Grenada Using Beetles to Fight Croton Scale Pest

ST. GEORGE’S, Grenada – Grenada is implementing a new strategy to deal with the croton scale disease that is affecting several fruit trees causing them to die and produce fewer fruits.

Plant affected by croton scale (file photo)“In an effort to further control the effects of the croton scale disease, the Ministry of Agriculture’s Pest Management Unit (PMU) has now taken a biological measure approach through the breeding and releasing of ladybird beetles that are expected to feed on and significantly minimize the effects of the pest,” the Ministry said in a statement.

Like other soft scale insect pests, female croton scales cause the most economic damage to host plants. The female croton scale produces large amounts of honeydew, or sugary frass (insect excrement) and is an ideal substrate for a fungus called sooty mold to grow.

The disease was spotted in Grenada last year and has since been reaping havoc on crops like soursop, plums, guavas, mangoes, and sugar apples.

Agriculture Minister Peter David told Parliament during the debate on the 2022 national budget that the Pest Management Unit will be purchasing thousands of ladybug beetles to be released here.

The beetles were brought into the island on Wednesday and the team at the Pest Management Unit has already started the process of releasing them in areas prone to the heavy infestation of the croton scale.

“Thirty thousand of the cryptolaemus ladybird beetles which are also known as Millie bug destroyer was procured and we will be using them to mitigate the effects of the croton scale disease, this is the same approach we adopted in the 90s when we had to deal with the mealybug infestation,” said Thaddeus Peters, the PMU head, who travelled to the United States to purchase the bugs.

The beetles were purchased from an Insectary in California, which coincidentally also supplied the country during the height of the mealybug outbreak.

The ministry said it expects to import more beetles because the first shipment is not expected to be sufficient to deal with the situation.

Peters said that once feeding is available for the beetles they are expected to survive and multiply, adding “and that will be a good thing because they are eating the pest away.

“When the beetles can no longer get the required feeding they will die naturally, so we don’t have to worry that they will cause or develop another problem. We use them in the 90s and if they were around now, they will naturally deal with the croton scale,” he said.