Garrards: Service with integrity

Include in your Flea and Cockroach treatments for outstanding results.
By Jeffrey Einam, Technical and Regulatory Affairs Manager, Bayer Environmental Science, ANZ

Starycide is a registered product for control of fleas, cockroaches and silverfish. It can best be described as an Insect Growth Regulator (IGR) and is designed primarily as a tank mix partner with residual sprays.

What makes Starycide different to most other registered IGR’s on the market?

The main differences between Starycide and other IGR’s are its mode of action and its residual control.

Triflumuron - Mode of Action

In order to grow an insect needs to shed its cuticle at various intervals.  This process of shedding the cuticle is called moulting. The cycle of moulting, growth and eventually sexual maturity is controlled by a range of hormones.

There are two main groups of IGR’s registered in Australia for Pest Control uses.

The first group of IGR’s are referred to as the Juvenile Hormone Analogues (JHA's for short) and includes the active ingredients Methoprene, Hydroprene, Fenoxycarb and Pyriproxyfen.
As the name implies, JHA's mimic the action of the hormone which keeps the insect in its juvenile form while developing.
The presence of a JHA tricks the insect.
• It moults to an oversized larvae and dies or develops into a sterile adult which may display symptoms such as curly wings.
• In either case no fertile eggs are laid and so no new generation develops. 
• Insects are generally only affected when exposed to the JHA just prior to the last moult; in fact there will be no noticeable affect at other times.  Adult insects and smaller larvae are unaffected.

 
Take Home Point: Whilst JHA’s prevent the development of fertile adults, insect species where the larval/juvenile stages are pests (eg Cockroaches) will NOT be measurably affected by an application of a JHA without the assistance of an adulticide. On the flip side, where the pest stage of the insect is only the adult (eg mosquitoes), the combination of an adulticide with a JHA can be very effective.

This second group of IGR’s are referred to as the chitin synthesis inhibitors (CSI’s for short) because they affect the production of chitin, the most important component of the insect cuticle. Insects must shed their cuticle at regular intervals in order to grow in size.  This group includes the active ingredients Triflumuron (Starycide), Lufenuron, Diflubenzuron and Flufenoxuron.

In a normal situation (left-hand side), the old cuticle is shed, the insect inflates its body size by taking in air and then the cuticle hardens to its new bigger size.  

Where a CSI has prevented the prior development of a new cuticle, the old one is shed, leaving the insect without a protective and supportive cuticle and it soon dies.

This is a very simplified interpretation of the effect and it is usually not the whole cuticle which fails to form.  What we generally see are weak points in the cuticle so that the insect doesn't have enough strength or leverage to escape from its old skin.  If it does escape then the thin points lead to dehydration or death by other external influences.

Starycide acts as a chitin synthesis inhibitor keeping the insect in its juvenile form while they develop.  Starycide affects insects at every larval stage when it goes through a moult.

This electron microscope image shows how the flea larva has died within its old cuticle after being affected by an application of Starycide.

Triflumuron - Residual Control

Triflumuron is extremely insoluble and will not dissolve in water or many other solvent types.

What does this mean for the PCO?

By being insoluble, it means Triflumuron is extremely unreactive and this translates into a compound that is very resilient to UV breakdown or alkaline surfaces (eg concrete) and lasts on surfaces far longer than any compound registered for Pest control.
And because Triflumuron targets a metabolic process absent in mammals and birds, it is also considered to have a very high margin of safety.
 
 
Fleas
Traditionally the insecticides used for flea control have been directed against the adult flea because this is what the client sees.  However these compounds are often much less effective against the larval stages and often they only last a month or two under practical conditions.

This graph shows the results of a field trial in Australia.  Flea problems existed both indoors and outdoors, and were sprayed with Triflumuron.  The adult flea population was monitored over the next few weeks.

It took 3-4 weeks for the flea population to disappear (which is about the life expectancy of adult fleas).  It was not necessary to spray again that season because the residual life can be about a year. In normal circumstances, it would not be acceptable to take that long to control adult fleas, which demonstrates why the combination of an adulticide (eg Temprid75, Cislin25) AND Starycide is the most robust option.
It is of course not possible to stop dogs and cats occasionally bringing home new fleas from untreated areas but these fleas will not be able to give rise to new pest populations.  Dogs and cats should be regularly treated with suitable flea control products.

 
Cockroaches
When Starycide was used alone, cockroach populations required 4 months to decline to low levels (95%+ control).  This level of control persisted for 40 weeks so residual life is very good.

But just like the flea example above, clients are certainly not prepared to wait for 4 months to get rid of their cockroach problem.  A tank mix of both Starycide and an adulticide results in a highly effective long term treatment.

Important Points
Because Triflumuron is extremely insoluble, Bayer’s formulation chemists devised a clever way to dilute the technical active ingredient by a factor of 10 so that measuring was more convenient. They did this by micronizing clay particles and using them to suspend Triflumuron in water. Before developing this process the use rates were difficult to measure out (0.5-2ml per litre). It was very easy to overdose or spill product which for some became quite costly. But at 10 times more dilute, Bayer could now put Triflumuron into a measure pack which was far more convenient.

It is however important to note that Starycide 48SC may leave visible residues on some surfaces. It is this micronized clay that can sometimes be visible. Operators need to be aware of this and apply to a small test area first. Dark colours and non-porous surfaces will be the most likely to show residues. For the prescribed use pattern for flea treatment, this should not cause many problems as applications to carpet and outdoor surfaces rarely show these residues. The good news is that these residues are easily removed with a damp cloth. With cockroach control involving application to crack and crevices, this should not pose a problem either. The use of the appropriate application equipment (as per the Starycide technical bulletin is recommended)

Starycide is compatible with most residual sprays on the market including the range from Bayer. If in doubt contact one of the friendly Bayer Sales representatives who can confirm for you.

 
When Should I use it?

For normal domestic annual cockroach and silverfish services the use of Starycide is probably not warranted. However if significant populations of either pests are being found, the small cost of adding in some Starycide is a wise choice.

For ALL flea infestations it is highly recommended to use Starycide with an adulticide such as Temprid75 or Cislin25. No other IGR will do a better job at managing the larval stages of the fleas due to its incredible residual control and UV stability. Remember, that the adult fleas which triggered the service call can be as low as 5% of the total flea problem at any one time. Addressing the adult stage only is a guarantee of call-backs.

For commercial cockroach control accounts, Starycide should be the foundation of your program. Its action on juvenile stages (which are a pest stage just like the adults) will bolster your residual spray and gel program to deliver a strong result. In the harsh and unpredictable environments of commercial accounts, a long lasting product resilient to breakdown is a huge advantage.   

Starycide Insect Growth Regulator

• Active Constituent(s): Contains 48g/L Triflumuron
• Description:

  For the control of silverfish, immature fleas and cockroaches in indoor and outdoor situations.

• SDS Expiry: 23/07/2017
• Associated Files: