As aphid species rely heavily on the endosymbiont Buchnera species to grow and develop, many aphid populations treated with antibiotics will not survive. However, our treatments did not affect aphid microbial communities when treated with antibiotics and other CECs, which is possibly why there were no discernable effects on the aphid population as a whole. While treatments used in our study have previously been demonstrated to have negative effects for at least two other species of insects, this work suggests that aphids are either not exposed to CECs through their host plant, or their bacterial symbionts are not sensitive to, or depleted enough, to alter their basic biology. Plants treated with antibiotics typically have lower levels of intracellular calcium due to chelation. However, in our study we did not notice any obvious signs of calcium stress , possibly due to the use of a hydroponic solution which contains more than enough metal ions to provide adequate nutrients to the plants, even with some chelating. We did notice an overall decrease in mass for plants treated with antibiotics likely due to a slowed growth rate from direct action of the antibiotics on plant growth. Overall, there were no discernible effects of CECs on the aphids’ populations and or microbes. However, there were reductions in plant growth when treated with antibiotics. This could pose a problem to growers, especially as antibiotics tend to be reapplied with each watering especially with manure from antibiotic-treated animals. These antibiotics could also hinder the growth of the plant’s rhizosphere which would add another problem for growers who rotate crops to reintroduce nitrogen into the soil . More studies will need to be performed to determine how CECs will affect root microbial communities in soil,macetas de plastico 30 litros the roots themselves in soil, and degradation of CECs in soil.Drought, rising temperatures and expanding human populations are increasing water demands. Many countries are extending potable water supplies by irrigating crops with wastewater.

Unfortunately, wastewater contains biologically active, long-lived pharmaceuticals, even after treatment. Run-off from farms and wastewater treatment plant overflows contribute high concentrations of pharmaceuticals to the environment. These pharmaceuticals then can be either directly ingested by insects or translocated through plants and then ingested by insects. I have determined the effects of CECs on four different insects, all with different feeding styles and exposure risk. Culex quinquefasciatus larvae reared in water contaminated with environmentally relevant concentrations of common CECs were affected both directly and indirectly. Acetaminophen alone and a mixture of contaminants were found to increase developmental time of larvae. Susceptibility to Bacillus thuringiensis subsp. israelensis toxin increased in larvae exposed to antibiotics, acetaminophen, or a mixture of PPCPs. Overall there were significant differences in the microbial community of C. quinquefasciatus in treated water. Within control groups, the predominant families of bacterial symbionts change with each larval instar despite consistent diets and rearing conditions, an effect that has been described in older life stages but not in larvae. This trend was also seen in hormone treatments, but not in the antibiotic or the mixture treatments. Richness and evenness were reduced in both antibiotic and mixture treatments, suggesting that antibiotics remove certain bacteria or inhibit them from increasing to proportions seen in the control treatment. Interestingly, the mixture treatments had greater richness and evenness compared to antibiotic alone treatments, possibly due to the other contaminants facilitating growth of different bacteria. Megaselia scalaris larvae reared on artificial diets spiked with contaminants of emerging concern at environmentally relevant concentrations displayed no oviposition preference for treated or untreated diets. Larvae exposed to caffeine in diets showed increased mortality, and larvae fed antibiotics and hormones showed signs of slowed development, especially in females. The normal sex ratio observed in M. scalaris from control diets was affected by exposure to caffeine and the pharmaceutical mixture treatments. There was an overall effect of treatment on the flies’ microbial communities; notably, caffeine-fed insects displayed higher microbial variability.

Trichoplusia ni larvae showed increased developmental time and mortality when reared on artificial diets containing antibiotics, hormones, or a mixture of contaminants. Mortality was also increased when T. ni were reared on tomatoes grown hydroponically with the same concentrations of antibiotics. The antibiotic-treated plants translocated ciprofloxacin through their tissues to roots, shoots, and leaves. Microbial communities of T. ni changed substantially between developmental stages and when exposed to CECs in their diets. Myzus persicae reared on bell peppers treated with CECs displayed no effects in population growth over nearly three generations and no effects on the aphids’ microbial communities. The M. persicae retained their proportionately largest family Enterobacteriaceae across all life stages and across all treatment groups. Interestingly, the greatest effect was noticed in the bell peppers themselves, which had decreased root and leaf growth in treatments containing antibiotics. Overall, our findings indicate that at environmentally relevant concentrations, CECs in reclaimed water can have biologically important effects on important insects. They also, illuminate the complexity of the effects CECs can have on insects with different feeding methods. While the research reported in this dissertation suggests that CECs in reclaimed water could have positive effects on certain pests , they could have unintended negative effects on other insects and how humans interact with them. Effects described here have substantial potential consequences for forensics and IPM strategies. The results show increased developmental time and mortality in insects would alter biological time-clocks for forensic entomology and for dosage practices for IPM . Determining whether or not these PPCPs could influence pathogen transmission in insect-plant interactions is also of concern. Because many of the insects studied here are lower trophic level organisms, the potential for bio-magnification or unexpected chemical modification as CECs move through the food webs are serious concerns. There is also the possibility of pharmaceuticals affecting the rhizosphere of plants in soil and influencing plant health, but more research is still needed to determine precise effects.Soybean is an important biotech food, vegetable, and field crop that provides oil , protein , and carbohydrate to millions of people worldwide. Furthermore, soybean is a promising sustainable source of bio-fuels in North America, South America, and Europe . Zinc deficiency has been recognized globally as a major micro-nutrient stress that lowers crop yield and productivity around the world . Zn deficient soils occur in nearly 30% of the world’s arable lands. Selection and breeding of plant genotypes for Zn efficiency , defined as the ability of plants to maintain reasonable yield under Zn deficiency, is considered a sustainable approach to increase plant production on low Zn soils .

