Selected Biochemical Markers Change after Oral Administration of Pesticide Mixtures in Honey Bees

Abstract

The honey bee is an important pollinator. In the environment, it can be exposed to many harmful factors, such as pesticides. Nowadays, attention is paid to evaluating the potentially harmful effects of these substances. This study aimed to evaluate the effect of worst-case environmental concentrations of pesticide mixtures on honey bee survival and selected physiological markers (the activity of ALT, AST, ALP, and GGTP, and the concentration of albumin, creatinine, urea, and uric acid). Pesticides of three different groups (insecticide—acetamiprid, herbicide—glyphosate, and fungicide—tebuconazole) and their mixtures were resolved in 50% (w/v) sucrose solution and given to bees ad libitum. After 24 h, hemolymph was collected. All mixtures caused higher mortality than single pesticides. Pesticides in mixtures caused disturbances in biochemical markers, and in some cases the interaction between pesticides was synergistic. The mixtures had individual effects on physiology, and the results were sensitive to changes in proportions.

Biochemical Indicators and Mortality in Honey Bee (Apis mellifera) Workers after Oral Exposure to Plant Protection Products and Their Mixtures

“…In the literature, there are no data on the effect of acetamiprid at this dose on the analyzed indicators. At higher concentrations in an acute toxicity test (200,000 ppb), acetamiprid increased AST and ALT activities in the hemolymph [45]. This insecticide (600, 1200, 2400, 6000, and 60,000 ppb) also affected polyphenol oxidase, carboxylesterase, and the detoxification enzyme GST [46].…”

“…Glyphosate can affect honey bees' antioxidant levels and detoxification indicators, depending on the concentration, application method, and age of the bees [9,47]. AST, ALT, ALP, and GGTP activities did not change in the acute toxicity test (20,000,000 ppb) [45]. Using glyphosateadded syrup at concentrations of 0.1 and 1 ppb, Almasri et al observed changes in ALP activity in the intestinal tissue (usually an increase, but these changes were not statistically significant).…”

“…The effect of fungicides, including tebuconazole, on honey bees' biochemical markers has not been well-investigated [18]. In an acute toxicity test (625,000 ppb), tebuconazole increased ALP activity in hemolymph [45].…”

Availability of Using Honeybees as Bioindicators of Pesticide Exposure in the Vicinity of Agricultural Environments in Taiwan

“…Given the fact that the mean concentration of herbicides was much higher than that of fungicides in sick/dead bees (286 ng/g vs. 155 ng/g, Figure 2 ), the sick bees could be mostly attributed to exposure to herbicides. It is also likely that the death and sickness of bees could have been caused by the synergistic effect of mixtures of a variety of pesticides, with 1.74 pesticides detected from a sick/dead bee on average [ 23 , 24 ].…”

“…There have been a number of studies investigating the relationships between bees and pesticides. It was found that insecticides are a lethal threat, whereas herbicides and fungicides could cause a variety of health effects on bees; synergistic effects are even observed when mixtures of various pesticides are applied [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. Other studies demonstrate significant pesticide exposure for bees, indicating the prevalent use of pesticides, even though several bees’ main activity regions are not intended for pesticide use [ 25 , 26 , 27 ].…”