Pyribria

Pyribria is an insect growth regulator based on pyriproxyfen. It works nothing like a conventional insecticide: it mimics the insect's own juvenile hormone, so treated immatures never complete metamorphosis into adults and treated adults lay eggs that do not hatch. Against whitefly and scale — pests whose damage comes from sheer population growth — breaking the cycle is more durable than killing the adults present today. It is also comparatively gentle on predatory and parasitic insects, which makes it a natural fit for IPM.

Characteristics

• —Juvenile hormone mimic — stops metamorphosis and egg hatch
• —Excellent on whitefly, scale insects and psyllids
• —Breaks the population cycle rather than treating the symptom
• —Comparatively soft on predators and parasitoids — suits IPM programmes
• —IRAC Group 7C — no cross-resistance with Groups 1, 3, 4 or 28
• —Long residual effect from a single application

How it works

Pyriproxyfen mimics juvenile hormone, the signal that tells an insect larva to stay a larva. Held artificially high, the hormone signal prevents the final moult to the adult form, and in treated adults it prevents embryonic development in the eggs they lay. Adults already present are not killed, so judge the result after a generation, not after a week. IRAC Group 7C.