Gardeners are being urged to be wary of aphids as they plague gardens this spring due to the warm weather. Higher numbers of the rose-killing bugs are expected to soar in the UK as a result of climate breakdown. According to the Royal Horticultural Society, as many as 600,000 of its members have complained about dozens of insects on their acres, roses and honeysuckle plants, which has led to aphids hitting the top spot in their ranking of gardener queries.
The sap-sucking insects thrive in warm and dry weather intensified by climate breakdown. While frost can kill the insects, the change in weather patterns has resulted in frost appearing less often.
Hayley Jones, the principal entomologist at the RHS, said: “Climate change and more pronounced warm spells in many parts of the country could be a boon for some of the 500 species of aphid found in the UK, but there are other factors at play, including predator populations, the effect of climate change on general plant health and temperature swings and extremes.”
There are currently over 500 species of aphid found in UK gardens, commonly recognised as blackfly, greenfly and plant lice. The insects can be red, yellow, black, green, brown or pink and they feed by sucking sap from plants, causing severe damage to their host plants including distored growth, sooty mould and transmitting plant viruses. In some cases, they can also cause death.
However, now aphids are also spreading to plants they never used to feed on in the UK.
The RHS is urging gardeners to support research into an aphid that has only recently affected buddleia, causing distinctive distortion to the leaves. The RHS is also requesting that the public submit information on the RHS website to help track its spread.
Insects are a significant part of the garden food chain, being fed on by birds, earwigs, ladybirds, and other larger insects. The surging number of aphids exceeding the number of predators results in an out-of-control population, leading to visible damage to plants, which is happening this spring, according to RHS.
The charity is currently finding environmentally friendly ways to manage the insects, as it does not recommend the use of harmful pesticides. One of their trials involves growing poached egg plants alongside cabbages to find out whether it will encourage predatory hoverfly larvae. They have also installed earwig shelters in the RHS Garden Wisley orchard.
The results are expected next year and, if successful, the RHS will encourage widespread use of these methods, reports The Guardian.
Hayley Jones added: “Aphid biology means they are well-placed to make the most of a warm spring; aphids are a bit like Russian dolls, being born pregnant with the next generation so their populations can boom rapidly.
“Understanding how they can be managed through simple planting choice or encouragement of natural predators will help minimise damage and potential plant losses while maintaining a healthy garden ecosystem.”