Aphids have been a particularly challenging pest to get under control in our high tunnel strawberries this year. They quickly colonized the strawberries we had growing all winter and took off as the weather warmed (Figure 1). In my first attempt to knock them back I introduced 2,000 lacewing larvae (22-Apr), too little too late. I decided to take the ‘opportunity’ at hand to evaluate four OMRI approved insecticide options. Applications began when populations were much higher than what growers should tolerate, so I would anticipate you would see even better results if you intervene at the first signs of infestation. Table 1 shows the products, active ingredient (A.I.), application rate and dates of applications. The change in aphid populations over the course of this trial are shown in Figure 2. In entomological tradition, I surveyed the aphid population prior to treatment (1-May) to get a baseline. As you can[Read More…]

This winter-spring has been my first excursion into growing strawberries in a high tunnel. It didn’t take much for our own Wenjing Guan to convince me to plant some; who doesn’t love to eat fresh strawberries? We planted them back in October and I just peeked at them every couple of weeks throughout the winter, looking for hungry herbivores wanting to share the impending treats. There were spider mites at first (Figure 1) and we made a few releases of the predatory mites Phytoseiulus persimilis and sachets containing Amblyseius (Neoseiulus) Californians. Figure 1. Two-spotted spider mites on strawberry leaves (above) and under a microscope camera (below). This spring, when the weather started warming up and the extra cover was lifted inside the tunnels we found less mites, almost none at all at this point, but an explosion of aphids (Figure 2) and an increasing presence of whiteflies (Figure 3). The[Read More…]