Life Strategies in Placozoa

Placozoans are essential reference species for understanding the origins and evolution of the animal organization. However, little is known about their life strategies in natural habitats. Here, by establishing long-term culturing for four species of Trichoplax and Hoilungia, we extend our knowledge about feeding and reproductive adaptations relevant to their ecology and immune mechanisms. Three modes of population growth depended upon feeding sources, including induction of social behaviors and different reproductive strategies. In addition to fission, representatives of all haplotypes produced swarmers, which could be formed from the lower epithelium (with greater cell-type diversity) as a separate asexual reproduction stage. In aging culture, we reported the formation of specialized structures (spheres) from the upper cell layer as a part of the innate immune defense response with the involvement of fiber cells. Finally, we showed that regeneration could be a part of the adaptive reproductive strategies in placozoans and a unique model for regenerative biology in general.

Pemantauan Keanekaragaman Hama dan Musuh Alami Tanaman Ubi Jalar dengan Pitfall Trap

The abundance of pest and natural enemy populations on a land can be given in the diversity and abundance of feeding sources and other available resources. The purpose of this study was to determine the diversity of pests and natural enemies of sweet potato plants. Research on land with three types of sweet potatoes, namely yellow sweet potatoes with narrow leaves, yellow sweet potatoes with broad leaves, and sweet potatoes with white leaves. Around the research area are long beans, papaya, guava, soursop, and durian. Sampling of pests and natural enemies by using a pitfall trap. The data analyzed was in the form of the Shannon-Weaver (H') diversity index. The index of pest diversity of the order Coleoptera on narrow-leaved yellow sweet potato, broad-leaved yellow sweet potato, and white sweet potato was 0,160; 0,1270; and 0,1300. The index of pest diversity of the order Orthoptera on narrow-leaved yellow sweet potato, broad-leaved yellow sweet potato, and white sweet potato was 0,3585; 0,3599; and 0,3632. The index of pest diversity of the order Hemiptera on narrow-leaved yellow sweet potato, broad-leaved yellow sweet potato, and white sweet potato was 0,0635; 0,0771; and 0,1300. Diversity index of natural enemies of the order Araneae on narrow-leaved yellow sweet potato, broad-leaved yellow sweet potato, and white sweet potato 0.2180; 0.3061; and 0.2705. The three sweet potato fields had a low diversity index.

The potential risk of enzootic Trypanosoma cruzi transmission inside four training and re-training military battalions (BITER) in Colombia

Background Colombia’s National Army is one of the largest military institutions in the country based on the number of serving members and its presence throughout the country. There have been reports of cases of acute or chronic cases of Chagas disease among active military personnel. These may be the result of military-associated activities performed in jungles and other endemic areas or the consequence of exposure to Trypanosoma cruzi inside military establishments/facilities located in endemic areas. The aim of the present study was to describe the circulation of T. cruzi inside facilities housing four training and re-training battalions [Battalions of Instruction, Training en Re-training (BITERs)] located in municipalities with historical reports of triatomine bugs and Chagas disease cases. An entomological and faunal survey of domestic and sylvatic environments was conducted inside each of these military facilities. Methods Infection in working and stray dogs present in each BITER location was determined using serological and molecular tools, and T. cruzi in mammal and triatomine bug samples was determined by PCR assay. The PCR products of the vertebrate 12S rRNA gene were also obtained and subjected to Sanger sequencing to identify blood-feeding sources. Finally, we performed a geospatial analysis to evaluate the coexistence of infected triatomines and mammals with the military personal inside of each BITER installation. Results In total, 86 specimens were collected: 82 Rhodnius pallescens, two Rhodnius prolixus, one Triatoma dimidiata and one Triatoma maculata. The overall T. cruzi infection rate for R. pallescens and R. prolixus was 56.1 and 100% respectively, while T. dimidiata and T. maculata were not infected. Eight feeding sources were found for the infected triatomines, with opossum and humans being the most frequent sources of feeding (85.7%). Infection was most common in the common opossum Didelphis marsupialis, with infection levels of 77.7%. Sylvatic TcI was the most frequent genotype, found in 80% of triatomines and 75% of D. marsupialis. Of the samples collected from dogs (n = 52), five (9.6%; 95% confidence interval: 3.20–21.03) were seropositive based on two independent tests. Four of these dogs were creole and one was a working dog. The spatial analysis revealed a sympatry between infected vectors and mammals with the military population. Conclusions We have shown a potential risk of spillover of sylvatic T. cruzi transmission to humans by oral and vectorial transmission in two BITER installations in Colombia. The results indicate that installations where 100,000 active military personnel carry out training activities should be prioritized for epidemiological surveillance of Chagas disease. Graphical abstract

