San Diego Floral Association
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Friend or Foe: Ladybug Larvae
Reprinted from: January/February 2009, Volume 100, Number 1
Ladybug larvae are fierce predators, as seen here attacking a red aphid.
Photo: Ron Hay
Ladybugs (Coccinellidae)—also known as ladybirds and lady beetles—are probably the most recognizable insects in your garden besides bees. With the rounded red back sprinkled with black polka dots, ladybugs are as iconic as they are helpful. Well known for their pest-management abilities, gardeners far and wide actively encourage their stays; some gardeners even purchase the hungry beetles from local nurseries to help when their plants are infested with pests like aphids. With over 400 species in North America, they are an organic gardener’s delight.
Less recognizable to the untrained eye, however, is the ladybug larvae. Small, long, black and spiney, with little yellowish-orange stripes, the alligator-like ladybug larva looks far removed from its future, adult self, and can get confused with more destructive insects’ young. It is for this reason that many gardeners accidentally spray the ladybug larvae from their plants’ leaves, thinking they’re ridding themselves of a foe, when in actuality, they’re killing one of the best garden friends they could have.
Like the adult ladybug, the ladybug larvae feeds on your garden foes, and has a particular affinity for aphids, though they will also feed on scale, mites, insect eggs, thrips and more (even each other if they run out of food!). Voracious eaters who can eat their weight in prey each day, they’ll travel the length of your garden and back looking for pests to eat over the approximate 10-20 days of this life-cycle. They make their way through your garden on six, developed looking legs, as they are wingless. Protecting these larvae as they munch their way to adulthood can lead to significant pest management benefits. You’re most likely to start seeing these friends in your garden in mid-to-late summer, though they can appear earlier depending on temperature and other weather conditions.
Of course, in addition to keeping your eye out for larvae, keep your eye out for ladybug eggs and ladybug pupa. Ladybug eggs are very small, about one millimeter in size, and can range between cream and orange in color. They are tall and slender and are usually laid in small clusters near prey on leaves and plant stems. Pupa—the stage between larva and adulthood—are usually found attached to the underside of a leaf; they are slightly round, and are already sporting the spots that will make them so distinctive as adults. —Amy R. Wood
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