Osmia Lignaria Research Articles

Olfactory Response of Megachilid Bees, <I>Osmia lignaria</I>, <I>Megachile rotundata</I>, and <I>M. pugnata</I>, to Individual Cues from Old Nest Cavities

The megachilid bees Osmia lignaria Say, Megachile rotundata (F.), and M. pugnata Say were tested for attraction to various components associated with their old nest cavities, or chemical extracts of these components, using a Y-tube olfactory response bioassay. Female bees of these species are known to nest in or near old nest cavities, implying that remnant nest components are important cues for bees looking for nest cavities. Significant results show that female bees were attracted to components that may provide species-specific cues or indicate conspecific nesting activity. Specifically, O. lignaria females showed attraction only to the female cocoon. M. rotundata females were attracted to intact nest cells, the fecal material on the outside of a cocoon, leaf pieces used as nest cell lining, and the extract of leaf pieces. M. pugnata females were attracted to the whole nest cell, the paper straw nesting material with attached cocoon, and feces.

Orchard pollination in Capitol Reef National Park, Utah, USA. Honey bees or native bees?

Capitol Reef National Park in central Utah, USA surrounds 22 managed fruit orchards started over a century ago by Mormon pioneers. Honey bees are imported for pollination, although the area in which the Park is embedded has over 700 species of native bees, many of which are potential orchard pollinators. We stud- ied the visitation of native bees to apple, pear, apricot, and sweet cherry over 2 years. Thirty species of bees visited the Xowers but, except for pear Xowers, most were uncommon compared to honey bees. Evidence that honey bees prevented native bees from foraging on orchard crop Xowers was equivocal: generally, honey bee and native bee visitation rates to the Xowers were not negatively correlated, nor were native bee visitation rates positively correlated with distance of orchards from honey bee hives. Conversely, competition was tentatively suggested by much larger numbers of honey bees than natives on the Xowers of apples, apricots and cherry; and by the large increase of native bees on pears, where honey bee numbers were low. At least one-third of the native bee species visiting the Xowers are potential pollinators, including cavity-nesting species such as Osmia lignaria propinqua, currently managed for small orchard pollination in the US, plus several fossorial spe- cies, including one rosaceous Xower specialist (Andrena milwaukiensis). We suggest

PTINUS SEXPUNCTATUS PANZER (COLEOPTERA: ANOBIIDAE, PTININAE) NEWLY RECORDED IN NORTH AMERICA

ABSTRACT The Palearctic spider beetle, Ptinus sexpunctatus Panzer (Anobiidae: Ptininae), is newly recorded in North America from collections in Nova Scotia, Canada, and Pennsylvania and Utah in the United States. It is also newly recorded in association with the native blue orchard mason bee, Osmia lignaria Say (Hymenoptera: Megachilidae). Its presence on the continent is briefly discussed in the context of mechanisms of introduction of invertebrates to North America.

NOTES ON THE NATIVE BEE POLLINATORS IN NEW YORK APPLE ORCHARDS

We surveyed apple orchards in the Finger Lakes region of New York State. Pollinator guilds included many honey bees and native bee species known to be effective pollinators of apples. Of the 31 native bee species collected, 14 species belong to eight subgenera of Andrena. Cavity-nesting mason bees were represented by a single female blue orchard bee, Osmia lignaria Say. The most numerous bees were mining bees in the genus Andrena. This paper serves as a preliminary look at the native bee pollinators in apple orchards in New York State.

Bee Population Returns and Cherry Yields in an Orchard Pollinated with Osmia lignaria (Hymenoptera: Megachilidae)

During 1998–2003, we used populations of the solitary bee Osmia lignaria Say to pollinate a commercial sweet cherry orchard in northern Utah. Bee densities released each year ranged from 1290 to 1857 females/ha, with approximately twice as many males. Female progeny produced each year were greater than parental populations released, except in 2003, when nesting was poor due to bird predation. Despite poor weather during bloom, and in contrast to most other local producers, the study orchard produced harvestable crops in 1999 (2,964 kg/ha) and 2001 (3,154 kg/ha). In 1998 and 2000, record yields were obtained (10,625 and 12,096 kg/ha, respectively). Including only those years with harvestable crops, average production was 2.2 times higher in 1998–2003 (when O. lignaria populations were used) compared with 1992–1997 (when 10 Apis mellifera hives were used). This is the first study reporting multiyear cherry yields in an orchard pollinated with O. lignaria in North America.

