geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Bottom-up and top-down control of pear psylla (Cacopsylla pyricola): Fertilization, plant quality, and the efficacy of the predator Anthocoris nemoralis


, : Bottom-up and top-down control of pear psylla (Cacopsylla pyricola): Fertilization, plant quality, and the efficacy of the predator Anthocoris nemoralis. Biological control: theory and application in pest management 43(3): 257-264

Herbivore population dynamics are governed both by bottom-up (plant-mediated) and by top-down (natural enemy-mediated) processes, with the potential for interaction between them. Pear psylla (Cacapsyllapyricola Foerster) is a phytophagous pest in pear orchards. Pear psylla is commonly attacked by several different natural enemies, but it may escape control, especially if fertilizer additions and new shoot production are not carefully managed. We tested the hypothesis that plant quality mediates the efficacy of an important, natural enemy of pear psylla, Anthocoris nemoralis. One year-old caged Bartlett pear trees were fertilized at either low (5 mM N) or high (20 mM N) levels of nitrogen, then either psylla or psylla and Anthocoris were added to each tree. We measured plant growth, psylla population size, and Anthocoris establishment to determine effects of fertilizer and predation on psylla population dynamics. Trees receiving more N were taller, had longer total branches, a greater total number of leaves, and higher leaf nitrogen content. Psylla populations were also larger in the high N treatment. Anthocoris establishment and reproduction was positively related to the density of psylla at the time predators were added. And although psylla densities were, over-all, lower on trees where Anthocoris was present, the level to which Anthocoris suppressed psylla was not significantly affected by fertilizer level. These results indicate that the. efficacy of this predator is not strongly mediated by plant quality, at least at the local (i.e. tree) scale. Minimizing fertilizer additions to the minimum level required for proper fruit set is likely to be an important feature of successful pear psylla biocontrol programs.

US$19.90

DOI: 10.1016/j.biocontrol.2007.09.001


Other references

W.Heinen, 1967: Ion accumulation in bacterial systems, III Respiration-dependent accumulation of silicate by a particulate fraction from Proteus mirabilis cell-free extracts. Membrane fragments of Proteus mirabilis, precipitating between 25,000g and 100,000g (105g heavy particle fraction) after sonic treatment of the cells, were found to accumulate silicate along with the consumption of extra oxygen. The extra O2 consu...

Freese, A.S., 1977: So, do we want to be doctors?. Tic 36(6): 13-14

Purnell, J.Q.; Peppone, L.J.; Alcaraz, K.; McQueen, A.; Guido, J.J.; Carroll, J.K.; Shacham, E.; Morrow, G.R., 2012: Perceived discrimination, psychological distress, and current smoking status: results from the Behavioral Risk Factor Surveillance System Reactions to Race module, 2004-2008. We examined the association between perceived discrimination and smoking status and whether psychological distress mediated this relationship in a large, multiethnic sample. We used 2004 through 2008 data from the Behavioral Risk Factor Surveillan...

Spahn, D.R., 2003: Artificial oxygen carriers: status 2002. Vox Sanguinis 83 Suppl 1: 281-285

Vongsuvanlert, V.; Tani, Y., 1988: L iditol production from l sorbose by a methanol yeast candida boidinii kloeckera sp no. 2201. Production of L-iditol (iditol) from L-sorbose (sorbose) with D-sorbitol dehydrogenase coupled with NADH regeneration under methanol oxidation was studied with the resting cell system of a methanol yeast, Candida boidinii (Kloeckera sp.) no. 2201....

Alimov, K.B., 1980: Pathogenesis of scanned spleen symptoms. Sovetskaia Meditsina: 115-118

Takaoka, H.; Takeuchi, M.; Odake, M.; Yokoyama, M., 1992: Assessment of myocardial oxygen consumption (Vo2) and systolic pressure-volume area (PVA) in human hearts. Several studies have recently reported that the relationship between myocardial oxygen consumption per beat (Vo2) and left ventricular (LV) systolic pressure-volume area (PVA), which represents total mechanical energy generated by contraction, is...

Freiberg, A.A.; Fish, D.N.; Louis, D.S., 1993: Hand manifestations of oxalosis. Oxalosis is an unusual metabolic disease that results either from an inherited hepatic enzyme deficiency or as the result of poor oxalate clearance during chronic hemodialysis. We present two cases of oxalosis and describe the hand manifestations...

Chen Jin-Shi; Chu Xue-Lei; Shao Mao-Rong; Zhong Hua, 1991: Carbon isotope study of the Permian-Triassic boundary sequences in China. Systematic investigations for carbon isotopes on five stratigraphic sections of the marine carbonate strata from the Upper Permian to the Lower Triassic in the southern China have been conducted. The results obtained in these sections indicate the...

Tezuka, Y., 2017: Topological Polymer Chemistry Designing Complex Macromolecular Graph Constructions. The precision design of topologically intriguing macromolecular architectures has continuously been an attractive challenge in polymer science and polymer materials engineering. A class of multicyclic polymer topologies, including three subclasses...