Effects of reducing sample size on density estimates of citrus rust mite (Acari: Eriophyidae) on citrus fruit: simulated sampling.
نویسندگان
چکیده
The consequence of reducing sample size on the accuracy and precision of estimates of citrus rust mite, Phyllocoptruta oleivora (Ashmead), densities on oranges was investigated. The sample unit was a 1-cm2 surface area on fruit. Sampling plans consisting of 360, 300, 200, 160, 80, 48, 36, or 20 samples per 4 ha were evaluated through computer simulations by using real count data from 32 data sets of 600 sample units per 4 ha. The original and reduced sampling plans were hierarchical with different numbers of sample areas per 4 ha, trees per area, fruit per tree, and samples per fruit. Individual estimates (n=100 simulations per data set) using each plan were sometimes considerably below or above target densities. In an original set of count data with a mean of six mites per cm2, simulations of 36 samples per 4 ha produced individual estimates ranging from one to 16 mites per cm2, whereas 80 samples per 4 ha produced estimates ranging from two to 10 mites per cm2. The plans consisting of 36 or more samples were projected to provide precision levels of 0.25 (SEM/mean) or better at densities of five or more mites per cm2 based on log-data, a projection that needs to be verified under real-grove situations. Each plan consistently provided mite detection in these sampling simulations except those consisting of 20 or 36 samples, which sometimes failed to detect mites when the target density was less than five mites per cm2. The study provided insight into the probable precision, accuracy and detection thresholds for eight candidate sampling plans varying from relatively low to high resource input.
منابع مشابه
Hall et al.: Citrus Rust Mite & the Negative Binomial 1 CITRUS RUST MITE (ACARI: ERIOPHYIDAE) COUNTS ON FRUIT AND THE NEGATIVE BINOMIAL DISTRIBUTION
Count data for the number of citrus rust mites per cm 2 on fruit across a 4-ha (10acre) area of orange trees followed the negative binomial probability distribution 79% of the time based on chi-square tests. A correlation of r = 0.993 was found between observed counts and counts projected based on the distribution. A common k of 0.149 was computed but generally appeared more suitable for mean d...
متن کاملBiological control of citrus insect pests in Turkey
The usage and acceptability of biological control methods are set to increase in agriculture in the future because of food safety and pesticide residue issues. Biological control implementation in Turkey started with control of cottony cushion scale Icerya purchasi (Homoptera: Margarodidae) through the introduction and release of Rodolia cardinalis (Coleoptera: Coccinellidae) in citrus plantati...
متن کاملControl of Tylenchulus semipenetrans on Citrus With Aldicarb, Oxamyl, and DBCP.
Soil application of DBCP (l,2-dibromo-3-chloropropane) and foliar applications of oxamyl (methyl N',N'-dimethyl-N-[(methylcarbamoyl)oxy]-l-thiooxamimidate) were compared for control of Tylenchulus semipenetrans in a grapefruit (Citrus paradisi) orchard, DBCP reduced nematode populations and increased fruit growth rate, fruit size at harvest, and yield compared to the untreated controls in the 2...
متن کاملTwo Species of Cecidomyiidae Predacious on Citrus Rust Mite, Phyllocoptruta Oleivora, on Florida Citrus
متن کامل
Effect of foliar application of some nutrient elements on traits related to fruit splitting of Page mandarin
Preharvest fruit splitting disorder causes significant damage to producers of sensitive citrus cultivars, therefore, proper management of tree nutrition with key elements reduces the probability the occurrence of this disorder can be effective in reducing fruit splitting. Accordingly, to investigate the effects of foliar application of 1% potassium nitrate, 1% calcium nitrate and 0.5% boric aci...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Journal of economic entomology
دوره 98 3 شماره
صفحات -
تاریخ انتشار 2005