Problem: Are you fuchsias wilting, yellowing and covered with a sticky flack funk? When you caress your poor geranium’s leaves, do clouds of insects rise up and send you running? Another gardening nightmare! Whiteflies weaken flowering plants by drinking them dry.

Detection: Year-round pets outdoors in mild climates, whiteflies also thrive in homes and greenhouses. Difficult to see nymphs, covered in white fuzz, hide on lower leaves and quickly grow to be very visible adults. Tacky "honeydew" droppings are another whitefly indicator. Females lay up to 400 eggs each; you can almost see you pest’s population explode.

Solution: Whiteflies are tough to manage, so try multiple methods. Yellow sticky cards (sold in many nurseries, garden centers and greenhouse catalogues) will trap adults. Vacuum airborne whiteflies when cooler temperatures slow their flight. In greenhouses, release Encarsia formosa, tiny beneficial wasps that eat and lay eggs in whitefly nymphs. Horticultural oil, and are chemical options.

Greenhouse whitefly (T. vaporariorum) nymphs (Photo courtesy of T. Perring, University of California, Riverside, CA).

Greenhouse whitefly (T. vaporariorum) on the lower surface of a pumpkin (Cucurbita maxima) leaf.