The Experts below are selected from a list of 135 Experts worldwide ranked by ideXlab platform
Y.h Prévost - One of the best experts on this subject based on the ideXlab platform.
-
Seasonal feeding patterns of Insects in cones of tamarack, Larix laricina (Du Roi) K. Koch (Pinaceae)
Forest Ecology and Management, 2002Co-Authors: Y.h PrévostAbstract:Abstract Insects feeding on female reproductive structure (FRS) (conelets and cones) of tamarack, Larix laricina (Du Roi) K. Koch, (Pinaceae) were surveyed and the Insects’ seasonal damage to the FRS was assessed during 1990 on five trees in Thunder Bay, Ontario, Canada. Sixteen insect species representing six orders were feeding in these FRS; 10 species were on cones and Seeds, while the other six were predators or parasitoids of the cone Insects. Eight insect species were new records of feeding within tamarack cones, the most notable being the larch casebearer, Coleophora laricella (Hubner) (Tortricidae). The initial feeding of Insects on tamarack FRS started shortly after pollination (27 May) and intensive feeding continued during the next 5 weeks when most of the damage occurred. Many FRS did not show symptoms when the Insects were feeding internally, but symptoms became visible as the cones matured. One hundred percent of the cones examined in this 1 year study were damaged, and about only 1% of the 5900 cones dissected had one filled Seed. Insects were responsible for a portion of the low filled Seed, but lack of pollination also played an important part as there were few pollen cones in 1990. Exposure of larch Seeds to −20 °C for 12 weeks killed 100% of the overwintering Seed chalcid larvae, whereas 98% of the chalcids exposed to 4 °C survived. Exposure of larch Seed to extreme cold may be a way to curb shipping live Megastigmus from one region to another. To significantly increase viable Seed productivity in tamarack, FRS must be protected from the cone fly maggot, Strobilomyia sp., which appeared to cause a high incidence of damage to cones and Seeds, as well as from the various Lepidopterans. This is especially true in years of low pollen production and in high value Seed production areas.
Alain Roques - One of the best experts on this subject based on the ideXlab platform.
-
Role of insect vectors in epidemiology and invasion risk of Fusarium circinatum, and risk assessment of biological control of invasive Pinus contorta
Biological Invasions, 2016Co-Authors: Eckehard G. Brockerhoff, Alain Roques, Margaret Dick, Rebecca Ganley, Andrew J. StorerAbstract:Pitch canker, caused by the pathogen Fusarium circinatum, is a serious disease of pines, Pinus species. It is a threat to natural and planted pine forests, and to date it has invaded countries across five continents. Pine-feeding Insects can play a key role in the epidemiology of the disease, as wounding agents allowing pathogen access or as vectors transmitting the pathogen from infected to healthy trees. We reviewed the role of Insects in the epidemiology of pitch canker worldwide and assessed which Insects are present in New Zealand that may act as wounding agents or vectors to determine whether pathogen invasion could adversely affect Pinus radiata plantation forests and urban trees. We also evaluated whether cone or Seed Insects of pines could be introduced as biological control agents of invasive Pinus contorta and how this may affect the impact of a potential F. circinatum invasion. As there are no native pines or other Pinaceae in New Zealand, there are only a few pine Insects, mainly accidental introductions. None of the Insects recorded on pines in New Zealand is likely to be a vector, suggesting low disease risk. Of six potentially suitable biocontrol candidates, the European pine cone weevil Pissodes validirostris is the most promising regarding host specificity and impact on Seed production, but there is uncertainty about its ability to act as a vector of F. circinatum. Our methodology to review and evaluate the vector potential of pine associates can be used as a generic framework to assess the potential impacts of F. circinatum invasion.
