Florida Entomologist (2000) 83, 446-458

James H. Tsai, Jin-Jun Wang and Ying-Hong Liu (2000)
Sampling of Diaphorina citri (Homoptera: Psyllidae) on orange Jessamine in Southern Florida
Florida Entomologist 83 (4), 446-458
Abstract: Dispersion indices and related statistics of Asian citrus psyllid, Diaphorina citri Kuwayama, on orange jessamine [Murraya paniculata (L.) Jack] shoots in southern Florida from 1998 to 1999 were determined with 235 data sets and used to develop sampling plans. Three regression models, Taylor's power law, Iwao's patchiness regression, and k = c +dm [k = m²/ (S² - m)] (where k is the parameter for the negative binomial distribution) were used to analyze the data. Taylor's power law (alpha = 0.3407 ± 0.03, b = 1.2971 ± 0.03, r² = 0.88) fit the data better than Iwao's model (alpha = -0.3217 ± 0.12, ß = 1.6979 ± 0.06, r² = 0.76). Taylor's b and Iwao's ß were both significantly > 1, indicating that D. citri populations were aggregated. Iwao's alpha was significantly < 0, indicating that the basic distribution component of D. citri was the individual insect. The slope d (0.7489 ± 0.48) was indistinguishable from 0, indicating the existence of a common k (estimated as 1.2741). The incidence (P₁ , proportion infested) and mean density (m) relationship was developed by negative binomial distribution (NBD) basis and Nachman's model [ln (m) = 0.2277 + 1.2444 ln (-ln (P₀ )] (where P₀ = Proportion of uninfested sampling units in a sample). The NBD was appropriate for studying D. citri distribution based on comparison of NBD basis and Nachman's models. The relationship to determine sample sizes for fixed levels of precision and fixed-precision-level stop lines for sequential sampling was also developed.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Full text of article
Database assignments for author(s): James H. Tsai, Jin-Jun Wang

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
population dynamics/ epidemiology

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Diaphorina citri	Citrus (genus)	U.S.A. (SE)