Effects of boron on feeding, survival and immature development of the Tomato Leafminer, Tuta absoluta

The tomato leaf miner Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a significant pest of tomato originating from South America. It has high reproductive capacity on tomato, while it also occurs on other plants of the Solanaceous family (aubergine, potato, weed species e.g. Solanum nigrum). It can cause up to 100% yield loss and its presence may have serious consequences for trade (export), being a quarantine pest. Current management of this pest includes extensive use of chemical insecticides. In other pest management systems, organic alternatives such as boron (boric acid) have been used as environmentally safe products for pest control. Previous studies have found that boric acid has a delayed action in insects, possibly through disruption of water regulation in the insect. The scope of the present study was to determine any negative effects of boron on the immature development, survival and fitness of the tomato leafminer. In greenhouse experiments, adult T. absoluta, from a colony reared on tomato plants, were caged on tomato plants treated with two levels of soluble boric acid (300 and 600ppm), as well as on untreated control tomato plants. Adults were then removed and the emerged larvae were checking daily for ecdysis and survivorship. Pairs of emerged adults were re-caged on different plants of the same treatment and the total number of eggs laid was counted daily to determine fecundity rate. Results and discussion will be presented and discussed.