-
Seed wasp invasions promoted by unregulated Seed trade affect vegetal and animal biodiversity
Integrative Zoology, 2012Co-Authors: Marie-anne Auger-rozenberg, Alain RoquesAbstract:Cone and Seed Insects are considered the most important predators of tree Seeds during the pre-dispersal phase of development. Among them, exotic Seed chalcids in the genus Megastigmus invaded Europe as a result of the rapidly-increasing and mostly unregulated Seed trade for afforestation and ornamental plantations. Unlike their economic impact in Seed orchards, until recently, little attention was paid to the ecological impact of these Insects. In the present study, selected case studies of alien Megastigmus spp. were considered to assess their specific impact on the potential of natural regeneration of native woody plants and on the native entomofauna competing for Seed resource. We re-analyzed data from former studies that did not focus on these ecological interactions and, here, present previously unpublished results. Seeds of Douglas-fir, true cedars, true firs and wild roses were sampled all over Europe, and the relative importance of the native and invasive chalcid species was assessed as well as their specific impact on Seed yield. In most cases, the recent arrival of alien chalcids resulted in a significant decrease in the regeneration potential of the host trees. In the absence of competitors, alien chalcids occupied the entire Seed niche in Douglas-fir, but their impact tended to decrease after the arrival of invasive Seed bugs. In firs, alien chalcids tended to displace the native chalcids, but not in wild roses and cedars, where their damage was increasing. Different biological traits that might explain invasive success of alien chalcids are discussed. However, no general invasive patterns seem to exist.
-
INVAGRAINES - Invasions de peuplements forestiers par des insectes séminiphages exotiques : mécanismes, conséquences écologiques et moyens de surveillance
2006Co-Authors: Alain Roques, Marie-anne Auger-rozenberg, Solène Boivin, Marie-louise Cariou, Jean-francois Silvain, Bruno FadyAbstract:The project aimed at contributing to understand the ecological and genetic mechanisms underlying the possibilities of establishment of exotic Insects in the genus Megastigmus (Hymenoptera: Torymidae), specialized in the exploitation of forest Seeds, and at defining suitable methods of monitoring and management of the invasive insect populations. For that, we intended to compare two distinct models host Seed/ Megastigmus, crossing different first date of invasion and taxonomic structure of the forests: (i) true firs (Abies)/Megastigmus where the resource, indigenous, is exploited by a native species, M. suspectus, in competition with at least 5 invasive species of North American origin, and (ii) true cedars (Cedrus)/Megastigmus where the resource, itself exotic, is exploited by 2 invasive species without native candidates. In a large Seed sampling, involving 169 Abies stands in France and 55 in other European countries (Germany, Belgium, Bulgaria, Denmark, Spain, Greece, Italy, Norway, Poland, Romania, Switzerland, Tchéquie) and from the Middle East (Lebanon, Turkey), 90% of the Seed lots presented chalcid damage, with a rate of attack higher than 50% in ca. 1/3 of them. On the whole, 5 invasive species coming from North America were observed (M. rafni, M. pinus, M. milleri, M. specularis, and M. lasiocarpae) beside the native species M. suspectus. At present, exotic chalcids largely predominate in Western Europe, displacing the native Seed chalcids. M. rafni appears to be the most important species especially in natural fir stands with a much larger range than in the 1990s. In a similar way on Cedar, the exotic species M. schimitscheki, largely expanded since its introduction in the early 1990s and it supplants from now the other species introduced since a longer date (years 1950), M. pinsapinis, who was the only species observed in the years 1980. Several biological features likely to be implied in the apparent competitive superiority of both M. rafni and M. schimitscheki were examined in comparison to these of native species and dominated exotic species: length of female ovipositor, capability of developing in unpollenated Seeds, parthenogenesis, phenology of adult emergence, prolonged diapause. These elements appear relatively contradictory between them to explain the statute dominating of M. rafni, at least. For instance the species has the longest ovipositor, allowing it to oviposit in all cone species independently of cone size, and is capable of developing until adult in unpollenated Seeds. However, it is the latest species to emerge and it is not a thelytokous species conversely to the native M. suspectus. Bag tests were carried out using simultaneously or not the different species to look for resource sharing but the results will be available only during summer 2006 following adult emergence. On cedar, the same bagging experiments showed a division of the niche between M. schimitscheki and M. pinsapinis. Both prefer the apical part of the cone in non-competition situation but when the two species are placed in the same bag, their attacks added on the apical part rather than distribute on the cone. When Insects from North America were compared with these of Europe using mtDNA sequencing (cyt b), it appeared with no doubt that the individuals present in Europe belong well to North-American species, in particular M. milleri who was regarded as absent from Europe until the end of 1990s. This study in addition showed that the species M. pinus, presents in many European sites, has two haplotypes very different, suggesting two cryptic species. A phylogeographic study of