Theresa L. Pitts-Singer

Bio: Theresa L. Pitts-Singer is an academic researcher from Agricultural Research Service. The author has contributed to research in topics: Megachilidae & Megachile rotundata. The author has an hindex of 22, co-authored 61 publications receiving 1398 citations. Previous affiliations of Theresa L. Pitts-Singer include United States Forest Service & Utah State University.

The Alfalfa Leafcutting Bee, Megachile rotundata: The World's Most Intensively Managed Solitary Bee*

Abstract: The alfalfa leafcutting bee (ALCB), Megachile rotundata F. (Megachildae), was accidentally introduced into the United States by the 1940s. Nest management of this Eurasian nonsocial pollinator transformed the alfalfa seed industry in North America, tripling seed production. The most common ALCB management practice is the loose cell system, in which cocooned bees are removed from nesting cavities for cleaning and storage. Traits of ALCBs that favored their commercialization include gregarious nesting; use of leaves for lining nests; ready acceptance of affordable, mass-produced nesting materials; alfalfa pollination efficacy; and emergence synchrony with alfalfa bloom. The ALCB became a commercial success because much of its natural history was understood, targeted research was pursued, and producer ingenuity was encouraged. The ALCB presents a model system for commercializing other solitary bees and for advancing new testable hypotheses in diverse biological disciplines.

Crop production in the USA is frequently limited by a lack of pollinators.

Abstract: Most of the world's crops depend on pollinators, so declines in both managed and wild bees raise concerns about food security. However, the degree to which insect pollination is actually limiting current crop production is poorly understood, as is the role of wild species (as opposed to managed honeybees) in pollinating crops, particularly in intensive production areas. We established a nationwide study to assess the extent of pollinator limitation in seven crops at 131 locations situated across major crop-producing areas of the USA. We found that five out of seven crops showed evidence of pollinator limitation. Wild bees and honeybees provided comparable amounts of pollination for most crops, even in agriculturally intensive regions. We estimated the nationwide annual production value of wild pollinators to the seven crops we studied at over $1.5 billion; the value of wild bee pollination of all pollinator-dependent crops would be much greater. Our findings show that pollinator declines could translate directly into decreased yields or production for most of the crops studied, and that wild species contribute substantially to pollination of most study crops in major crop-producing regions.

Pesticide Exposure Assessment Paradigm for Solitary Bees

Abstract: Current pesticide risk assessment for bees relies on a single (social) species, the western honey bee, Apis mellifera L. (Hymenoptera: Apidae). However, most of the >20,000 bee species worldwide are solitary. Differences in life history traits between solitary bees (SB) and honey bees (HB) are likely to determine differences in routes and levels of pesticide exposure. The objectives of this review are to: 1) compare SB and HB life history traits relevant for risk assessment; 2) summarize current knowledge about levels of pesticide exposure for SB and HB; 3) identify knowledge gaps and research needs; 4) evaluate whether current HB risk assessment schemes cover routes and levels of exposure of SB; and 5) identify potential SB model species for risk assessment. Most SB exposure routes seem well covered by current HB risk assessment schemes. Exceptions to this are exposure routes related to nesting substrates and nesting materials used by SB. Exposure via soil is of particular concern because most SB species nest underground. Six SB species (Hymenoptera: Megachilidae - Osmia bicornis L., O. cornifrons Radoszkowski, O. cornuta Latreille, O. lignaria Say, Megachile rotundata F., and Halictidae - Nomia melanderi Cockerell) are commercially available and could be used in risk assessment. Of these, only N. melanderi nests underground, and the rest are cavity-nesters. However, the three Osmia species collect soil to build their nests. Life history traits of cavity-nesting species make them particularly suitable for semifield and, to a lesser extent, field tests. Future studies should address basic biology, rearing methods and levels of exposure of ground-nesting SB species.

Ecological, behavioral, and biochemical aspects of insect hydrocarbons*

Abstract: ▪ Abstract This review covers selected literature from 1982 to the present on some of the ecological, behavioral, and biochemical aspects of hydrocarbon use by insects and other arthropods. Major ecological and behavioral topics are species- and gender-recognition, nestmate recognition, task-specific cues, dominance and fertility cues, chemical mimicry, and primer pheromones. Major biochemical topics include chain length regulation, mechanism of hydrocarbon formation, timing of hydrocarbon synthesis and transport, and biosynthesis of volatile hydrocarbon pheromones of Lepidoptera and Coleoptera. In addition, a section is devoted to future research needs in this rapidly growing area of science.

Nutritional composition and safety aspects of edible insects

Abstract: Insects, a traditional food in many parts of the world, are highly nutritious and especially rich in proteins and thus represent a potential food and protein source. A compilation of 236 nutrient compositions in addition to amino acid spectra and fatty acid compositions as well as mineral and vitamin contents of various edible insects as derived from literature is given and the risks and benefits of entomophagy are discussed. Although the data were subject to a large variation, it could be concluded that many edible insects provide satisfactorily with energy and protein, meet amino acid requirements for humans, are high in MUFA and/or PUFA, and rich in several micronutrients such as copper, iron, magnesium, manganese, phosphorous, selenium, and zinc as well as riboflavin, pantothenic acid, biotin, and in some cases folic acid. Liabilities of entomophagy include the possible content of allergenic and toxic substances as well as antinutrients and the presence of pathogens. More data are required for a thorough assessment of the nutritional potential of edible insects and proper processing and decontamination methods have to be developed to ensure food safety.

Insect seminal fluid proteins: identification and function.

Abstract: Seminal fluid proteins (SFPs) produced in reproductive tract tissues of male insects and transferred to females during mating induce numerous physiological and behavioral postmating changes in females. These changes include decreasing receptivity to remating; affecting sperm storage parameters; increasing egg production; and modulating sperm competition, feeding behaviors, and mating plug formation. In addition, SFPs also have antimicrobial functions and induce expression of antimicrobial peptides in at least some insects. Here, we review recent identification of insect SFPs and discuss the multiple roles these proteins play in the postmating processes of female insects.

Potential and challenges of insects as an innovative source for food and feed production

Abstract: Edible insects, a traditional food all over the world, are highly nutritious with high fat, protein and mineral contents depending on the species and thus represent a noteworthy alternative food and feed source and a potential substitute e. g. for fishmeal in feed formulae. Research is required to develop and automatize cost-effective, energy-efficient and microbially safe rearing, harvest and post harvest processing technologies as well as sanitation procedures to ensure food and feed safety and produce safe insect products at a reasonable price on an industrial scale especially in comparison to meat products. In addition, consumer acceptance needs to be established. Potential and challenges along the production chain of insects for food and feed are discussed based on published data and future research needs are derived from recent literature. Industrial relevance text With the increasing demand in alternative protein sources world-wide, insects represent an innovative food and feed source rich in high quality protein as well as other beneficial nutritional ingredients such as fat, minerals and vitamins. Despite traditional knowledge about insects and their harvest in the wild, for the industrial mass production of safe insects and insect products for consumption and for processing into food and feed, the development of rearing, harvest as well as post-harvest technologies is required.

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

Abstract: 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.