Post-release evaluation of Eretmocerus hayati Zolnerowich and Rose in Australia

2008 ◽  
Vol 99 (2) ◽  
pp. 193-206 ◽  
Author(s):  
P.J. De Barro ◽  
M.T. Coombs
Keyword(s):  
Bemisia Tabaci ◽  
Host Plants ◽  
World Wide ◽  
Order Of Magnitude ◽  
Biotype B ◽  
Magnitude Increase ◽  
B Biotype

AbstractBemisia tabaci biotype B is a significant pest of agriculture world-wide. It was first detected in Australia in 1994. Assessments of the potential of parasitoids already present in Australia to control this pest indicated that two species of Eretmocerus and 11 species of Encarsia were present, but they did not exert sufficient control with a combined average of 5.0±0.3% apparent parasitism of 4th instars. Further, only 25% of samples containing biotype B had parasitised individuals present. The surveys also identified that fewer B biotype were being parasitised compared with the Australian indigenous biotype. Overall, Er. mundus was the most abundant parasitoid prior to the introduction. Previous research indicated that Er. hayati offered the best prospects for Australia and, in October 2004, the first releases were made. Since then, levels of apparent parasitism have averaged 29.3±0.1% of 4th instars with only 24% of collections having no parasitism present. Eretmocerus hayati contributed 85% of the overall apparent parasitism. In addition, host plants of the whitefly with low or no parasitism prior to the release have had an order of magnitude increase in levels of parasitism. This study covers the establishment of the case to introduce Er. hayati and the post-release establishment period November 2004–March 2008.

Response of the polyphagous whitefly Bemisia tabaci B-biotype (Hemiptera: Aleyrodidae) to crop diversification – influence of multiple sensory stimuli on activity and fecundity

2006 ◽  
Vol 96 (1) ◽  
pp. 15-23 ◽  
Author(s):  
T.L. Bird ◽  
K. Krüger
Keyword(s):  
Host Plant ◽  
Bemisia Tabaci ◽  
Host Plants ◽  
Threshold Model ◽  
Choice Test ◽  
Crop Diversification ◽  
Sensory Stimuli ◽  
Tomato Cultivars ◽  
Polyphagous Insects ◽  
B Biotype

AbstractA fundamental question concerning crop diversification is which mechanisms determine pest population size in polycultures compared to monocultures. It has been proposed that polyphagous insects experience a difficulty in decision-making when selecting food and oviposition sites in the presence of different host plants. This hypothesis was tested in the extremely polyphagous whitefly Bemisia tabaci (Gennadius) B-biotype, where behaviour (movement) and fecundity of females were compared in choice and no-choice experiments in the laboratory. Two parallel tests, one on different crops, including cucumber, bean and tomato, and one on different tomato cultivars, were conducted using both a mixture of crops and of tomato cultivars, as opposed to the same crop or cultivar respectively. Bemisia tabaci showed a distinct behavioural preference for cucumber when exposed to different crops simultaneously suggesting that B. tabaci has no difficulty in choosing a host plant, i.e. in making a decision, when one of the plants offered in the choice test is a high-ranking host plant. Conversely, when only low-ranking hosts of similar, but not identical, signatures were present, female whiteflies appeared to have difficulty in making a decision, resulting in increased movement and reduced fecundity. This is consistent with both the hypothesis that polyphagous insects have a problem selecting a host plant when given multiple choices and with the hierarchy threshold model, under which egg loads are lessened between periods of searching for better host plants. The study illustrates how insect behaviour can be affected by intercropping not only with different crops, but also with different cultivars of the same crop, thus potentially providing a simple and efficient way of reducing whitefly population build-up.

