scholarly journals Presence of Pathogen-killed Larvae Influences Nesting Behavior of the Alfalfa Leafcutting Bee (Hymenoptera: Megachilidae)

2021 ◽  
Author(s):  
Ellen G Klinger ◽  
Dennis L Welker ◽  
Rosalind R James
Keyword(s):  
Natural Environment ◽  
Fungal Spores ◽  
Field Studies ◽  
Behavioral Changes ◽  
Nesting Behavior ◽  
Megachile Rotundata ◽  
Fungal Exposure ◽  
Nesting Sites ◽  
Alfalfa Seed ◽  
Nesting Patterns

Abstract The alfalfa leafcutting bee (Megachile rotundata (Fabricius)), a commercial pollinator used for alfalfa seed production, is susceptible to chalkbrood disease via ingested fungal spores. Diseases of insects can elicit behavioral changes in their hosts, but there are no recorded behaviors of alfalfa leafcutting bees in response to this fungal exposure. We conducted field studies to determine whether bees in pathogen-dense environments altered their nesting patterns, specifically if bees exposed to fungal spores produced higher numbers of nest cells and whether the proportions of nest cells that failed as eggs or small larvae (a state known as ‘pollen ball’) were greater. We found that our control bees, nontreated bees which were not exposed to chalkbrood spores other than those in the natural environment, had the highest proportion of pollen ball cells. Bees experimentally exposed to infective spores created the lowest number of nests and the fewest cells. Bees experimentally exposed to heat killed noninfective spores produced the greatest number of nests and cells overall and the greatest number of healthy progeny. We conclude that there are underlying behaviors that are elicited in response to the presence of chalkbrood spores that reduce the proportion of failed nest cells (grooming) and increase retention of bees at nesting sites (delay of bee emergence). Through further study of these behaviors, bee managers can potentially increase the productivity of their bee populations.

EFFECT OF TWO INSECT VIRUSES AND TWO ENTOMOPATHOGENIC FUNGI ON LARVAL AND PUPAL DEVELOPMENT IN THE ALFALFA LEAFCUTTING BEE, MEGACHILE ROTUNDATA (FAB.) (HYMENOPTERA: MEGACHILIDAE)

1990 ◽  
Vol 122 (5) ◽  
pp. 1039-1040 ◽  
Author(s):  
D.W. Goerzen ◽  
M.A. Erlandson ◽  
K.C. Moore
Keyword(s):  
Apis Mellifera ◽  
Insect Pest ◽  
Microbial Control ◽  
Western Canada ◽  
Pest Species ◽  
Megachile Rotundata ◽  
Pupal Development ◽  
Canadian Prairies ◽  
Alfalfa Seed ◽  
Beneficial Insect

The alfalfa leafcutting bee, Megachile rotundata (Fab.), is an important pollinator of alfalfa in western Canada and is widely utilized for alfalfa seed production (Richards 1984). As a beneficial insect, the alfalfa leafcutting bee must be considered, along with the honey bee, Apis mellifera L., as a non-target organism of importance in evaluations of potential microbial control agents for use against major insect pest species on the Canadian prairies.

scholarly journals How Nature Walk Program Affects the Behavior of Children with Learning Disabilities

2020 ◽  
Vol 3 (4) ◽  
Author(s):  
Jocelyn Alberto Floresca ◽  
Keyword(s):  
Learning Disabilities ◽  
Social Relationships ◽  
Natural Environment ◽  
Emotional Behavior ◽  
Behavioral Changes ◽  
Actual State ◽  
Outdoor Activities ◽  
Health And Wellbeing ◽  
State Of Mind

Experience with nature is particularly known to influence a person’s health and wellbeing. This case study identified behavioral changes in children with learning disabilities who underwent the Nature Walk Program. An intervention tool designed to let the participants experience nature activities. The study’s participants have cases of mild autism and down’s syndrome. Undergoing the Nature Walk Program resulted in the increased positive desire to participate in succeeding intervention sessions, improvement in their memory level, and awareness and sensitivity to the natural surroundings. All of these led to positive behavioral changes. Another important factor found in the success of the program as an intervention tool is the facilitators’ knowledge in handling the activities, which helps in the success of this endeavor. The study’s intervention tool hopes to be a model and instrument in affecting participants’ awareness of themselves with the aid of the natural environment through carefully selected outdoor activities. As a conclusion, utilizing the natural environment can also affect emotional behavior, social relationships, and the actual state of mind of children with learning disabilities.

scholarly journals How to organise limited space: Micro-regionalisation of La Digue island (Seychelles)

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Maciej Henryk Jędrusik
Keyword(s):  
Natural Environment ◽  
Field Observation ◽  
Spatial Dynamics ◽  
Field Studies ◽  
Spatial Development ◽  
Social Processes ◽  
Environmental Features ◽  
Limited Space ◽  
Functional Regions ◽  
Individual Features

Abstarct Islands, especially small ones, are commonly studied as microcosms of natural and social processes. In this article, La Digue island (10 km2) in the Seychelles archipelago was treated as such. An attempt was made to analyse the significance of the natural environment for the features of spatial development under conditions of intense globalisation. For this purpose, functional micro-regions were determined, along with their genesis and evolution. Spatial dynamics and individual features of space are presented as chorème (Brunet 1986). The analysis was based on data from a library query and field observation and field studies in July 2018. Twelve functional regions were determined. Analysis of the distribution and evolution of their functions reveals a high dependence on natural environmental features, especially topography, and thus confirms (at the scale in question) a geographical determinism.

