Summer may be when crops thrive, but so do insects. Vanessa Phillips reports on some bugs to look out for this summer.

They can lead gardeners to despair and ruin crops seemingly overnight, but not all bugs are bad. In the home garden there's a whole functional ecosystem, says Nelson entomologist Richard Toft.

Some insects are predators or parasites, he says, while others have dual roles - such as the Asian paper wasp, which are useful to have around if you're growing cabbages because their favourite food is the larvae of the nuisance white butterflies, but on the downside they also like monarch caterpillars.

Some bugs help break down compost, while others are helpful pollinators.

Mr Toft says that when it comes to pest control, gardeners need to use a bit of common sense, because the use of toxic insecticides can also harm helpful insects.

"It becomes a personal choice issue," Mr Toft says.

"Once you go down that chemical treatment route you are often committed to it because you are reducing the numbers of predators as well."

He explains that in many cases the damage done to crops by insects is related to appearance, or "the yuck factor", and the produce may still be edible.

With the varroa bee mite meaning there's less bees around to pollinate crops, people should also put in plants that will encourage pollinators and predators into the garden, he says. Hoverflies, for example, are attracted by flowers such as alyssum, and will help pollinate crops, but their larvae are also predators of aphids and scale, Mr Toft says.

Click here to read the entire article