Rearing Theretra oldenlandiae (Lepidoptera: Sphingidae) Larvae on an Artificial Diet.

The hawk moth Theretra oldenlandiae (Fabricius) is an important insect pest because in the larval stage it feeds on agricultural crops and ornamental plants such as the eddoe and garden balsam. In this study, we established methods for rearing T. oldenlandiae in the laboratory using an artificial diet containing dry powder of a wild grass Cayratia japonica (Thunb.) Gagnep. Several artificial diets were tested with different ratios of a commercial diet, Insecta LFM, and the dry leaf powder, and including different antibiotics, and the composition of the standard diet on which larvae performed best was determined. The standard diet contains 20 g of Insecta LFM, 4 g of leaf powder, 100 ml of water, 75 mg of chloramphenicol, and 200 µl of propionic acid. Larvae reared on the standard diet became larger pupae than those reared on C. japonica leaves. This result suggests that the larvae have growth potential that is masked on C. japonica leaves, and that C. japonica may not be the most suitable host species for T. oldenlandiae larvae in terms of nutrient level.

Investigation of adverse effect of coexisting aminopolycarboxylates on the determination of rare earth elements by ICP-MS after solid phase extraction using an iminodiacetate-based chelating-resin.

When iminodiacetic acid chelating-resin solid phase extraction (SPE) was used for the preconcentration of rare earth elements (REEs) in river water samples around sewage treatment plant (STP), low recovery values for heavy REEs were observed. In order to find out the reason for the low recovery, in the present paper, organic ligands in the STP effluent, which may compete with iminodiacetic acids, were analyzed by GC-NPD. It was found that EDTA was contained in the STP effluent at several-100 nM level and interfered with the adsorption of REEs, especially heavy REEs (present at pM level) on the chelating-resin due to the formation of stable complexes. Therefore, acid treatment was applied to decompose EDTA molecules. As a result of acid treatment with HNO3 and H2O2 at 170 °C for 4 h, all REEs were almost quantitatively recovered from the STP effluent with chelating-resin SPE with good reproducibility. After the acid treatment and subsequent 40-times preconcentration with SPE, all REEs in river water samples were precisely determined by ICP-MS at several-10 to sub pg mL-1 levels.