Photostory: Zombie effect on bee populations prompts thesis study

More than 10,000 honeybees thrive in a manmade hive located behind the Moffett lab on the secluded eighth floor of Hensill Hall. This is one of four hives purchased from beekeepers that are maintained by appointed faculty and students in the biology department at SF State for research purposes.

[/media-credit] More than 10,000 honeybees thrive in a manmade hive located behind the Moffett lab on the secluded eighth floor of Hensill Hall. This is one of four hives purchased from beekeepers that are maintained by appointed faculty and students in the biology department at SF State for research purposes.

As a precaution to feisty bees, Maria José Pastor wears a bee suit while opening one of the hives on the eighth floor of Hensill Hall Tuesday, Dec. 9. The recently recurring rain and dark clouds prevented bees from efficiently leaving the hive to forage, which could have resulted in a ferociously buzzing colony.

[/media-credit] As a precaution to feisty bees, Maria José Pastor wears a bee suit while opening one of the hives on the eighth floor of Hensill Hall Tuesday, Dec. 9. The recently recurring rain and dark clouds prevented bees from efficiently leaving the hive to forage, which could have resulted in a ferociously buzzing colony.

Despite recent efforts, honey bees are experiencing a rapid decline in population caused by the parasitic fly Apocephalus borealis.

The microscopic fly, often referred to as the zombie fly, begins the death sentence of the bee by injecting its eggs into the abdomen of a living bee. The eggs hatch into larvae that feed on the insides of the bee, causing it to lose control of its body.

Maria José Pastor collects dead and living bees with a pair of tweezers by scouring a plastic sheet located at the entrance of a hive on the eighth floor of Hensill Hall Tuesday, Dec. 9. Dead bees are significant specimens because it allows for zombie flies to be hatched in a controlled manner for further research.

[/media-credit] Maria José Pastor collects dead and living bees with a pair of tweezers by scouring a plastic sheet located at the entrance of a hive on the eighth floor of Hensill Hall Tuesday, Dec. 9. Dead bees are significant specimens because it allows for zombie flies to be hatched in a controlled manner for further research.

Maria José Pastor holds open a sample bag containing a live specimen from her collecting process Tuesday, Dec. 9. The bee is kept isolated in the envelope for a few days until its demise and then inspected for the number of pupae that emerged from the infected body.

[/media-credit] Maria José Pastor holds open a sample bag containing a live specimen from her collecting process Tuesday, Dec. 9. The bee is kept isolated in the envelope for a few days until its demise and then inspected for the number of pupae that emerged from the infected body.

Biology major Maria José Pastor is an undergrad at SF State who specializes in apiology, or the study of honey bees. She is assisting graduate student Erika Bueno with her master’s thesis that focuses on the effects of the zombie fly on the circadian rhythms and behavior of honey bees.

Once the bee dies, the larvae crawl out of the bee’s neck, metamorphose to pupae and emerge as flies to repeat the cycle, explains Pastor.

With the magnification of a microscope, Maria José Pastor dissects an infected bee to examine the internal damage produced by the parasitic fly in the Entomology Lab at SF State Wednesday, Dec. 3.

[/media-credit] With the magnification of a microscope, Maria José Pastor dissects an infected bee to examine the internal damage produced by the parasitic fly in the Entomology Lab at SF State Wednesday, Dec. 3.

Maria José Pastor separates a bee’s head from its thorax to determine an approximate age and collect data on the frequency of a fly’s decision to choose a bee based on its level of maturity.

[/media-credit] Maria José Pastor separates a bee’s head from its thorax to determine an approximate age and collect data on the frequency of a fly’s decision to choose a bee based on its level of maturity.

Recent reports of slow declines in bee populations have also been attributed to impaired protein production, changes in agricultural practice, or unpredictable weather. The deterioration, known as colony collapse disorder, or CCD, was said to have affected the bees where the A. borealis parasite was first discovered.

It is routine to find a brain still intact in a bee after its death but Maria José Pastor is astonished when a living larva is found to have completely devoured this bee’s brain.

[/media-credit] It is routine to find a brain still intact in a bee after its death but Maria José Pastor is astonished when a living larva is found to have completely devoured this bee’s brain.

It has been less than a decade since professor John Hafernik recognized A. borealis as a threat to the honeybee society and there are still several hypotheses that scientists are suggesting about the dilemma.

Maria José Pastor records data in the Entomology Lab by placing the bee in an envelope with the date it is collected, the date it is inspected and the number of pupae found. Pastor references the pupae count to monitor population growth of the parasite. Thus far, the most recorded is 13 in a single honeybee.

[/media-credit] Maria José Pastor records data in the Entomology Lab by placing the bee in an envelope with the date it is collected, the date it is inspected and the number of pupae found. Pastor references the pupae count to monitor population growth of the parasite. Thus far, the most recorded is 13 in a single honeybee.

“There are so many unanswered questions and as much as that is a pain and scary, it’s still really interesting. It’s the depth of just —‘What is this?’ ‘What is that?’ ‘Why is this happening?’ — and I think that is what’s most interesting about this project,” said Pastor.

Honeybees provide the earth with much more than just honey and beeswax. They are the essential building blocks in the continuation of agricultural systems around the world.

After the sun sets, Maria José Pastor collects bees that leave their hive to migrate toward overhead lights on the third floor landing of Hensill Hall. It is a sign of parasitic behavior when a honeybee abandons the hive at night because they are diurnal insects.

[/media-credit] After the sun sets, Maria José Pastor collects bees that leave their hive to migrate toward overhead lights on the third floor landing of Hensill Hall. It is a sign of parasitic behavior when a honeybee abandons the hive at night because they are diurnal insects.

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