Bee Population Returns and Cherry Yields in an Orchard Pollinated with <I>Osmia lignaria</I> (Hymenoptera: Megachilidae)

During 1998-2003, we used populations of the solitary bee Osmia lignaria Say to pollinate a commercial sweet cherry orchard in northern Utah. Bee densities released each year ranged from 1290 to 1857 females/ha, with approximately twice as many males. Female progeny produced each year were greater than parental populations released, except in 2003, when nesting was poor due to bird predation. Despite poor weather during bloom, and in contrast to most other local producers, the study orchard produced harvestable crops in 1999 (2,964 kg/ha) and 2001 (3,154 kg/ha). In 1998 and 2000, record yields were obtained (10,625 and 12,096 kg/ha, respectively). Including only those years with harvestable crops, average production was 2.2 times higher in 1998-2003 (when O. lignaria populations were used) compared with 1992-1997 (when 10 Apis mellifera hives were used). This is the first study reporting multiyear cherry yields in an orchard pollinated with O. lignaria in North America.

Olfactory cues and nest recognition in the solitary bee Osmia lignaria

Abstract. The use of olfactory cues for nest recognition by the solitary bee Osmia lignaria is studied in a greenhouse environment. Glass tubes are provided as nesting cavities to allow the in‐nest behaviour of bees to be observed. In addition, each glass tube is cut into three sections for experimental manipulation and for subsequent chemical analysis. Nesting females drag their abdomen along the tube before exiting, spiral inside the tube, and sometimes deposit fluid droplets from the tip of the abdomen. For the manipulation, the outer section, the middle section, or both sections are removed and replaced with similar clean glass tube sections, and the behaviour exhibited by test females is recorded upon arrival in front of the nesting site and inside the nesting tubes. The resulting hesitation behaviour displayed by females after treatments appears to indicate the loss of some olfactory cues used for nest recognition inside the entire nest. Chemical analysis of the depositions inside the nesting tube, as well as analysis of the cuticular lipids of the nesting bees, reveals the presence of free fatty acids, hydrocarbons and wax esters.

Effect of Temperature on Osmia lignaria (Hymenoptera: Megachilidae) Prepupa–Adult Development, Survival, and Emergence

Effect of Temperature on Osmia lignaria (Hymenoptera: Megachilidae) Prepupa–Adult Development, Survival, and Emergence

Effect of Temperature on <I>Osmia lignaria</I> (Hymenoptera: Megachilidae) Prepupa–Adult Development, Survival, and Emergence

The solitary bee Osmia lignaria Say continues to be developed as an orchard pollinator in the United States and southern Canada. Female bees are active during the early spring and construct nests consisting of a linear series of unlined cells delimited by mud partitions. Cells are provisioned with a pollen/nectar mass on which an egg is deposited, and nests are sealed with a mud plug. In 1997, we initiated two experiments on the development, mortality, and emergence of O. lignaria at selected laboratory temperature regimes and outdoors. In the first experiment (published previously), we compared temperature treatments for their adequacy in maintaining healthy O. lignaria populations. In a second experiment (reported here), we determined the relationship between rearing temperatures and prepupa-adult development rates as well as emergence time and longevity after wintering and incubation the following spring. We observed important differences in O. lignaria prepupa versus pupa responses to selected temperature treatments. The relationship between temperature and days to pupa was U-shaped, with additional time to transit the prepupa-pupa interval at temperatures above and below 26 degrees C. The negative relationship between temperature and the length of the pupa to adult interval contrasts with the U-shaped thermal response observed for prepupae. Thus, with each increase in thermal heat units over the range of temperature treatments tested, we observed an additional reduction in the pupa-adult interval. Individuals reared at constant 18 degrees C required 2.4 times as many days to transit the pupa-adult interval compared with those at constant 32 degrees C. Our results suggest that there is a need for the development of regionally adapted, latitude-specific breeding populations of this outstanding orchard crop pollinator.

Flower Phenology and Pollen Choice of <I>Osmia lignaria</I> (Hymenoptera: Megachilidae) in Central Virginia

Abstract Interest in native bees as alternative pollinators of agricultural crops has greatly increased in recent years. These bees do not produce honey but are often excellent pollinators, not aggressive, and not subject to a multitude of pest and regulatory problems. Herein we report the results of a 2-yr study of the eastern subspecies of Osmia lignaria Say, a univoltine, early-spring, mason bee. Our objective was to determine pollen choice of a wild population of O. lignaria lignaria Say throughout the period of nest construction and relate this to the phenology of local floral resources. Artificial nesting sites were provided and pollen provisions were sampled from nest cells constructed over a 7-wk period. Pollen was identified and quantified with scanning electron microscopy. Approximately 20 types of pollen were found in bee nest provisions, selected from 80 flowering species. Pollen choice changed over time in accord with flower phenology and pollen availability. Eastern redbud (Cercis canadensis...

