Since it was first formally recorded there in 2005, the Nearctic pine tortoise scale Toumeyella parvicornis (Cockerell) (Hemiptera: Coccidae) has caused severe decline of the Caribbean pine, Pinus caribaea var. bahamensis (Grisebach) W. H. Barrett & Golfari, in the pine forests on the Turks and Caicos Islands (TCI). The scale infestations reduce host vigor, cause dieback and high levels of mortality. Honeydew excreted by the insects enables the growth of associated sooty molds to smother the under-storey plants inhibiting their growth. Surveys carried out on the islands suggest that the entire Caribbean pine population in the TCI is under immediate threat from this invasive pest, with potentially devastating effects on the pineyard ecosystem. The biology, distribution, impact and economic importance of the pine tortoise scale are reviewed.

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The diversity of synthetic pesticides has been reduced through regulation especially in the European Union leading to a resurgence of interest in natural plant products for pest control. Here we investigated two Asteraceae species, Tithonia diversifolia and Vernonia amygdalina that are used by farmers in Africa in bio rational pest control to determine the chemical basis of activity against pests of stored legumes and identify plant compounds with commercial potential. The cowpea beetle, Callosobruchus maculatus, an ubiquitous pest of African stored grain legumes, was exposed to extracts of both plant species at 10, 1 and 0.1% w/v and fractions of these extracts at representative concentrations. Extracts and fractions were toxic to recently emerged adults, but did not reduce oviposition by those females that survived. The sesquiterpene, Tagitinin A, was isolated from one of the active fractions and identified using H1 and C13-NMR and shown also be toxic to C. maculatus and so partially explains the activity of the whole plant. Other compounds in the active fractions were identified, at least to structural class, using high resolution mass spectroscopy (HRESI-MS). Sequiterpenes and flavones were common to fractions from both plants. Stigmostane steroidal saponins were the most abundant secondary metabolites in V. amygdalina.

Abstract. Larvae of Phormia regina (Meigen) (Diptera: Calliphoridae) were reared, in isolation, upon either lamb's liver or meridic diets that varied in protein-and carbohydrate-content. An artificial diet containing 53% protein (by mass of dry ingredients) resulted in the heaviest P. regina pupae and shortest development time when compared with larvae reared upon lamb's liver and all other diets. In diets where the concentration of protein was less than that of carbohydrate, the level of carbohydrate became important. In a diet containing 22.6% protein it was neither the diet with the highest (51%) nor lowest (17%) concentration of carbohydrate that adversely affected development. Specifically, an intermediate level of carbohydrate (33.9%) resulted in an extended larval period, together with increased mortality and reduced pupal weights. Larvae reared in groups of 10 on either liver or a diet containing 53% protein were heavier than those reared in isolation. Group-rearing hastened development on liver, but not on the meridic diet. The results are discussed in relation to the nutritional ecology of saprophagous calliphorids.

Abstract-A methanol extract of the pod surfaces of Cajanus cajan, a feeding stimulant for fifth-instar Helicoverpa armigera, was shown to contain four main phenolic compounds. Three of these were identified as isoquercitrin, quercetin, and quercetin-3-methyl ether, by comparing UV spectra and HPLC retention times with authentic standards. The fourth compound was isolated by semipreparative HPLC and determined to be 3-hydroxy-4-prenyl-5-methoxystilbene-2-carboxylic acid (stilbene) by NMR spectroscopy and mass spectrometry. Quercetin, isoquercitrin, and quercetin-3-methyl did not affect the selection-behavior of fifth-instar H. armigera. However, larvae were deterred from feeding on glass-fiber disks impregnated with the stilbene. Furthermore, larvae exposed to quercetin-3-methyl ether consumed significant amounts of both disks. In a binary-choice bioassay, a combination of quercetin-3-methyl ether and the stilbene on one disk and pure quercetin-3-methyl ether on the other disk resulted in increased consumption of both glass-fiber disks by larvae. In contrast, consumption was reduced if the combination was presented to larvae on one disk with purified stilbene on the other disk. Cajanus cajan cultivars that varied in their susceptibility to H. armigera were surveyed for the presence of the four phenolic compounds. An absence of quercetin and higher concentrations of isoquercitrin than the cultivated variety characterized pod surface extracts of pod-borer-resistant cultivars. In addition, the ratio of the stilbene to quercetin-3-methyl ether was greater in the pod-borer-resistant cultivars. These findings * To whom correspondence should be addressed. E-mail. p.stevenson@kew.org

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Two novel epimeric compounds, viminadione A (1) and viminadione B (2), have been isolated by bioassay-guided fractionation of the aerial parts of Callistemon viminalis and their structures (including relative stereochemistry at C-7, C-8, and C-9) elucidated by spectroscopic methods. Viminadione A (1) exhibits moderate insecticidal activity in comparison with natural pyrethrum extract. Viminadione B (2) is less active.