Biotype-dependent secondary symbiont communities in sympatric populations of Bemisia tabaci

2007 ◽  
Vol 97 (4) ◽  
pp. 407-413 ◽  
Author(s):  
E. Chiel ◽  
Y. Gottlieb ◽  
E. Zchori-Fein ◽  
N. Mozes-Daube ◽  
N. Katzir ◽  
...  
Keyword(s):  
Bemisia Tabaci ◽  
Host Plants ◽  
Virus Transmission ◽  
Symbiotic Bacterium ◽  
Infection Frequency ◽  
Sympatric Populations ◽  
Bacterial Composition ◽  
Secondary Symbiont ◽  
Q Biotype ◽  
B Biotype

AbstractThe sweet potato whitefly, Bemisia tabaci, harbors Portiera aleyrodidarum, an obligatory symbiotic bacterium, as well as several secondary symbionts including Rickettsia, Hamiltonella, Wolbachia, Arsenophonus, Cardinium and Fritschea, the function of which is unknown. Bemisia tabaci is a species complex composed of numerous biotypes, which may differ from each other both genetically and biologically. Only the B and Q biotypes have been reported from Israel. Secondary symbiont infection frequencies of Israeli laboratory and field populations of B. tabaci from various host plants were determined by PCR, in order to test for correlation between bacterial composition to biotype and host plant. Hamiltonella was detected only in populations of the B biotype, while Wolbachia and Arsenophonus were found only in the Q biotype (33% and 87% infection, respectively). Rickettsia was abundant in both biotypes. Cardinium and Fritschea were not found in any of the populations. No differences in secondary symbionts were found among host plants within the B biotype; but within the Q biotype, all whiteflies collected from sage harboured both Rickettsia and Arsenophonus, an infection frequency which was significantly higher than those found in association with all other host plants. The association found between whitefly biotypes and secondary symbionts suggests a possible contribution of these bacteria to host characteristics such as insecticide resistance, host range, virus transmission and speciation.

scholarly journals Microsatellites reveal extensive geographical, ecological and genetic contacts between invasive and indigenous whitefly biotypes in an insular environment

2006 ◽  
Vol 87 (2) ◽  
pp. 109-124 ◽  
Author(s):  
H. DELATTE ◽  
P. DAVID ◽  
M. GRANIER ◽  
J. M. LETT ◽  
R. GOLDBACH ◽  
...  
Keyword(s):  
Host Plants ◽  
Prior Information ◽  
La Réunion ◽  
Clustering Methods ◽  
Temporal And Spatial Distribution ◽  
Use Of Data ◽  
Resident Populations ◽  
Temporal And Spatial ◽  
Biotype B ◽  
B Biotype

Human-mediated bioinvasions provide the opportunity to study the early stages of contact between formerly allopatric, divergent populations of a species. However, when invasive and resident populations are morphologically similar, it may be very difficult to assess their distribution in the field, as well as the extent of ecological overlap and genetic exchanges between invasive and resident populations. We here illustrate the use of data obtained from a set of eight microsatellite markers together with Bayesian clustering methods to document invasions in a group of major tropical pests, Bemisia tabaci, which comprises several morphologically indistinguishable biotypes with different agronomic impacts. We focus on the island of La Réunion, where an invasive biotype (B) has recently been introduced and now interacts with the resident biotype (Ms). The temporal and spatial distribution, host-plant range and genetic structure of both biotypes are investigated. We showed (i) that, without prior information, clustering methods separate two groups of individuals that can safely be identified as the B and Ms biotypes; (ii) that the B biotype has invaded all regions of the island, and showed no signs of genetic founder effect relative to the Ms biotype; (iii) that the B and Ms biotypes coexist in sympatry throughout most of their geographical ranges, although they tend to segregate into different host plants; and finally (iv) that asymmetrical and locus-specific introgression occurs between the two biotypes when they are in syntopy.

