The cotton mealybug (CMB), Phenacoccus solenopsis, also known as the solenopsis mealybug, is a highly polyphagous and invasive global insect pest of cotton. Damage to cotton by this pest includes limiting yield potential (plant stunting and/or mortality) and marketability through effects on lint quality (boll characteristics and lint contamination). This project was designed to continue the lines of investigation commenced in DAQ1204 and provide research outcomes to underpin the successful implementation of

IPM in cotton production systems with CMB as an important and recurring element of the pest spectrum.

CMB is believed to be native to North America and was first reported from cotton growing areas in Texas in the early 90s. CMB has since been recognised as a globally invasive species, and poses a significant threat to the world’s major cotton industries in Asia (India, Pakistan), Brazil and China. In Australia, economically damaging outbreaks of CMB on cotton were reported from the Burdekin and Emerald region of Central Queensland in 2010.

It is well established from research done overseas and in Australia that CMB is easily controlled by naturally occurring predators (lacewings, various coccinellid beetles) and a parasitic wasp in agroecosystems where beneficial arthropod populations are not exposed to the detrimental effects of disruptive agents such as broad-spectrum insecticides. In Australian cotton production systems where a number of key insect pests often require chemical control, anecdotal reports from growers and consultants indicate a potential link between control of other sucking pests (e.g. mirids, aphids) using broad-spectrum insecticides, and the severity of CMB infestations, presumably mediated through the effects of the insecticides used on beneficial arthropod communities. Such a putative cause-effect relationship is consistent with the rising pest status of CMB since 2010, as evidenced by the recurrence of infestations and expansion of its distribution into southern Queensland and New South Wales in 2017.