Effects of crude extract fractions of Adenocalymma nodosum (Bignoniaceae) on duration of pupa stage emergence of Tenebrio molitor (Coleoptera: Tenebrionidae) and phytotoxicity on vegetable crops

The search for insecticides from plants is increasing to provide sustainable protection of stored grains. Plants from the Cerrado (Savannah-type) biome of Brazil are potential sources of bioactive substances. The duration of pupa stage was similar among various fractions. The fraction F1, at 0.01% was selective for 1-day-old pupae, but was toxic to 2-days-old pupae. The fraction F2 at 0.1% was toxic to 1- or 2-days- old pupae and completely prevented the emergence of T. molitor adults than fraction F3. The fraction F3, at 0.01% and 0.1% was toxic to 1- and 2-days-old pupae. The crude extract from A. nodosum leaves contained essential oils, carbohydrates, flavonoids and traces of saponinic heterosides. At 0.5 and at 5.0 mg.Kg -1 crude extracts, the germination was maximum in onion ( Allium cepa L. (Alliaceae)) and lowest in lettuce (Lactuca sativa L. (Asteraceae)). The seedlings were tallest in A. cepa . The fraction F3 had potential to control T. molitor in stored grains. The crude extract from leaves of A. nodosum inhibited the germination and growth of test plants.