C. nigritus are a type of ladybird beetle. These predatory beetles are high density feeders and prey on a range of armoured scales, including Red Scale. The adults are black in appearance and about 4-5mm in length. A mature female can lay up to 200 eggs during her life time (about 50 days). Both adults and larvae feed on scale insects. The adult beetle lays her eggs as she moves over the fruit feeding. When the egg hatches, the small larva emerges and immediately begins to feed on the readily available food source. The larva continues to develop and once mature, it migrates to a secluded location to pupate, normally under leaves or on the trunk of the tree. C. nigritus will survive high and low temperatures but prefer temperatures of between 20 to 30º C. C. nigritus beetles are normally released in areas of an orchard that has a high population of active scale insects (‘hot spots’). C. nigritus are supplied in paper packets with 50 beetles in each packet. Distribute one packet of beetles over 3 trees by lightly tapping the bottom of the overturned packet. Releases of C. nigritus after insecticide application should be in line with recommendations (Please contact us at contact@duroibugs.co.za with any technical or related queries). Releases are most effective if done in the late evening.

Recommended Release Rates: 500 to 2000 beetles per hectare, released in ‘hot spots’. After release, the beetles rapidly disperse over the treated area and begin feeding. Eventually egg-laying will commence. It will take about 4 - 5 weeks before C. nigritus larvae are observed feeding on the target pest. Adult beetles may be difficult to find after release but this should not be of concern. To ensure that C. nigritus have established, it is recommended that an experienced scout do regular monitoring after the release. Significant control can be attained with the minimum recommended release rate of 500 beetles per ha but high pest populations may take longer to control, and require ‘booster’ releases in ‘hot spots’.