Observations on the Association between Some Buprestid and Cerambycid Beetles and Black Frankincense Resin Inducement

Samburu resin harvesters in northern Kenya maintain that frankincense resin flow from Boswellia neglecta and Commiphora confusa is induced by insect larval activity. Observations on the insects’ larval behaviour support these claims. During the frankincense harvest, buprestid beetle larvae, identified as a Sphenoptera species, are found under B. neglecta resin, eating the monoterpene-rich inner bark, which apparently stimulates the trees to produce copious amounts of fresh resin. The same behaviour was observed with cerambycid beetle larvae, identified as Neoplocaederus benningseni Kolbe, on C. confusa trees. Remarkably, these insects have developed the capacity to digest the resin-saturated inner bark and overcome the toxic, repellent characteristics of oleo-monoterpenes. The frankincense resin also appears to act as a protective covering during the insects’ larval and pupal stages. Excessive tree damage was not noted from these insect invasions. Even though the tree species are from different genera, the resin produced by both is black, with a very similar aromatic chemical profile. The question thus arises as to whether the larval feeding behaviour of these beetle species has an influence, not only on the physical appearance but also on the chemical composition of the resins.

Valorization of waste bark for biorefineries: chemical characterization of Eucalyptus camaldulensis inner and outer barks

Bark wastes today are viewed as a high-value resource for biorefinery due to their chemical richness and diversity. This work presents a comprehensive chemical characterization of the inner bark and the outer bark of Eucalyptus camaldulensis cultivated in Algeria. The extractives were first isolated with an Accelerated Solvent Extractor (ASE) and then analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). The content of pre-extracted bark in cellulosic polysaccharide and free sugar monomers was determined by Gas Chromatography (GC). The hemicellulose composition and amount was determined after the acid methanolysis and GC. The amount of lignin was determined gravimetrically by the Klason lignin method and the acid soluble lignin was determined by the UV method. Formic and acetic acids in the bark were determined by HPLC after alkaline hydrolysis. It was found that the extractives content were similar in the outer bark (0.85%) and the inner bark (0.88%). The cellulose content was higher in the outer bark (33.4%) than in the inner bark (28.7%). Lignin and the total hemicellulose contents were more abundant in the outer bark (31.7, 26.2%) than in the inner bark (28.6, 19.3%) whereas, sugar monomers were more abundant in the inner bark (4.4%) than in the outer bark (3.8%). The variation in acetic and formic acids and ash contents between the outer bark (1.5, 0.006 and 2.5%) and the inner bark (1.3, 0.005 and 2.4%) was small. The obtained results showed that the bark can be considered a suitable feedstock for lignocellulosic biorefinery and also for the extraction of bioactive compounds that can be used in different sectors.

Pharmacognostic, Phytochemical, Physico-chemical Standardization of Casuarina equisetifolia Stem-Inner bark

Over three thousand years in India, the Ayurvedic system of medicine has been in use. The phytomedicine, which is modernized method of formulating different kinds of herbal medicines, has yielded a new herbal product as well as new system of herbal medicine. The plant Casuarina equisetifolia is evergreen tree; belongs to family Casuarinaceae generally, attain height up to 50 m, introduced into India. The presence of different chemical constituents responsible for pharmacological activity such as analgesic, anti-inflammatory, Anti-histaminic, Wound healing. This research article highlighted Pharmacognostic account as well as physico-chemical evaluation, which shows how it will effective in the treatment of disease and disorder using herbal medicine. In addition to that, the Stem-inner bark of Casuarina equisetifolia is phytochemically evaluated using three different extract of Casuarina equisetifolia such as Methanol, Ethanol and Aqueous extract to show which secondary metabolites are present and result is that Methanol extract shows maximum Phenol, Tannin, flavonoid and Terpenoid content followed by Ethanol extract and then aqueous extract so that one can conclude stem-inner bark of Casuarina equisetifolia responsible for different pharmacological activity.

