Overview of the occurrence and prevention of Bemisia tabaci invasion in China

摘要Biological invasion refers to the process of invading into another new environment through natural or man-made means from the original place of existence,which includes several stages of introduction, colonization, incubation, diffusion and outbreak.Bemisia tabaci is a worldwide important agricultural pest composed of multiple biotypes. Studies have confirmed that the B biotype Bemisia tabaci that invaded China has been genetically differentiated, and the Q biotype Bemisia tabaci has replaced the B biotype in most areas of China. Bemisia tabaci has become the dominant biotype in the field.

Comparative Demographic Traits of the Whitefly (Bemisia tabaci) B Biotype against different Host Plants

The sucking pests, especially whitefly, have damaged various fields and fruit crops across the globe. The study of life-history is of prime importance to monitor the dynamics for preference of a species to its host. This study tested the prevalence and preference of a whitefly species, Bemisia tabaci (Gennadius) B biotype (Hemiptera: Aleyrodidae) on tomato, cotton, pepper, and okra as hosts using age-stage two-sex life table. Results revealed the highest pre-adult developmental duration, survival rate, and fecundity on tomato while the lowest values on okra. Population parameters such as the net reproductive rate (R0), intrinsic rate of increase (r), and finite rate of increase (λ) were demonstrated longer on cotton and tomato compared to much lower R0, r, and λ on pepper and okra. Okra responded significantly differently in the case of the mean generation time, T among all tested genotypes. These findings suggest the possibility of summer vegetables as more favorable hosts for B. tabaci. © 2021 Friends Science Publishers

Antibiosis and antixenosis resistance to oviposition by Bemisia tabaci (Gennadius) B biotype (Hemiptera: Aleyrodidae) in soybean genotypes

ABSTRACT: This study was aimed at assessing some biological parameters of Bemisia tabaci B biotype at immature stages to examine antibiosis in six soybean genotypes, besides antixenosis resistance to oviposition in choice and non-choice tests, under greenhouse and laboratory conditions. Between April 2016 and August 2016, bioassays were carried out at the Laboratory of Applied Entomology at College of Agricultural Sciences at Federal University of Grande Dourados (UFGD) Dourados (MS), Brazil. The following variables were evaluated: egg incubation period, nymphal and egg-to-adult duration, egg and nymph viability, and egg-to-adult survival on the soybean genotypes 68i70 RSF IPRO, M6210 IPRO, MS 947 IPRO, BMX Potência RR, M6410 IPRO, and ANTA 82 RR. Antixenosis resistance to oviposition by the silverleaf whitefly was found for MS 947 IPRO, while oviposition was highest for ANTA 82 RR, M6210 IPRO, and M6410 IPRO. The genotype MS 947 IPRO adversely affected egg and nymph viability, and egg-to-adult survival rates was the lowest among genotypes (59.75%), suggesting antibiosis resistance to this pest.

Siklus hidup dan statistik demografi kutukebul Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) biotipe B dan non-B pada tanaman cabai (Capsicum annuum L.)

<p>The whitefly <em>Bemisia tabaci</em> (Gennadius) biotype B also known as <em>Bemisia </em><em>argentifolii </em>(Gennadius) is a more malignant whitefly biotype in damaging plants compared to non-B biotype. Currently the whitefly <em>B. tabaci</em> biotype B has been reported its existence in Indonesia. Basic information such as life cycle, length of life, fecundity, and breeding ability of a whitefly is important information as a basis in preparing the whitefly control strategy. The aim of this research was to study the life cycle and demographic statistic of the <em>B. tabaci</em> biotype B and the non-B biotype on chili pepper. The study was conducted by observing the development of the whiteflies from eggs to adult in a grow chamber that the temperature and lighting were controlled. Observations were made on several aspects of biology and some parameters of demographic statistics. The results showed that the biotype B of <em>B. tabaci</em> has several different biological aspects with the non-B whitefly in chili pepper. The life cycle of the biotype B of <em>B. tabaci </em>and the non-B were different, 33.27 and 30.86 days respectively. The biotype B of <em>B. tabaci </em>had a net reproduction rate (R₀) which was similar to that of the non-B biotype as well as the average of its generation. However, the intrinsic increase rate (r) of the biotype B <em>B. tabaci</em> was 2.5 times shorter than the non-B biotype. The biotype B of <em>B. tabaci </em>doubled its population (DT) 2 times faster than the non-B biotype. It is clear that the biotype B of <em>B. tabaci </em>potentially more dangerous than the non-B.</p>

Identification of the B, Q, and native Brazilian biotypes of the Bemisia tabaci species complex using Scar markers

The objective of this work was to develop sequence-characterized amplified region (Scar) markers to identify the B, Q, and native Brazilian biotypes of the sweet potato whitefly [Bemisia tabaci (Hemiptera: Aleyrodidae)]. Random amplified polymorphic DNA (RAPD) amplification products, exclusive to the B and Brazilian biotypes, were selected after the analysis of 12,000 samples, in order to design a specific Scar primer set. The BT-B1 and BT-B3 Scar markers, used to detect the B biotype, produced PCR fragments of 850 and 582 bp, respectively. The BT-BR1 Scar marker, used to identify the Brazilian biotype, produced a PCR fragment of 700 bp. The Scar markers were tested against the Q biotype, and a flowchart was proposed to indicate the decision steps to use these primers, in order to correctly discriminate the biotypes. This procedure allowed to identify the biotypes that occur in field samples, such as the B biotype. The used set of primers allowed to discriminate the B, Q, and native Brazilian biotypes of B. tabaci. These primers can be successfully used to identify the B biotype of B. tabaci from field samples, showing only one specific biotype present in all cultures.

Specific identification, biology and symptoms of whitefly species infesting sunflower in South India

Whitefly species related to sunflower was identified as Bemisia tabaci (Gennadius). Further the identified whitefly species was confirmed to be indigenous B. tabaci on molecular basis by using B-biotype specific SCARs and biological silver leaf assay on sensitive pumpkin (cv Big variety). None of the whitefly samples could positive for the presence of B biotype. The results of the study on the pest life cycle under the laboratory conditions showed that, B. tabaci passed through four nymphal instars before the adult stage. The mean duration values of these stages were 5.6, 4.2, 4.4 and 5.6 days respectively. The total duration of the life cycle of B. tabaci ranged from 23- 42 days at the temperature of 29±2°C with a mean of 34.5. The damage to sunflower crop caused by the whitefly species is discussed with a special emphasis on its ability to transmit leaf curl viral disease.