ABSTRACT
Ecological analyses of the small and lesser-known insect order Mecoptera in Thailand are presented. Specimens were collected monthly over a period of 12 consecutive months, using both Malaise and pan traps, from 29 sampling sites located in 18 national parks throughout Thailand. A total of 21 species in four genera were identified from 797 specimens, including Panorpa (1 species), Neopanorpa (18 species), Bittacus (1 species), and Terrobittacus (1 species), with the latter genus representing a new genus record to Thailand. Neopanorpa harmandi, N. siamensis, N. byersi, and N. malaisei were the most abundant species, representing 27.4%, 11.3%, 10.3% and 8.8% of the total specimens, respectively. The species with the highest frequency, as indicated by the high percentage of species occurrence (%SO), was N. siamensis (51%), followed by N. byersi (34%), N. harmandi (34%), N. spatulata (27%), and N. inchoata (27%). Eleven species (52%) exhibited specific regional occurrences. N. tuberosa and N. siamensis had the widest distribution, being found in almost all regions except for western and southern regions for the first and second species, respectively. The seasonal species richness of Mecoptera was high during the rainy season in the northern, northeastern, central, eastern, and western regions, with the highest richness observed in July (15 species), followed by the hot (10 species) and cold seasons (7 species), while there was no significant difference in species richness between seasons in the southern region. Multiple regression models revealed a negative association between species richness and abundance of Mecoptera with both elevation and temperature, and a positive association between rainfall and species evenness. It is predicted that climatic changes will have a detrimental effect on the mecopteran community. The results of this study enhance the understanding of the ecological aspects of Mecoptera, offering crucial insights into its biodiversity and distribution, which are vital for conservation and forest management.
ABSTRACT
The present study aims to evaluate the different nanoparticles (Cu NPs, KI NPs, Ag NPs, Bd NPs, and Gv NPs) against 4th instar Spodoptera frugiperda larvae as well as the microbial toxicity, phytotoxicity, and soil pH. Nanoparticles were tested at three concentrations (1000, 10000, and 100000 ppm) using two methods (food dip and larvae dip) against S. frugiperda larvae. Results (from the larval dip method) showed that among the nanoparticles, the KI NPs caused 63%, 98%, and 98% mortality within 5 days in the treatment of 1000, 10000, and 100000 ppm, respectively. After 24 h post treatment, a 1000 ppm concentration showed 95%, 54%, and 94% germination rates in Metarhizium anisopliae, Beauveria bassiana, and Trichoderma harzianum, respectively. The phytotoxicity evaluation clearly showed that NPs did not affect the morphology of the corn plants after the treatment. The soil nutrient analysis results showed that no effect was observed in soil pH or soil nutrients compared to control treatments. The study clearly showed that nanoparticles are caused toxic effect against S. frugiperda larvae.
ABSTRACT
Species of Paramyrothecium that are reported as plant pathogens and cause leaf spot or leaf blight have been reported on many commercial crops worldwide. In 2019, during a survey of fungi causing leaf spots on plants in Chiang Mai and Mae Hong Son provinces, northern Thailand, 16 isolates from 14 host species across nine plant families were collected. A new species Paramyrothecium vignicola sp. nov. was identified based on morphology and concatenated (ITS, cmdA, rpb2, and tub2) phylogeny. Further, P. breviseta and P. foliicola represented novel geographic records to Thailand, while P. eichhorniae represented a novel host record (Psophocarpus sp., Centrosema sp., Aristolochia sp.). These species were confirmed to be the causal agents of the leaf spot disease through pathogenicity assay. Furthermore, cross pathogenicity tests on Coffea arabica L., Commelina benghalensis L., Glycine max (L.) Merr., and Dieffenbachia seguine (Jacq.) Schott revealed multiple host ranges for these pathogens. Further research is required into the host-pathogen relationship of Paramyrothecium species that cause leaf spot and their management. Biotic and abiotic stresses caused by climate change may affect plant health and disease susceptibility. Hence, proper identification and monitoring of fungal communities in the environment are important to understand emerging diseases and for implementation of disease management strategies.
ABSTRACT
Thailand is known to be the largest producer of kaffir lime leaf products in the global market. In 2021, leaf blight was found on kaffir lime plants (Citrus hystrix DC.) in Lamphun Province of northern Thailand. This disease has been associated with significant economic losses. However, there have been no prior reports of leaf blight on kaffir lime plants in Thailand or anywhere else in the world. In this study, causal fungi were isolated from lesions of kaffir lime plants and a total of three fungal isolates were obtained. All causal fungi were identified as Lasiodiplodia chinensis based on morphological characteristics and the phylogenetic analysis of combined sequences of the internal transcribed spacer (ITS) of ribosomal DNA, the translation elongation factor 1-alpha (tef-1), ß-tubulin (tub), and RNA polymerase II subunit (rbp2) genes. Pathogenicity tests were conducted and the results revealed that all isolated fungi caused symptoms of leaf blight on inoculated leaves. This outcome was similar to symptoms that naturally occur and have been observed in the field. This is the first report on kaffir lime leaf blight caused by L. chinensis. Our study will provide information of high value for the development of effective strategies for the monitoring and prevention of this disease.
ABSTRACT
Longhorn beetles are highly diversified and important for agriculture and health of the environment. However, the fauna and ecology of these beetles are not well known in Thailand. This study is the first to report the biodiversity, elevation, and seasonal distribution of longhorn beetles. Specimens were collected by malaise traps from 41 localities in 24 national parks throughout the country during 2006-2009. The traps were operated at each site for 12 consecutive months with a monthly service. A total of 199 morphotaxa in 36 tribes of 6 subfamilies were identified from 1376 specimens. Of these, 40.7% and 14.5% of total taxa were singletons and doubletons, respectively. The Shannon diversity index and observed species richness at Panernthung, Loei Forest Unit and Mae Fang Hotspring were high at 0.96 (30), 0.88 (50), and 0.86 (34), respectively. Local richness ranged between 3 and 50 species, while the species richness estimator showed between 6 and 1275 species. The most relatively abundant species, Nupserha lenita, Pterolophia sp.1, Oberea sp.3, Acalolepta pseudospeciosa, and Ac. rustricatrix represented 4.80%, 4.80%, 4.80%, 4.5%, and 4.43% of the species, respectively. The species with the widest distribution range of percentage of species occurrence (% SO) was Pt. sp.1 (63.4%), followed by Ac. rustricatrix (39%) and Moechotypa suffusa (39%). In a significantly negative relationship between species richness and elevation (p > 0.05, R2 = 0.04), the species richness pattern showed a hump-shaped curve that peaked at the middle elevation (501-1000 m asl). Regarding seasonal variation, most of the species occurred during the hot season (March-April) and peaked in early rainy season (May), while a low number of species were found during the mid-rainy (June-October) and cold season (November-February). Ordination analysis indicated that the distribution of most species was associated with regions and forest type, and most of the species correlated with forest located at middle and low elevation. The results of this study indicated the very high biodiversity of longhorn beetles in Thailand, which suggests that an understanding of their seasonal and elevational distribution will be of value to agriculture management and conservation. They also indicated that malaise traps are appropriate for the evaluation of biodiversity.
ABSTRACT
Proturan fauna of Thailand has so far been poorly known, only two contributions being hitherto published. Imadaté (1965) recorded 26 species from around the country and Nakamura and Likhitrakarn (2009) reported eight species including three new species from Doi Suthep-Pui National Park, Chiang Mai Province.
