![MELBOURNE, AUSTRALIA - MAY 14: Museum Victoria entomologist Dr Ken Walker poses for a photo in Fitzroy Gardens on May 14, 2015 in Melbourne, Australia. Dr Walker has surveyed what plants and animals call Melbourne home. (Photo by Darrian Traynor/Fairfax Media) *** Local Caption *** Dr Ken Walker](http://web.archive.org./web/20161028173618im_/http://www.smh.com.au/content/dam/images/g/s/a/l/4/e/image.imgtype.articleLeadwide.620x349.png/1477400235152.png)
Museum Victoria entomologist Dr Ken Walker. Photo: Darrian Traynor
The days are longer and lighter. And while the temperatures haven't been typically spring-like, the annual explosion of backyard bugs is on. So who is your friend and who is your foe? The answers might come as a surprise.
Friends
Hoverflies: Their stripy belly can lead them to be confused with wasps - but Dr Webb says the well-named hoverflies are "one of the good guys in the garden". Good pollinators and they also eat pests such as aphids. A wet spring has prompted good plant growth - which means loads of food for hoverflies.
These are the guys who eat the sap-sucking aphids during their grub phase, in the process doing gardeners everywhere a favour. "I call them our biological spray can," Dr Walker says. Gardeners can encourage hoverflies by having nectar-producing flowers plants around the garden.
![Having a hoverfly in the garden is a good thing.](http://web.archive.org./web/20161028173618im_/http://www.smh.com.au/content/dam/images/g/s/7/p/p/3/image.imgtype.articleLeadwide.620x349.png/1477099170634.png)
Having a hoverfly in the garden is a good thing. Photo: Peter Marriott
Spiders: They are a much under-rated regulator of the insect population. And here's why spiders are most definitely our friends. "Globally, each year spiders eat the equivalent to the weight of the human population in insects," Walker says. "Without them we would have an explosion of insects. They perform a really important job."
The bad reputation spiders have is largely unfounded. In Australia there are only two spiders that can be problematic: the Sydney funnel web spider and the red back spider. There is an antivenom for both species. "Perception is the problem," Walker says. "It's more dangerous to drive to the supermarket."
![Like many spiders, the wolf spider is a handy insect to have around.](http://web.archive.org./web/20161028173618im_/http://www.smh.com.au/content/dam/images/g/s/7/q/6/y/image.imgtype.articleLeadwide.620x349.png/1477099170699.png)
Like many spiders, the wolf spider is a handy insect to have around. Photo: Museum Victoria, David Paul
Bees: There are around 2000 native bee species in Australia - around 200 to 300 in Melbourne alone. They deserve their reputation as top pollinators but they are also food for crab spiders and birds such as bee-eaters. In 1822 the European honeybee was brought to Australia - not as a pollenator or honey manufacturer but as a source of wax for candles.
Australian bees don't produce wax, as they are solitary insects and live in the ground or in holes in trees. As backyard buddies go, these guys are the bees' knees. Native or not.
![A native Australian bee.](http://web.archive.org./web/20161028173618im_/http://www.smh.com.au/content/dam/images/g/s/7/p/g/3/image.imgtype.articleLeadwide.620x349.png/1477028009356.png)
A native Australian bee. Photo: David Paul, Museum Victoria
Flies: You wouldn't think the old blowy would be your friend. But they perform an important task: waste removal. Even a dead, poisoned rat isn't off limits. "They will basically move in and reduce the carcass down to a skeleton," Walker says.
Flies can also play an important role as pollenators with some orchid species.
![A blow-fly can also be a garbo.](http://web.archive.org./web/20161028173618im_/http://www.smh.com.au/content/dam/images/g/s/7/q/7/5/image.imgtype.articleLeadwide.620x349.png/1477442918060.png)
A blow-fly can also be a garbo. Photo: Rodney Start Museum Victoria
Wasps: Like spiders, wasps provide a great insect population control service. But it can be nasty. "If you believe in karma don't come back as an insect, it's a brutal world," Walker jokes. The spider-hunting wasp, for example, can paralyse a huntsman before dragging it into its lair in the ground. The wasp then lays an egg on the spider's body and the hatched grub eats the legs and vital organs before emerging.
More commonly seen in backyards are European wasps, which this summer are forecast to be low in numbers. The wet spring isn't good news for them as 80 per cent nest in the ground - which has been soggier than usual.
