

'') it showed a preference for the former. If the available prey consisted primarily of the silverleaf whitefly (>75%), its preference was for the later stage nymphs of that species rather than any other stage.

Use in biological control

''M. caliginosus'' is used in Europe in the biological control of whitefly in tomato crops in greenhouses. It can survive for some time on its host plants in the absence of insect prey, can feed on pests other than whitefly, and has the additional advantage of being able to move freely from plant to plant. Due to a taxonomic revision, the species used in biocontrol is now properly identified as '' Macrolophus pygmaeus''. Following its success in Europe, North American growers hoped to import it for biological control. However, regulatory authorities are reluctant to issue import permits for non-native generalist predators because of the possibility of them escaping into the wider environment with

unintended consequences In the social sciences, unintended consequences (sometimes unanticipated consequences or unforeseen consequences) are outcomes of a purposeful action that are not intended or foreseen. The term was popularised in the twentieth century by Ameri ...

. So a search was undertaken in North America for an indigenous natural enemy for use in greenhouses there, and the mirid ''

Dicyphus hesperus ''Dicyphus hesperus'' is a species of true bug in the family Miridae. It is a generalist predator of other insects and also feeds on plant tissues. It is native to North America and has been used there in biological control of agricultural pests ...

'' was found suitable to fulfil the role. In the Mediterranean area, another mirid bug, '' Dicyphus tamaninii'', occurs naturally and often spontaneously takes up residence in greenhouses growing tomatoes. Experiments were undertaken to establish how this and ''M. caliginosus'' interact with each other and what level of control of whitefly is established when they are both present in a crop. It was found that there was little competition between either the adults or the nymphs and that they did not prey on each other. When used alone, ''D tamaninii'' was more effective than ''M. caliginosus'' in reducing whitefly populations. A combination was as effective as either used separately.

References

{{Taxonbar, from=Q5989133 Insects described in 1951 Dicyphini