Assessing delayed and acute toxicity of five formulated fungicides to Osmia lignaria Say and Apis mellifera

Lors d'etudes sur la pollinisation de vergers commerciaux de cerisiers, nous avons observe d'eventuels effets non intentionnels des pulverisations de fongicides sur Osmia lignaria Say. Les pulverisations consistaient en un melange en cuve de fongicides benomyl, captane, iprodione ou propiconazole avec des adjuvants et des engrais foliaires. Le matin apres les pulverisations, les comportements de retour au nid, de nidification et de butinage des femelles bien etablies ont ete affectes. L'intensite des effets non intentionnels observes a varie en fonction de la nature des melanges et de l'heure du traitement. Nous avons donc estime au laboratoire la toxicite eventuelle par voie orale et par contact de cinq formulations de fongicides (Tab. I) sur O.lignaria et Apis mellifera L. Afin de determiner les effets toxiques retardes, O. lignaria et A. mellifera ont ete exposees a des doses de fongicides uniques mais fortes et leur survie a ete comparee a celle des temoins sur 7j. Pour les produits qui presentaient une toxicite aigue aux fortes doses, on a determine les valeurs de la DL 50 orale et de la DL 50 par contact. Il s'agit, a notre connaissance, du premier test complet de toxicite orale et par contact sur une espece d'Osmia. L'exposition par voie orale et par contact a de fortes doses de benomyl et d'iprodione n'a affecte la survie d'aucune des especes (Tab. II, Figs. 1-4). L'huile de margousier (Melia azadirach ou « neem tree ») fortement concentree n'a pas affecte O. lignaria (Tab. II, Figs. 1-2). Des applications topiques de cette huile ont montre des effets toxiques retardes pour A. mellifera, mais aucun effet toxique aigu n'est apparu (Tab. Il, Fig. 3). Le propiconazole n'a pas ete toxique par contact pour O. lignaria ni pour A. mellifera (Tab. Il, Figs. 1-3), mais l'a ete par voie orale (Tabs. II, III, Figs. 2, 4). Le captane est reste sans effet sur A. mellifera, mais a presente des effets toxiques retardes par contact et par voie orale pour O. lignaria (Tabs. II, III, Figs. 1-5). Comme l'on si attendait, le dimethoate a ete toxique pour les deux especes (Tab. III). Le benomyl ne semble etre toxique pour aucune des deux especes. Etant donnes les effets observes du captane sur les femelles d'O. lignaria, l'utilisation de ce fongicide devrait etre evite lorsque cette espece visite activement la zone a traiter. Le captane peut ne pas affecter l'activite pollinisatrice des adultes d'A. mellifera, on sait neanmoins que le captane et l'iprodione tuent le couvain d'abeilles et reduisent donc la force de la colonie. L'huile de margousier pourrait etre un fongicide compatible avec les abeilles durant la periode de pollinisation, si l'exposition directe est evitee. Pour empecher les abeilles de consommer du nectar contamine par le propiconazole, nous suggerons de ne pas utiliser ce pesticide pendant les miellees. Pour conclure, a l'exception de l'action du captane sur O. lignaria, les produits testes devraient etre non toxiques pour les deux especes d'abeilles et la fonction pollinisatrice ne devrait pas etre affectee tant que l'exposition directe est evitee. Il est pourtant necessaire de poursuivre les recherches sur les effets subletaux et les effets de synergie avec d'autres fongicides et les substances qui sont couramment ajoutees aux melanges de cuve.

Oxygen Consumption During the Life Cycles of the Prepupa-Wintering Bee <I>Megachile rotundata</I> and the Adult-Wintering Bee <I>Osmia lignaria</I> (Hymenoptera: Megachilidae)

We studied the oxygen consumption of two megachilid bees (Hymenoptera: Megachilidae), Megachile rotundata (F.) and Osmia lignaria Say, at selected, biologically relevant intervals throughout their respective life cycles. The U-shaped oxygen consumption curve and the static weights of wintering (nonfeeding) prepupae that we observed during the life cycle of M. rotundata support previous arguments for a winter diapause similar to that observed in other Hymenoptera. For O. lignaria, which overwinters as an adult, we found stepwise increases in oxygen consumption and continuous weight loss throughout the wintering period. However, our observations on adult O. lignaria wintering requirements are consistent with the previously published results for overwintering M. rotundata prepupae and reveal sharply increasing survival rates when wintered for a minimum of 3 mo. We interpret the greatly reduced survival in both M. rotundata and O. lignaria, as an indication that a critical biological process, diapause, is disrupted among individuals wintered for <3 mo. In the continued development of these two species as commercial scale pollinators on an ever-increasing list of target crops, any similarities or contrasts observed between the “summer bee,” M. rotundata, and the “spring bee,” O. lignaria, although of interest from a biological perspective, will probably have important implications in the continued development of sustainable population management protocols.

