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Despite extensive work on both insect disease and plant reproduction, there is little research on the intersection of the two. Insect-infecting pathogens could disrupt the pollination process by affecting pollinator population density or traits. Pathogens may also infect insect herbivores and change herbivory, potentially altering resource allocation to plant reproduction. We conducted a meta-analysis to (1) summarize the literature on the effects of pathogens on insect pollinators and herbivores and (2) quantify the extent to which pathogens affect insect traits, with potential repercussions for plant reproduction. We found 39 articles that fit our criteria for inclusion, extracting 218 measures of insect traits for 21 different insect species exposed to 25 different pathogens. We detected a negative effect of pathogen exposure on insect traits, which varied by host function: pathogens had a significant negative effect on insects that were herbivores or carried multiple functions but not on insects that solely functioned as pollinators. Particular pathogen types were heavily studied in certain insect orders, with 7 of 11 viral pathogen studies conducted in Lepidoptera and 5 of 9 fungal pathogen studies conducted in Hymenoptera. Our results suggest that most studies have focused on a small set of host-pathogen pairs. To understand the implications for plant reproduction, future work is needed to directly measure the effects of pathogens on pollinator effectiveness.

Seed production can be affected by water availability and also depend on the amount (pollen intensity) and quality of pollen deposited. The way pollen receipt on the stigma translates into seeds produced follows that of a saturating dose-response. Not only can water availability and pollen intensity each influence seed production, these factors could interact in their effects on seed production. Changes to the relationship between seed production and pollen intensity can in turn influence pollinator effectiveness and pollinator-mediated selection. We asked how water availability affected indices of plant fitness (seed set, fruit set and seed mass) and the relationship between pollen intensity and seed production in Phacelia parryi . We conducted a greenhouse experiment where we manipulated water availability (either high- or low-water) to pollen recipient plants and hand-pollinated each plant with a range of pollen intensities. We conducted 703 hand-pollinations on 30 plants. For each hand-pollinated flower we measured pollen deposited, seed production and seed mass. We then generated a piecewise regression of the relationship between pollen intensity and seed production, and determined average effects of water on plant fitness measures. This experiment was paired with a field observational study aimed to document natural variation in pollen deposition. Average seed production per fruit was 21 % higher in the high-watered plants. The relationship between pollen intensity and seed production differed between the two water treatments. Plants under high-water exhibited a wider range in which pollen deposition increased seed production. Average natural pollen intensities fell within different regions of the piecewise regression for low- and high-water plants. Water availability can alter the efficiency by which pollen received is translated into seeds produced. Our greenhouse data suggest that only under certain pollen intensity environments will water availability affect how pollen received is translated into seeds produced., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Annals of Botany Company.)

Premise: Outcrossing species depend on pollen from conspecific individuals that may not be exposed to the same abiotic conditions as maternal plants. Additionally, many flowers receive heterospecific pollen, which can also influence seed production. Studies aimed to understand how abiotic conditions influence seed production tend to focus on maternal conditions and leave unexplored the effect of abiotic conditions experienced by pollen donors. We tested how water availability to pollen donors, both conspecific and heterospecific, influenced the seed production of recipient plants exposed to different water availability regimes., Methods: In a greenhouse setting we manipulated the water availability (low- or high-water treatment) to potted recipient plants (Phacelia parryi), to conspecific pollen donors, and to heterospecific pollen donors (Brassica nigra). We hand pollinated recipient plants with different pollen mixes that represented all combinations of conspecific pollen mixed with heterospecific pollen. From these hand pollinations we determined the amount of pollen that was transferred, pollen volume, pollen shape, and seed production., Results: Higher water availability to conspecific pollen donors led to higher seed production. Under low water availability to heterospecific pollen donors, seed production was unaffected by recipient or conspecific pollen donor treatment. Under high water availability to heterospecific pollen donors, seed production was highest when conspecific pollen donors and pollen recipients also received the high-water treatment., Conclusions: Environmental conditions of pollen donors can influence the seed production of maternal plants. These results illustrate potential impacts of environmental heterogeneity on post-pollination events that lead to seed production and thus impact a pollinator's contribution to plant fitness., (© 2019 Botanical Society of America.)