M. rafni using both mitochondrial and nuclear markers EF-1alpha elongation gene, ITS2) showed the existence of two distinct clades separated by strong genetic distances (3.5%), suggesting different routes of invasion. A set of 6 microsatellite markers was used to analyse the genetic structure of the populations of M. rafni in the areas of origin and invasion. The results suggested an absence of structure according to the fir host species, but a clear differentiation of the Danish populations, which have a very low variability, suggesting a probable bootleneck. On Cedrus, 5 loci microsatelittes were used to study the genetic structuring of the populations of Megastigmus schimitscheki. Populations of the native zone (Cyprus, Turkey) were highly polymorphic and spatially structured, and largely differentiated from those of the introduction zone of southeastern France, fewly polymorphic. We suggested a strong bottleneck connected to a recent and limited introduction, even limited to only one origin. Only two of these populations show a stronger differentiation however, and are both located on the current face of expansion in direction of the Alps of the South. The invasive history of the exotic species on Cedar and fir trees thus appears largely different. The additional impact of the invasive exotic species on the potential of natural regeneration of the European fir plantations is quantitatively consequent. Whereas in the years 1980, Seed damage by M. suspectus very seldom exceeded 15%, percentages of attack higher than 50% are not rare any more (17.6% of the cases) due to the addition of the exotic species. On the other hand, the qualitative impact on the genetic pool of the fir plantations seemed much more limited. In particular, self-fertilized fir trees were equally infested as cross-fertilized trees. On a more general level, the taxonomic closeness of the native trees with respect to original host of the exotic insect seemed to constitute a relevant criterion to estimate the probability of establishment of exotic Insects associated to forest trees. We also developed simple and cheap methods for monitoring insect infestation in Seed lots at importation, based on differential flotation in solvents related to Seed density. A booklet will be published gathering these data. We expect it could help in defining regulations at importation of forest Seeds whereas such regulations do not exit in th European Union yet, and thus favour invasion of exotic Seed Insects
-
Potential invasion of China by exotic insect pests associated with tree Seeds
Biodiversity and Conservation, 2003Co-Authors: Alain Roques, Marie-anne Auger-rozenberg, J.h. Sun, O. HuaAbstract:A total of 39 insect species, mostly Seed chalcids in the genus Megastigmus (Hymenoptera), but also midges (Diptera), are listed as potential Seed-borne invaders of Chinese conifers. Although the number of native Seed Insects per conifer genus does not differ between China and other biogeographical regions, there are significantly fewer Seed Insects associated with each conifer genus in China than potential invaders. The eventual success of the invaders is likely to depend on the presence of native Chinese conifers that are congeneric with the original host, or on the presence of the original host as an exotic. When a substantial entomofauna is already associated with cones, competition for Seed resources may limit the potential impact of invaders because Seed Insects are usually the last organisms to colonize the cone. A survey of 26 fir species, both native and introduced to Europe, showed that overall Seed infestation by five species of exotic chalcids is negatively correlated to levels of damage by native Insects, except on the original hosts of the chalcids. Similar patterns are hypothesized for native firs, spruces, Douglas firs, and larches in China. Uncontrolled importation of Seeds and nuts of broad-leaved trees could also facilitate the introduction of Seed chalcids, Seed bruchids, tortricid moths and nut weevils into China. Only six species of Seed chalcids are present in China, out of the 72 known to attack broad-leaved Seeds over the world.
-
detection and evaluation of Seed damage of cypress cupressus sempervirens l in italy
Seed Science and Technology, 2000Co-Authors: Andrea Battisti, G Frigimelica, M Guido, Raffaella Cantini, E Feci, Alain RoquesAbstract:The damage to cypress Seed caused by Insects and tree pathogens was estimated in a plantation of a clone patented for resistance to cypress canker (Agrimed 1) and in a stand heavily attacked by the canker, which is caused by the fungus Seiridium cardinale. Five Seed quality categories were identified based on X-ray analysis. Filled Seeds were more abundant in the clonal plantation whereas empty Seeds prevailed in the stand. Seed damage by Insects, a Seed bug (Orsillus maculatus) and a Seed chalcid (Megastigmus wachtli), was higher in the stand whereas the brown degeneration of the gametophyte occurred more frequently in Seed from the clonal plantation. Cones infected with S. cardinale produced fewer filled Seeds and more empty Seeds than healthy cones. An incubation experiment conducted with Seed from healthy and fungus-infected cones allowed to detect the presence of pathogens and to evaluate the germination capacity of the Seed for each of the five Seed quality categories. In healthy cones the pathogens, mainly S. cardinale and Pestalotiopsis funerea, were associated with Seed damage by Insects. Seed germination occurred almost exclusively for filled Seeds. These findings may support the suitability of X-ray analysis in the assessment of cypress Seed quality and emphasize the role of Seed Insects in disseminating the fungus among cypress cones.
