| arthropod invasion disrupts cycas micronesica seedling recruitment. | we recently described characteristics of reproductive effort for the cycad cycas micronesica on the island of guam. the data were serendipitously recorded just prior to the devastating invasion of the armored scale aulacaspis yasumatsui. this invasion decimated the cycad population and after six years of infestation no recruitment is occurring among the survivors. we describe various underlying mechanisms that may explain how this homopteran insect has eliminated host recruitment among categorie ... | 2011 | 22446554 |
| vertical stratification in arthropod spatial distribution research. | spatial heterogeneity within individual host trees is often overlooked in surveys of phytophagous arthropod abundance and distribution. the armored scale aulacaspis yasumatsui is controlled by the predator rhyzobius lophanthae to a greater degree on leaves at 75-cm height than on leaves at ground level within its host tree cycas micronesica. the direct influence of elevation on the predator indirectly generates vertical heterogeneity of the scale insect. arthropod sampling schemes that fail to i ... | 2013 | 24567772 |
| does cycad aulacaspis scale (aulacaspis yasumatsui, hemiptera: diaspididae) play a direct role in causing soil phytotoxicity? | cycad aulacaspis scale (cas, aulacaspis yasumatsui, hemiptera: diaspididae) was accidentally introduced to guam in 2003, and has caused acute mortality of the dominant, endemic forest tree cycas micronesica. a phytotoxic legacy in the soils beneath cycad trees killed by cas over a period of about three years has been demonstrated. the origin of the toxicity may be large quantities of cas-encrusted cycad leaf litter. we explore the possibility that a major contribution to this toxic legacy may co ... | 2014 | 25083170 |
| canopy and knowledge gaps when invasive alien insects remove foundation species. | the armored scale aulacaspis yasumatsui invaded the northern range of the cycad cycas micronesica in 2003, and epidemic tree mortality ensued due to a lack of natural enemies of the insect. we quantified cycad demographic responses to the invasion, but the ecological responses to the selective removal of this foundation species have not been addressed. we use this case to highlight information gaps in our understanding of how alien invasive phytophagous insects force cascading adverse ecosystem ... | 2013 | 23847712 |
| increased threat of island endemic tree's extirpation via invasion-induced decline of intrinsic resistance to recurring tropical cyclones. | cycas micronesica populations in guam have been threatened by the invasion of the armored scale aulacaspis yasumatsui. i integrate four factors that illuminate an acute need for intervention to reduce an unprecedented threat caused by the invasion. first, mechanical failure of healthy c. micronesica trees during catastrophic winds is rare because of the cycad tree's unique pachycaulis stem design. second, tree-winching and three-point bend stress tests revealed the natural resistance to damage f ... | 2013 | 23802037 |
| temperature-dependent demography of aulacaspis yasumatsui (hemiptera: diaspididae). | aulacaspis yasumatsui takagi continues to threaten the extinction of the endemic and endangered cycas taitungensis (shen et al.) in taiwan. failure to understand its population demographic parameters in detail will continue to hinder the success of pest management practices. an in-depth knowledge of the development, survival, and fecundity of a. yasumatsui under different environmental conditions is necessary to understand its' population growth. the demography of a. yasumatsui was studied in th ... | 2012 | 23156153 |
| three invasive insects alter cycas micronesica leaf chemistry and predict changes in biogeochemical cycling. | leaf litter chemical traits were measured for cycas micronesica plants in guam following leaf herbivory by the scale aulacaspis yasumatsui, the butterfly chilades pandava caterpillar, or the leaf miner erechthias sp. to determine the influence of the non-native pests on litter quality. scale herbivory increased litter phenols above those of undamaged leaves but did not influence lignin or cellulose concentrations. butterfly caterpillar herbivory increased litter phenols above and decreased litte ... | 2016 | 27829976 |
| boomeranging in structural defense: phytophagous insect uses cycad trichomes to defend against entomophagy. | plant defensive behaviors that resist arthropod herbivory include trichome-mediated defenses, and variation in plant trichome morphology and abundance provides examples of the mechanistic complexities of insect-plant interactions. trichomes were removed from cycas revoluta cataphylls on the island of guam to reveal aulacaspis yasumatsui scale infestation, and predation of the newly exposed insects by pre-existing rhyzobius lophanthae beetles commenced within one day. the quotient of predated/tot ... | 2012 | 22990448 |