Selection Forces Driving Herding of Herbivorous Insect Larvae

Herding behavior is widespread among herbivorous insect larvae across several orders. These larval societies represent one of several different forms of insect sociality that have historically received less attention than the well-known eusocial model but are showing us that social diversity in insects is broader than originally imagined. These alternative forms of sociality often focus attention on the ecology, rather than the genetics, of sociality. Indeed, mutually beneficial cooperation among individuals is increasingly recognized as important relative to relatedness in the evolution of sociality, and I will explore its role in larval insect herds. Larval herds vary in in the complexity of their social behavior but what they have in common includes exhibiting specialized social behaviors that are ineffective in isolated individuals but mutually beneficial in groups. They hence constitute cooperation with direct advantages that doesn’t require kinship between cooperators to be adaptive. Examples include: trail following, head-to-tail processions and other behaviors that keep groups together, huddling tightly to bask, synchronized biting and edge-feeding to overwhelm plant defenses, silk production for shelter building or covering plant trichomes and collective defensive behaviors like head-swaying. Various selective advantages to group living have been suggested and I propose that different benefits are at play in different taxa where herding has evolved independently. Proposed benefits include those relative to selection pressure from abiotic factors (e.g., thermoregulation), to bottom-up pressures from plants or to top-down pressures from natural enemies. The adaptive value of herding cooperation must be understood in the context of the organism’s niche and suite of traits. I propose several such suites in herbivorous larvae that occupy different niches. First, some herds aggregate to thermoregulate collectively, particularly in early spring feeders of the temperate zone. Second, other species aggregate to overwhelm host plant defenses, frequently observed in tropical species. Third, species that feed on toxic plants can aggregate to enhance the warning signal produced by aposematic coloration or stereotyped defensive behaviors. Finally, the combination of traits including gregariousness, conspicuous behavior and warning signals can be favored by a synergy between bottom-up and top-down selective forces. When larvae on toxic plants aggregate to overcome plant defenses, this grouping makes them conspicuous to predators and favors warning signals. I thus conclude that a single explanation is not sufficient for the broad range of herding behaviors that occurs in phylogenetically diverse insect larvae in different environments.

A brief overview of acute poisoning in sheep

Acute poisoning in sheep can occur following ingestion of toxic plants, including plants that they may eat normally such as ivy (Hedera spp.) and plants they avoid unless other forage is unavailable. Poisoning with plants containing grayanotoxins (Pieris and Rhododendron spp.) is very common in sheep, particularly when the weather is poor and they are hungry. Oak (Quercus spp.) poisoning is also relatively common in sheep, particular in years with a heavy acorn crop. Numerous plants contain cardiac glycosides and are a potential risk to sheep. Sudden death is frequently the first signs of plant toxicosis in livestock. Bites from adders (Vipera berus berus) may also occur in sheep but are likely to be underreported as the actual biting event is not witnessed. Envenomation may result in swelling and haematological, renal, hepatic and cardiac effects. Overdosage of drugs with a narrow therapeutic index may also be a risk. One such example is closantel which can result in blindness. Management of acute poisoning in sheep is supportive including removal from exposure, and providing analgesia, rehydration and potentially a rumenotomy for plant exposure in valuable animals.

Impact of Shodhana on Semecarpus anacardium Nuts

Semecarpus anacardium is classified in Ayurveda under the category of toxic plants. However, this toxic plant is reported to possess anti-inflammatory activity, anti-arthritic effect, antioxidant activity, antimicrobial activity, anti- carcinogenic activity, hypoglycemic activity, cardioprotective, hepatoprotective, neuroprotective, and hypolipidemic activity etc. All these activities are attributed to its various constituents like phenolic compounds, flavonoids, carbohydrates, alkaloids, steroids, etc. In Ayurveda, a series of pharmaceutical procedures which converts a poisonous drug into a safe and therapeutically effective medicine is termed as Shodhana. Shodhana improves the yield, decreases the phenolic and flavonoid content; and converts toxic urushiol into nontoxic anacardol derivative thereby reducing toxicity of nuts of Semecarpus anacardium. There are reports of alteration in pharmacology and phytochemistry of nuts of Semecarpus anacardium due to Shodhana.

Gross Anatomical Study of Congenital Meningoencephalocoele and Craniofacial Deformities in A Kid

Background: Occurrence of congenital anomalies are less common in small ruminants, especially in goats compared to sheep. Most common cause for the congenital deformities in new born ruminants is due to the ingestion of toxic plants during gestation. Congenital meningoencephalocoele with associated craniofacial deformities is a rare occurrence in goats. Materials: A day old crossbred kid was presented with cranial defects and protrusion of brain through the defect. Detailed examination of the animal revealed cranioschisis in the frontal and parietal region along with presence of cleft lip, cleft palate and accessory ear lobe on the right side. Herniation of meninges and brain was exposed directly and was not covered by skin. There were two parietal cranial defects separated by a plate of bone. Result: Postmortem examination of the animal showed bilateral cleft lip and cleft palate with lateral deviation of nasal septum and deformation of premaxillary region. On reflection of skin over the frontal region, revealed frontal cranioschisis and the brain was situated subcutaneously. There were total of three cranial defects (two in the parietal and one in the frontal region) separated by small plates of bone in between them. This present study explains the anatomical aspects of cranioschisis, meningoencephalocoele, cleft lip, cleft palate and associated craniofacial abnormalities in a day old kid.