Diversity and interactions among triatomine bugs, their blood feeding sources, gut microbiota and Trypanosoma cruzi in the Sierra Nevada de Santa Marta in Colombia

Chagas disease remains a major neglected disease in Colombia. We aimed to characterize Trypanosoma cruzi transmission networks in the Sierra Nevada de Santa Marta (SNSM) region, to shed light on disease ecology and help optimize control strategies. Triatomines were collected in rural communities and analyzed for blood feeding sources, parasite diversity and gut microbiota composition through a metagenomic and deep sequencing approach. Triatoma dimidiata predominated, followed by Rhodnius prolixus, Triatoma maculata, Rhodnius pallescens, Panstrongylus geniculatus and Eratyrus cuspidatus. Twenty-two species were identified as blood sources, resulting in an integrated transmission network with extensive connectivity among sylvatic and domestic host species. Only TcI parasites were detected, predominantly from TcIb but TcIa was also reported. The close relatedness of T. cruzi strains further supported the lack of separate transmission cycles according to habitats or triatomine species. Triatomine microbiota varied according to species, developmental stage and T. cruzi infection. Bacterial families correlated with the presence/absence of T. cruzi were identified. In conclusion, we identified a domestic transmission cycle encompassing multiple vector species and tightly connected with sylvatic hosts in the SNSM region, rather than an isolated domestic transmission cycle. Therefore, integrated interventions targeting all vector species and their contact with humans should be considered.

The dietary, productivity, and economic value of swiftlet (Aerodramus fuciphagus) farming in East Kalimantan, Indonesia

Mursidah, Lahjie AM, Masjaya, Rayadin Y, Ruslim Y, Judinnur MB, Andy. 2021. The dietary, productivity, and economic value of swiftlet (Aerodramus fuciphagus) farming in East Kalimantan, Indonesia. Biodiversitas 22: 2528-2537. Edible-nest swiftlets have many health benefits. The availability of edible-nest swiftlets from caves is decreasing, while the demand for edible-nest swiftlets is getting higher. Swiftlet farming is carried out to meet this demand. The location of swiftlet farming should be close to the feeding sources. Swiftlet is flying insectivorous animals. A financial feasibility assessment is carried out to determine the feasibility of the business. This study aims to determine the composition of land cover, determine the insect order of feed sources, and analyze the production and financial feasibility of swiftlet farming. The study was carried out from June to December 2019. The composition of land cover was determined using the supervised classification method, the order of insects was known using the insect determination key, while production and financial feasibility were analyzed using the Net B/C, NPV, IRR, and PP methods. The observed location and swiftlet farming were determined purposefully. The results of this study show that the land cover was dominated by shrubs (56.58%) and secondary forest (27.3%); both types of land cover are suitable for swiftlet farming locations. The dominant insects found in shrubs and wetland shrubs are Diptera (78.25%), in rice fields are Diptera (86.7%) and in oil palm plantations are Diptera (29.4%) and Hymenoptera (27.78%). Edible-nest swiftlets harvest begins in the third year, with a production period of between 17-34 years. From the financial feasibility, it can be concluded that swiftlet farming is feasible.

Diversity structure of the microbial communities in the guts of four neotropical termite species

The termite gut microbiome is dominated by lignocellulose degrading microorganisms. This study describes the intestinal microbiota of four Argentinian higher termite species with different feeding habits: Microcerotermes strunckii (hardwood), Nasutitermes corniger (softwood), Termes riograndensis (soil organic matter/grass) and Cornitermes cumulans (grass) by deep sequencing of amplified 16S rRNA and ITS genes. In addition, we have performed a taxonomic and gut community structure comparison incorporating into the analysis the previously reported microbiomes of additional termite species with varied diets. The bacterial phylum Spirochaetes was dominant in the guts of M. strunckii, N. corniger and C. cumulans, whereas Firmicutes predominated in the T. riograndensis gut microbiome. A single bacterial genus, Treponema (Spirochaetes), was dominant in all termite species, except for T. riograndensis. Both in our own sequenced samples and in the broader comparison, prokaryotic α-diversity was higher in the soil/grass feeders than in the wood feeders. Meanwhile, the β-diversity of prokaryotes and fungi was highly dissimilar among strict wood-feeders, whereas that of soil- and grass-feeders grouped more closely. Ascomycota and Basidiomycota were the only fungal phyla that could be identified in all gut samples, because of the lack of reference sequences in public databases. In summary, higher microbial diversity was recorded in termites with more versatile feeding sources, providing further evidence that diet, along with other factors (e.g., host taxonomy), influences the microbial community assembly in the termite gut.

