Farming with Native Pollinators
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Master Gardeners Module – Insects part II Alex Wild Beneficials (pollinators and pest suppressors) Overview • Native pollinators • Pest suppressors Resources: Xerces.org Pollinator Partnership These sites will provide planting lists to enhance native pollinators, fact sheets to construct native bee nests, and other information Pollinator quiz • How many species of native bees do we have in New York? – 480 spp. • In North America? – 4000 spp. • Which group of insects is second only to bees as effective pollinators? – Flies (Diptera) • Can you name two other groups of insects that are important pollinators? – Beetles (Coleoptera) – Butterflies/moths (Lepidoptera) Global pollination crisis • Pollinators provide vital ecosystem services and are critical in maintaining global biodiversity of plants • Decline in pollinators coincides with decline in many plant species • Drivers of pollinator decline include habitat loss and fragmentation, agrochemicals, pathogens, alien species, climate change and the interactions between them. • Pollinator loss impacts wider ecosystem stability, crop production, food security and human welfare – Declines in honeybees (CCD and other factors) – Declines in native pollinators Murder hornets (Vespa mandarinia) European honeybees are defenseless against the JGH (Japanese Giant Hornet); the JGHs can slaughter 30,000 honeybees in an hour or two BUT….the Japanese honeybee, which has evolved with the Japanese hornet has a special defense against the hornet Murder hornets (Vespa mandarinia) European honeybees are defenseless against the JGH (Japanese Giant Hornet); the JGHs can slaughter 30,000 honeybees in an hour or two BUT….the Japanese honeybee, which has evolved with the Japanese hornet has a special defense against the hornet • Considered to be a mutualistic Pollination relationship • Primitive plants – wind pollinated and water “pollinated” • Co-evolution of flowering plants & insects • Pollination usually involves a “reward” in exchange for carrying pollen Deception in the pollinator world • Male bees are sometimes “tricked” by orchids that mimic female bees • A reward of pollen or nectar is not provided – “pseudocopulation” • Slits made by carpenter bees by-pass pollen to steal nectar; sometimes these slits are used by honeybees and others Bombus bimaculatus Types of pollinators • Cantharophily - beetle pollination • Myophily – fly pollination • Sphecophily - wasps • Myrmecophily - ants • Phalaenophily - moths • Psychophily – butterflies • Anthrophily? - humans • Different levels of specialization (eg. Fig wasp) Insects and plant reproduction • Anthipholous (flower- frequenting) insect taxa include: Bees/wasps, moths/butterflies, beetles, flies and thrips • Pollen: protein, fat, starch, sugar, vitamins • Nectar: high in sugars Sumatran corpse flower is 20 feet tall, 16 feet wide and smells like rotting flesh Native bees US forest service Bees • Evolved from wasp-like (carnivorous) ancestors • Adapted to a new food resource • Radiation of bees coincides with radiation of flowering plants • Bees provision their offspring with pollen instead of dead insects Masarine wasps Native bees of New York Andrenidae Halictidae (477 spp.) Rusty-patched bumble bee (Bombus affinis) Apidae Megachilidae Native pollinators in the landscape • Over 50 spp. of native bees visit cucurbit crops, sunflowers and tomatoes in CA • Over 80 spp. of native bees pollinate berry crops in the northeast • Study in Alberta Canada showed that Canola farmers could make more money by leaving a portion (up to 30%) of their Canola crop in wildflowers for native bees for pollination rather than renting honey bees • Use of native bees adds a layer of security in the face of honey bee declines "Bombyliidae 3 by kadavoor" Mason bees pollinate fruit crops • One acre of apples can be pollinated by 250 mason bees. • It would take 1.5-2 hives of honey bees to do the same job • Mason bees thrive in cold climates and “buzz pollinate” • Mason bee nest sites can be supplemented with native bee boxes (see Xerces.org • for instructions Enhancing nesting sites fact sheet on xerces.org Native bees • Tend to be more versatile than honeybees • Can be active when conditions are too wet or cold for honeybees • Can “buzz pollinate” flowers releasing pollen from deep within the anthers of flowers such as native cranberry, blueberry, and huckleberry resulting in larger and more abundant fruit Habropoda laboriosa Is capable of visiting 50,000 blueberry flowers in her short life….enough to produce 6000 blueberries worth $20 Native bees • Long tongued bees (Apidae and Megachilidae) prefer deep flowers • Short tongued bees (i.e. Colletidae) prefer shallower flowers Nesting space for native bees • About 30% of