ALFALFA PESTS IN SAMARA REGION FOREST-STEPPE

2016 ◽  
Vol 1 (4) ◽  
pp. 28-32
Author(s):  
Перцева ◽  
Elena Pertseva
Keyword(s):  
Field Studies ◽  
Forest Steppe ◽  
Research Station ◽  
Adelphocoris Lineolatus ◽  
Age Related ◽  
The Family ◽  
Different Types ◽  
Alfalfa Seed ◽  
Seed Yields ◽  
Selection Of

The purpose of research is alfalfa yields increasing by crops of different ages in the conditions of forest-steppe of the Samara region. Field studies were carried out in breeding crop rotation of department introduction, selection of feed and oilseeds Volga research station named after P.N. Konstantinov in 2014. Entomofauna alfalfa crops of different varieties and ages were studied mowing butterfly net. More numerous entomofauna was recorded in crops of alfalfa 2011 compared with age-related crops in 2008. Specialized herbivores studied culture were found in the growing season 2014 agrocenoses alfalfa crops – alfalfa tolstonozhka (Bruchophagus roddi Guss), alfalfa semyaed (Tychius flavus), alfalfa weevils (Sitona humeralis Steph.), Alfalfa bug (Adelphocoris lineolatus Goeze), leaf alfalfa weevil larvae (Phytonomus variabilis Hbst.) and larvae of alfalfa bollworm (Heliothis viriplaca Hfn.). Forms relating to herbivores Polyphagous and Oligophagous cereals were also recorded. In addition agrocenoses met: Entomophages predator’s cocktsinellidy (Coccinellidae), different types of spiders (Arachnida) and representatives of the family of grasshoppers (Tettigonioidea). Large foliage of alfalfa plants was recorded under option Population 4. Several smaller foliage of plants observed in crops of alfalfa 2011 compared with planting in 2008. On the 3-year agrocenoses best foliage appeared on variety Guzel which had the lowest figures in the age crops. Alfalfa seed yields mainly depend on the age of the studied agrocenosis culture. Alfalfa crop given harvest seeds in 3.6-4.7 times more than the age-crops in 2008. The highest seed yield was obtained from the varieties of Emerald in 2008 and in 2011.

NUMBER OF INSTARS OF LARVAE OF THE ALFALFA LEAFCUTTER BEE, MEGACHILE ROTUNDATA (F.) (HYMENOPTERA: MEGACHILIDAE)

1987 ◽  
Vol 119 (10) ◽  
pp. 859-865 ◽  
Author(s):  
G.H. Whitfield ◽  
K.W. Richards ◽  
T.M. Kveder
Keyword(s):  
Linear Regression ◽  
Frequency Distribution ◽  
Direct Observation ◽  
Field Studies ◽  
Accurate Method ◽  
Head Capsule ◽  
Physical Injury ◽  
Megachile Rotundata ◽  
Head Capsule Width ◽  
Leafcutter Bee

AbstractThe number of instars of larvae of the alfalfa leafcutter bee, Megachile rotundata (F.), was determined by direct observation, frequency distribution plots, and linear regression of head-capsule measurements. For all three methods, developmental polymorphism was observed; larvae were grouped according to the number of instars. The majority of larvae (77%) had four larval instars and the remainder had five. Mortality of bee larvae, apparently a result of physical injury during measurement of head-capsule width, was high but results were based on data for 259 individuals that completed development to the prepupal (= pharate pupa) stage. Direct observation of larval moults was found to be the only accurate method for determining instar designation but analysis of head-capsule width did describe the number of instars present in a population and provided estimates of head-capsule width for each instar. A morphological key for separation among four instars is presented as a practical alternative for instar determination in field studies.

scholarly journals Impact of soil contamination on the growth and shape of ant nests

2018 ◽  
Vol 5 (7) ◽  
pp. 180267 ◽  
Author(s):  
Jean-Baptiste Leclerc ◽  
Jennifer Pinto Silva ◽  
Claire Detrain
Keyword(s):  
Small Groups ◽  
Fungal Spores ◽  
Key Factors ◽  
Myrmica Rubra ◽  
Ant Colonies ◽  
Immune Priming ◽  
Insect Societies ◽  
Nesting Sites ◽  
High Consistency ◽  
Lethal Doses

