Pelatihan Agro Eco-System Analysis Petani Ketela Pohon dalam Teknik Pengelolaan Organisme Pengganggu Tanaman

<em><strong>Training on Agro Eco-System Analysis for Cassava Farmers in Plant Pest Organism Management Techniques</strong>. </em>Pest population fluctuations in cassava plants tend to increase and spread rapidly in drought fields and a monoculture cropping pattern with close spacing therefore the presence of pests planted is highly dependent on agro-ecosystem conditions. Therefore ecological-based pest control is very necessary. To maintain the stability of the plant ecosystem, basic skills are needed in conducting agroecosystem analysis (AESA). Based on the analysis results obtained recommendations for appropriate ecosystem management for each growing season and facilitate farmers in determining good cultivation techniques regarding pest control, cropping patterns, soil and water conservation as well as natural enemies that are appropriate for their plants. AESA activities are carried out so that farmers understand and are skilled in managing their cassava plantations because Randotonda Village is a producer of "Nuabosi" cassava which is known as a regional superior product. The activity is carried out in a participatory manner by directly involving the participating farmers as observers, fact seekers and decision-makers for the management of their agroecosystems through discussion and manifesting current real conditions with the hope that in the future they can manage their cropping agroecosystems properly. The highest increase in farmer understanding occurred in natural enemy components of 91.67% while the average increase in farmer understanding for all agro-ecosystem components was 57.14%. All participants were able to perform AESA very well which was indicated by the ability of farmers to make recommendations for managing cassava agroecosystems for the next planting season.

Phytochemicals as Biopesticides against the Pinewood Nematode Bursaphelenchus xylophilus: A Review on Essential Oils and Their Volatiles

The impacts of a rapidly changing environment together with the growth in global trade activities has promoted new plant pest pandemic events in forest ecosystems. The pinewood nematode (PWN), Bursaphelenchus xylophilus, causes strong worldwide economic and ecological impacts. Direct control is performed through trunk injection of powerful nematicides, however many of these (hemi)synthetic compounds have raised ecological and human health concerns for affecting non-target species and accumulating in food products. As sustainable alternatives, essential oils (EOs) have shown very promising results. In this work, available literature on the direct activity of EOs against PWN is reviewed, as a contribution to advance the search for safer and greener biopesticides to be used in sustainable PWD pest management strategies. For the first time, important parameters concerning the bioassays performed, the PWNs bioassayed, and the EOs used are summarized and comparatively analyzed. Ultimately, an overview of the chemical composition of the most active EOs allowed to uncover preliminary guidelines for anti-PWN EO efficiency. The analysis of important information on the volatile phytochemicals composing nematicidal EOs provides a solid basis to engineer sustainable biopesticides capable of controlling the PWN under an integrated pest management framework and contributes to improved forest health.

Morphological characteristics and resistance to the pest of local corn variety of “Jago Leke” genetic resources in West Nusa Tenggara

Jago Leke is a local variety of sticky corn in the City of Bima which is very familiar and spread in the Province of NTB, especially on Sumbawa Island. This corn has a fluffier and sweet taste. However, at present its existence is in danger of being displaced by hybrid corn, which in recent years has been mass-cultivated in almost all areas on the island of Sumbawa. The purpose of this study was to determine the morphological characters and resistance to pests of sticky corn of the Jago Leke variety in an effort to preserve potential genetic resources. The method used in this research is observation and interviews. The results showed that the jago leke seed had an early maturity of 60 days, reddish stem color, shorter plant height than corn in general, small cobs, and red young cob hair. The main plant pest organisms that attack this jago leke plant are grasshoppers, stem borers, leaf blight, and leaf rust. Plant pest organism attack symptoms occur in both the vegetative and generative phases with different attack intensities.