Hisashi Kajimura - One of the best experts on this subject based on the ideXlab platform.
-
Seed-Insect Fauna in Pre-Dispersal Acorns of Quercus Variabilis and Q. Serrata and Its Impact on Acorn Production
2003Co-Authors: Hiroshi Fukumoto, Hisashi KajimuraAbstract:Seed-insect fauna in pre-dispersal acorns of Quercus variabilis Blume and Q. serrata Thunb. ex Murray and impact of the Insects on acorn production were investigated in broad-leaved forests of central Japan. In Q. variabilis, Curculio robustus (Roelofs), curculio weevil (unidentified species), Poecilips cardamomi (Schaufuss), blastobasid moth (unidentified species), Pammene nemorosa Kuznetzov, Cydia glandicolana (Danilevsky) and Characoma ruficirra (Hampson) attacked pre-dispersal acorns. These Insects damaged more than 50% (site A) and less than 25% (site B) of the initial number of female reproductive organs of plants. By contrast, pre-dispersal acorns of Q. serrata were attacked by seven insect species: Mechoris ursulus (Roelofs), Curculio sikkimensis (Heller), P. cardamomi, cynipid wasp (unidentified species), Cydia danilevskyi (Kuznetzov), C. glandicolana and Cydia amurensis (Danilevsky). These Insects damaged less than 10% of the organs (site A and B). Thus, it is clear from our field data that Seed-insect fauna was markedly different between Q. variabilis and Q. serrata, and the Insects had a more serious effect on acorn production in Q. variabilis than in Q. serrata. A germination test of insect-damaged Q. variabilis acorns was carried out in the laboratory. Germination rate of acorns damaged by curculio weevils was significantly lower than that of the sound acorns, particularly when there was a larger endosperm loss of the damaged acorns. Thus, predation by Seed Insects would have a negative effect on acorn germination.
-
Guild structures of Seed Insects in relation to acorn development in two oak species
Ecological Research, 2001Co-Authors: Hiroshi Fukumoto, Hisashi KajimuraAbstract:We investigated patterns of acorn growth in Quercus variabilis Blume and Quercus serrata Thunb., seasonal trends in emergence of Seed Insects found in the acorns, oviposition periods of the Insects and falling periods of insect-infested acorns. In Q. variabilis, two insect guilds were associated with acorn development: (i) the immature acorn feeding (IAF) guild [Curculionidae sp., Poecilips cardamomi (Schaufuss), and Characoma ruficirra (Hampson)]; and (ii) the mature acorn feeding (MAF) guild [Curculio robustus (Roelofs), Curculio sikkimensis (Heller), and Cydia glandicolana (Danilevsky)]. In Q. serrata, there were three guilds: (i) the pistillate flower feeding (PFF) guild (cynipid wasp); (ii) the IAF guild [sap absorption by Mechoris ursulus (Roelofs)]; and (iii) the MAF guild (M. ursulus, C. sikkimensis, Cydia danilevskyi (Kuznetzov), C. glandicolana and Autostichidae sp.). The succession of guilds during acorn development may be a consequence of the use by different species of the limited food resource. The lack of a PFF guild in Q. variabilis that was found in our field site would have a positive effect on IAF guilds in utilizing the acorns.
-
Effects of insect predation on hypocotyl survival and germination success of maturequercus variabilis acorns
Journal of Forest Research, 2000Co-Authors: Hiroshi Fukumoto, Hisashi KajimuraAbstract:The rates of hypocotyl and radicle survival and of germination success were investigated in mature acorns of Quercus variabilis Blume in relation to endosperm loss due to Seed Insects. The acorns were damaged by curculio weevils (Coleoptera: Curculionidae) and moths, including tortricid moths (Lepidoptera: Tortricidae); the former were more abundant than the latter. Acorns damaged by curculio weevils showed a significantly lower germination rate when there was a large endosperm loss than the rate for sound acorns. The survival rate of the hypocotyl and radicle also decreased as endosperm loss increased. These results suggest that acorn germination is directly inhibited by damage to the hypocotyl and radicle, which depends on the amount of endosperm eaten by the weevils. However, the germination rate of acorns with hypocotyl and radicle was consistently high, irrespective of the degree of endosperm loss, which suggests that weevil-damaged acorns probably germinate, provided the hypocotyl and radicle survive until the cessation of damage.
