Monday, January 14, 2013

Passionvine Hopper AKA Fluffy Bums!

This insect is really starting to pick up in numbers in the garden at the moment, with young nymphs and adults being seen in large groups on any stressed plant.
Only part of the large colony living on our fig tree

In my garden, this means the fig and lemon which we don't waste water on because they're to be removed soon.  I also find them in small numbers on other plants that are slightly stressed.  From this, I know that plants which are not healthy are more susceptible than others.

The Passionvine Hopper (Scolypopa australis) is a member of the Ricaniidae family, from which Australia appears to be 'blessed' (sigh) with a large number of species.  They feed on pretty much any soft-stemmed areas of a plant, sucking sap, but in my garden they mainly affect fruit trees, ferns and tall or vine like soft-stemmed plants such as passionfruit, tomatoes and sunflowers.

The adults are approximately 5mm long, with wings that make them appear brown and moth-like, until closer inspection shows the wings to have a lacy, brown, mottled pattern.  Their heads are fairly broad in comparison to their size and when feeding their wing tips are raised, making them look like they're sticking their bums in the air.  When disturbed, they jump making a clicking noise.

Here I notice the adults from the end of December to as late as May, with the largest numbers being from February.  When we first moved into this property we did a large amount of pruning back in an attempt at revitalising several ailing shrubs and fruit trees.  This took place in March and at times there were so many of the adult hoppers around we were covered in them.

The egg laying tends to take place from mid-summer until the adults die off and are inserted into soft, dead or dying stems in long rows.  This leaves obvious scaring and can cause dieback of stems.  I have found in the past that our lonely Dicksonia antartica's fronds are badly affected.  The egg stage lasts for around 6 months, effectively over winter, and as a result there is only one generation of Passionvine Hoppers in a year.

The nymphs generally emerge between October and December, taking 3 months to reach maturity.  They also jump when disturbed.

Scolypopa australis nymph on a sunflower stem
The Passionvine Hopper's feeding and egg laying activities cause additional stress, wilt and dieback on affected plants.  They also exude honeydew, which attracts moulds and causes further plant stress.  The honeydew is known to be collected by ants and bees.  In some cases, the honeydew formed from feeding activity on toxic plants has led to poisonous honey being made and causing sickness in humans.  In addition, it is suspected that Passionvine Hopper's may be a vector for disease.

So, what do you do about these annoying pests in the garden?

The first thing you should do is simply observe.  Which plants are affected and how badly?  Is there something about the plant that could be attracting them?  Is it stressed through lack of water / too much or too little sun / not enough nutrients / poor soil quality?

The next thing to do is to correct the conditions that are causing the poor health in the affected plants.  Improve the watering, apply compost, mulch around the plants, spray with a seaweed solution and perhaps water with some 'magic potion'.

Once the weather cools and there is more rain around, examine the plants where the most adults were seen.  Is there evidence of scarring from egg laying activity?  If possible, and the damage is excessive, prune the affected branches and destroy them (don't compost them!).  

If this is not possible, then don't fear because in an organic garden (which of course you have, don't you?) there are predators and parasites who will take out large numbers of the eggs and emerging nymphs.  

Past studies in Australia have shown that around 35% of the eggs are parasitised, mainly by tiny parasitic wasps.   Many more of the eggs are destroyed either by unintentional damage from the adult Passionvine Hoppers, or by predation from lacewing larvae.  In addition, lacewing larvae, spiders and some bird species are known to predate the emergent nymphs.

Using chemicals, including pyrethrums or neem oils, when sprayed onto colonies of Passionvine Hopper will also affect the predatory and parasitic insects who are helping to keep things under control.  Even these commonly used organic chemicals should be avoided wherever possible. 

Passionvine Hoppers are perhaps more a seasonal inconvenience than a serious pest in home gardens.  It is only where we reach for the chemical solution that they can become a real problem.

---- edit 10 Jan 2014 ---

After finally taking out the fig tree in early spring, we've had very little sign of passionvine leaf hopper in the garden at all this year.  As suspected the fig tree was the main plant in which eggs were being laid and hopefully this has broken the cycle we had in our garden.

1 comment:

  1. Thanks for this - it's great to get a non-spraying perspective! I have noticed a lot of the fluffybums on my dandelions lately!