Tridepsides from the endophytic fungus colletotrichum gloeosporioides associated with a toxic medicinal plant tylophora ovata

Introduction Bioactive secondary metabolites from the microbes living in frigid, toxic or other extreme environments are emerging as a new medicinal resource. Here, we report the discovery of new antidiabetic and anti-inflammatory compounds with novel structures from endophytic fungi hosted toxic medicinal plant. Methods The endophytic fungus isolated from toxic plants was fermented and extracted. The obtained extracts were purified with preparative HPLC to yield pure compounds. The purified compounds were examined by PTP1b inhibition and NO inhibition assays to evaluate their bioactivities. Results One new tridepsides (Compound 1), one new benzeneacetic acid derivative (Compound 3) and five known compounds (Compounds 2 and 4-7) were isolated from the ethyl acetate extract of Colletotrichum gloeosporioides, an endophytic fungus obtained from a toxic medicinal plant Tylophora ovata. Their structures were determined by spectroscopic data (1D and 2D NMR, HRESIMS) analyses. Compound 2 showed significant inhibitory activity against PTP1b with an IC50 value of 0.84 μM. Compounds 2 and 3 exhibited moderate inhibitory activities against the NO (nitric oxide) release in LPS-induced RAW 264.7 cells at 10 μM with percent inhibition of 39% and 33%, respectively. Conclusion The Compound 2 has potent PTP1b inhibitory effect indicating its antidiabetic potential and thus might be considered a lead compound for antidiabetic drug development.

Rapid Identification of Common Poisonous Plants in China Using DNA Barcodes

Toxic plants have been a major threat to public health in China. However, identification and tracing of poisoned species with traditional methods are unreliable due to the destruction of plant morphology by cooking and chewing. DNA barcoding is independent of environmental factors and morphological limitations, making it a powerful tool to accurately identify species. In our study, a total of 83 materials from 26 genera and 31 species of 13 families were collected and 13 plant materials were subjected to simulated gastric fluid digestion. Four markers (rbcL, trnH-psbA, matK, and ITS) were amplified and sequenced for all untreated and mock-digested samples. The effectiveness of DNA barcoding for the identification of toxic plants was assessed using Basic Local Alignment Search Tool (BLAST) method, PWG-Distance method, and Tree-Building (NJ) method. Except for the matK region, the amplification success rate of the remaining three regions was high, but the sequencing of trnH-psbA and ITS was less satisfactory. Meanwhile, matK was prone to be more difficult to amplify and sequence because of simulated gastric fluid. Among the three methods applied, BLAST method showed lower recognition rates, while PWG-Distance and Tree-Building methods showed little difference in recognition rates. Overall, ITS had the highest recognition rate among individual loci. Among the combined loci, rbcL + ITS had the highest species recognition rate. However, the ITS region may not be suitable for DNA analysis of gastric contents and the combination of loci does not significantly improve species resolution. In addition, identification of species to the genus level is sufficient to aid in the clinical management of most poisoning events. Considering primer versatility, DNA sequence quality, species identification ability, experimental cost and speed of analysis, we recommend rbcL as the best single marker for clinical identification and also suggest the BLAST method for analysis. Our current results suggest that DNA barcoding can rapidly identify and trace toxic species and has great potential for clinical applications. In addition, we suggest the creation of a proprietary database containing morphological, toxicological and molecular information to better apply DNA barcoding technology in clinical diagnostics.

A REVIEW ON TOXICITY OF GUNJA (ABRUS PRECATORIUS)

Gunja (Abrus precatorius Linn.) is a toxic plant which is described in various Samhita and other Ayurvedic texts. In Sushruta Samhita Vishaja dravyas are classified into Sthavara, Jangama and Kritima Visha. Gunja is mentioned in Sthavara Visha. In Sthavara Visha it is mentioned under Moolaja Adhisthan, which is one of the ten Adhisthan of Sthavara Visha. According to Rasa Tarangani Sthavara Visha are further divided into Mahavisha and Upavisha. Gunja is mentioned in Upavisha which is less potent toxic than Mahavisha. All parts of the plant are toxic, but the most toxic part is the seed which contains the active principle abrin. According to the modern concept, it is an irritant organic poison. In the Ayurvedic concept, if toxic plants are used after Shodhana process, they are useful in various types of diseases. The main aim of this study is to collect all the information related to Gunja and its toxicity. Keywords: Gunja, Visha, Toxicity, Abrin, Shodhana