Spatial distribution pattern and sequential sampling plans for Bactrocera oleae (Gmelin) (Dip: Tephritidae) in olive orchards

Abstract

The distribution of adult and larvae Bactrocera oleae (Diptera: Tephritidae), a key pest of olive, was studied in olive orchards. The first objective was to analyze the dispersion of this insect on olive and the second was to develop sampling plans based on fixed levels of precision for estimating B. oleae populations. The Taylor's power law and Iwao's patchiness regression models were used to analyze the data. Our results document that Iwao's patchiness provided a better description between variance and mean density. Taylor's b and Iwao's b were both significantly more than 1, indicating that adults and larvae had aggregated spatial distribution. This result was further supported by the calculated common k of 2.17 and 4.76 for adult and larvae, respectively. Iwao's a for larvae was significantly less than 0, indicating that the basic distribution component of B. oleae is the individual insect. Optimal sample sizes for fixed precision levels of 0.10 and 0.25 were estimated with Iwao's patchiness coefficients. The optimum sample size for adult and larvae fluctuated throughout the seasons and depended upon the fly density and desired level of precision. For adult, this generally ranged from 2 to 11 and 7 to 15 traps to achieve precision levels of 0.25 and 0.10, respectively. With respect to optimum sample size, the developed fixed-precision sequential sampling plans was suitable for estimating flies density at a precision level of D=0.25. Sampling plans, presented here, should be a tool for research on pest management decisions of B. oleae.

Tritrophic relations and spatial distribution of fruit flies (Diptera: Tephritidae) in the Cerrado and Caatinga regions in Piauí, Brazil

“…Studies evaluating the population distribution of fruit flies associated with host plants are useful to understand the real biotic potential of these species (Zucchi, 2000;Midgarden et al, 2014;Enkerlin et al, 2015;Arbab and Mirphakhar, 2016;Nicácio et al, 2019;Teixeira et al, 2021). It is important to understand these introductions in ecotonal areas, whose relationships are mixed and with high structural complexity, provide locational and behavioral information for insect management tactics of economic importance (Costa-Coutinho et al, 2019).…”

Dispersion and Binomial Sequential Sampling Plan for Lesser Date Moth <em>Batrachedra</em> <em>amydraula</em> (Lepidoptera: Batrachedridae) Infesting Date Palm Plantations

“…Several sequential sampling programs have been developed to estimate the densities of numerous pests infesting crops, such as aphids (Hemiptera) [30][31][32][33][34][35], lepidopteran pests [36][37][38], and coleopteran pests [39][40][41], as well as the insects attacking the fruit trees, such as fruit flies and borers [42][43][44].…”