Impact of temperature on food intake and growth in juvenile burbot

The effect of temperature on food consumption, food conversion and somatic growth was investigated with juvenile burbot Lota lota (age 0 years). Juvenile burbot showed a significant dome shaped relationship between relative daily food consumption ( C _R) and temperature ( T ) with C _R = − 0·00044 T ² + 0·01583 T  − 0·06010; ( n  = 90, r ² = 0·61). Maximum C _R was at 17·9° C (95% CL 17·2–18·6° C). The temperature related instantaneous growth rate ( G ) also followed a dome shaped function with G  = − 0·000063 T ² + 0·002010 T  − 0·007462; ( n  = 95, r ² = 0·57), with maximum growth rate at 16·0° C (95% CL 15·3–16·6° C). A significant linear relationship was found between the water temperature and the conversion coefficient ( C _C) with C _C = − 1·63 T  + 59·04; ( n  = 80, r ² = 0·74). The results indicate that juvenile burbot in large lakes benefit from higher water temperatures in the littoral zone, by increased food uptake and growth, especially during the warm summer months. Because profundal water temperatures do not reflect the optimal temperature for food consumption in large burbot, temperature is unlikely to be the main proximate factor for the obligate littoral‐profundal migration of juvenile burbot observed in many lake populations.     

Tree population dynamics in Kibale National Park, Uganda 1975–1998

Changes in species composition, stem abundance, and basal area of trees taller than or equal to 10 m in a medium altitude tropical rain forest at the Ngogo study area, Kibale National Park, Uganda are described for the period between 1975 and 1998 ( n  = 23 years). Two enumeration episodes were conducted in 263 plots of 5 m by 50 m during 1975–80 and 1997–98. During this period, species richness decreased by 3% (from 92 to 89). Species diversity (H') also declined slightly from 2.97 to 2.86. The number of trees recorded in the sample plots decreased by 8% (from 2545 to 2329), while basal area decreased from 49.48 m² ha⁻¹ to 48.68 m² ha^−1. However, stem abundance and basal area increased for some species.     

Visual, semi-quantitative assessments allow accurate estimates of leafminer population densities: an example comparing image processing and visual evaluation of damage by the horse chestnut leafminer Cameraria ohridella (Lep., Gracillariidae)

Abstract: Qualitative or semi-quantitative visual assessments are most often used for estimating population size of herbivorous insects. The precision of these estimates, however, is often difficult to establish. A 'simulation game' with the horse chestnut leafminer, Cameraria ohridella Deschka & Dimic (Lep., Gracillariidae) shows that visual, semi-quantitative assessments can provide accurate information. Damaged areas of 411 horse chestnut leaves collected in 100 sites were closely related to mine numbers despite some variability in mine and leaf size ( R ² = 0.915; n  = 411; P < 0.001). On the basis of this relationship, two methods of population assessment are compared: (i) digital image processing of leaf damage and (ii) visual assessment using a damage key reflecting the relative infested area on each leaf (0, 0%; 1, 0–2%; 2, 2–5%; 3, 5–10%; 4, 10–25%; 5, 25–50%; 6, 50–75%; 7, 75–100%). Both methods used to estimate damage presented a similar, close relationship to the 'real' numbers of mines ( R ² = 0.858; n  = 777; P < 0.001 for image processing and R ² = 0.905; n  = 777; P < 0.001 for visual assessment). The potential of using visual assessments as an accurate and fast method in situ at the tree scale is discussed.     

Bird diversity: a predictable function of satellite-derived estimates of seasonal variation in canopy light absorbance across the United States

Aim  To investigate the relationships between bird species richness derived from the North American Breeding Bird Survey and estimates of the average, minimum, and the seasonal variation in canopy light absorbance (the fraction of absorbed photosynthetically active radiation, fPAR) derived from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS).
Location  Continental USA.
Methods  We describe and apply a 'dynamic habitat index' (DHI), which incorporates three components based on monthly measures of canopy light absorbance through the year. The three components are the annual sum, the minimum, and the seasonal variation in monthly fPAR, acquired at a spatial resolution of 1 km, over a 6-year period (2000–05). The capacity of these three DHI components to predict bird species richness across 84 defined ecoregions was assessed using regression models.
Results  Total bird species richness showed the highest correlation with the composite DHI [ R ² = 0.88, P  < 0.001, standard error of estimate (SE) = 8 species], followed by canopy nesters ( R ² = 0.79, P  < 0.001, SE = 3 species) and grassland species ( R ² = 0.74, P  < 0.001, SE = 1 species). Overall, the seasonal variation in fPAR, compared with the annual average fPAR, and its spatial variation across the landscape, were the components that accounted for most ( R ² = 0.55–0.88) of the observed variation in bird species richness.
Main conclusions  The strong relationship between the DHI and observed avian biodiversity suggests that seasonal and interannual variation in remotely sensed fPAR can provide an effective tool for predicting patterns of avian species richness at regional and broader scales, across the conterminous USA.     