Trypanosoma cruzi infection in Triatoma infestans and high levels of human–vector contact across a rural-to-urban gradient in the Argentine Chaco

Background Peri-urban and urban settings have recently gained more prominence in studies on vector-borne transmission of Trypanosoma cruzi due to sustained rural-to-urban migrations and reports of urban infestations with triatomines. Prompted by the finding of Triatoma infestans across the rural-to-urban gradient in Avia Terai, an endemic municipality of the Argentine Chaco, we assessed selected components of domestic transmission risk in order to determine its variation across the gradient. Methods A baseline vector survey was conducted between October 2015 and March 2016, following which we used multistage random sampling to select a representative sample of T. infestans at the municipal level. We assessed T. cruzi infection and blood-feeding sources of 561 insects collected from 109 houses using kinetoplast DNA-PCR assays and direct enzyme-linked immunosorbent assays, respectively. We stratified triatomines according to their collection site (domestic or peridomestic), and we further categorized peridomestic sites in ecotopes of low- or high-risk for T. cruzi infection. Results The overall adjusted prevalence of T. cruzi-infected T. infestans was 1.8% (95% confidence interval [CI] 1.3–2.3) and did not differ between peri-urban (1.7%) and rural (2.2%) environments. No infection was detected in bugs captured in the urban setting; rather, infected triatomines were mainly collected in rural and peri-urban domiciles, occurring in 8% of T. infestans-infested houses. The main blood-feeding sources of domestic and peridomestic triatomines across the gradient were humans and chickens, respectively. The proportion of triatomines that had fed on humans did not differ between peri-urban (62.5%) and rural (65.7%) domiciles, peaking in the few domestic triatomines collected in urban houses and decreasing significantly with an increasing proportion of chicken- and dog- or cat-fed bugs. The relative odds ratio (OR) of having a T. cruzi infection was nearly threefold higher in bugs having a blood meal on humans (OR 3.15), dogs (OR 2.80) or cats (OR: 4.02) in a Firth-penalized multiple logistic model. Conclusions Trypanosoma cruzi transmission was likely occurring both in peri-urban and rural houses of Avia Terai. Widespread infestation in a third of urban blocks combined with high levels of human–triatomine contact in the few infested domiciles implies a threat to urban inhabitants. Vector control strategies and surveillance originally conceived for rural areas should be tailored to peri-urban and urban settings in order to achieve sustainable interruption of domestic transmission in the Chaco region.

Unraveling the Importance of Triatomine (Hemiptera: Reduviidae: Triatominae) Feeding Sources in the Chagas Disease Context

The triatomines are vectors of Trypanosoma cruzi (Chagas, 1909), the etiologic agent of Chagas disease. All species are strictly hematophagous, and the hosts used by vector species are important to understand the transmission dynamics of T. cruzi, and eventually, for the development of effective control strategies in endemic countries. In the current review, we gather a comprehensively number of literature reporting triatomine feeding sources, using rigorous targeted search of scientific publications, which includes research papers and reviews to put together the most recent findings of the feeding behavior in triatomines and their applications for vector control of Chagas disease. Our main findings suggest that the main feeding source in triatomines is the human blood (22.75%), T. dimidiata (Latreille, 1811) (Hemiptera: Reduviidae) is the most frequent (13.68%) triatomine species in this type of study, and most of the studies on feeding sources (47.5%) are conducted in the domestic and peri-domestic environment.

Stereochemistry of Astaxanthin Biosynthesis in the Marine Harpacticoid Copepod Tigriopus Californicus

The harpacticoid copepod Tigriopus californicus has been recognized as a model organism for the study of marine pollutants. Furthermore, the nutritional profile of this copepod is of interest to the aquafeed industry. Part of this interest lies in the fact that Tigriopus produces astaxanthin, an essential carotenoid in salmonid aquaculture. Here, we study for the first time the stereochemistry of the astaxanthin produced by this copepod. We cultured T. californicus with different feeding sources and used chiral high-performance liquid chromatography with diode array detection (HPLC-DAD) to determine that T. californicus synthesizes pure 3S,3’S-astaxanthin. Using meso-zeaxanthin as feed, we found that the putative ketolase enzyme from T. californicus can work with β-rings with either 3R- or 3S-oriented hydroxyl groups. Despite this ability, experiments in the presence of hydroxylated and non-hydroxylated carotenoids suggest that T. californicus prefers to use the latter to produce 3S,3’S-astaxanthin. We suggest that the biochemical tools described in this work can be used to study the mechanistic aspects of the recently identified avian ketolase.