My Research: both current and past projects


My fun little project for 2015 which took about a week to complete Blueberry Crop vs. Maple Tree Flowers


I didn't have a title for this experiment (2013), but here are a few photos to start with. Essentially, when you find a cell with two eggs on one mass provision in Osmia lignaria, are both eggs/larvae from the same mother? 


Here's one of my sites with all the open tray system of condos. I have three sites this year, two in the Cowichan district on Vancouver Island, and one here on Saturna Island.

Here's a female working away at her little "block" of cells in a normal situation. She's currently laying down mud in the cell to the right.

In a different tray, this shows a cell with two eggs on the mass provisioning. (April 24)

Here's another angle showing the same cell. (April 24)

More photos to come...




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Does Inclination of Trap Nest Boxes Determine Larval Orientation For Orchard Mason Bee (Osmia lignaria propinqua Cresson) When They Spin Their Cocoon For Metamorphosis?

G.E. Hutchings                                                                                                    2011.November.15

 

Abstract  It has been hypothesized from previous research, that the popular orchard mason bee (Osmia lignaria propinqua Cresson), orients itself as a larva within its brood cell, in the "entrance pointing aft" direction for re-emergence next spring. By "feeling" the insides of the mud cell divisions on the inside walls when the larva has consumed its mass provisioning and ready to manufacturing its cocoon, it has been stated that the larva orients itself in the "proper" direction. I have demonstrated that gravity is more likely a determinant when it comes to bee larval alignment as opposed to the larva "feeling" or sensing the fore and aft position within its cell. I performed this exercise by having the trap nest boxes in three different positions, level, inclined and declined, in relation to the positioning of the trap nest box from a front to back. Three experiment sites were set up in the Capital Regional District of Victoria and I show my results comparing the volume of each orientation and the number of cocoons that were oriented in the opposite direction of the correct way to the outlet of the channel for re-emergence. The application of this information may have implications for agricultural pollination stations when using this particular species of bee for pollination if the entire trap nest box does not have the cocoons extracted at the end of the season for cleaning. If the bees that are pointing in the "wrong" direction proceed in the path that they are pointing and essentially chew their way through their adjacent and preceeding siblings (formally behind them in the queue for emergence), do they re-orient themselves upon commencement of their emergence sensing that they are going the wrong way, or do they have to chew their way through whatever blocks their path?

 

Introduction

 The organism

      The popular Orchard Mason Bee, (Osmia lignaria propinqua Cresson), is gaining much notice in the fruit growing industry as a highly benificial bee to utilise for pollination service. This species of bee takes readily to human-provided domiciles in the way of trap nesting boxes set up near fruit orchards. Much research has gone into investigating the most prefered size of hole and length of channel length for mother bees to select when providing for their offspring, especially when the emphasis is for female progeny as a preference for future agents of pollination. It was determined that the most optimal size of channel is ~8mm and if the size of channel is smaller, there is a higher chance that mother bees, should they select this channel, will oviposit a higher percentage of male progeny (Tepedino & Torchio, 1989). Previous research demonstrated that short length channels are conducive for a higher percentage of males and that 29 cm is the most efficient length if one wants the highest yield of females for subsequent years (Hutchings 2005).  ............

Figure 1. Interior view of trap nest channel showing mother bee provisioning for each offspring bee with a mixture of pollen and nectar. She first establishes each cell size with a marker, then lays down a back wall. Then she conducts foraging trips for both nectar and pollen, returning to the nest and regurgitates nectar, turns around within the channel or reverses out to the entrance, turns around and backs up to the nectar and scrapes off her pollen load from her abdominal venter - scopa, on to the nectar surface. Each subsequent cell is produced stacked adjacent to the previous one and the size of the mass provisioning depends on the sex of the bee which is pre-determined by the cell marker designating whether it be a female (larger bee) or male (smaller bee). The single egg is laid on end atop the mass provisioning. A final vestibular cell is left at the outlet end with a final end cap constructed on the outside of the channel. The larva feeds directly on the mass provisioning and as it grows, moults between each body expansion. The final moult enables the larva to finally develop an anus where it defecates and begins spinning its cocoon where it will diapause over the winter and metamorphosizes into an adult, ready to emerge the following spring.


