Common names: Lantana bug
Orthezia insignis (Lantana bug), is an elegantly structured scale insect no farmer wants to see. Kozar (2004) proposed that this species be placed in the genus Insignothezia. The new name, Insignothezia insignis, is gaining popularity in economic as well as other forms of literature.
How to recognise a Lantana bug
The Lantana bug is easily distinguishable from other scale insects. The body of the adult female is oval, about 1.5 mm long and 1.3 mm wide, with parallel brittle, white wax plates. The wax plates curve slightly upwards giving them an elegant appearance highlighted by long dark legs and antennae. Though many other scale insects attach their ovisac to their host plants, the Lantana bug carry their ovisac attached to the body. With the exception of the ovisac, immature females resemble the adults, but are smaller in size.
Contrarily, adult males are single winged, appear greyish with powdery wax, have a longer body (about 2.0 mm) and are covered with short hair. They have compound eyes, long slender legs and the abdomen terminates in a caudal tuft of white wax filaments arising from the antepenultimate segment. Males are however rarely produced (Green 1922).
Getting around
Scale insects are generally not particularly mobile and spend their entire life cycle on a single host plant. Though not able to disperse for long distances, this scale insect is mobile in comparison to its completely sessile relatives (Fowler 2005) such as armoured scale insects. The Lantana bug has been reported to be transported a distance by water, wind, animal agents etc. (Green 1992), thus spreading by accidental introduction and often becoming a serious pest in the introduced locality (Booth et al. 1995).
Distribution
O. insignis is widespread, occurring in Afrotropical, Australasian, Neotropical, Oriental as well as Palaearctic regions. The species is common and widespread in South Africa (Julien & Griffiths 1998), with a recent record reported from Gauteng, Rietondale (Sethusa et al. 2014).
Habitat
The Lantana bug is a plant pest collected from its hosts.
Food
The Lantana bug is polyphagous – feeding on about 34 plant species (Ben-Dov et al. 2008). The bug, however, prefers woody hosts and feeds on their shoots and twigs. The species is reported to be a pest of tea and coffee (Green 1922) and mostly found on trees and shrubs of the Verbenaceae. Ezzat (1956) recorded O. insignis as a pest of a wide range of crops including sugarcane, citrus, potatoes, tomatoes, chrysanthemums, jacaranda as well as Casuarina.
SEX and LIFE CYCLES
Sex:
For O. insignis, reproduction is parthenogenetic (Epila 1986). There are three instar stages in females and four in males; this mainly due to the differences in appearance and functionality of the male and female mature stages.
Family life
Colonies consisting of all life stages of the bug are often encountered on a single host. Embryogenesis is characterised by three colour changes, i.e. the white newly laid eggs, followed by a light yellow stage and then the brown just prior to hatching (Epila 1986). The newly emerged nymphs have no wax. The wax accumulates as the bug grows and is used to construct the ovisac in the adult stage.
THE BIG PICTURE
Friends and foes
The Lantana bug feeds by sucking sap from the phloem of its host. As a by-product, the bug excretes honeydew, which attracts ants and also provides a substrate for growth of sooty moulds (Green 1922). The moulds results in badly fouled leaves and fruit, and often the quality of the fruit (and subsequently the price consumers and/or trading partners are willing to pay) is reduced.
Poorer world without me
The species is commonly called the Lantana bug mainly due to its preference of Lantana species as hosts. In South Africa, the species was considered as a biological control agent for the notorious weed Lantana camara. Results of the investigative study showed, however, that the species only have localised impact (http://www.arc.agric.za/arc-ppri/Pages/Lantana-camara.aspx). Its use as a biological control agent is furthermore discouraged by its polyphagous character, whereby damage to non-targeted plants cannot be excluded (Green 1922).
People and I
The Lantana bug is a polyphagous pest. During international trading of food produce, a phytosanitary certificate should guarantee absence of the species in the consignment. If encountered at farms or other forms of property, the species should be controlled using pesticides. Care should, however, be taken to ensure that the pesticides administered do not affect its natural enemies, since the enemies are believed to play a vital role in management and/or control of the Lantana bug (Green 1922).
Conservation status and what the future holds
This species has not been assessed. Lantana bug is a common pest and is not a threatened species.
Relatives
The Lantana bug is distinguishable from the other Orthezia species by the lack of waxy cover on their dorsum, leaving an olive-green coloured body exposed (Green 1922).
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hemiptera
Family: Ortheziidae
Genus: Orthezia
Species: Orthezia insignis Browne, 1887
References and further reading
- Ben-Dov, Y., Miller, D.R. & Gibson, G.A.H. 2006. ScaleNet: A database of scale insects of the world. Available online: http://www.sel.barc.usda.gov/HYPERLINK “http://www.sel.barc.usda.gov/scalenet/scalenet.htm”scalenet/scalenet.htm
- Booth, R.G., Cross, A.E., Fowler, S.V. & Shaw, R.H. 1995. The biology and taxonomy of Hyperaspis pantherina (Coleoptera: Coccinellidae) and the classical biological control of its prey, Orthezia insignis (Homoptera: Ortheziidae). Bulletin of Entomological Research 85(3): 307–314.
- Epila, J.S.O. 1986. Aspects of the biology of Orthezia insignis Browne (Ortheziidae: Homoptera) infesting Hamelia sphaerocarpa Ruiz & Pav. (Rubiaceae) in Uganda – I. Life history. International Journal of Tropical Insect Science 7,1: 53–59.
- Ezzat, Y.M. 1956. Studies on the ‘Kew bug’ Orthezia insignis Browne [Coccoidea –Ortheziidae]. Bulletin Société Entomologique d’Egypte 40: 415–431.
- Fowler, S.V. 2005. The successful control of Orthezia insignis on St. Helena Island saves natural populations of endemic gumwood trees, Commidendrum robustum. Second International Symposium on Biological Control of Arthropods, Davos, Switzerland, pp. 52–63. http://www.bugwood.org/arthropod2005/vol1/2b.pdf
- Green, E.E. 1922. The Coccidae of Ceylon. Part V. London, UK: Dulou & Co, pp. 347–472.
- Julien, M.H. & Griffiths, M.W. 1998. Biological control of weeds: a world catalogue of agents and their target weeds, 4th ed. CAB Publishing, CAB International, Wallingford, UK.
- Sethusa, M.T., Millar, I.M., Yessoufou, K., Jacobs, A., Van der Bank, M. & Van der Bank, H. 2014. DNA barcode efficacy for the identification of economically important scale insects (Hemiptera: Coccoidea) in South Africa. African Entomology 22: 257–266.
Author: Mamadi Theresa Sethusa
Threatened Species Programme
March 2015