Ecosystem productivity can be predicted from potential relative growth rate and species abundance

We show that ecosystem-specific aboveground net primary productivity (SANPP, g g⁻¹ day⁻¹, productivity on a per gram basis) can be predicted from species-level measures of potential relative growth rate (RGR_max), but only if RGR_max is weighted according to the species' relative abundance. This is in agreement with Grime's mass-ratio hypothesis. Productivity was measured in 12 sites in a French Mediterranean post-agricultural succession, while RGR_max was measured on 26 of the most abundant species from this successional sere, grown hydroponically. RGR_max was only weakly correlated ( r ² = 0.12, P  < 0.05) with field age when species abundance was not considered, but the two variables were strongly correlated ( r ² = 0.81, P  < 0.001) when the relative abundance of species in each field was taken into account. SANPP also decreased significantly with field age. This resulted in a tight relationship ( r ² = 0.77, P  < 0.001) between productivity and RGR_max weighted according to species relative biomass contribution. Our study shows that scaling-up from the potential properties of individual species is possible, and that information on potential and realized species traits can be integrated to predict ecosystem functioning.     

Use of flow cytometry for enumeration of Mycoplasma mycoides subsp. mycoides large-colony type in broth medium

Aims:  The potential of using flow cytometry (FC) in combination with a fluorescent dye (SYBR green-I) for rapidly estimating Mycoplasma mycoides subSPS. mycoides large-colony type (MmmLC) in broth culture was examined.
Methods and Results:  The FC analysis was performed by staining the MmmLC cells with a fluorescent dye, SYBR green-I (SYBR), and the results were compared with plate count method (colony forming units, – CFUs). There was a good correlation (linear regression, r ² = 0·93) between mycoplasma counts determined by FC (cells ml⁻¹) and by traditional plate count method (CFU ml⁻¹). The lowest bacterial concentration detected by FC and traditional plate count was of the order of 10⁴ cells ml⁻¹ and 10³ CFU ml⁻¹, respectively. FC method allowed results in 20–30 min, whereas at least 24 h were necessary to obtain results with the traditional plate count method (CFU).
Conclusion:  Growth rates of MmmLC in broth medium determined by FC were highly reproducible and correlated well with mycoplasma counts assessed by the plate count method.
Significance and Impact of the Study:  These findings suggest that FC could be a good alternative to replace other time-consuming techniques that are currently used to enumerate mycoplasma in broth medium, such as plate count method (CFU).     

Morphological and geographic variation of the cycad Dioon edule Lindl. (Zamiaceae): ecological and evolutionary implications

The relationship in geographical distribution and morphological variation of leaflet width and length (diagnostic trait), between and within populations of Dioon edule Lindl., has been investigated throughout its known range in eastern Mexico (from the states of Nuevo León to Veracruz, north to south, respectively). A total of 1832 leaflets were measured for width and length from 154 plants distributed amongst five populations using four leaflet replicas from each of three leaves per plant. For leaflet width and length the variation among populations indicated significant stat-istical differences ( F _4,147 = 125.83; P  < 0.0001; R ² = 92.17% and F _4,147 = 9.04; P  < 0.001; R ² = 26.8%), respectively. With respect to leaflet width, the multiple range test showed three groups with a north to south distributional relationship along the range of the species. The correlation coefficient among paired populations, respect to geographical distance and the absolute value of the mean difference of leaflet width in each population, was positive, and different from zero ( r  = 0.82; P  = 0.013). A great variation of important ecological and evolutionary parameters was shown.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 465–470.     

Automated concentration and recovery of micro-organisms from drinking water using dead-end ultrafiltration

Aims:  Concentration of pathogens diluted in large volumes of water is necessary for their detection. An automated concentration system placed online in drinking water distribution systems would facilitate detection and mitigate the risk to public health.
Methods and Results:  A prototype concentrator based on dead-end hollow fibre ultrafiltration was used to concentrate Bacillus atrophaeus spores directly from tap water. Backflush was used to recover accumulated particulates for analysis. In field tests conducted on a water utility distribution system, 3·2 × 10⁴–1·4 × 10⁶ CFU ml⁻¹ (6·1 × 10⁶–3·0 × 10⁸ CFU) were recovered from the filter when 2·9 × 10⁷–1·0 × 10⁹ CFU were spiked into the system. Per cent recovery ranged from 21% to 68% for flow volumes of 15–21 l. Tests using spore influent levels <10 CFU l⁻¹ (spike < 1000 CFU) yielded 23–40% recovery for volumes >100 l.
Conclusions:  B. atrophaeus spores at levels <10 CFU l⁻¹ were concentrated directly from tap water using an automated dead-end hollow-fibre ultrafiltration system.
Significance and Impact of the Study:  The prototype concentrator represents a critical step towards an autonomous system that could be installed in drinking water distribution lines or other critical water lines to facilitate monitoring. Recovered samples can be analysed using standard or rapid biosensor methods.     