the 4000 native bee species are solitary wood nesters • About 70% are solitary ground nesters • Bumble bees are social ground nesters Bumble bees Social and can sting repeatedly in defense of their underground colonies The vast majority of •Carpenter bees native bees are solitary, with single females provisioning their offspring in a single burrow Solitary bees rarely sting people Carpenter bee vs. bumble bee Megachilidae – Leaf-cutting bee Pollination on 2 wings • Diptera – among the earliest pollinators • Second only to bees and in some cases as effective Plant/insect co-evolution • One of the 3 largest families of animals on the planet (> 160,000 spp.) • Over 70 different families of Diptera include anthipholous species • Over 1000 flowering plant species are documented to be pollinated or visited by anthipholous flies • More than 100 cultivated plants are pollinated by flies Larson, Inouye and Kevan, unpubl; Heath 1982 Mitra and Banerjee 2007 Clement et al. 2007 Hansen 1983 Examples of fly-pollinated produce • Mango • Cashew • Tea • Cacao • Onions • Strawberries • Cauliflower • Mustard • Carrots • Apples • Leeks • cassava Photos by Alex Wild Syrphidae – “flower flies” or “hover flies” • Most lack specialized structures to carry pollen • Platycheirus spp. enlarged tarsi to squeeze pollen out of anthers • Some accumulate pollen in their hairs Syrphid fly larvae provide pest suppression • Some species of hover flies lay their eggs in vegetation • Their larval forms prey on soft-bodied insects like aphids • Bee flies also prey upon and parasitize other insects eggs and larvae Bee fly larvae parasitize a tiger beetle larva Eristalis sp. (Syrphidae) • used in greenhouse pollination of peppers (Jarlan et al. 1997) • laboratory-reared and used in the production of seeds for seed banks (Rosso et al. 1994; Gladis 1994). Muscidae and Calliphoridae spp. • Disposable pollinators • Easy to rear • Don’t sting • Do not leave and return with potential contamination • Work in cold temperatures • Raised commercially • Used as pollinators for – Canola – Sunflower – Buckwheat – Garlic – Lettuce – Peppers – To increase production of greenhouse tomatoes, peppers and umbelliferous plants (celery, carrot, many aromatic herbs) http://www.forkedtreeranch.com/ Bee flies • Large family (>4500 spp) • Adults feed on pollen and are the main pollinators of some desert plant species • Larval stages are predators or parasitoids of eggs and larvae of other insects (females often lay eggs in the burrows of beetles or solitary wasps Bee fly (Bombylius major) visiting a spring beauty, Claytonia virginica. Image courtesy of Beatriz Moisset and bees) Xenox tigrinus mating "Lepidophora lepidocera" by Bruce Marlin "Bombyliidae mating" by Charles Mays "12Sep Ft Union National Monument 44-1" by Vaughn Wasem "Unidentified Beeflies" by D momaya Flies as pollinators in the forest understory Herbaceous plants and shrubs with numerous small inconspicuous flowers • Small flies – Phoridae – Sciaridae – Mycetophilidae – Piophilidae – Bibionidae – Culicidae Flies as pollinators in arctic and alpine systems Soldier fly (Diptera: Stratiomyidae) Fig. 1 Relative importance of flies, bees and beetles in plant- flower visitor systems relative to latitude (Kanstrup and Olesen 2000) Specialization between plants and pollinators to form a Specialized pollinators “pollinator guild” helps to ensure that pollen is transferred to the same species Lapeirousia anceps is pollinated by Moegistorhynchus longirostris (Diptera: Nemestinidae) Beetles as pollinators Beetles comprise the largest set of pollinating animals, due to sheer numbers. They are responsible for pollinating 88% of the 240,000 flowering plants globally (U.S. Forest Service) Photos: Hilton Pond Center Beetles • Probably the oldest anthipholous group • Still pollinate some of the ancient lineages of plants (i.e. magnolia, spicebush) • Beetles rely heavily “smell” and prefer “spicy” varieties • Also capable of color vision Pollination by butterflies & moths • Daytime active • Good color vision • Less efficient at pollen transport than other insects (long legs; lack pollen carrying structures) • Many flowering plants have obligate butterfly pollinators Pollination by moths • Many are nocturnal (not all) • Flowers that bloom nocturnally are often white or dull in color • Produce high quantities of nectar but may be specialized (nectar may be difficult to reach) Hawk moth (Agrius convolvuli) visits a lily (Crinum bulbispermum) . The lily is one of some twenty African plant species with floral tubes that match in length the four-inch proboscis of that hawk moth, suggesting the plants and the hawk moths have coevolved in response to each other Aposematism • Insects often sequester secondary compounds from the plants they visit and use them to produce their own