Insect pollinators

Pollination of Helianthus species is predominantly by honeybees and bumblebees (Cockerell, 1914), although other insects may be active. Helianthus are all-day flowers, presenting a continuous pollen and nectar resource for bees and other insects. Jerusalem artichoke, like nearly all Helianthus species, is largely self-incompatible, and as a consequence, cross-pollination is essential for the production of viable seed, with self-pollination being a rare event. 

---

Cycads pollination by insects may be one of the earliest forms of insect-pollination. Like conifers, cycads bear their reproductive cells in cones rather than flowers. Individual cycad plants are either male or female, male plants having pollen cones and female plants, seed cones. Fertilization requires transfer of pollen grains from pollen cones to seed cones. The role of insects in this process has received attention in a cycad commonly known as the cardboard palm (Zamia furfuracea). This is a handsome horticultural plant with... 

Insofar as the cardboard palm and its weevil provide a good model, early insect-pollination must have been a rather messy, essentially accidental process. As time passed, however, interactions between plant and animal became more refined. For a more elegant arrangement, we return to flowering plants and consider the... 

McGregor, S. E. 1977. "Insect pollination of cultivated crop plants." U.S. Department of Agriculture Handbook No. 496, 411... 

Herrera, C.M. (1996). Floral traits and plant adaptation to insect pollinators a devil s advocate approach. In Floral Biology, eds. S. . H. Barrett and D. G. Lloyd, pp. 65-87. New York Chapman Hall. 

Pellmyr, O., Tang, W Groth, I., Bergstrom, L. G. and Thien, L. B. (1991). Cycad cone and angiosperm volatiles inferences for the evolution of insect pollination. Biochemical Systematics and Ecology 19 623-627. 

Chapters in this volume consider how plants use chemicals to defend themselves from insect herbivores the complexity of floral odors that mediate insect pollination tritrophic interactions of plants, herbivores, and parasitoids, and the chemical cues that parasitoids use to find their herbivore hosts the semiochemically mediated behaviors of mites pheromone communication in spiders and cockroaches the ecological dependence of tiger moths on the chemistry of their host plants and the selective forces that shape the pheromone communication channel of moths. 

Many flowering plants attract insect pollinators by releasing odorant molecules that mimic an insect s natural food sources or potential egg-laying sites. Plants pollinated by flies or beetles that normally feed on or lay their eggs in dung or carrion sometimes use foulsmelling compounds to attract these insects. 

Miliczkey, E.K. Osgood, E.A. "The effects of spraying with SEVIN-4-OIL on insect pollinators and pollination in a spruce-fir forest" Tech. Bull. No. 90., Life Sciences and Ag. Exp. Sta. Orono, Me., 1979. 

McGregor, S.E., Insect Pollination of Cultivated Crop Plants, USDA-ARS Agricultural Handbook. 496, Washington, DC, 1976. 

Types of insect pollinators Traits of floral volatiles... 

To date, little information exists about how insects respond to individual components found in floral scents, even though it is known that they can distinguish between complex floral scent mixtures. It is still unclear whether insect pollinators use only a few compounds present in a scent for floral identification or whether they use information from all scent compounds. Recently, it was shown that honeybees can use all floral volatiles to discriminate subtle differences in the scent of four snapdragon cultivars that emit the same volatile compounds but at different levels (26). 

Maples are characterized by the shape of their leaves, which in most species are broadly palmate with a three- or five-lobed outline, and are arranged in an opposite fashion on their branches. Maples have seasonally deciduous foliage, which is shed in the autumn. The leaves of many species of maples develop beautiful yellow, orange, or red colors in the autumn, prior to shedding for the winter. Maple flowers appear early in the springtime, and consist of non-showy, rather inconspicuous inflorescences. The flowers of some species produce nectar and are insect-pollinated, while other species shed their pollen into the air and are wind-pollinated. Maples have distinctive, winged seeds known as samaras, which are arrar ed in opposite pairs. 

From the assemblages of fossil pollen, palynologists make inferences about the types of forests or other plant communities that may have occurred in the local environment. These interpretations must be made carefully, however, because species are not represented in the pollen record in ways that directly reflect their abundance as mature plants. For example, pollen of wind-pollinated species is relatively abundant in lake sediments, whereas species that are insect pollinated are not well... 

Insect-pollinated plants are called Entomopkilous. These, being dependent upon the visits of insects for fertilization, possess brilliantly colored corollas, have fragrant odors, and secrete nectar, a sweet liquid very attractive to insects, which are adapted to this work through the possession of a pollen-carrying apparatus. Example Orchids. 

---