Ecogrow

Argentinian Scarab Cyclocephala signaticollis

Life Cycle


Identify | Damage to: Turf - Field Crops - Glasshouses | How to Control | Application | Hint

Turf:

The Argentine scarab is native to Uruguay and Argentina. . Larvae of this scarab were first collected lawns in Sydney (NSW) suburbs in the late 1940's The Argentinian scarab was most likely introduced by a ship tha thad previously berthed at Buenos Aires (South America). In the 1950's the Argentinian scarab had become widespread throughout Sydney being collected as far as Parramatta and in Canberra .

Egg laying occurs from mid-November through to early January. Up to 50-60 eggs are laid by the female. Argentinian scarab has a one year life cycle. Larvae may live for up to 10 months. The larval stage is from January to November. Final instar larvae feed during autumn and spring. Larval counts up to 350 insects per square metre have been recorded in Canberra.

Field grown crops:

The insect's grubs are very damaging root feeders. This causes the plant to weaken and may die in times of slight heat or water stress. This can be identified easily as effected plants loose their stability and wilt. Unless the pest is treated they will continue to feed on the roots and the plant will die regardless of water content in the soil. This is easily seen throughout the growing areas. Individual plants, which are located in areas where other plants appear to be growing well, will die. With increased populations of the insect, and the insect's grubs, increased numbers of dying plants will be obvious.

Scarab beetle grubs are also known to burrow into tubors eg: potatoes and kumara, resulting in decreased crop yield.

Scarab beetles and their grubs are considered a relatively minor pest of glasshouses. Should you see this happening in your glasshouse careful searches should be made to locate and identify the pest. It is more likely that it may be Black Vine Weevil, which causes almost identical injury and is a much more common pest of glasshouses throughout Australia.

Glasshouses:

The insect's grubs are very damaging root feeders. This causes the plant to weaken and may die in times of slight heat or water stress. This can be identified easily as effected plants loose their stability and wilt. Unless the pest is treated they will continue to feed on the roots and the plant will die regardless of water content in the soil. This is easily seen throughout the growing areas. Individual plants, which are located in areas where other plants appear to be growing well, will die. With increased populations of the insect, and the insect's grubs, increased numbers of dying plants will be obvious.

Scarab beetle grubs are also known to burrow into tubors eg: potatoes and kumara, resulting in decreased crop yield.

Scarab beetles and their grubs are considered a relatively minor pest of glasshouses. Should you see this happening in your glasshouse careful searches should be made to locate and identify the pest. It is more likely that it may be Black Vine Weevil, which causes almost identical injury and is a much more common pest of glasshouses throughout Australia.

Control:

It is of the utmost importance to wash the nematodes from the turf into the soil surface after application. Apply at dusk when damaging sunlight is at a minimum. Soil temperature must be within the range of 15-30 C. Area to be be treated should be thoroughly moistened before applying to enable the nematodes to travel on a film of moisture in the soil. Immediately after applying, water the turf again to wash the nematodes from the grass onto the soil surface.

Apply nematodes uniformly to ensure that each square metre receives the same amount of nematodes. Use a two-way drenching pattern, applying half of the total solution in each direction.

Method:

Use 1 tub for 200-250 square metres depending on the severity of infestation. Add 1 tub to at least 40 litres of water at (10-25 C), at least 10 minutes before use and stir well to suspend nematodes. Conversely use 1/5 of a tub each time to 9 litres of water i.e. 1 bucket.

A watering can (9 litres) with a fine rose (nozzle) can be used to apply the solution. Agitate or stir the suspension each time before pouring more solution into the watering can.

Apply in sections. A length of garden hose may be useful for visually marking of each section. It is also advisable to familiarise your self with how much area will be covered by your watering can by using plain water before applying nematode solution. The recommendation of 1 tub per 40 litres of water in a minimum requirement and as a rule of thumb the more water applied with the nematodes the more even the coverage will be. Ensure your application is watered in well but avoid flooding or application eveness may be affected.

NB:
Calculations of 40 litres of water per 200-250 metres squared are based on the following;

200 litres of water per 10,000 metres squared (1 ha) since a higher output will come from a watering can i.e. 200 litres water per 1000 metres squared. 20 litres water per 100 metres squared so 40 litres water per 200 metres squared.

Hint

Underfoot the turf feels spongy and soft and can be rolled back like a loose carpet due to the destruction of the roots, causing the turf to loose it's grip on the soil.

Watch birds carefully if they are paying particular attention to the turf in a specific area, it is likely there are abundant pests in the soil. Treat the area immediately otherwise the turf may be destroyed.


Larvae

Pubation

Adult