Individual crop size increases predispersal predation by beetles in a tropical palm

2020 ◽  
pp. 1-4
Author(s):  
Morgana Maria Arcanjo Bruno ◽  
Klécia Gili Massi ◽  
Alexander V. Christianini ◽  
John du Vall Hay

Abstract Predispersal seed predation is one of the main causes of seed mortality in plant populations, contributing to decreased plant recruitment. Seed loss has previously been found to be related to crop size. Thus, we examined the influence of individual crop size on predispersal seed predation by beetles in the palm Syagrus flexuosa in the Brazilian savanna. The study was carried out in three tropical woodland savanna sites, where we sampled the total seed crop of 46 fruiting palms and checked the presence of beetle larvae inside all seeds per plant. We observed predispersal seed predation of S. flexuosa from all sites and a high variation in the number of seeds preyed on per individual palm. Crop size had a positive influence on the number of seeds lost to predispersal seed predators. Variations in levels of predispersal seed predation may also be accounted for by the reproductive phenology of S. flexuosa. If fruits are not available at the same time, less resource is available for predators and therefore a high proportion of seeds may be preyed on. Thus, our study demonstrates that an individual plant trait, crop size, is an important predictor of beetle seed damage per palm and a driver of the number of seeds lost to predispersal seed predators.

Insects ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 721
Author(s):  
Eduardo T. Mezquida ◽  
Paula Caputo ◽  
Pablo Acebes

Seed predation is an antagonistic interaction that negatively affects the performance of individual plants and can limit plant population dynamics. In animal-dispersed plants, crop size is an important determinant of plant reproductive success through its effect on seed dispersers and predators. Seed traits, such as size or chemical composition, can also increase the tolerance to seed predators or reduce their performance. We investigated the interaction between Quercus faginea and two specialized pre-dispersal insect seed predators (weevils and moths) during two years of contrasting crop size to determine the consequences of oak reproductive investment on seed production and insect performance. Crop size was 44% lower and acorns were 32% smaller in the second year, although acorn predation by insects was proportionally similar between both years at the population level. Individual trees producing larger crops showed a lower incidence of insect predators during the year of abundant acorn production, whereas trees producing bigger acorns experienced higher seed predation rates by insects, and acorns held more insect larvae in the low crop year. Competition between insects increased when acorn production was low, and higher tannin content in acorns further constrained the number of weevil larvae developing together in the same acorn. However, the abundance and size of insect larvae produced per tree were similar between the two crop years, and this was due to larvae often depleting acorn reserves when resources were low. Oak reproductive output increased nearly two-fold during the large crop year. Crop size variation, acorn production in a given year and acorn size and chemical composition seem to be important traits for reducing damage by insect predators in Quercus faginea and improve oak reproductive success.


2016 ◽  
Vol 36 (02) ◽  
pp. 91-96 ◽  
Author(s):  
Abraham Yirgu

AbstractThis study on predispersal seed predation of the leguminous speciesVachellia abyssinica(Hochst. Ex. Benth.) Kyal & Boatwr.,Senegalia senegal(L.) Britton,Vachellia seyal(Del.) P.J.H. Hurter, andVachellia tortilis(Forssk.) Galasso & Banfi was conducted around Lake Langano and Menagesha Forest in Ethiopia to identify the associated seed predators and determine their impact on seed germination. Eight seed beetlesBruchidius albosparsus(Fåhraeus, 1839),B. aurivillii(Blanc, 1889),B. djemensisDecelle 1971,B. discoidalis(Fåhraeus, 1839),B. sinaitus(K. Daniel, 1907),B. silaceus(Fåhraeus, 1839),B. sp 411,B. simulans(Anton and Delobel, 2003), and one unidentified species of Cerambycidae were found associated with seeds of theseAcaciaspecies. These predators damaged less than 9% of seeds of these species, which exhibited lower germination. This study provides unrecorded lists of predispersal seed predators associated with seeds ofVachelliaandSenegaliaspecies in Ethiopia, and some associations are new. There is need to assess the distribution, abundance and effects of predispersal seed predators on otherVachellia, as well as other tree species.


1996 ◽  
Vol 6 (2) ◽  
pp. 65-69 ◽  
Author(s):  
Jeff Ollerton ◽  
Andrew Lack

AbstractPredispersal seed predation may have implications for plant population dynamics and the evolution of plant traits, but assessing the level of seed predation for an individual plant is not always straightforward. Seeds of Lotus corniculatus (Fabaceae) are often only partially eaten by a weevil seed predator, Apion loti. Samples of these seeds were tested for viability and subsequent seedling vigour. A large proportion of these damaged seeds were viable, and the resulting seedlings almost as vigorous as those from undamaged seeds. The ubiquity of these findings, and their ecological significance, is discussed.


