Biology subjects

Navarro, I.

Publications and source records attributed to Navarro, I..

4 recordsLinked to original sources

bioRxiv2026

Pollinator Plant Network Interactions of Bees (Hymenoptera: Anthophila) in an Urban Garden

Amongst ever increasing habitat loss and compounding environmental stressors, urban pollinator gardens can provide refugia and support native bees. However, gardens are rarely assessed for their effectiveness in providing adequate habitat. This study focuses on a recently established local campus pollinator garden in California. Using diversity observations from the early 2000s garden and non-lethal sampling techniques, we characterized visitation frequencies between flowers and urban bees. We generated a bipartite interaction network and found that despite the gardens relatively small size, the network showed greater specialization and modularity, as well as lower nestedness than expected by chance. Across 12 flower species, we observed two non-native pollinators, the western honey bee (Apis mellifera) and the alfalfa leafcutter (Megachile rotundata), along with at least nine native bee species across three families (Apidae, Halictidae, Megachilidae). Although this garden was designed for native bees, honey bees represented over 80% of visitation events and thus suggests that the garden needs adjustments to provide more forage for native bees. Honey bees occupied the most central and connected position in the network, followed by native sweat bees (Family: Halictidae) which both had generalist patterns. Whereas other bees showed evidence of specialization (Genus: Mellisodes). We found a significant positive relationship between inflorescence count and honey bee abundance but not with native bee abundance. To better steward native bees that possess a range of floral specializations, managers may consider increasing plant species diversity rather than relying on a few but highly abundant flowering plants.

ecology↗

bioRxiv2026

Playback calls help to increase the detectability of Coturnix coturnix (Common quail), a cryptic and widespread galliform

In cryptic or difficult-to-detect bird species, the monitoring schemes based on generalist detection methods may introduce bias into abundance estimates and population indices. This the case of the Coturnix coturnix (Common quail), a migratory Palearctic galliform, in which the use of passive detection methods within breeding birds monitoring schemes may not be efficient owing to its complex socio-sexual system and migratory behavior. For the first time, C.coturnix detectability was simultaneously compared using standard passive, generalist multispecies survey methods from the Pan-European Common Bird Monitoring Scheme (PECBMS) and a species-specific active survey employing female call playback. Surveys were conducted at 1,077 listening points within 107 transects over four breeding seasons (2022-2025) in open farmland landscapes dominated by cereal crops in Extremadura, south-western Spain. Detection counts differed substantially between methods: active surveys increased expected counts by 72% (95% CI: 59-85%) compared to passive surveys. The increase in C.coturnix detections elicited by playback showed a non-linear, density-dependent pattern, being highest at low passive abundances per listening point (maximum at 3-4 individuals) and stabilizing at intermediate abundances. This indicates that call playback is particularly effective at detecting individuals that would otherwise remain undetected. Our findings suggest that passive, multispecies surveys may underestimate C.coturnix abundance, especially in low-density populations. Integrating species-specific active methods into monitoring programs can improve detectability, generate more reliable population indices, and support evidence-based conservation and management strategies for this elusive species. LAY SUMMARYO_LIBird monitoring schemes guide conservation decisions across Europe, but generalist schemes based on passive methods may miss species that are hard to detect such as C.coturnix Common quail, a migratory farmland bird that hides in dense crops. In practice, only males spontaneously calling can be detected, hence passive methods could lead to underestimates of its abundance and even false absences in low-density areas. C_LIO_LIWe compared standard passive surveys with surveys that added a recorded female call (playback) to stimulate male responses. Across 1,077 listening points monitored over four breeding seasons in southwestern Spain, playback increased the number of birds detected by 72% compared with passive methods alone. C_LIO_LIThe improvement was strongest where C.coturnix numbers were low, showing that many individuals remain undetected without playback. Incorporating simple, species-specific methods into monitoring programs can produce more reliable population estimates and strengthen conservation and management decisions for this elusive species. C_LI

ecology↗

bioRxiv2021

Production of Volatile Moth Sex Pheromones in Transgenic Nicotiana benthamiana Plants

Plant-based bio-production of insect sex pheromones has been proposed as an innovative strategy to increase the sustainability of pest control in agriculture. Here we describe the engineering of transgenic plants producing (Z)-11-hexadecen-1-ol (Z11-16OH) and (Z)-11-hexadecenyl acetate (Z11-16OAc), two main volatile components in many Lepidoptera sex pheromone blends. We assembled multigene DNA constructs encoding the pheromone biosynthetic pathway and stably transformed them in Nicotiana benthamiana plants. The constructs comprised the Amyelois transitella Atr{Delta}11 desaturase gene, the Helicoverpa armigera farnesyl reductase HarFAR gene, and the Euonymus alatus diacylglycerol acetyltransferase EaDAct gene in different configurations. All the pheromone-producing plants showed dwarf phenotypes, whose severity correlated with pheromone levels. All but one of the recovered lines produced high levels of Z11-16OH but very low levels of Z11-16OAc, probably as a result of recurrent truncations at the level of the EaDAct gene. Only one plant line (SxPv1.2) was recovered harbouring an intact pheromone pathway and producing moderate levels of Z11-16OAc (11.8 {micro}g g-1 FW), next to high levels of Z11-16OH (111.4 {micro}g g-1). Z11-16OAc production was accompanied in SxPv1.2 by a partial recovery of the dwarf phenotype. SxPv1.2 was used to estimate the rates of volatile pheromone release, which resulted in 8.48 ng g-1 FW per day for Z11-16OH and 9.44 ng g-1 FW per day for Z11-16OAc. Our results suggest that pheromone release acts as a limiting factor in pheromone bio-dispenser strategies and establish a roadmap for biotechnological improvements.

synthetic biology↗

bioRxiv2020

Antifibrotic activity of a rho-kinase inhibitor restores outflow function and intraocular pressure homeostasis

Glucocorticoids are widely used as an ophthalmic medication. A common, sight-threatening adverse event of glucocorticoid usage is ocular hypertension, caused by dysfunction of the conventional outflow pathway. We report that netarsudil, a rho-kinase inhibitor, rapidly reversed glucocorticoid-induced ocular hypertension in patients whose intraocular pressures were uncontrolled by standard medications. Mechanistic studies in our established mouse model of glucocorticoid-induced ocular hypertension show that netarsudil both prevented and reversed intraocular pressure elevation. Further, netarsudil reversed characteristic steroid-induced pathologies as assessed by quantification of outflow function and tissue stiffness, and morphological and immunohistochemical indicators of tissue fibrosis. Thus, rho-kinase inhibitors act directly on conventional outflow cells to efficaciously prevent or reverse fibrotic disease processes in glucocorticoid-induced ocular hypertension. These data motivate a novel indication for these agents to prevent or treat ocular hypertension secondary to glucocorticoid administration, and demonstrate the antifibrotic effects of rho-kinase inhibitors in an immune-privileged environment.

physiology↗