Like Bloodroot and many other spring ephemerals, Trout-Lily (also known as Dog-tooth Violet and Adder’s Tongue) remains closed at night and on overcast days. On sunny days, bees are its main pollinators, but it is visited by many other insects, including Red-necked False Blister Beetles that feed on both its pollen and ovules.
When a bee visits a Trout-Lily flower, it usually removes half of the available pollen in one visit. In no apparent hurry, it often pauses in the middle of collecting to groom itself and pack pollen into the pollen baskets on its hind legs. It then heads directly back to its hive to unload the pollen. Unfortunately for the Trout Lily, this hampers cross-pollination, as it severely limits the amount of pollen that reaches other Trout Lily flowers. As compensation, Trout Lily has two sets of anthers – one set opens one day, the other opens the next, preventing a bee from collecting all the pollen from a given flower in one day, giving other insects the opportunity to cross-pollinate. (Photo: Red-necked False Blister Beetle)
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
If you find a blossoming Trout Lily in the woods it is quite likely that you will also find one of its most common pollinators, the Red-necked False Blister Beetle (Asclera ruficollis), on it. Ardent pollen eaters, this group of beetles obtain their common name because many species cause blisters when pinched or squashed against skin. Adults mate on flower heads during pollen feeding. Both sexes feed on pollen, which acts as an attractant, but the female will not accept the male until her gut is packed full of pollen. She stores the pollen in a special intestinal sack in which an enzyme causes the pollen to partially germinate — this causes the indigestible covering of the pollen grain to rupture. She then digests the contents of the pollen grain, which she uses to manufacture eggs.