Pollinating Efficacy of Osmia cornifrons and Osmia lignaria subsp. lignaria (Hymenoptera: Megachilidae) on Three Brassicaceae Species Grown Under Field Cages

Until 1997, honey bees, Apis mellifera L., were used to pollinate Brassicaceae grown in field cages at the North Central Regional Plant Introduction Station (NCRPIS), at Ames, IA. At this time, a solitary bee, Osmia cornifrons (Radoszkowski), was first employed to pollinate the crop in field cages; however, a native bee species, Osmia lignaria subsp. lignaria Say, out-competes O. cornifrons in central Iowa for artificial nesting sites erected for rearing. The purpose of this study was to investigate the efficacy of these two solitary bee species for producing Brassica napus, B. rapa, and Sinapis alba seed in field cages. There was no difference in seed production for the S. alba accession, PI 209022, or the B. rapa accession, PI 278766, between the two species of Osmia. But, the B. rapa accession, PI 392025, and the B. napus accession, PI 469944, produced significantly more seed when pollinated by O. lignaria subsp. lignaria than by O. cornifrons. Because the native bee is easier to rear and maintain, it will be the pollinator of choice for control pollinating collections of Brassicaceae species maintained at NCRPIS. The commercial use of O. lignaria subsp. lignaria or the related subspecies, O. lignaria subsp. propinqua, should be investigated for improving the production of canola and rapeseed.

Effect of Wintering Duration and Temperature on Survival and Emergence Time in Males of the Orchard PollinatorOsmia lignaria(Hymenoptera: Megachilidae)

We measured winter survival, emergence time following incubation at 20°C, and postemergence longevity in males of the orchard pollinator Osmia lignaria Say exposed to 25 artificial wintering treatments differing in duration (30, 90, 150, 210, and 270 d) and temperature (0, 4, 7, 10, and 13°C). For all temperatures, survival was highest at 90 d of wintering. Temperatures ≥10°C were unsuitable for wintering O. lignaria populations even for short periods. At 7°C, bees showed increased mortality, signs of excessive fat body depletion, and decreased longevity when wintered for >150 d. Wintering durations ≥210 d required temperatures ≤4°C for acceptable survival. Time to emerge following incubation at 20°C decreased with increasing wintering duration and wintering temperature. Many bees emerged before incubation when wintered for long periods at the warmest temperatures. Postemergence longevity was highest when bees were wintered at 0°C for 210 d. Managing the activity of O. lignaria to coincide with fruit tree bloom initiation is much more easily accomplished with the use of populations exhibiting short emergence times. Several wintering treatments that resulted in acceptable survival and longevity (150 d at 0, 4 and 7°C, and 210–270 d at 0 and 4°C), produced mean emergence times ≤5 d. Our results can be used to establish appropriate wintering regimes for O. lignaria populations managed to pollinate orchard crops differing in bloom time (from almonds in February to apples in May), and therefore, allowing for shorter or longer wintering durations.

A method to feed individual bees (Hymenoptera: Apiformes) known amounts of pesticides

We devised a simple method (flower) to feed bees individually, and compared it with two other methods commonly used (film and vial). We tested the three methods on two solitary species, Osmia lignaria and Megachile rotundata, and one social species, Apis mellifera, under four different light regimes (natural, artificial, plant growth and darkness). The flower method was the most effective for all three bee species: 90-95% of the bees fed under natural light, 80-95% under artificial light, 75-100% under plant growth light, and 45-70% in darkness. Percent success was 0-50% with the film canister method, and 0-60% with the glass vial method. The flower method may allow more comprehensive future evaluation of pesticide effects on bees. oral toxicity test / individual feeding / Osmia lignaria / Apis mellifera / Megachile rotundata

Consistent mixing of near and distant resources in foraging bouts by the solitary mason bee Osmia lignaria