![A European wasp.](http://web.archive.org./web/20161028173618im_/http://www.smh.com.au/content/dam/images/g/s/7/q/9/7/image.imgtype.articleLeadwide.620x349.png/1477027707327.png)
A European wasp. Photo: Ken Walker Museum Victoria
Foes
Aphids: If you're an aphid, this has been a great spring. Wet weather means plants grow and for these "plant lice" it's time to gorge. "Aphids are happy because there has been a lot of fresh plant growth about for them to eat," said Melbourne Museum senior curator of entomology Ken Walker.
![Aphids love a wet spring.](http://web.archive.org./web/20161028173618im_/http://www.smh.com.au/content/dam/images/g/s/7/z/4/3/image.imgtype.articleLeadwide.620x349.png/1477028398212.png)
Aphids love a wet spring. Photo: Peter Marriott, Museum Victoria
But for the gardener, aphids are a foe: the sap-sucking insects can spread plant viruses and their sucking of plant juices which weakens and stresses the plant.
Cabbage white butterfly: The sight of this most common of backyard butterflies is unwelcome for anyone with a veggie patch. The cabbage white butterfly lays eggs that hatch hungry caterpillars with a keen taste for beans, broccoli, peas and cabbage plants.
![A gardeners' nightmare: the cabbage white butterfly.](http://web.archive.org./web/20161028173618im_/http://www.smh.com.au/content/dam/images/g/s/7/z/9/l/image.imgtype.articleLeadwide.620x349.png/1477028540306.png)
A gardener's nightmare: the cabbage white butterfly. Photo: Patrick Honan, Museum Victoria.
They lay 20-30 eggs and so it's not long before signs of infestation become clear. Generally speaking, butterflies should be encouraged in the garden: they are tremendous pollinators and a food source for birds.
Cicadas: "We have the privilege of having the loudest cicada in the world," Walker says, almost with pride. What is it? The green grocer cicada. This noise polluter has a number of aliases, including the double drummer and yellow Monday. All are common names for the same thing: Cychila australica. At 120 decibels its call is up there with a rock concert or a jackhammer.
![The call of the greengrocer cicada is 120 decibels.](http://web.archive.org./web/20161028173618im_/http://www.smh.com.au/content/dam/images/g/s/7/y/y/2/image.imgtype.articleLeadwide.620x349.png/1477028218216.png)
The call of the greengrocer cicada is 120 decibels. Photo: Heath Warwick, Museum Victoria.
When asked if this critter is friend or foe, Walker is diplomatic. "It depends who you ask," he says. "They make a wonderful meal for a bird, given their size." Just don't ask the outdoor entertainer, perhaps.
Mosquitoes: Brace yourselves. A wet spring means water has collected in gardens all over the place. From pooling pot plant saucers, to leaking into kids' toys and dripping into buckets. That means there are mosquito nurseries galore in suburban back gardens. Once laid in water, it only takes three to four weeks for this insect to go from egg to adult. Sydney University medical entomologist Cameron Webb said in her brief lifetime the female mozzie can lay up to 500 eggs, usually in two batches. But while the mozzie falls into the foe category, remember that it is only the female mosquito that needs blood to feed and mature her eggs. The male doesn't bite and can be a great pollinator.
![Only the mosquito bites - the male is a friend.](http://web.archive.org./web/20161028173618im_/http://www.smh.com.au/content/dam/images/g/s/7/z/1/k/image.imgtype.articleLeadwide.620x349.png/1477030171871.png)
Only the female mosquito bites - the male is a friend. Photo: Stephen Doggett, NSW Health Pathology.
Native Australian mosquitoes meanwhile are a much friendlier bunch: they exist in low numbers in the bush and (double bonus) they don't all bite people. Some native mozzies exclusively feast on frogs, for example.
Ticks: Specifically the Australian paralysis tick, which is found up and down the east coast of Australia. It can be a problem along eastern coastal areas of Victoria and NSW, especially northern Sydney suburbs where homes back onto bushland. The tick life cycle is active throughout the year but they reach adulthood this time of year - coinciding with people getting outdoors more.
![A bite from the Australian paralysis tick can have nasty consequences.](http://web.archive.org./web/20161028173618im_/http://www.smh.com.au/content/dam/images/g/s/7/z/9/m/image.imgtype.articleLeadwide.620x349.png/1477028540696.png)
A bite from the Australian paralysis tick can have nasty consequences. Photo: Stephen Doggett NSW Health Pathology
Its bite can prompt allergic reactions and sometimes an ongoing allergy to mammalian meat. "For those that get it, everything from a red steak to marshmallows that contain beef gelatin can illicit an allergic reaction," Dr Webb says.