2008 ◽  
Vol 140 (3) ◽  
pp. 297-305 ◽  
Author(s):  
Royce Steeves ◽  
Vazrick Nazari ◽  
Jean-François Landry ◽  
Christian R. Lacroix

AbstractThe Gulf of St. Lawrence aster, Symphyotrichum laurentianum (Fernald) G.L. Nesom (Asteraceae), a small annual halophyte endemic to disturbed and highly transient habitats in the Gulf of St. Lawrence, is classified as “threatened” by the Committee on the Status of Endangered Wildlife in Canada. Lepidopteran larvae that are predispersal seed predators of the Gulf of St. Lawrence aster are reported for the first time from populations in Prince Edward Island National Park. DNA barcoding was used to identify the seed predators tentatively as larvae of the casebearing moth Coleophora triplicis McDunnough (Lepidoptera: Coleophoridae), which is typically associated with a related halophyte, Solidago sempervirens L. (Asteraceae). These larvae were found to consume a large proportion of seeds from one of two aster populations in Prince Edward Island National Park and may be yet another risk to the survival of this threatened species.


2017 ◽  
Vol 23 (1) ◽  
Author(s):  
A. B. SAGADE

The study of the effect of three well known mutagens, ethyl methane sulphonate (EMS), methyl methane sulphonate (MMS) and gamma rays (GR) on the yield contributing traits of the urdbean variety TPU-4 were carried out in the M3 generation. Effect of selected mutagenic treatments/doses of EMS (0.02, 0.03 and 0.04 M), MMS (0.0025, 0.05 and 0.01 M) and (GR) (30, 40 and 50 KR) on different yield contributing traits like plant height, plant spread, number of pods per plant, pod length, number of seeds per pod, seed yield per plant and 100 seed weight were analyzed in the M3 populations of the variety TPU-4. Seeds of M2 plants and control were harvested separately and sown to raise M3 population.. Genetic variabilty in the mutagen administered M3 progeny of the urdbean variety TPU-4 was analyzed by employing statistical methods. Data on mean values and shift in the mean of seven quantitative traits was evaluated on individual plant basis. The experimental findings revealed that concentrations / dose of the all these mutagens showed inhibitory effect on plant height, number of pods per plant, pod length and number of seeds per pod. Lower concentrations of mutagens exerted a promotory effect on plant spread, 100 seed weight and seed yield per plant while higher concentrations of these mutagens inhibited them to different extent.


1972 ◽  
Vol 52 (6) ◽  
pp. 1067-1072 ◽  
Author(s):  
M. C. J. VAN ADRICHEM

Several population samples of Rubus idaeus subspp. strigosus Michx. (raspberries) were collected in British Columbia and northern Alberta and a number of characters were studied and compared with the cultivar Trent. Significant differences between populations were found for cane length, number of buds per cane, percentage of buds growing, number of inflorescences and flowers per bud, fruit and seed weight. There was a positive correlation between the total seed weight and the number of seeds, and between the total seed and fruit weight. No distinct types could be established based on location or elevation. None of the populations showed significantly better winter hardiness than the cultivar Trent, and although some had a specific character that was superior, none was found to have overall superiority.


1997 ◽  
Vol 75 (2) ◽  
pp. 332-335 ◽  
Author(s):  
Michael A. Setterington ◽  
Daniel M. Keppie

Relationships between external cone characteristics (length, width, wet and dry mass), cone quality (total seed mass as a proportion of cone mass, total number of seeds per cone, total seed mass per cone), and number of cones in caches were evaluated for caches of jack pine (Pinus banksiana) cones belonging to red squirrels (Tamiasciurus hudsonicus) in two plantations in southern New Brunswick. Cone length and mass were good predictors of the total number of seeds per cone and total seed mass per cone. Length accounted for a small proportion of the variance of total seed mass as a proportion of cone mass. There was no relationship between the number of seeds or total seed mass per cone and the number of cones per cache.


1999 ◽  
Vol 15 (4) ◽  
pp. 463-479 ◽  
Author(s):  
João A. Madeira ◽  
G. Wilson Fernandes

Reproductive phenology of 13 sympatric taxa of Chamaecrista in three sections was surveyed at Serra do Cipó, south-east Brazil. Mean abundance of flowers and fruits per plant and mean number of aborted, predated, and surviving seeds per fruit were estimated. Monthly average number of developed seeds per fruit multiplied by the monthly mean number of fruits per plant gave the monthly average number of seeds produced by a plant of each taxon. Five types of phenological behaviour were differentiated by cluster analyses according to the season during which each species produced most of its mature seeds. This behaviour was related to the taxonomic section to which the taxa belong, to plant architecture, to geographical range, to seed predation and to local climatic seasonality. Herbs were more affected by variation in rainfall than shrubs and trees. Two species did not show any clear seasonal behaviour. Widespread taxa produced most of their mature seeds in the rainy season or immediately after it, and all but one of the narrowly distributed species produced most of their mature seeds in the dry season or in the transition from dry to rainy season. Seed predation is probably not an important selective force affecting reproductive phenology of larger taxa, while the smaller taxa seemed too constrained by abiotic factors for biotic factors to influence their phenology significantly.


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