Toxicity of diflubenzuron and pyriproxyfen to the predatory bug Podisus maculiventris

The susceptibility of the predatory pentatomid Podisus maculiventris (Say) to the insect growth regulators (IGRs) diflubenzuron and pyriproxyfen was investigated in the laboratory. Fifth‐instar nymphs were exposed to formulated materials of each compound via direct contact, residual contact and ingestion. Diflubenzuron was harmless to P. maculiventris by direct and residual contact, but was highly toxic when ingested via drinking water. Pyriproxyfen caused severe deformities at ecdysis whatever the method of exposure. Exposure of fifth instars to sublethal concentrations (around LC10) of both compounds had no adverse effects on reproduction of emerging adults. The data suggest that the use of these IGRs in the integrated management of insect pests should be evaluated with caution.