The adult female Maconellicoccus hirsutus is 2.5 – 4 mm long, soft-bodied, elongate oval and slightly flattened while males have one pair of very simple wings, long antennae, white wax filaments projecting posteriorly and no mouthparts (EPPO, 2005). The taxonomy is almost entirely based on the adult female and a good slide preparation of a female is required for identification on species level (EPPO, 2006). Slide-mounted females show the combination of 9-segmented antennae, anal lobe bars, numerous dorsal oral rim ducts on all parts of the body except the limbs and long and flagellate dorsal setae (EPPO, 2005). Eggs are pink, and appearance in life is orange pink to reddish, with the entire colony covered in a white, sticky, elastic, woolly, waxy ovisac material (EPPO, 2005; 2006). Immature instars, commonly referred to as \"crawlers\" are about 0.3 mm long and pink with the imature and newly developed adult females being greyish pink (EPPO, 2005). A guide to the distinguishing features of the different instars of M. hirsutus and other mealybug speces can be found in Gullan (2000). Additionally, a detailed identification key can be found in EPPO (2006) adapted from Williams (1996) distinguishing M. hirsutus from other species in the same genus. Ezzat (1958; in Francis & Francis, 2001) separates the genus Maconellicoccus from Paracoccus, the closest known relatives, by the following features in the adult female: Pseudo articulation in the 9th (terminal) antennal joint, Anterior leg with unequal tarsal digitules and Small oral collar tubular ducts present on both the dorsal and ventral sides of the body.

The life cycle of Maconellicoccus hirsutus has been studied in India. Each adult female lays 150–600 eggs over a period of about one week, and these hatch in 6–9 days. A generation is completed in about five weeks in warm conditions. In countries with a cool winter, the species survives cold conditions as eggs (Bartlett, 1978; in EPPO, 2005). There may be as many as 15 generations per year (Pollard, 1995; in EPPO, 2005) with three immature instars in the female and four in the male (Chong et al., 2008). Immature stages are often referred to as \"crawlers\" and are easily dispersed by water, wind or animal agents (EPPO, 2005).

While the primary host of Maconellicoccus hirsutus is the ornamental Hibiscus rosa-sinensis, M. hirsutus will also feed on and inhabit a wide range of predominantly woody plants, including many ornamentals (EPPO, 2005). Host records extend to 76 families and over 200 genera, with some preference for Fabaceae, Malvaceae and Moraceae (Mani, 1989 & Garland, 1998; in EPPO, 2005).

The reproduction of Maconellicoccus hirsutus is noted as pathenogenic in some areas such as Egypt and Bihar but bi-parental in others, such as West Bengal and probably the Caribbean (EPPO, 2005), however in a laboratory setting, pathenogenesis could not be induced (Chonget al., 2008). Life table analysis suggests that M. hirsutus has an enormous potential to increase its population level within a short period of time with each female capable of producing more than 150 female progeny in about 40 days under laboratory conditions (Chong et al., 2005).

While the primary host of Maconellicoccus hirsutus is the ornamental Hibiscus rosa-sinensis, M. hirsutus will also feed on a wide range of predominantly woody plants, including many ornamentals (EPPO, 2005). Host records extend to 76 families and over 200 genera, with some preference for Fabaceae, Malvaceae and Moraceae (Mani, 1989 & Garland, 1998; in EPPO, 2005). Colonies of M. hirsutus will form on and feed on the new growth of the host plant, severely distorting and stunting their growth (EPPO, 2005). While the insect feeds, it excretes sugary honeydew on which sooty mold develops, deteriorating the quality of the agricultural or forest product (Gonzalez-Gaona et al., 2010). As the plant dies back, M. hirsutus will migrate to healthy tissue, with the colonies migrating from shoot tips to twigs to branches and finally down the trunk (EPPO, 2005).

Long distance dispersal is likely achieved through transportation of host plants and possibly to a lesser extent, the transportation of fruit and flowers (EPPO, 2005)

Maconellicoccus hirsutus feeds on a large number of plant species, including many important horticultural and agricultural crops such as coffee, guava, citrus, grape, peanuts, rose, beans, coconuts, maize, sugar cane, soursop, soybean, cotton, and other fiber crops (Ranjan, 2006; Ujjan & Shahzad, 2007; Reddy et al., 2009). The feeding of M. hirsutus causes malformation of shoots and leaves believed to be caused by the injection of a toxic saliva (Kairo et al., 2000). In addition to lowering the aesthetics of the plant, this deformation can also result in lowered crop yields and plant mortality in heavy infestations (Kairo et al., 2000; Chong et al., 2008). Like other sap sucking insects, M. hirsutus also excretes a sugary honeydew on which sooty mold develops, further deteriorating the quality of the agricultural or forest product (Gonzalez-Gaona et al., 2010). The presence of large quantities of wax, characteristic of M. hirsutus infestations, also reduces the aesthetic and commercial value of ornamentals (Kairo et al., 2000). The overall potential annual cost of control and damages to the US economy from M. hirsutus has been estimated to be around US$ 700 million, with the global estimate being around US$ 5 billion (Ranjan, 2006).

Monitoring: Methods such as visual analysis and trapping of males using captive live virgin females have been utilised in the past with limited success (Gonzalez-Gaona et al., 2010). On the other hand, the use of sex pheremones inside delta-style traps has been shown to be effective for specific monitoring and determining the geographic distribution of M. hirsutus (Gonzalez-Gaona et al., 2010).

Preventative measures: Improvement of legislation and quarantine systems showed limited success in the Caribbean, with M. hirsutus still managing to spread to over 20 islands since 1994 (Kairo et al., 2000). Various quarantine security methods have shown promising results, including methyl bromide, irradiation, heat vapour treatment and hot water immersion (Zettler et al., 2002; Jacobsen & Hara, 2003; Follett, 2004; Hara & Jacobsen, 2005).

Chemical control: Use of pesticides in controlling M. hirsutus is generally ineffective partly because of its habit of hiding in crevices (EPPO, 2005) and because pesticides cannot penetrate the heavy layers of wax that shield the body (Kairo et al., 2000). Furthermore, rapid recolonisation and an extremely large host range and large host size in some cases makes it almost impossible to have a spraying program capable of bearing the cost and coping with the practicalities of treating the whole range of infested plants in an affected area (Sagarra & Peterkin, 1999).

Physical control: Physical control methods such as pruning and burning of infested hosts have been ineffective in slowing the spread of M. hirsutus (Sagarra & Peterkin, 1999).

Biological control: Biological control is seen as the most effective method of control (Kairo et al., 2000). A number of different parasitoids and predators have been trialled, the most effective of these being the parasitoid wasp Anagyrus kamali (Hymenoptera: Encyrtidae) from China, and the generalist predator Cryptolaemus montrouzieri (Coleoptera: Coccinellidae) from Australia (Kairo et al., 2000).

Please follow this link for more details on the management and control of Maconellicoccus hirsutus.