Figure 2. One site showing the orientation of the trap nest boxes with both inclined and declined angles. Several other trap nest boxes that were in the normal level position, provided the count for the level cocoons. These trap nest boxes were in an adjacent shelter next to, or contained with the inclined/declined boxes at the experiment sites.


Figure 3. Cocoon alignment within the channel of a declined trap nest box showing the cocoon on the right, in the opposite orientation compared to the other cocoons. The "nipple" end of the cocoon, plus the space in front of this part of the cocoon, shows the anterior or head end where the larva finished off spinning its cocoon.


Figure 4. Typical tray pulled out from a trap nest box showing the opposite oriented cocoons (arrows) situated within the other normally oriented cocoons.

Table 1. Final count of cocoons in their respective trap nest boxes of different angles showing the ratio of opposite and normal orientation contained within, for both male (m) and female (f) cocoons.

condo position    total cocoons (viable)    opp. pos. (m)    opp. pos. (f)        total opp. position / %
        level                     586                              27                        6                        33        5.6%
        down                    342                              73                        59                    132        38.6%
        up                        458                                0                        1                          1         0.2%


Figure 5. Substrate sample in the wild showing a tipped over trunk and root base of a coniferous tree where wood boring beetles exit leaving channels that cavity nesting bees utilise. These exit holes can sometimes be in a variety of angles.

Figure 6. An exit hole where a wood boring beetle has exited from the above trunk root base. Although this particular cavity has not been used by a bee.

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An Increase in Female Offspring of the Orchard Mason Bee (Osmia lignaria propinqua Cresson) In Relation To Deeper Channel Length: Manipulating Sex Ratio to Enhance Pollination

 

G.E. Hutchings                                                                              

 

Abstract   Offspring sex ratio in the Orchard Mason Bee, Osmia lignaria propinqua Cresson, by varying the lengths of nesting channels in artificial bee houses, commonly referred to as  condominiums. Three channel lengths were used and cocoons from each were extracted and placed in emergence vials. Each cocoon was measured (length only) and when bees emerged, they were sexed and released. Bees that died in the cocoon were also sexed. Results from three sites support the hypothesis that female cocoons are longer than male cocoons and that female eggs are deposited before males. These observations suggest that it will be possible to increase the number of pollinators (females) in condominiums by increasing the lengths of channels. Potentially these results can be applied to other bee species utilised in pollination as critical habitat is being reduced in many important agricultural areas of the world.

 

 

Keywords   Osmia, Orchard Mason Bee, cocoon size, position in channel, channel length, sex ratio

 

Introduction

 The Organism

      Osmia lignaria propinqua Cresson is distributed throughout Southwestern Canada and Western United States, extending to approximately 100˚W longitude. This bee species along with many other native species, play an integral role in the pollination system in North America. Similar to many parts of the globe, a North American pollination crisis looms due to loss of habitat and altered plant-pollinator interactions critical for crop production (Kremen & Ricketts 2000). O.l. propinqua is a univoltine species and has a protandrous emergence in early spring, triggered by suitable conditions and temperatures of approximately 13˚-15˚C. The sexes are dimorphic with the male being smaller and much shorter lived – the males being one of the first bees to emerge in the spring (Torchio 1989). The male emerges a few days earlier than the females and awaits nearby, sensing the female's emergence by detecting pheromones she elicits (Torchio 1989). The male immediately grasps the emerging female, often forcing copulation at a time when she is least able to fight him off. She may mate more than once during the first day but is ignored by males henceforth as she begins searching for a nest.