-
Effects of Insect Predation on Hypocotyl Survival and Germination Success of Mature Quercus variabilis Acorns
Journal of Forest Research, 2000Co-Authors: Hiroshi Fukumoto, Hisashi KajimuraAbstract:The rates of hypocotyl and radicle survival and of germination success were investigated in mature acorns ofQuercus variabilis Blume in relation to endosperm loss due to Seed Insects. The acorns were damaged by curculio weevils (Coleoptera: Curculionidae) and moths, including tortricid moths (Lepidoptera: Tortricidae); the former were more abundant than the latter. Acorns damaged by curculio weevils showed a significantly lower germination rate when there was a large endosperm loss than the rate for sound acorns. The survival rate of the hypocotyl and radicle also decreased as endosperm loss increased. These results suggest that acorn germination is directly inhibited by damage to the hypocotyl and radicle, which depends on the amount of endosperm eaten by the weevils. However, the germination rate of acorns with hypocotyl and radicle was consistently high, irrespective of the degree of endosperm loss, which suggests that weevil-damaged acorns probably germinate, provided the hypocotyl and radicle survive until the cessation of damage.
Andrew J. Storer - One of the best experts on this subject based on the ideXlab platform.
-
Role of insect vectors in epidemiology and invasion risk of Fusarium circinatum, and risk assessment of biological control of invasive Pinus contorta
Biological Invasions, 2016Co-Authors: Eckehard G. Brockerhoff, Alain Roques, Margaret Dick, Rebecca Ganley, Andrew J. StorerAbstract:Pitch canker, caused by the pathogen Fusarium circinatum, is a serious disease of pines, Pinus species. It is a threat to natural and planted pine forests, and to date it has invaded countries across five continents. Pine-feeding Insects can play a key role in the epidemiology of the disease, as wounding agents allowing pathogen access or as vectors transmitting the pathogen from infected to healthy trees. We reviewed the role of Insects in the epidemiology of pitch canker worldwide and assessed which Insects are present in New Zealand that may act as wounding agents or vectors to determine whether pathogen invasion could adversely affect Pinus radiata plantation forests and urban trees. We also evaluated whether cone or Seed Insects of pines could be introduced as biological control agents of invasive Pinus contorta and how this may affect the impact of a potential F. circinatum invasion. As there are no native pines or other Pinaceae in New Zealand, there are only a few pine Insects, mainly accidental introductions. None of the Insects recorded on pines in New Zealand is likely to be a vector, suggesting low disease risk. Of six potentially suitable biocontrol candidates, the European pine cone weevil Pissodes validirostris is the most promising regarding host specificity and impact on Seed production, but there is uncertainty about its ability to act as a vector of F. circinatum. Our methodology to review and evaluate the vector potential of pine associates can be used as a generic framework to assess the potential impacts of F. circinatum invasion.
Hiroshi Fukumoto - One of the best experts on this subject based on the ideXlab platform.
-
Seed-Insect Fauna in Pre-Dispersal Acorns of Quercus Variabilis and Q. Serrata and Its Impact on Acorn Production
2003Co-Authors: Hiroshi Fukumoto, Hisashi KajimuraAbstract:Seed-insect fauna in pre-dispersal acorns of Quercus variabilis Blume and Q. serrata Thunb. ex Murray and impact of the Insects on acorn production were investigated in broad-leaved forests of central Japan. In Q. variabilis, Curculio robustus (Roelofs), curculio weevil (unidentified species), Poecilips cardamomi (Schaufuss), blastobasid moth (unidentified species), Pammene nemorosa Kuznetzov, Cydia glandicolana (Danilevsky) and Characoma ruficirra (Hampson) attacked pre-dispersal acorns. These Insects damaged more than 50% (site A) and less than 25% (site B) of the initial number of female reproductive organs of plants. By contrast, pre-dispersal acorns of Q. serrata were attacked by seven insect species: Mechoris ursulus (Roelofs), Curculio sikkimensis (Heller), P. cardamomi, cynipid wasp (unidentified species), Cydia danilevskyi (Kuznetzov), C. glandicolana and Cydia amurensis (Danilevsky). These Insects damaged less than 10% of the organs (site A and B). Thus, it is clear from our field data that Seed-insect fauna was markedly different between Q. variabilis and Q. serrata, and the Insects had a more serious effect on acorn production in Q. variabilis than in Q. serrata. A germination test of insect-damaged Q. variabilis acorns was carried out in the laboratory. Germination rate of acorns damaged by curculio weevils was significantly lower than that of the sound acorns, particularly when there was a larger endosperm loss of the damaged acorns. Thus, predation by Seed Insects would have a negative effect on acorn germination.
