Bioactivity of Piper hispidinervum (Piperales: Piperaceae) and Syzygium aromaticum (Myrtales: Myrtaceae) oils, with or without formulated Bta on the biology and immunology of Spodoptera frugiperda (Lepidoptera: Noctuidae).

The combination of essential oils and Bacillus thuringiensis Berliner may represent an interesting control strategy. Thus, the study tested the following hypothesis: the combination of long pepper oil (Piper hispidinervum L.) and clove (Syzygium aromaticum L.) oils in two concentrations with Xentari WG (Bta) yields a more effective control of Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae) affecting biological and reproductive parameters and leading to changes in the levels of phenoloxidase and nitric oxide in the hemolymph of the pest. The results demonstrate that only long pepper oil, at the highest concentration with Xentari WG (Bta), promotes reduced larval survival. However, both oils with or without the insecticide interfere in the biology and humoral immunity of S.frugiperda. All treatments caused a decrease in the amount of eggs, except for the clove oil at both concentrations without Bta. Therefore, the use of these oils is a promising alternative for the integrated management of S. frugiperda; however, its association with Bta demonstrated no significant increase in their efficiency.

Effects of Piper hispidinervum on spermatogenesis and histochemistry of ovarioles of Spodoptera frugiperda.

The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), not only damages crops, but controlling its population also requires synthetic insecticides, which leads to selection of resistant populations and environmental contamination. Essential oils are an alternative for controlling this insect. There are few studies of the effects of these oils on the insect's reproductive system. We evaluated the effects of the long pepper, Piper hispidinervum, essential oil on the gonads of the armyworm and tested its possible influence on the fertility of this insect. Dosages of 30 and 50 mg/ml were tested in 3(rd) instar caterpillars using the leaf immersion method. Testes and ovarioles were collected, fixed with 10% formalin and embedded in Historesin. The sections were stained with toluidine blue and Mallory trichrome to detect connective tissue, periodic acid-Schiff to detect neutral carbohydrates, and bromophenol blue to detect proteins. We found that the long pepper essential oil affected negatively the spermatogenesis and altered the histochemistry of the ovarioles of S. frugiperda. The effects of long pepper oil suggest that it is a promising tool for controlling the armyworm pest.

Role of cysteine endopeptidases (EC 3.4.22) in rabbit meat tenderisation and some related changes.

The role of endogenous cysteine endopeptidases (EC 3.4.22; calpains and cathepsins B, L and H) in rabbit (Oryctolagus cuniculus L.) meat tenderisation and some related changes (formation of the 30 kDa fragment and myofibrillar structure weakening), during ageing (9 days at +4°C), was studied for different types of muscle (I, IIB and IID). The results strongly suggest that cysteine peptidases, possibly calpains, play a major role in rabbit meat tenderisation, myofibrillar structure weakening and formation of the 30 kDa fragment in type II muscles. Cathepsins B, L and H appear to have no role in these changes during rabbit meat ageing. The results also indicate that myofibrillar fragmentation and the contents of the 30 kDa fragment are good ageing indices for rabbit meat. Finally, it is suggested that the weakening of the myofibrillar structure, unlike the formation of the 30 kDa fragment, might be directly involved in rabbit meat tenderisation.