As entomopathogens are detrimental to the development or even survival of insect societies, ant colonies should avoid digging into a substrate that is contaminated by fungal spores. Here, we test the hypotheses that Myrmica rubra ant workers (i) detect and avoid fungus-infected substrates and (ii) excavate nest patterns that minimize their exposure to entomopathogenic spores. Small groups of M. rubra workers were allowed to dig their nest in a two-dimensional sand plate of which one half of the substrate contained fungal spores of Metarhizium brunneum , while the other half was spore-free. We found that the overall digging dynamics of M. rubra nests was not altered by the presence of fungus spores. By contrast, the shape of the excavated areas markedly differed: control nests showed rather isotropic patterns, whereas nests that were partially dug into a fungus-contaminated substrate markedly deviated from a circular shape. This demonstrates that the sanitary risks associated with a digging substrate are key factors in nest morphogenesis. We also found that M. rubra colonies were able to discriminate between the two substrates (fungus-infected or not). Furthermore, some colonies unexpectedly showed a high consistency in excavating mainly the infected substrate. This seemingly suboptimal preference for a contaminated soil suggests that non-lethal doses of fungal spores could help ant colonies to trigger ‘immune priming’. The presence of fungi may also indicate favourable ecological conditions, such as humid and humus-rich soil, that ants use as a cue for selecting suitable nesting sites.

scholarly journals Variation in Expression of Reference Genes across Life Stages of a Bee, Megachile rotundata

Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 36
Author(s):  
Junhuan Xu ◽  
Dennis L. Welker ◽  
Rosalind R. James
Keyword(s):  
Honey Bees ◽  
Reference Genes ◽  
Larval Growth ◽  
Environmental Toxins ◽  
Western United States ◽  
Life Stages ◽  
Megachile Rotundata ◽  
Alfalfa Seed ◽  
Transcription Data ◽  
Transcriptomic Studies

The alfalfa leafcutting bee, Megachile rotundata is widely used in the western United States as a pollinator for alfalfa seed production. Unfortunately, immatures experience high mortality in agriculturally managed populations. Quantified gene expression could be used to identify how this bee responds during different life stages to pathogens, environmental toxins, and other stresses, but stably expressed reference genes are needed to normalize transcription data. We evaluated twelve candidate genes for their transcription stability across different life stages, including during and after diapause. RPS18 and RPL8 were the two most stably expressed genes, followed by RPS5 and RPL27A. These genes were also very stable even during and after diapause, while the most variable genes being APN, PMIIM, NPC2, and Cr-PII had increased expression levels during larval growth and were also variable during and after diapause. The four reference genes we identified in M. rotundata may prove useful for transcriptomic studies in other bees as well, such as honey bees.

scholarly journals Photoperiod Effect on Megachile rotundata (Hymenoptera: Megachilidae) Female Regarding Diapause Status of Progeny: The Importance of Data Scrutiny

2020 ◽  
Vol 49 (2) ◽  
pp. 516-527
Author(s):  
Theresa L Pitts-Singer
Keyword(s):  
Regulatory Mechanism ◽  
Adult Emergence ◽  
Field Studies ◽  
Outcome Data ◽  
Western North America ◽  
Megachile Rotundata ◽  
Medicago Sativa L ◽  
Maternal Exposures ◽  
And Control ◽  
Long Photoperiod

Abstract Megachile rotundata F. populations are managed to pollinate alfalfa, Medicago sativa L. (Fabaceae), for seed production in western North America. Some progeny produced in summer by overwintered M. rotundata females enter diapause as prepupae to overwinter and become adults the following year. Other offspring avert diapause to undergo adult emergence in summer. The regulatory mechanism(s) of diapause induction or aversion is unknown; the process apparently involves multiple and integrated factors. This 4-yr study sought to determine effects of the exposure of mother bees to short, long, very long, and natural photoperiods on their production of non-diapausing and diapausing progeny. Just-emerged adult bees from both Utah and Canada sources were exposed to different photoperiods for 3 d in incubators and then released into field enclosures placed over blooming alfalfa. Control bees were those exposed to only outdoor conditions. Reproduction was monitored for each female bee, and offspring diapause outcome was recorded. Progeny outcome data were informative for only two of the four study years. Generally, progeny of Utah mothers exposed to long and very long photoperiods were more likely to be non-diapausers compared to progeny of mothers exposed to short and control photoperiods. Short and long (but not very long) photoperiod maternal exposures increased the likelihood of diapause aversion in Canada progeny. Performing multiyear field studies on geographically distinct populations is imperative for revealing environmental challenges and inconsistent bee performance that can impair analyses and interpretation. Future similar studies are needed to more fully evaluate photoperiod effects on diapause.

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