-
Guild structures of Seed Insects in relation to acorn development in two oak species
Ecological Research, 2001Co-Authors: Hiroshi Fukumoto, Hisashi KajimuraAbstract:We investigated patterns of acorn growth in Quercus variabilis Blume and Quercus serrata Thunb., seasonal trends in emergence of Seed Insects found in the acorns, oviposition periods of the Insects and falling periods of insect-infested acorns. In Q. variabilis, two insect guilds were associated with acorn development: (i) the immature acorn feeding (IAF) guild [Curculionidae sp., Poecilips cardamomi (Schaufuss), and Characoma ruficirra (Hampson)]; and (ii) the mature acorn feeding (MAF) guild [Curculio robustus (Roelofs), Curculio sikkimensis (Heller), and Cydia glandicolana (Danilevsky)]. In Q. serrata, there were three guilds: (i) the pistillate flower feeding (PFF) guild (cynipid wasp); (ii) the IAF guild [sap absorption by Mechoris ursulus (Roelofs)]; and (iii) the MAF guild (M. ursulus, C. sikkimensis, Cydia danilevskyi (Kuznetzov), C. glandicolana and Autostichidae sp.). The succession of guilds during acorn development may be a consequence of the use by different species of the limited food resource. The lack of a PFF guild in Q. variabilis that was found in our field site would have a positive effect on IAF guilds in utilizing the acorns.
-
Effects of insect predation on hypocotyl survival and germination success of maturequercus variabilis acorns
Journal of Forest Research, 2000Co-Authors: Hiroshi Fukumoto, Hisashi KajimuraAbstract:The rates of hypocotyl and radicle survival and of germination success were investigated in mature acorns of Quercus variabilis Blume in relation to endosperm loss due to Seed Insects. The acorns were damaged by curculio weevils (Coleoptera: Curculionidae) and moths, including tortricid moths (Lepidoptera: Tortricidae); the former were more abundant than the latter. Acorns damaged by curculio weevils showed a significantly lower germination rate when there was a large endosperm loss than the rate for sound acorns. The survival rate of the hypocotyl and radicle also decreased as endosperm loss increased. These results suggest that acorn germination is directly inhibited by damage to the hypocotyl and radicle, which depends on the amount of endosperm eaten by the weevils. However, the germination rate of acorns with hypocotyl and radicle was consistently high, irrespective of the degree of endosperm loss, which suggests that weevil-damaged acorns probably germinate, provided the hypocotyl and radicle survive until the cessation of damage.
-
Effects of Insect Predation on Hypocotyl Survival and Germination Success of Mature Quercus variabilis Acorns
Journal of Forest Research, 2000Co-Authors: Hiroshi Fukumoto, Hisashi KajimuraAbstract:The rates of hypocotyl and radicle survival and of germination success were investigated in mature acorns ofQuercus variabilis Blume in relation to endosperm loss due to Seed Insects. The acorns were damaged by curculio weevils (Coleoptera: Curculionidae) and moths, including tortricid moths (Lepidoptera: Tortricidae); the former were more abundant than the latter. Acorns damaged by curculio weevils showed a significantly lower germination rate when there was a large endosperm loss than the rate for sound acorns. The survival rate of the hypocotyl and radicle also decreased as endosperm loss increased. These results suggest that acorn germination is directly inhibited by damage to the hypocotyl and radicle, which depends on the amount of endosperm eaten by the weevils. However, the germination rate of acorns with hypocotyl and radicle was consistently high, irrespective of the degree of endosperm loss, which suggests that weevil-damaged acorns probably germinate, provided the hypocotyl and radicle survive until the cessation of damage.