The Lacewings Micromus angulatus and Chrysoperla carnea as Predators of the Rhododendron Aphid, Illinoia lambersi, Under Different Temperature Regimes

<i>Illinoia lambersi</i> is a key aphid pest in <i>Rhododendron</i> cultivation in northwestern Europe, where control measures still heavily rely on chemical insecticides. The present laboratory study assessed the predatory potential of the brown lacewing <i>Micromus angulatus</i> on a mix of late instars and adults of <i>I. lambersi</i> across three temperatures (15, 20, and 25 °C) and compared its performance with that of the commonly used green lacewing <i>Chrysoperla carnea</i> sensu lato. Predation rates were measured for third-instar larvae and adults of <i>M. angulatus</i> and for second- and third-instar larvae of <i>C. carnea</i>. Third instars of <i>M. angulatus</i> were highly effective, killing 30-52 aphids per day, with predation significantly increasing at 25 °C. At 15 °C, <i>M. angulatus</i> third instars performed similarly to <i>C. carnea</i> third instars; at 20 °C, <i>C. carnea</i> exhibited higher predation. In all cases, <i>M. angulatus</i> third instars outperformed <i>C. carnea</i> second instars. Female <i>M. angulatus</i> adults maintained steady predation rates (≈30-40 aphids per day) across temperatures, whereas males were less voracious. These findings highlight the potential of <i>M. angulatus</i> as a predator in both its larval and adult stages for integration into IPM programs targeting in particular early-season <i>I. lambersi</i> outbreaks under cool spring conditions. Further field studies are needed to validate laboratory findings and assess the performance of the predator across different <i>Rhododendron</i> cultivars.