Charles McClintock, Professional Products Business Manager for Sumitomo, explains why Sumilarv has remained a popular choice of IGR for the last 25 years.


Sumilarv was first introduced onto the market back in the 1990s. Based on the juvenile hormone mimic pyriproxyfen, it was novel insect growth regulation technology back then and remains so to this day.

Before insect growth regulators (IGRs) became available, professional pest managers used products that simply killed pest insects. However, with the arrival of Sumilarv, the industry had access to a very different type of product. It did not kill insects directly but interfered with their growth and reproduction. As a result Sumilarv was very much focused on population management, giving rise to the enduring slogan, “break the breeding cycle”. It took some time for the pest management industry to catch on but eventually, pest managers soon found Sumilarv was an ideal mixing partner for knockdown insecticides, as well as a standalone maintenance treatment.

The active ingredient in Sumilarv is unique in that it mimics the natural growth hormone in insects that is vital for growth and reproduction. By overdosing the insect with this growth hormone mimic, the range of effects include preventing pupation to adult form and causing a reduction in viable eggs in female insects. This makes it perfect as a catch-all for controlling insect populations that might be resistant to some knockdown insecticides.

The key targets for Sumilarv are fleas and cockroaches, the two most problematic pests for pest control professionals. The key life stage for Sumilarv activity is the pupal stage. As cockroaches undergo incomplete metamorphosis, they do not have a pupal stage, transitioning through various nymphal stages before reaching the adult stage. With no complete change in body form, Sumilarv does not have a large enough impact at moult to kill cockroaches, but it does cause deformity – the curly wing appearance. However, the important impact of Sumilarv on cockroaches is that it sterilises female cockroaches, which is an important factor in delivering population control, especially in insecticide-resistant populations.


Physical signs of Sumilarv exposure in cockroaches – abnormal wing formulation – ‘curly wing’ and supernumerary adults – last stage nymphs which fail to develop into adults (photo credit: MGK/Sumitomo)


In contrast, fleas undergo complete metamorphosis with multiple life stages culminating in pupation to adult form. At the time of launch, the understanding was that the Sumilarv mode of action primarily impacted the pupal stage, preventing the final stage larval instars from developing into adults. However, continued research over the last 25 years has discovered that Sumilarv actually impacts all life stages of the flea – affected eggs do not hatch and larval stages do indeed die when moulting, in addition to preventing pupation. This broad impact on the flea life cycle, coupled with its long residual performance, means it is an obvious inclusion in flea treatments and indeed a great standalone preventative treatment, especially in sensitive accounts.

The Sumilarv mode of action is also effective on a range of other insects including mosquitoes, midges, drain and latrine flies. During the past ten years a slow-release granule formulation of Sumilarv was developed specifically for aquatic uses where these pest insects are a problem. Sumilarv Granular is highly effective in suppressing the pupation of mosquitoes and midges, preventing disease transmission and nuisance biting during the warmer months.

The pre-dosed granular formulation, which is conveniently enclosed in a ‘tea bag’ style of sachet, allows for quick and accurate application. The use of Sumilarv for mosquito control has proven very effective as it harnesses the phenomena of auto dissemination; when adult mosquitoes visit a treated breeding site they pick up small doses of Sumilarv and transfer pyriproxyfen to untreated breeding sites. With pyriproxfen effective at doses as low as 0.012 parts per billion it means pest managers do not have to locate all breeding sites on a property – the mosquitoes help to treat breeding sites that may have been missed during inspection. With its unique performance benefits, Sumilarv is a key pest management tool, especially when dealing with large populations and accounts with high pest pressure, particularly mosquitoes in outdoor areas, cockroaches in commercial accounts and flea infestations.

Charles McClintock, Professional Products Business Manager, Sumitomo Chemical Australia