"Good bugs"

Natural enemies, or "good bugs", can provide a safe, environmentally friendly means of suppressing pests. Predators such as lady beetles and lacewings consume many prey during their lifetime. Another important group of predators are the spiders. Parasitoids, which include many wasps and flies, are more specialized than predators; the immature stage actually develops within the body of a single insect, ultimately killing it. 
Some flowers are better than others for attracting small wasps and flies that are predators or parasitoids of pest insects. Flower architecture and insect morphology are important in determining what’s a good bug flower. Many natural enemy species are around as adults only for short periods during the growing season, so to be useful, pollen and nectar must be available when the adults are active. This is most easily achieved by planting a mixture of plants that have relatively long blooming periods that overlap in time. In the home garden, sequential plantings of dill, coriander, and caraway can be made to provide a continuous source of their valuable flowers throughout the season.

Good Flowers For Bugs
Umbelliferae (Carrot Family)
caraway	Carum carvi
coriander (cilantro)	Coriandrum sativum
dill	Anethum graveolens
fennel	Foeniculum vulgare
flowering ammi or      Bishop's flower	Ammi majus
Queen Anne's Lace      (wild carrot)	Daucus carota
toothpick ammi	Ammi visnaga
wild parsnip	Pastinaca sativa
Compositae (Aster Family)
blanketflower	Gaillardia spp.
coneflower	Echinacea spp
coreopsis	Coreopsis spp.
cosmos	Cosmos spp.
goldenrod	Solidago spp.
sunflower	Helianthus spp.
tansy	Tanacetum vulgare
yarrow	Achillea spp.
Fabaceae (Bean Family)
alfalfa	Medicago sativa
big flower vetch	Vicia spp.
fava bean	Vicia fava
hairy vetch	Vicia villosa
sweet clover	Melilotus spp.
Brassicaceae (Mustard Family)
Basket-of-Gold      alyssum	Aurinium saxatilis
hoary alyssum	Berteroa incana
mustards	Brassica spp.
sweet alyssum	Lobularia maritima
yellow rocket	Barbarea vulgaris
wild mustard	Brassica kaber
Other plant families
buckwheat	Fagopyrum sagittatum
cinquefoil	Potentilla spp.
milkweeds	Asclepias spp.
phacelia (Note that many of these plants are considered weeds!)	Phacelia spp.