| development of teratocytes associated with microctonus aethiopoides loan (hymenoptera: braconidae) in natural and novel host species. | a laboratory study investigated development of teratocytes derived from the parasitoid microctonus aethiopoides loan in the natural host, sitona discoideus gyllenhal, and in three novel hosts, the introduced weed biological control agent rhinocyllus conicus (froehlich), and two new zealand native species nicaeana cervina broun and irenimus stolidus broun. weevils were exposed to parasitoids and then examined 6, 10 and 15 days post-parasitism for parasitoid stage and size, and teratocyte number a ... | 2001 | 11119771 |
| factors affecting parasitism by microctonus aethiopoides (hymenoptera: braconidae) and parasitoid development in natural and novel host species. | a laboratory study of aspects of parasitoid host acceptance, suitability and physiological regulation in natural and novel host species was carried out to investigate the degree of variability encountered with different hosts and to determine the value of such observations in host range determination. the parasitoid microctonus aethiopoides loan was exposed to a natural host, sitona discoideus gyllenhal (coleoptera: curculionidae) and three novel hosts, the new zealand native nicaeana cervina br ... | 2001 | 11567586 |
| virus-like particles in the ovaries of microctonus aethiopoides loan (hymenoptera: braconidae): comparison of biotypes from morocco and europe. | virus-like particles (mavlp) have been discovered in the ovarial epithelial cells of the solitary, koinobiont, endoparasitoid, microctonus aethiopoides loan (hymenoptera: braconidae) introduced to new zealand originally from morocco to control the lucerne pest sitona discoideus gyllenhal (coleoptera: curculionidae). mavlp have been found in all females examined. it has been suggested, although not demonstrated, that like many other such vlp found in parasitoids, mavlp might play a role in host i ... | 2006 | 16375917 |
| field parasitism of nontarget weevil species (coleoptera: curculionidae) by the introduced biological control agent microctonus aethiopoides loan (hymenoptera: braconidae) over an altitude gradient. | the parasitoid, microctonus aethiopoides loan (hymenoptera: braconidae) was introduced into new zealand in 1982 to control the alfalfa pest, sitona discoideus gyllenhal (coleoptera: curculionidae). studies have shown that a number of nontarget weevil species are attacked in the field by this parasitoid. a field study was carried out to investigate nontarget parasitism by m. aethiopoides over an altitudinal sequence from the target host habitat (alfalfa) into native grassland. three locations wer ... | 2007 | 17716473 |
| modeling embryo development of sitona discoideus gyllenhal (coleoptera: curculionidae) under constant temperature. | the alfalfa root weevil, sitona discoideus (coleoptera: curculionidae), is an important pest of alfalfa. the developmental rates of the embryo development were recorded at eight constant temperatures ranging from 8.5 to 30 degrees c. using 10 models (1 linear and 9 nonlinear), we evaluated the relationship between constant temperature and developmental rate. embryo development was shortest (8.5 d) and longest (69 d), at 28 and 8.5 degrees c, respectively. the threshold temperature (t0) and the t ... | 2008 | 19161679 |
| identification and electrophysiological studies of (4s,5s)-5-hydroxy-4-methyl-3-heptanone and 4-methyl-3,5-heptanedione in male lucerne weevils. | an investigation to identify a sex or aggregation pheromone of sitona discoideus gyllenhål (coleoptera: curculionidae) is presented. antenna flicking and attraction behaviors evoked by conspecifics of both sexes were recorded in arena bioassays, where attraction of females to males was observed. air entrainment of both males and females was conducted in separate chambers. gas chromatographic-mass spectrometric analysis of headspace volatiles revealed that two male-specific compounds, 4-methyl-3, ... | 2013 | 23238636 |
| above-belowground herbivore interactions in mixed plant communities are influenced by altered precipitation patterns. | root- and shoot-feeding herbivores have the capacity to influence one another by modifying the chemistry of the shared host plant. this can alter rates of nutrient mineralization and uptake by neighboring plants and influence plant-plant competition, particularly in mixtures combining grasses and legumes. root herbivory-induced exudation of nitrogen (n) from legume roots, for example, may increase n acquisition by co-occurring grasses, with knock-on effects on grassland community composition. li ... | 2016 | 27047522 |
| effects of elevated temperature and co2 on aboveground-belowground systems: a case study with plants, their mutualistic bacteria and root/shoot herbivores. | interactions between above- and belowground herbivores have been prominent in the field of aboveground-belowground ecology from the outset, although little is known about how climate change affects these organisms when they share the same plant. additionally, the interactive effects of multiple factors associated with climate change such as elevated temperature (et) and elevated atmospheric carbon dioxide (eco2) are untested. we investigated how et and eco2 affected larval development of the luc ... | 2013 | 24273544 |