Mário Eidi Sato

Host Ranges and Infestation Indices of Fruit Flies (Tephritidae) and Lance Flies (Lonchaeidae) in São Paulo State, Brazil

ABSTRACT The knowledge of the status of the different fruit fly species and their hosts is essential to manage these insects. This work reports the associations of tephritoid fly species (Tephritidae and Lonchaeidae) with fruits collected from 67 municipalities in Sã;o Paulo State, Brazil. From Mar 1997 to Sep 2003, a total of 536 fruit samples was collected from 63 plant species in 28 botanical families. From overall collections, the average infestation index ranged from 0.01 to 22.98 pupae per fruit. The highest infestation was observed in Cucurbita moschata (Dusc.) Poir, followed by Mangifera indica Linnaeus and Passiflora alata Curtis, with 107.14, 59.00, and 38.50 pupae/ fruit, respectively. The pupae/kg of fruit index ranged from 0.01 in Manihot esculenta Crantz to 277.91 in Citharexylum myrianthum Cham. In total 43,104 pupae and 26,368 adults of Tephritoidea were recovered from all collections. The following Tephritoidea adults were observed: Anastrepha amita Zucchi, Anastrepha bahiensis Lima, Anastrepha distincta Greene, Anastrepha. fraterculus (Wied.), Anastrepha grandis (Macquart), Anastrepha leptozona Hendel, Anastrepha obliqua (Macquart), Anastrepha pseudoparallela (Loew), Anastrepha serpentina (Wied.), Anastrepha sororcula Zucchi, Ceratitis capitata (Wied.) and Lonchaeidae. All host species infested by C. capitata or Anastrepha spp. also were infested by Lonchaeidae.

Fitness costs associated with milbemectin resistance in the two-spotted spider mite Tetranychus urticae

The two-spotted spider mite Tetranychus urticae Koch is one of the most important pests of a wide range of crops worldwide. Its control is still largely based on the use of acaricides. However, due to its short life-cycle, high fecundity and arrhenotokous reproduction, it is able to develop resistance to these compounds very rapidly. Preliminary studies for milbemectin resistance in T. urticae showed that, under laboratory conditions, such resistance was unstable in the absence of a selection pressure. The aim of this study was to evaluate the possible fitness costs associated with milbemectin resistance in T. urticae. Comparison of biological traits between resistant and susceptible strains indicated the occurrence of fitness costs associated with milbemectin resistance. The resistant strain showed a longer juvenile development period for females, lower fecundity and a higher proportion of males among the progeny. The figures for net reproductive rate (R 0), intrinsic rate of natural increase (r m) and finite rate of increase (λ) were higher in the susceptible strain. The instability of milbemectin resistance can be exploited in resistance management programmes.

A New Arbitrary Shape DCT for Object-Based Image Coding

Publisher Summary This chapter proposes an image coding scheme that expresses an arbitrary shape region by using block-based orthogonal basis functions. Transform coding for arbitrary shape regions is one of the key issues of object-based image coding. Such schemes are divided into two categories. This chapter focuses on the second category that is Region Filling DCT (RF-DCT), Shape Adaptive DCT (SA-DCT), and Region Support DCT (RS-DCT). RF-DCT makes rectangular blocks by filling the outside of the region, and applies the conventional two dimensional DCT to the blocks. Hence, the number of samples to be coded is increased. In SA-DCT, one dimensional DCT is applied to each horizontal line, shifting the coefficients to low frequency side; also, one dimensional DCT is applied to vertical lines. In this scheme, the shift of the coefficients decreases vertical correlation. In RS-DCT, pixels in the region are expressed approximately by using a limited number of basis functions of DCT. High coding performance is obtained by the proper selection of basis functions since it uses the same number of basis functions as that of pixels to be coded and the selected basis functions are nearly orthogonal.