Development of silverleaf assay, protein and nucleic acid-based diagnostic techniques for the quick and reliable detection and monitoring of biotype B of the whitefly, Bemisia tabaci (Gennadius)

2007 ◽  
Vol 97 (5) ◽  
pp. 503-513 ◽  
Author(s):  
K.S. Shankarappa ◽  
K.T. Rangaswamy ◽  
D.S. Aswatha Narayana ◽  
A.R. Rekha ◽  
N. Raghavendra ◽  
...  
Keyword(s):  
Bemisia Tabaci ◽  
Scar Marker ◽  
Cost Effective ◽  
Diagnostic Techniques ◽  
Detection Methods ◽  
Agricultural Pests ◽  
Sequence Characterized Amplified Region ◽  
The North ◽  
Biotype B ◽  
B Biotype

AbstractThe aim of this study was to develop and optimize silverleaf bioassay, esterase analysis and PCR-based techniques to distinguish quickly and reliably biotype B of the whitefly, Bemisia tabaci (Gennadius), from Indian indigenous biotypes. Zucchini and squash readily develop silverleaf symptoms upon feeding by the B biotype, but they are not readily available in Indian markets. A local pumpkin variety ‘Big’ was, therefore, used in silverleaf assay, which developed symptoms similar to those on zucchini and squash and can be used reliably to detect B biotype. Analysis of non-specific esterases of B and the indigenous biotypes indicated both quantitative and qualitative differences in esterase patterns. Two high molecular weight bands were unique to B biotype and they occurred in abundance. These esterases were used to develop quick and field-based novel detection methods for differentiating B from the indigenous biotypes. Development of these simple and cost-effective protocols has wider application as they can be potentially used to identify other agricultural pests. Mitochondrial cytochrome oxidase I gene sequences and randomly amplified polymorphic DNA (RAPD) polymorphisms, generated using the primer OpB11, were also found useful for detecting B. tabaci biotypes. A B biotype-specific RAPD band of 800 bp was sequenced, which was used to a develop sequence characterized amplified region (SCAR) marker. The SCAR marker involved the development of B biotype-specific primers that amplified 550 bp PCR products only from B biotype genomic DNA. Silverleaf assay, esterases, RAPDs or a SCAR marker were used in combination to analyse whitefly samples collected from selected locations in India, and it was found that any of these techniques can be used singly or in combination to detect B biotype reliably. The B biotype was found in southern parts of India but not in the north in 2004–06.

scholarly journals Identification, geographical distribution and host plants of Bemisia tabaci (Genn.) biotypes (Homoptera: Aleyrodidae) in the State of Paraná, Brazil

2000 ◽  
Vol 29 (3) ◽  
pp. 597-603 ◽  
Author(s):  
Sueli S. Martinez ◽  
Alfredo O. R. de Carvalho ◽  
Luiz G. Vieira ◽  
Liliane M. Nunes ◽  
Anésio Bianchini
Keyword(s):  
Geographical Distribution ◽  
Bemisia Tabaci ◽  
Banding Pattern ◽  
Host Plants ◽  
Ornamental Plants ◽  
The State ◽  
The North ◽  
Rapd Pcr ◽  
Biotype B

This work was carried out in order to identify Bemisia tabaci (Genn.) biotypes present in the state of Paraná and to determine their geographical distribution and host plants. About 50 adults were collected in several host crops, weeds and ornamental plants in North, Northwest, Northeast, West and Central areas of the state, from January to May, 1998 and 1999. The species were identified by means of RAPD-PCR, using the primer Operon H-16. Whitefly populations were detected mainly from February on, in both years, seldom achieving more than one adult per leaf. The insect was found in only 66% of the sampled areas. Bean golden mosaic was almost never observed during the period. Both biotype A and biotype B of B. tabaci were found in the State of Paraná, the last one being more restricted to the north region. Although biotype B was found colonising a wider range of host plants, it has not spread out in all the state and most of the whitefly specimens found are still the biotype A. A banding pattern distinct of those obtained for A and biotype B of B. tabaci was obtained exclusively with the populations collected from cassava, thus indicating the possible presence of a biotype specific for this crop.

scholarly journals Biology of Bemisia tabaci (Genn.) B-biotype and parasitism by Encarsia formosa (Gahan) on collard, soybean and tomato plants

