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Biology and life table of Tetranychus neocaledonicus on lima bean

Gomes Neto, Antonio Vieira, Silva, Paulo Roberto Ramalho, Melo, José W. S., Melo Júnior, Luiz Carlos de, França, Solange Maria de
International journal of acarology 2017 v.43 no.8 pp. 622-626
Phaseolus lunatus, Tetranychus, adults, eggs, females, hosts, immatures, inventories, life tables, lima beans, longevity, males, mites, nymphs, oviposition, pests, photoperiod, relative humidity, sex ratio, viability
The objective of this work was to evaluate the potential of the use of lima bean (Phaseolus lunatus) as hosts of the mite Tetranychus neocaledonicus. For such, the biology and fertility life table of T. neocaledonicus on P. lunatus plants were evaluated. The experiment was carried out in a controlled environment at 25 ± 1°C and 75 ± 10% relative humidity (RH), with a 12-h photoperiod. The eggs used in the experiments were from inventories. Evaluations were performed twice daily in the immature stage. While in the adult stage, a single evaluation was carried out, in which reproductive aspects of T. neocaledonicus were analysed, being determined the daily oviposition and the longevity of females and males. The average life cycle of females and males was 11.94 and 11.48 days, respectively. For females, the development of the mobile period of larva, protonymph, and deutonymph presented an average of 2.23, 1.17, and 1.24 days, respectively, and for males, an average of 2.20, 1.06, and 1.21 days, respectively. Regarding the post-embryonic non-mobile periods of protochrysalis, deutochrysalis, and teleiochrysalis, the averages obtained were 0.66, 0.76, and 0.78 days, respectively, for females and males 0.62, 0.68, and 0.73 days, respectively. The sex ratio was 0.77 and the average longevity of females and males was 44.30 and 48.30 days, respectively. In the life table parameters, the following variables were measured: intrinsic rate of increase (rₘ), 0.14 f/f/d; mean generation duration (T), 21.2 days; net reproductive rate (R₀), 24.7 individuals; finite rate of increase (λ), 1.16 f/f; and population doubling time, 4.64 days. Therefore, lima bean allows the development and reproduction of the mite T. neocaledonicus. The rapid development, allied to the high viability of immature forms and the high oviposition of females, suggests that this mite can achieve pest status in this crop.