Female bees are usually confronted with a choice among several flower species that differ in their location and abundance within the community, and in the efficiency with which their pollen and nectar can be harvested. We investigated the effects of distance and flower density of two flower species on pollen collection by providing nest locations for the mason bee Osmia lignaria in natural settings. Distance weakly affected pollen use; on average, bees nesting near a flower species tended to collect more of its pollen than did bees nesting at a greater distance. Flower density did not predictably impact pollen use, and use did not track changes in density during the season. Bees consistently mixed pollen from more distant species, despite substantial added foraging costs, and also mixed when one species was an order of magnitude less abundant than the other. Bees require nectar as well as pollen to feed their offspring, and our preliminary data suggest that the efficiencies of pollen and nectar collection are inversely related between the two flower species, which would favor visitation to both species. Bees appear to collect some pollen from the low-pollen, high-nectar plant while visiting it for nectar. Thus, a nectar-collecting constraint may favor collecting pollen from mixtures of species. Key words: central place foraging, complementary nutrients, nectar, Osmia, pollen, resource abundance, solitary bee, spatial distribution. [Behav Ecol 14:141–149 (2003)]

Use of novel pollen species by specialist and generalist solitary bees (Hymenoptera: Megachilidae)

If trade-offs between flexibility to use a range of host species and efficiency on a limited set underlie the evolution of diet breadth, one resulting prediction is that specialists ought to be more restricted than generalists in their ability to use novel resource species. I used foraging tests and feeding trials to compare the ability of a generalist and a specialist solitary mason bee species to collect and develop on two pollen species that are not normally used in natural populations (novel pollens). Osmia lignaria (Hymenoptera: Megachilidae) is a generalist pollen feeder; O. californica, is more specialized. Adults of the specialist were more limited in use of novel hosts, but only in some contexts. Both bee species refused to collect one novel pollen. The specialist accepted a second novel pollen only when it was presented along with its normal pollen, whereas the generalist collected novel pollen whether presented alone or with normal pollen. Surprisingly, larvae of the specialist were more flexible than were generalists. The specialist grew well on mixtures of normal and novel pollen species, in some cases better than on its normal host alone. Larvae of the generalist grew more poorly on all diets containing novel pollens than on their normal host. Data on these two species of bees suggest that specialization by itself need not reduce flexibility on novel hosts. The findings also provide information about mechanisms of specialization in bees. Similar to some folivores, specific cues of the pollen host and the bee's interpretation of these contribute, along with foraging economics, to pollen choice by adults. The ability of the larvae to cope with specific components of one pollen species need not interfere with its ability to use others.

Management ofOsmia lignaria(Hymenoptera: Megachilidae) Populations for Almond Pollination: Methods to Advance Bee Emergence

The objective of this study was to find one or more rearing methods that would allow us to release Osmia lignaria Say populations from natal nests to pollinate February-flowering almonds, Prunus amygdalus Batsch, in California’s Central Valley. We exposed three phenologically distinct O. lignaria populations (early-, mid-, and late-flying) to different temperature treatments through development and wintering for a total of nine rearing treatments. These treatments combined three approaches to obtain early bee emergence: (1) exposing bees to warmer or fluctuating temperatures, or both, during development; (2) exposing bees to warmer wintering temperatures; and (3) using early-flying bee populations from Central Valley California latitudes. Extended periods of high prewintering temperatures resulted in apparent fat body consumption of prewintering adults and reductions in springtime adult longevity. In general, temperature treatments that promoted rapid immature development, and thus longer wintering periods, resulted in earlier spring emergence patterns of bees well timed with bloom period of almonds. Warmer wintering periods also resulted in earlier emergence. In addition to providing good bee-bloom synchrony, several treatments also yielded vigorous emerging populations, rapid establishment and nesting, and population increases. The potential importance of our results to anticipated increases in the demand for pollination services in California’s Central Valley almonds is discussed.

Development and Emergence of the Orchard PollinatorOsmia lignaria(Hymenoptera: Megachilidae)

Abstract The solitary bee Osmia lignaria Say has been developed as an orchard pollinator in the western United States. Immatures develop through the spring and summer. By late summer, bees become adults and remain in this stage inside their cocoons throughout the winter. In this study, we reared O. lignaria at various temperature regimes in the laboratory and outdoors. Developmental rates increased with temperature: bees reared at 18°C took >120 d to complete development, whereas bees reared at 29°C took half that long. Bees reared outdoors under fluctuating ambient conditions took ≈95 d. At 18°C, some bees were unable to complete prepupal dormancy. Different developmental stages responded differently to the various temperature regimes. Fluctuating temperatures averaging 22°C significantly shortened the dormant prepupal stage, and, as a result, bees developed faster than at the equivalent constant temperatures. Bees that developed faster (29°C and fluctuating temperatures) could be wintered as early as Au...

Exceptional cherry production in an orchard pollinated with blue orchard bees

Poor pollination is a common cause of low fruit set in cherry orchards, and a high population of pollinators is therefore required. Osmia lignaria, the blue orchard bee, has been used successfully in Utah as an alternative to honey bees.