Numerous studies have examined the reproductive systems of threatened orchids to develop effective conservation strategies. However, the detrimental effects of seed predators on seed production are often overlooked. In this study, we evaluated the impact of the seed-parasitic fly Japanagromyza tokunagai on the seed production of the endangered orchid Cephalanthera falcata, based on observations from five locations over one year and from a single location over four years in Chiba Prefecture, Japan. Our findings showed that J. tokunagai caused 100% capsule damage across all sites and years examined. Although some infested fruits still produced seeds in certain locations and years, the quantities were very low. Consequently, we observed a 99.1-100% reduction in seed production across all populations investigated. These results suggest that reduced seed production could limit generational turnover, potentially threatening the reproductive success and long-term survival of C. falcata, at least in the populations studied. This highlights the need to mitigate the negative impact of J. tokunagai on seed production in C. falcata. Combining artificial pollination with the bagging of individual inflorescences could be an effective approach, capable of increasing seed production by more than 100-fold. Given the fungal dependence and low germination rates of C. falcata, future work should also examine seedling recruitment to better understand the impacts of seed loss and improve estimates of long-term resilience., Competing Interests: Declaratins. Conflict of interest: The authors declare no conflict of interest., (© 2025. The Author(s) under exclusive licence to The Botanical Society of Japan.)

The genetic identity of the reptilian tick, Amblyomma helvolum, infesting wild green iguanas (Iguana iguana) in Taiwan, was examined. Genetic identity was determined by analyzing the 16S mitochondrial DNA gene sequences obtained from 11 Taiwan A. helvolum compared with other Amblyomma species, with two Dermacentor species and two Rhipicephalus species serving as outgroups. Phylogenetic analysis revealed that all the Taiwan specimens were genetically affiliated with a monophyletic group of A. helvolum and can be discriminated from other Amblyomma species. Our results provide the first genetic identification of adult A. helvolum ticks infesting wild iguanas in Taiwan. Further studies focused on the seasonal prevalence and vectorial capacity of A. helvolum for various tick-borne pathogens will help to clarify the epidemiological significance of this species and its impact on animal and human health in Taiwan., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Premise: Seed production is frequently limited by the receipt of insufficient or low-quality pollen, collectively termed "pollen limitation" (PL). In taxa with gametophytic self-incompatibility (GSI), incompatible pollen can germinate on stigmas but pollen tubes are arrested in styles. This allows for estimates of pollen performance before, during, and after self-recognition, as well as insight into the factors underlying pollen quality limitation in GSI taxa., Methods: We scored pollen performance following self and outcross pollinations in Argentina anserina to identify the location of self-recognition and establish the relationship between pollen tubes and seed production. We then estimated quantity and quality components of PL from >3300 field-collected styles. We combined our results with other studies to test the prediction that low pollen quality, but not quantity, drives higher PL in self-incompatible (SI) taxa than in self-compatible taxa (SC)., Results: Self and outcross pollen germinated readily on stigmas, but 96% of germinated self-pollen was arrested during early tube elongation. Reproduction in the field was more limited by pollen quality than by quantity, and pollen failure near the location of self-recognition was a stronger barrier to fertilization than pollen germination. Across 26 taxa, SI species experienced stronger pollen quality, but not quantity, limitation than SC species., Conclusions: Evaluating pollen performance at multiple points within pistils can elucidate potential causes of pollen quality limitation. The receipt of incompatible pollen inhibits fertilization success more than insufficient pollen receipt or poor pollen germination in A. anserina. Likewise, pollen quality limitation drives high overall PL in other SI taxa., (© 2022 The Authors. American Journal of Botany published by Wiley Periodicals LLC on behalf of Botanical Society of America.)

Purpose: Co-invasion of naïve ecosystems by non-native parasites is a serious threat to global biodiversity, though such events are difficult to detect early in the invasion process. Green iguanas (Iguana iguana) are an emerging invasive species and have colonised several countries in the Asia-Pacific. A survey was undertaken to determine whether parasites of the green iguana had co-invaded naïve ecosystems with their introduced host., Methods: Over a 10-month period, wild green iguanas were trapped and euthanised in Singapore. All animals were necropsied and sampled for parasites. Parasites were then identified morphologically and subsequently characterised molecularly at the cytochrome c oxidase I (COI) locus., Results: The reptile nematode Ozolaimus megatyphlon was found in 38% of the sampled green iguanas, with burdens of 100 + worms in all infected animals. This represents the first recorded co-invasion of this species with wild green iguanas in the Asia-Pacific. Based on the molecular characterisation of the cytochrome c oxidase I (COI) locus, the first DNA barcode is provided for O. megatyphlon., Conclusion: For the first time, the reptile nematode Ozolaimus megatyphlon is shown to be invasive and to have colonised the Asia-Pacific region with its introduced host, the green iguana. The DNA barcode provided here will facilitate future monitoring programmes as O. megatyphlon invades new habitats and countries.