High recovery of stilbene glucosides by acetone extraction of fresh inner bark of Norway spruce

Stilbenes are plant polyphenols that have shown beneficial pharmacological activities in a variety of diseases. The considerable amount of stilbene glucosides in spruce inner bark encouraged us to develop a straightforward and simple method of extraction with high recovery and yield. Stilbene glucosides from fresh inner bark of Norway spruce were extracted in one simple step with acetone at 20 °C. After three weeks of soaking in acetone, the extracts were dried and the composition was determined by GC-FID using a short and a long column (HP-5) and GC-MS (HP-1). The amount of the extracted compounds was also compared with a similar extract from air dried inner bark samples. The extracts from the fresh sample contained 30–50% of stilbene glucosides and the average yield [0.185 g extract/g bark] was as good as or slightly better than in previously reported works. However, no drying, milling, or sequential extractions with different solvents in elevated temperatures were needed. Moreover, this study revealed that the drying process can decrease the amount of extractable stilbenes significantly. Therefore, this method can be considered as an alternative for preparative isolation of stilbene glucosides, especially isorhapontin and astringin from inner bark of Norway spruce.

Stored water in the inner bark and sapwood: Atypical patterns of daily discharge and recharge, radial osmotic gradient and freezing resistance

Stored water in inner tissues can affect plant water balance and its freezing resistance. We studied the water storages in the inner bark and sapwood of Araucaria araucana, a species with thick inner bark. Specifically, we analyzed its daily behavior, the driving force to radial water movement and its freezing resistance. The whole-stem water content and diameter and sap flow increased in the morning and decreased in the afternoon. An osmotic gradient between stem tissues was involved in the morning water storage recharge. There were no lags in the onset of sap flow between different stem positions, however sap flow at 6m height was higher than basal sap flow in the afternoon, at the time that sapwood water content started to decline followed by the inner bark. Extracellular freezing was delayed down to -6˚C in the inner bark and to -8˚C in the leaves. The unusual diurnal pattern of internal water use may enhance freezing resistance as a consequence of the lower water content and higher osmotic potential when the lowest temperatures occur. The contribution of stem tissues to daily water use and the pattern of ice nucleation observed make this species less susceptible to drought and very low temperatures.

Biological Strategies of Invasive Bark Beetles and Borers Species

The present study attempts to identify the biological characteristics of invasive (high-impact in the secondary area) bark beetles and borers species, contributing to their success in an invaded area. We selected 42 species based on the CABI website data on invasive species and information on the most studied regional faunas. Four groups of species with different invasion strategies were identified based on the cluster and factor analysis. The first one (inbred strategy) is characterized by flightless males, xylomycetophagy, low fecundity (~50 eggs), inbreeding, polyvoltinism, and polyphagy. Species with an aggressive strategy are poly- or monovoltine, feeds on a limited number of hosts, larval feeding on the inner bark, are often associated with phytopathogens, and produce aggregation pheromones. Representatives of the polyphagous strategy have a wide range of hosts, high fecundity (~150 eggs), larval feeding on wood, and their life cycle is at least a year long. For the intermediate strategy, the typical life cycle is from a year or less, medium fecundity, feed on inner bark tissues, mono- or oligophagy. Comparison with low-impact alien species showed that the most significant traits from the viewpoint of the potential danger of native plant species are high fecundity, polyvoltinism, presence of symbiotic plant pathogens, long-range or aggregation pheromones.

Geosmithia morbida (thousand cankers disease).

Thousand Cankers Disease is a disease complex native to the western United States that affects many Juglans and Pterocarya species, i.e. walnut and wingnut trees. It is caused by the fungus Geosmithia morbida, which is vectored by the walnut twig beetle (Pityophthorus juglandis), and possibly by other insects. The beetle carries fungal spores that are introduced into the tree during gallery construction, and the fungus then causes cankers in the inner bark that disrupt the flow of nutrients throughout the tree, often leading to its death. In recent years the disease has been reported in several eastern states, and also in Italy. Long-distance spread is thought to be a result of the movement of infected and infested wood.