2008 ◽  
Vol 65 (6) ◽  
pp. 639-642 ◽  
Author(s):  
Karina Manami Takahashi ◽  
Evoneo Berti Filho ◽  
André Luiz Lourenção
Keyword(s):  
Plant Species ◽  
Bemisia Tabaci ◽  
Comparison Study ◽  
Encarsia Formosa ◽  
Tomato Plants ◽  
Glycine Max L ◽  
Biotype B ◽  
Polyphagous Insect ◽  
Hatching Eggs ◽  
B Biotype

The silverleaf whitefly Bemisia tabaci (Genn.) B-biotype (= B. argentifolii) (Hemiptera: Aleyrodidae) is a polyphagous insect attacking many plant species of economic importance. A comparison study was conducted on the duration of the egg-to-adult period, and the percentage of hatching eggs of Bemisia tabaci (Genn.) B-biotype on collard (Brassica oleracea L. var. acephala D.C.), soybean(Glycine max (L.) Merr.) and tomato (Lycopersicon esculentum Mill.) plants, as well as the egg-to-adult period of Encarsia formosa (Gahan) on the 1st, 2nd, 3rd and 4th whitefly nymphal instars on these three plant species. The experiments were conducted in a laboratory (25ºC, 70 ± 10% RH, 14-hour photophase). The duration of the egg-to-adult period of B. tabaci was 19.8 days on collard, 21.2 days on soybean and 22.0 days on tomato. The number of hatched eggs was higher on collard when compared to soybean and tomato plants. Concerning E. formosa regardless of plant species, the duration for the egg-to-adult period was shorter for the 3rd and 4th instar nymphs as compared with the other instars.

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

2018 ◽  
Vol 14 (3) ◽  
pp. 143
Author(s):  
Purnama Hidayat ◽  
Hazen Arrazie Kurniawan ◽  
Lutfi Afifah ◽  
Hermanu Triwidodo
Keyword(s):  
Life Cycle ◽  
Bemisia Tabaci ◽  
Chili Pepper ◽  
Reproduction Rate ◽  
Increase Rate ◽  
Biological Aspects ◽  
Biotype B ◽  
Length Of Life ◽  
Net Reproduction ◽  
B Biotype

<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 (R<sub>0</sub>) 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>

scholarly journals Hydraulic transmissivity inferred from ice-sheet relaxation following Greenland supraglacial lake drainages

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ching-Yao Lai ◽  
Laura A. Stevens ◽  
Danielle L. Chase ◽  
Timothy T. Creyts ◽  
Mark D. Behn ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Ice Sheet ◽  
Drainage System ◽  
Greenland Ice Sheet ◽  
Field Observations ◽  
Surface Uplift ◽  
Drainage Networks ◽  
Order Of Magnitude ◽  
Lake Drainage ◽  
Magnitude Increase

AbstractSurface meltwater reaching the base of the Greenland Ice Sheet transits through drainage networks, modulating the flow of the ice sheet. Dye and gas-tracing studies conducted in the western margin sector of the ice sheet have directly observed drainage efficiency to evolve seasonally along the drainage pathway. However, the local evolution of drainage systems further inland, where ice thicknesses exceed 1000 m, remains largely unknown. Here, we infer drainage system transmissivity based on surface uplift relaxation following rapid lake drainage events. Combining field observations of five lake drainage events with a mathematical model and laboratory experiments, we show that the surface uplift decreases exponentially with time, as the water in the blister formed beneath the drained lake permeates through the subglacial drainage system. This deflation obeys a universal relaxation law with a timescale that reveals hydraulic transmissivity and indicates a two-order-of-magnitude increase in subglacial transmissivity (from 0.8 ± 0.3 $${\rm{m}}{{\rm{m}}}^{3}$$ m m 3 to 215 ± 90.2 $${\rm{m}}{{\rm{m}}}^{3}$$ m m 3 ) as the melt season progresses, suggesting significant changes in basal hydrology beneath the lakes driven by seasonal meltwater input.

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