Macrolophus

Fieber, 1858

plant bug

Species Guides

4

Macrolophus is a of plant bugs in the Miridae, containing at least 20 described . Several species, notably M. pygmaeus and M. melanotoma, are economically important as agents in European vegetable crops and greenhouses. These species are predatory on key agricultural pests including aphids and whiteflies, though they can also complete development feeding solely on plant juices. Species within this genus are morphologically similar and have historically been confused, necessitating molecular and morphometric tools for reliable identification.

Macrolophus mimuli by (c) Andrew Meeds, some rights reserved (CC BY), uploaded by Andrew Meeds. Used under a CC-BY license.Macrolophus by (c) portioid, some rights reserved (CC BY), uploaded by portioid. Used under a CC-BY license.Macrolophus brevicornis by Ilona Loser. Used under a CC BY-SA 3.0 license.

Pronunciation

How to pronounce Macrolophus: /məˈkroʊloʊfəs/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

within Macrolophus are morphologically very similar and difficult to distinguish by external features alone. M. pygmaeus and M. melanotoma (formerly M. caliginosus) are particularly challenging to separate; multivariate morphometric analysis of measurements can discriminate males of these two species. Molecular identification using species-specific primers for mitochondrial regions provides reliable differentiation where is inconclusive.

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Habitat

Vegetable crops, greenhouses, and native flora including Dittrichia viscosa and tomato. have been observed in both cultivated agricultural settings and wild plant that serve as sources for colonizing crops.

Distribution

Europe; established recorded in New Zealand (Auckland, first detected 2007). GBIF distribution records indicate presence in Denmark, Norway, and Sweden.

Diet

Zoophytophagous: predatory on prey including aphids (Myzus persicae) and whiteflies (Trialeurodes vaporariorum, Aleyrodidae), but capable of completing nymphal development feeding only on plant juices. Macrolophus pygmaeus has been observed to kill prey without consumption.

Life Cycle

development and nymphal instars complete in approximately 13 and 20-22 days respectively at 23°C with 16:8 light cycle when feeding on prey. Development time increases significantly when feeding only on plant juices. longevity exceeds 50 days in females; preoviposition period approximately 6 days. approximately 0.06-0.07.

Behavior

Males show higher electroantennogram responses to plant volatiles than females. M. melanotoma exhibits greater olfactory responses to plants than non-hosts, while M. pygmaeus shows similar responses to both. Both prefer their respective host plants in olfactory assays. Prey searching and host plant selection involve perception of ubiquitous volatile organic compounds rather than characteristic host-specific compounds.

Ecological Role

agent () in agricultural , reducing pest including aphids and whiteflies in vegetable crops and greenhouses. Macrolophus pygmaeus induces resistance in susceptible tomato plants against root-knot (Meloidogyne spp.), reducing and by 37-53%.

Human Relevance

Economically important for in European greenhouse vegetable production. Used in inoculative releases for of whiteflies and aphids. Confusion between M. pygmaeus and M. melanotoma has led to misidentification in mass rearing and release programs, with consequences for biocontrol efficacy. Susceptible to , with lethal and sublethal effects reported.

Similar Taxa

  • DicyphusBoth belong to tribe Dicyphini and share similar body plans and zoophytophagous habits; Macrolophus generally larger and more robust
  • NesidiocorisAnother dicyphine used in ; Nesidiocoris tenuis is more aggressive and can cause plant damage, whereas Macrolophus are generally considered less damaging to crops

Sources and further reading