How did you do on #bugronomy?

For a fortnight from the 14th September, BCG ran an insect identification quiz on twitter as part of the GRDC funded ‘Supporting the sustainable use of insecticides and local on-farm implementation of integrated pest management (IPM) strategies in the GRDC southern region’ project.

BCG posted two pictures each day with an attached poll to anonymously provide a response to the prompt: Am I a ‘friend’ (beneficial) or ‘foe’ (pest)? Or to identify what had happened to the insect from a multiple choice list. Answers were revealed for all of that week’s questions on Friday, with useful resources. 

The GRDC funded ‘Supporting the sustainable use of insecticides and local on-farm implementation of integrated pest management strategies in the GRDC southern region’ project aims to raise awareness and build knowledge relating to the risk, occurrence, impact and management of insecticide resistance.

As part of the project the GRDC Best Practice Management Guides and podcasts were published, one of each on Redlegged Earth Mite, Diamond Back Moth and Green Peach Aphid were created, as well as the delivery of a series of webinars, presentations at various events, and the twitter quiz campaign.

The campaign had high levels of engagement, with an average of 92.6 people responding to each question. Five of the questions had over 100 votes, and the questions with lower levels of engagement tended to be those where people were less confident in their answers (indicated by either the majority of those who answered answering incorrectly or the majority of people answering correctly but with a narrow margin between the correct answer and an incorrect answer).

If you’re not on twitter or missed the quiz, test your knowledge below (answers at the end of the article).

Week 1

  1. Native budworm larvae
  2. Hoverfly larvae
  3. Diamondback moth larvae
  4. Armyworm larvae
  1. Friend
  2. Foe

  1. Hoverfly larva
  2. Native budworm larva
  3. Armyworm larva
  4. Diamondback moth larva
  1. Diamondback moth larva
  2. Vegetable weevil larva
  3. Stiletto fly larva
  4. Hoverfly larva
  1. Cabbage aphid
  2. Oat aphid
  3. Green peach aphid
  4. Turnip aphid
  1. Diamondback moth larva
  2. Hoverfly larva
  3. Native budworm larva
  4. Armyworm larva
  1. Aphid has shed it’s skin
  2. Aphid parasitised by wasp
  3. Aphid infected by fungus
  1. Russian wheat aphid
  2. Green peach aphid
  3. Turnip aphid
  4. Blue green aphid

Week 2

  1. Green lacewing larva
  2. Brown lacewing larva
  3. Ladybird larva
  1. Lucerne leaf roller
  2. Pasture webworm
  3. Cabbage white butterfly
  4. Etiella
  1. Purple scum springtail
  2. Lucerne flea
  3. Rutherglen bug
  4. Whirlygig mite
  1. Friend
  2. Foe
  1. Blue oat mite
  2. Redlegged earth mite
  3. Balaustium mite
  4. Bryobia mite
  1. Argentine scarab
  2. Black headed cockchafer
  3. Carabid beetle
  4. Click beetle
  1. Common brown earwig
  2. European earwig
  1. Vegetable beetle
  2. Click beetle
  3. Predatory shield beetle
  4. Cutworm

Answers

Week 1

It is Diamondback moth. These larva when disturbed are known to wriggle violently and can be found hanging from a fine thread. This time of year it is good to keep an eye out in canola crops. Resources that may help are here.

There are a few species of ladybird of which both the nymphs and adults are important predators of things like aphids and helicoverpa eggs and small larva. The juvenile is not necessarily pretty, but is an insect eating machine.

The native budworm is the common species in winter crops of the southern region and does not present the challenges that cotton bollworm does in more northern areas. This is why ID is important, get it wrong, and your sprays may not work. More info at https://bit.ly/3ktS3Rt

While adults feed on pollen/honeydew, hoverfly larvae love eating aphids. Larvae are commonly confused with pest grubs such as the diamondback moth which look similar to the untrained eye.

Aphids can be difficult to ID and have fine details that separate species. Where they live is commonly used as a guide to ID. This one is actually a Cabbage Aphid. Find below a couple of resources, one is a back pocket guide that can help ID the different species.

GRDC Crop Aphids – back pocket guide https://bit.ly/3iRxbTT

cesaraustralia PestNote on cabbage aphid https://bit.ly/2E7lCZl

There are several species of armyworm presently found in southern Australia that are difficult to distinguish. Barley is generally one of the most susceptible crops, although they will attack other cereals and pasture. More info at: https://bit.ly/3ceerLK

Aphid parasitised by wasp

Predatory wasps are part of the beneficial ranks. By laying eggs inside their host, they not only raise the next generation of their own species, but limit the next generation of the pest. https://bit.ly/3iFo3kO

This one was Green Peach Aphid. Correct identification is important as some species (such as GPA) have evolved resistance to many insecticides and need careful consideration of product choice. More info here.

Week 2

There are two lacewing species, green and brown. Larvae of both species are predatory, the green lacewing larva recognised by the trophy cabinet of carcases on its back used for camoflage. Only adult brown lacewing are predatory.

This one was Lucerne Seed Web Moth. For many regions in Australia, monitoring would have commenced or is about to, protecting vulnerable pulse crops before larva burrow into pods. SARDI have made predicting flights a little easier with their updated model, just input your location here. More info here.

Lucerne flea are a green-yellow globular insect commonly found in broadleaf crops and pastures. Lucerne fleas have a furcula underneath their abdomen that acts like a spring and enables them to ‘spring off’ vegetation when disturbed. More info here.

The picture is of a Carabid larva, which sits in the beneficial ranks. It can be easily confused with many other establishment pests to the untrained eye and is distinguished by a few features outlined in the picture.

Redlegged Earth Mite is exhibiting increasing concerns of resistance to both SP and OP chemistries in the southern and western regions. More info here.

This is the Adult of the larva presented in the fourth question for week 2 – and a beneficial species. Nocturnal in nature, carabid beetles eat a wide range of soft-bodied prey such as caterpillars, aphids, wireworms, earwigs and slugs.

This is the common brown earwig. Adults are approximately 35 mm long and have a distinctive orange triangle behind the head on the elytra (wing case). The common brown earwig is generally solitary unlike pest European earwigs. They are predatory, attacking soft-bodied insects and mites.

The spined predatory shield bug attacks various caterpillars, including native budworm and armyworms. They use their piercing mouthparts to suck out insect body contents. They also produce some pretty cool eggs!

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