Effects of Ibuprofen and Caffeine Concentrations on the Common Bed Bug (Cimex lectularius L.) Feeding and Fecundity

Bed bugs are ectoparasites of humans and require a blood meal for their growth and reproduction. Since humans consume Ibuprofen as pain medication and drink coffee (caffeine), bed bugs are likely to acquire these drugs through blood feeding. In this study, we determined the biological effects of Ibuprofen and caffeine on bed bug feeding, fecundity and egg hatch. Five concentrations of Ibuprofen and caffeine were incorporated into reconstituted human blood (RHB). Control treatment had no Ibuprofen or caffeine. Each treatment had six replications. Groups of 20 adult bed bugs (10 males: 10 females)/treatment/replication were pre-weighed, allowed to feed for 45 minutes, and then reweighed. After feeding, bed bugs were transferred into a glass jar equipped with harborage and all the jars were placed in an environmental chamber undisturbed for three 7-day intervals to determine fecundity and nymph emergence. Ibuprofen data showed that the mean mass of the 20 adult bed bugs increased by 0.1074 g (125.65%) in the control but by 0.1336 g (157.30%) at 200 ppm after feeding. After 7 days, 306 and 146 eggs were laid by the 60 female bed bugs fed on 0 and 200 ppm Ibuprofen, respectively. After 2 weeks, 94% eggs hatched with no significant differences amongst treatments. In the caffeine experiments, the bed bug mean mass increases were 0.1219 g (163.90%) in control and 0.0790 g (104.62%) at 50 ppm caffeine. After 7 days, 264 eggs were laid by 60 female bed bugs in control but only 81 eggs were laid at the 50 ppm. Nymph emergence was >80% for all caffeine concentrations after 2 weeks. These results demonstrated that increasing Ibuprofen concentrations had positive effects on mass gain but negative effects on egg laying capacity of bed bugs. Caffeine concentrations had negative effects on bed bug feeding, fecundity and egg hatch.