Biotransfer, Bioaccumulation and Effects of Herbivore Dietary Co, Cu, Ni, and Zn on Growth and Development of the Insect Predator Podisus maculiventris (Say)

Abstract

Increased metal availability in the environment can be detrimental for the growth and development of all organisms in a food web. In part, this toxicity is due to biotransfer or bioaccumulation of metals between trophic levels. We evaluated the survival, growth, and development of a generalist Hemipteran predator (Podisus maculiventris) when fed herbivorous prey (Spodoptera exigua) reared on artificial diet amended with Cu, Zn, Ni, and Co. Predator nymphs were fed S. exigua larvae raised on diet amended with sublethal (Minimum Sublethal Concentration or MSC) or lethal (Minimum Lethal Concentration or MLC) concentrations of each metal, as well as control diet. We determined if metals were biotransferred or bioaccumulated from the diet to herbivore and predator, as well as if predator growth or survival was affected by herbivore diet. Podisus maculiventris fed herbivores raised on MLC levels of both Cu and Zn took significantly longer to mature to adults, whereas their overall survival was not affected by prey diet metal concentration for any metal. Adult weights were significantly reduced for predators raised on herbivores reared on diets amended with the MLC of Cu and Zn. Copper and Zn were bioaccumulated from diet to herbivore and from herbivore to predator, whereas Ni was biotransferred (although concentrations decreased as trophic level increased). The pattern for Co was more complex, with biotransfer the main outcome. Our results show that availability of metals in a food web can affect growth and development of a hemipteran predator, and that metals are transferred between trophic levels, with metal-specific biotransfer and bioaccumulation outcomes.

Transfer of heavy metals through terrestrial food webs: a review

“…Boyd and Wall (2001) found similar results suggesting that Ni could be passed from herbivorous to carnivorous insects. A laboratory study by Cheruiyot et al (2013), using caterpillars of Spodoptera exigua (Lepidoptera: Noctuidae) raised on metal-amended artificial diet and then fed to the predator Podisus maculiventris (Hemiptera: Pentatomidae), found that Cu and Zn were bioaccumulated whereas Co and Ni were not. These studies show that metals may be transferred between invertebrates; however, more research should focus on such transfers, as metals may continue to pose a risk to invertebrates by moving through food webs well after point sources of metal pollution have been closed (Babin-Fenske and Anand 2010, 2011).…”

The Role of Heavy Metals in Plant Response to Biotic Stress

“…Boyd and Moar [ 138 ] reported that tissues of the Ni hyperaccumulator S. polygaloides was toxic to S. exigua when plants hyperaccumulated Ni. Cheruiyot et al [ 139 ] used artificial diets to determine lethal and sub lethal concentrations of four metals (Co, Cu, Ni and Zn) to S. exigua . Another experiment explored the toxicity of four metals hyperaccumulated by plants (Cd, Ni, Pb and Zn) and searched if metal combinations might broaden the defensive effectiveness of metals in S. polygaloides [ 127 ].…”

Influence of heavy metal contamination on urban natural enemies and biological control

“…HM exposure can alter natural enemy development time, adult weight, longevity and starvation tolerance. HM contaminated prey or water sources have been revealed to lengthen development time [44][45][46][47][48]. For example, when feeding on hosts contaminated with copper (Cu), Nasonia vitripennis (Hymenoptera: Pteromalidae), exhibited lengthened developmental time and reduced emergence of adult parasitoids from the pupal stage [45].…”