      A suitable nest may consist of a large fissure in the bark of a tree, a hollow, hardened stem of a plant, or any orifice of suitable width and depth. Preferred nesting sites are abandoned insect burrows excavated in trees or wood (Torchio & Tepedino 1980). Human-made provisions may consist of cracks in buildings, splits between roof or wall siding, holes where objects have been removed such as a large ...
First year's experiment to find the most efficient length of tray
 
 
Development of nest cell by adult female.
 Cutaway of interior of typical channel
 
 
 
and from the last page:

Discussion

 

 

       Therefore, there is a trend towards more female offspring with a longer channel length tray condominium, size of cocoon per sex is larger for females and females are towards the innermost portions of all condominiums regardless of length whereas males are conversely situated at the outermost portions. These statistical facts are all based upon the channel width for this experiment consistently being 7.0 mm since width can effect provisioning and sex-determination during oviposition. condominium design is important therefore in manipulating sex of offspring, numbers of female versus males, as well as prevention of certain parasitoid wasps. Monodontomerus spp. of wasps are capable of penetrating extremely small openings into inner cell galleries of the Orchard Mason Bee and this is usually done in the latter stages of the flight season of this bee and extends well past this date. Therefore it is critical to have thick enough edges of each tray as well as close fitting tops for prevention of parasitoid activity. With plastic tape along the entire edges of the see-through covers of each tray, this parasitoid wasp is unable to penetrate into the cocoons even after the adult flight season of the Orchad Mason Bee is completed.

and it continues...
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As of May 10, 2011, here's some photos.
Top female has finished her channel and has most likely started the adjacent channel (down). The last 4-6 cells (closest to entrance), are most likely males whilst all the interior ones (12-15 cells) are females. If I had a 4" channel, there most likely would be about 80% males.
 
Certain inclination/declination angles are attractive or not, to egg-laying females.
 
I have various lengths here ranging from 10" to 14". Some of the trays are from inclining condos, and some are from declining condos, just like shingles of a roof or side of building but what about open stems in a natural setting that are pointing upwards to the sky? How do they lay them and what position do the larvae orient themselves upon spinning their cocoons? Which way do they emerge?
It still makes me laugh when I read reference material and some websites saying that the length of condo shouldn't be more than 6"! Did they do any experiments with this? Have most folks just copied what one person said and believe it? At one show, years ago, I even had a lady telling me that my condos wouldn't work, even though I had the photos right in front of her showing previous year's results. She had a retail outlet in Victoria and sold some commercial manufactured condos but obviously wasn't an entomologist.
 
 
 
Recent correspondence on one of my listserves of which I won't put on his name, but the comments are rather fitting:
 
Sent: Tuesday, May 31, 2011 12:11 PM
Subject: Re: Academic publishing: reducing the costs

I read an interesting book this winter on some famous natural history people thru the ages. One of the chapters was on the post-Wallace/Darwin era in England and specifically made a comment about a noteworthy time when the rich or well-connected associated with biology eventally ended up with control of science publishing. Arguably, it stills remains that way today, but hopefully the 'times are a changin' (Bob Dylan had his 70th birthday last week!).
 
Anyone preparing an article for publication in a science journal must be dumbfounded on how much the page charges are for many journals, especially now with widespread online publication. Of course, some authors may not pay that much attention tp page charges if their department is rich or well-connected.
 
Since I personally do not have a university portal to free journal publications, I am mistyfied that the public does not have 100% access to any article by an author employed by a public institition, or anyone at a private research facility (e.g. Harvard U.) funded by public grants. Shouldn't the public own the results of their research, including their publications (the frosting on the cake). How can these authors give away the copyrights to private publishers, work that should belong to everybody? If someone pay their taxes, doesn't it also belong to them? 
 
Hopefully, e.g. ZooKeys and ZooTaxa represent a model for most science journals in the future.
 
Book publications are a significantly different topic since many may not be be 'peer-reviewed' in the traditional sense.
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