Considerable differences in response to low Zn stress are known to exist among genotypes of bread wheat , rye, triticale , rice, tomato , and common bean . Variations in shoot or leaf based parameters together with higher internal Zn utilization can be the principal factors in differential ZE in crop plants . Preliminary studies in common bean indicated that leaf physiological parameters such as leaf area are a useful criteria for ZE screening . Currently, there is little information regarding response of stomatal conductance to low Zn stress. Many earlier studies of low Zn stress focused on economically important cereal species. Few studies have been conducted in soybean,cultivo hidroponico and fewer have tested hydroponics as a growing media. It has been shown that critical Zn deficiency level for soybean leaves was 15 µg g-1 . In a field study in Central Turkey, Zn deficient calcareous soils were shown to reduce yield and cause the development of visual symptoms on young leaves of soybean plants . Many soybean genotypes are being developed in the U.S. but little is known about their reaction to low Zn stress. Therefore, the objectives of this study were to: develop a suitable hydroponics-based method for ZE screening of soybean plants to identify more Zn efficient and less Zn efficient genotypes; and detect genotypic ZE variation in soybean using physiological parameters such as leaf area, chlorophyll contents, stomatal conductance, nutrient concentration, and plant biomass. Available Zn concentrations around 1 to 2 pM has already been shown to induce Zn deficiency in bread wheat and common beans . Accordingly, our experiments successfully induced Zn deficiency at this concentration level in hydroponics. Based on our results, it appears that hydroponics with chelate buffers is feasible for screening soybean ZE trait. The soybean genotypes tested in this study had considerable variability and physiological responses to low Zn stress in hydroponics. Total leaf area, chlorophyll content, and leaf Zn concentration levels were all high in MZE genotypes. At the same time LZE soybean genotypes had various visible symptoms which indicated unfavorable Zn levels. This is consistent with previous findings that soybean plants showed chlorosis and brown leaf patches in calcareous soils . In terms of overall assessment genotypes “Williams” and “Hampton” were the most Zn efficient and inefficient, respectively . Although chlorosis is the most prominent symptom of low Zn stress, there is limited info on the effect of Zn deficiency on chlorophyll content levels. Leaf chlorophyll content was greater for MZE genotypes such as “Williams” and “Pella86” compared with LZE genotypes. Our results suggest that increased chlorosis was the cause of reduced SPAD levels. This is in agreement with the previous findings on wheat and common beans .It is interesting to note that Fe concentrations were considerably high for some genotypes such as “Thomas” . The lack of correlation with ZE trait across the genotypes tested may indicate that stomatal conductance could not be used for early detection of Zn stress in soybean.

Significant differences between soybean genotypes in shoot Zn and N concentration were observed in low-Zn grown plants in hydroponics. Although there was no significant correlation between shoot nutrient concentration and ZE trait, LZE genotypes were characterized by slightly lower concentration of Zn, Fe, and N . This data are in agreement with previous findings showing that Zn efficient wheat varieties transported more Zn from roots to shoots than Zn inefficient varieties under Zn deficiency in the early field growth stages in bread wheat . Pharmaceuticals have been increasingly prescribed for the past 30 y, and prescription rates have almost tripled in just the past 14 y . In 2013, animals grown for human consumption were treated with 9.1 × 106 kg of antibiotics; of those, 6.6 × 106 kg were used for the purpose of increasing production . Many antibiotics and other common contaminants of emerging concern  can be excreted by both humans and animals with little change in their chemical structure . Not surprisingly, pharmaceuticals have been appearing in wastewater, surface waters, and in some cases tap water, over the past few years . Standard wastewater treatment facilities are not equipped to completely remove pharmaceuticals , resulting in these compounds being found in effluent. In addition, even higher concentrations of many pharmaceuticals are released during heavy storms in the untreated wastewater overflow, which then directly contaminate the environment . These pharmaceuticals have been found at biologically active concentrations in surface waters around the world . There is also an increasing effort to use reclaimed wastewater in drought-affected areas, such as Southern California . In agriculture/livestock operations, pharmaceuticals are found in manure that is used as fertilizer, effectively compounding the pharmaceutical concentrations . Current research shows these chemicals tend to be both pseudopersistent in soil and detrimental to soil and rhizosphere microbes . Our recent studies of the effects of pharmaceuticals on aquatic insects show that, at concentrations found in reclaimed water, these CECs can alter development of the mosquito Culex quinquefasciatus, its susceptibility to a common larvicide, and its larval microbial communities . Watts et al. showed 17α- ethinylestradiol, a common birth control agent, and Bisphenol-A, a common plasticizer, can cause deformities in the midge Chironomus riparius. However, because larval forms of aquatic insects develop directly in the contaminated water, their constant exposure is likely greater than most terrestrial insects. Interestingly, many CECs, which were not designed specifically to impact microbes, have been shown to affect microbial communities. For example, caffeine, a common mental stimulant, can alter biofilm respiration, and diphenhydramine, an antihistamine, has been shown to modify the microbial community of lake biofilms .