In a typical case of protector turning predator, a so-called "inert" chemical used on almonds, wine grapes, and tree fruits to improve the performance of pesticides has been found killing the larvae of honey bees that are vital for pollination.
This was revealed in a new study, conducted by researchers from Penn State and the U.S. Department of Agriculture. it said the chemical has been exposing honey bee larvae vulnerable to a deadly virus.
Chris Mullin, Penn State's entomology professor noted that adjuvants had been in use for improving the toxicities of pesticides. He pointed to the trend of rising use of adjuvants during blooming periods when the bulk of the honey bee colonies is active.
Beekeepers were also complaining about dying or dead brood in hives after pollination of almond. The findings of the study have been published in Scientific Reports.
For the study, the researchers used organosilicone adjuvant, Sylgard 309 to track the former's ill effects on the honey bee larvae.
"In the lab, we found that the commonly used organosilicone adjuvant, Sylgard 309, negatively impacts the health of honey bee larvae by increasing their susceptibility to a common bee pathogen, the Black Queen Cell Virus," said Julia Fine, a graduate student in entomology from Penn State.
She said the results are explicit that the symptoms found in hives after almond pollination are a case of organosilicone adjuvant residues stepping up viral pathogens.
Fine also noted the current classification of organosilicone adjuvants' by the U.S. Environmental Protection Agency as "biologically inert" and that is making the chemical appear as having no reaction to living things.
The researchers drew their key findings after raising honey bee larvae in a lab, under controlled conditions. In the early stages of development, the team exposed the larvae to low dose of Sylgard 309 through the diet. A section of the larvae was also exposed to viral pathogens on day 1 of the experiment.
"We found that bees exposed to the organosilicone adjuvant had higher levels of Black Queen Cell Virus," said Fine.
Damage To Immunity Gene
Noticing the subdued expression of an immunity gene called "18-wheeler" in the larvae treated with the adjuvant and the virus jointly, the researchers concluded that the adjuvant has indeed lowered the immunity of larvae and heightened the risk of virus attack and faster mortality.
"Taken together, these findings suggest that exposure to organosilicone adjuvants negatively influences immunity in honey bee larvae, resulting in enhanced pathogenicity and mortality," said Fine.
Honey Bees In Trouble
Meanwhile, a pamphlet at the Pennsylvania State Beekeepers Association (PSBA) said: "Honey bees are in trouble."
This was shown at the booth of 2017 state farm show and reiterated by its former president as well.
Charlie Vorisek, a former president of the association said $1 million worth of honey bees is brought from the south every spring to replace dead bees. This is to ensure smooth pollination in farms as bees are indispensable for pollination before plants produce fruit.
One-third of food consumed by humans comes from insect-pollinated plants, according to the PSBA and it added that honey bees are responsible for 80 percent of insect pollination.
"You do not need a honey bee for strawberries, but you're going to get more strawberries, and you're going to get bigger strawberries with honey bees," Carns said.