Divergent abiotic spectral pathways unravel pathogen stress signals across species

Plant pathogens pose increasing threats to global food security, causing yield losses that exceed 30% in food-deficit regions. Xylella fastidiosa (Xf) represents the major transboundary plant pest and one of the world’s most damaging pathogens in terms of socioeconomic impact. Spectral screening methods are critical to detect non-visual symptoms of early infection and prevent spread. However, the subtle pathogen-induced physiological alterations that are spectrally detectable are entangled with the dynamics of abiotic stresses. Here, using airborne spectroscopy and thermal scanning of areas covering more than one million trees of different species, infections and water stress levels, we reveal the existence of divergent pathogen- and host-specific spectral pathways that can disentangle biotic-induced symptoms. We demonstrate that uncoupling this biotic–abiotic spectral dynamics diminishes the uncertainty in the Xf detection to below 6% across different hosts. Assessing these deviating pathways against another harmful vascular pathogen that produces analogous symptoms, Verticillium dahliae, the divergent routes remained pathogen- and host-specific, revealing detection accuracies exceeding 92% across pathosystems. These urgently needed hyperspectral methods advance early detection of devastating pathogens to reduce the billions in crop losses worldwide.

Analyses of symbiotic bacterial communities in the plant pest Bemisia tabaci reveal high prevalence of Hemipteriphilus asiaticus on the African continent

Microbial symbionts are widespread in insects and some of them have been associated to adaptive changes. Primary symbionts (P-symbionts) have a nutritional role that allows their hosts to feed on unbalanced diets (plant sap, wood, blood). Most of them have undergone genome reduction, but their genomes still retain genes involved in pathways that are necessary to synthesize the nutrients that their hosts need. However, in some P-symbionts, essential pathways are incomplete and secondary symbionts (S-symbionts) are required to complete parts of their degenerated functions. The P-symbiont of the phloem sap-feeder Bemisia tabaci, Portiera aleyrodidarium, lacks genes involved in the synthesis of vitamins, cofactors, and also of some essential amino-acids. Seven S-symbionts have been detected in the B. tabaci species complex. Phenotypic and genomic analyses have revealed various effects, from reproductive manipulation to fitness benefits, notably some of them have complementary metabolic capabilities to Portiera, suggesting that their presence may be obligatory. In order to get the full picture of the symbiotic community of this pest, we investigated, through metabarcoding approaches, the symbiont content of individuals from Burkina Faso, a West African country where B. tabaci induces severe crop damage. While no new putative B. tabaci S-symbiont was identified, Hemipteriphilus, a symbiont only described in B. tabaci populations from Asia, was detected for the first time on this continent. Phylogenetic analyses however reveal that it is a different strain than the reference found in Asia. Specific diagnostic PCRs showed a high prevalence of these S-symbionts and especially of Hemipteriphilus in different genetic groups. These results suggest that Hemipteriphilus may affect the biology of B. tabaci and provide fitness advantage in some B. tabaci populations.

Towards a phylogenetic ecology of plant pests and pathogens

Plant–pathogens and insect pests, hereafter pests, play an important role in structuring ecological communities, yet both native and introduced pests impose significant pressure on wild and managed systems, and pose a threat to food security. Global changes in climate and land use, and transportation of plants and pests around the globe are likely to further increase the range, frequency and severity of pest outbreaks in the future. Thus, there is a critical need to expand on current ecological theory to address these challenges. Here, we outline a phylogenetic framework for the study of plant and pest interactions. In plants, a growing body of work has suggested that evolutionary relatedness, phylogeny, strongly structures plant-pest associations—from pest host breadths and impacts, to their establishment and spread in new regions. Understanding the phylogenetic dimensions of plant-pest associations will help to inform models of invasive species spread, disease and pest risk in crops, and emerging pest outbreaks in native plant communities—which will have important implications for protecting food security and biodiversity into the future. This article is part of the theme issue ‘Infectious disease macroecology: parasite diversity and dynamics across the globe’.

Occurrence and spread of Ceroplastes cirripediformis Comstock (Hemiptera: Coccomorpha: Coccidae) in India

The notoriously destructive and invasive soft scale, Ceroplastes cirripediformis Comstock (Hemiptera: Coccomorpha: Coccidae), is recorded for the first time from India. The scale is redescribed to facilitate its identification and information on its host range, natural enemies and distribution is provided. An identification key to the Indian species in this genus is given. Management options in the event of an outbreak are discussed briefly. The establishment of this scale insect warrants special attention in India as it is a potentially damaging plant pest and has a broad host range across many plant families.