Insect Pollinated Crops, Insect Pollinators and US Agriculture: Trend Analysis of Aggregate Data for the Period 1992–2009

In the US, the cultivated area (hectares) and production (tonnes) of crops that require or benefit from insect pollination (directly dependent crops: apples, almonds, blueberries, cucurbits, etc.) increased from 1992, the first year in this study, through 1999 and continued near those levels through 2009; aggregate yield (tonnes/hectare) remained unchanged. The value of directly dependent crops attributed to all insect pollination (2009 USD) decreased from $14.29 billion in 1996, the first year for value data in this study, to$10.69 billion in 2001, but increased thereafter, reaching $15.12 billion by 2009. The values attributed to honey bees and non-Apis pollinators followed similar patterns, reaching$11.68 billion and $3.44 billion, respectively, by 2009. The cultivated area of crops grown from seeds resulting from insect pollination (indirectly dependent crops: legume hays, carrots, onions, etc.) was stable from 1992 through 1999, but has since declined. Production of those crops also declined, albeit not as rapidly as the decline in cultivated area; this asymmetry was due to increases in aggregate yield. The value of indirectly dependent crops attributed to insect pollination declined from$15.45 billion in 1996 to $12.00 billion in 2004, but has since trended upward. The value of indirectly dependent crops attributed to honey bees and non-Apis pollinators, exclusive of alfalfa leafcutter bees, has declined since 1996 to$5.39 billion and $1.15 billion, respectively in 2009. The value of alfalfa hay attributed to alfalfa leafcutter bees ranged between$4.99 and $7.04 billion. Trend analysis demonstrates that US producers have a continued and significant need for insect pollinators and that a diminution in managed or wild pollinator populations could seriously threaten the continued production of insect pollinated crops and crops grown from seeds resulting from insect pollination

The H1 backward calorimeter BEMC and its inclusive electron trigger

A sandwich type lead-scintillator electromagnetic calorimeter with wavelength shifter optical readout has been successfully operated at the DESY ep collider HERA in the H1 detector for three years. The mechanical design of the calorimeter together with the associated electronics and the inclusive electron trigger as well as its performance and stability in test beams and at the ep collider HERA are described in detail

The H1 backward calorimeter BEMC and its inclusive electron trigger

A sandwich type lead-scintillator electromagnetic calorimeter with wavelength shifter optical readout has been successfully operated at the DESY ep collider HERA in the H1 detector for three years. The mechanical design of the calorimeter together with the associated electronics and the inclusive electron trigger as well as its performance and stability in test beams and at the ep collider HERA are described in detail

Solitary bees as pollinators

Besides the wind, insects are the main pollinating agents and many of them are hymenopterans. However, among the 20,000 species of bees (Superfamily Apoidea), only a very restricted group has been domesticated for commercial crop pollination, including social and solitary species. The honey bee Apis mellifera L. has been the first domesticated pollinator species, anyway, many cultivated crops benefit largely from the activity of other pollinators, especially when honey bees cannot provide a sufficient pollination service. This occurrence is particularly frequent in crops blooming in early spring or in crops with flowers not enough attractive to honey bees, i.e. because of low nectar and pollen production or for particular flower shapes. In addition to these ecological aspects, which are the result of a long history of coevolution between insects and flowers, modern agriculture and the well-known difficulties that honey bees are suffering of, create new concern that a general decline in the native pollinator populations will have unavoidable consequences on crop production due to insufficient pollination service. The most striking contradiction of the “industrial” extensive monocultures is that on one side they put in forth the need of enormous number of pollinators to satisfy the vast number of flowers contemporarily ready to be pollinated; on the other side, they cancel from the agroecosystem uncultivated meadows, edges and forests, which serve as refuge and conservation areas. The immediate repercussion on pollinating insects is the lack of continuity in blooms: on large areas, flowers are extremely abundant during the short blooming period of the main crops and nearly almost absent in the remaining part of their reproductive season (what is called “green desert”). In addition, very often a dramatic reduction of adequate nesting sites and materials may strongly limit the reproductive success, while, up today, the knowledge about the acute and chronic effects of pesticides on native bees is still insufficient

A global quantitative synthesis of local and landscape effects on wild bee pollinators in agroecosystems

Bees provide essential pollination services that are potentially affected both by local farm management and the surrounding landscape. To better understand these different factors, we modelled the relative effects of landscape composition (nesting and floral resources within foraging distances), landscape configuration (patch shape, interpatch connectivity and habitat aggregation) and farm management (organic vs. conventional and local-scale field diversity), and their interactions, on wild bee abundance and richness for 39 crop systems globally. Bee abundance and richness were higher in diversified and organic fields and in landscapes comprising more high-quality habitats; bee richness on conventional fields with low diversity benefited most from high-quality surrounding land cover. Landscape configuration effects were weak. Bee responses varied slightly by biome. Our synthesis reveals that pollinator persistence will depend on both the maintenance of high-quality habitats around farms and on local management practices that may offset impacts of intensive monoculture agriculture