Christmas Beetle, Christmas Beetles
Christmas beetles (Genus: Anoplognathus) are well-known in Australia and South Africa. Within the genus, there are a total of 35 species, all of which look similar. They get their common names from the time of year they are most abundant, however, can emerge as early as November. If you live in Australia or South Africa, you may know these insects from the shrill noises they create while flying. Likewise, you may know them for their love of Eucalyptus, which they sometimes feed on in large flocks, causing complete losses of foliage in a matter of days.
A pest of Eucalyptus plants. They feed gregariously as adults, causing quick losses of foliage.
Although a pest, they also provide beneficial services to the environment that can't be replicated by humans.
Adults: Scarabs are stout and chunky beetles. Typically, beetles that belong in the genus Anoplognathus possess brown-tan wing casings (elytra). Some species display white or black markings on the wing casings, too. Others possess iridescent exoskeletons, giving them a metallic finish when the light reflects from them. Larvae: The grubs are distinctively C shaped, usually pale yellow-whitish with an orange-brown head. They can sometimes take years to reach maturity.
Larvae feed on the roots of lawns. Patches of grass can suddenly appear brown and dried out. Adults emerge and feed on the leaves of host plants; which is Eucalyptus in most cases. Beetles feed in swarms, so are of particular risk to plantations. Feeding damage to trees causes leaves to appear ripped and jagged. The main central vein is left in most cases. Most trees will recover.
Australia and South Africa
Scarab beetles can provide an array of benefits to the wider ecosystem and should be tolerated in low numbers. They also have an array of natural enemies to help keep their numbers at bay. Proper lawn maintenance may be beneficial at keeping grub numbers low. General feeding, regular watering, aerating and scarifying are good maintenance practices. Removal of leaf litter and plant debris can also help make green spaces less attractive to beetles looking for a good hiding spot. Chafer grubs thrive in dry soil, so regularly watering your lawn to keep the soil moist will help to deter them and will aid the grass recovery. Following the end of the warm season (end of the summer to autumn), you should scarify and aerate flower beds and turf. This should reveal any overwintering larvae in the soil. They can then be collected and placed somewhere for the birds or relocated elsewhere. It's thought that compressing the lawn in spring can make it difficult for females to lay eggs in the soil come summer. Placing a mesh-type netting around trees and shrubs may help to prevent damage by adult beetles. If available, beneficial nematodes can be diluted in water and sprinkled on lawns. Also, if you have chickens in your garden, they can help to control the larval stage of these beetles. A range of insects and animals eat beetle grubs. Sometimes it's worth waiting for other insects to take care of your pests if you would consider the infestation as average. Parasitic wasps and flies use grubs to feed their own larvae. Likewise, bats, rodents, birds and reptiles feast on the beetles as adults. Before you sow your seeds, let your chickens loose on your veg patch. They will clear the area of grubs, caterpillars or any overwintering pupae near the surface.
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