Electrical signalling and cytokinins mediate effects of light and root cutting on ion uptake in intact plants

Nutrient acquisition in the mature root zone is under systemic control by the shoot and the root tip. In maize, exposure of the shoot to light induces short-term (within 1–2 min) effects on net K⁺ and H⁺ transport at the root surface. H⁺ efflux decreased (from −18 to −12 nmol m⁻² s⁻¹) and K⁺ uptake (∼2 nmol m⁻² s⁻¹) reverted to efflux (∼−3 nmol m⁻² s⁻¹). Xylem probing revealed that the trans-root (electrical) potential drop between xylem vessels and an external electrode responded within seconds to a stepwise increase in light intensity; xylem pressure started to decrease after a ∼3 min delay, favouring electrical as opposed to hydraulic signalling. Cutting of maize and barley roots at the base reduced H⁺ efflux and stopped K⁺ influx in low-salt medium; xylem pressure rapidly increased to atmospheric levels. With 100 m m NaCl added to the bath, the pressure jump upon cutting was more dramatic, but fluxes remained unaffected, providing further evidence against hydraulic regulation of ion uptake. Following excision of the apical part of barley roots, influx changed to large efflux (−50 nmol m⁻² s⁻¹). Kinetin (2–4  µ m ), a synthetic cytokinin, reversed this effect. Regulation of ion transport by root-tip-synthesized cytokinins is discussed.     

Aboveground biomass estimation of the shrubs, Echiochilon fruticosum (Desf.) and Helianthemum kahiricum (Del.) in the arid zone rangelands of Tunisia

The knowledge of the plant biomass is very important for the assessment of the rangeland productivity. It could help to select the appropriate species for the improvement of natural ecosystems (rehabilitation, restoration and seedling). By examining different correlations between the biomass production and the volume parameters of two North African shrub species of high range value ( Echiochilon fruticosum Desf. and Helianthemum kahiricum Del.), we aimed to establish the appropriate regression models, which could be useful for the prediction of the productivity of these species. The data showed a significant relationship between the total biomass (TB) production and the mean diameter (MD) of the studied species ( R ² = 0.65 for Echiochilon and R ² = 0.75 for Helianthemum ). Likewise, annual fresh production (leaves and current-year shoots) was well correlated with MD of Helianthemum ( R ² = 0.82). However, the correlation between these two parameters was relatively low for Echiochilon ( R ² = 0.42).     

Population energy use scales positively with body size in natural aquatic microcosms

Aim  We test the 'energetic equivalence rule' (EER) – the idea that the amount of energy used by a population per unit area per unit time is independent of body mass – in meio-invertebrate communities from a series of natural, multitrophic aquatic 'rock pool' microcosms. Our study represents the first rigorous test of the EER at local scales of observation in a community of naturally coexisting species.
Location  Discovery Bay, Jamaica.
Method  We estimated population energy use (PEU) for every occurrence of every species of meio-invertebrate fauna found in each of 29 microcosms (233 observations of 31 species) using estimates of population density obtained in January 2005 in combination with published metabolism–mass relations for closely related taxa.
Results  In the rock pool system as a whole, population density decreased ( ancova : b  = –0.38 (–0.55 to –0.19), r ² = 0.19, P  < 0.001) and PEU increased with body mass ( ancova : b  = 0.55 (0.36–0.73), r ² = 0.28, P  < 0.001).
Main conclusions  The positive PEU–body mass relation found here suggests that larger organisms are energetically dominant and points to the importance of size-structured competition in these systems. Our results contrast those obtained in the few other previously published tests of the EER and challenge the idea that all species use similar amounts of energy regardless of their size.     

Abrupt change in primary productivity in a littoral zone of Lake Biwa with the development of a filamentous green-algal community

1. Some characteristics of the photosynthesis and primary production of benthic and planktonic algal communities were investigated in a littoral zone covered with gravel in the north basin of Lake Biwa, paying special attention to the recent development of filamentous green algae (FGA) in the benthic algal community.
2. P_max (maximum gross photosynthesis rate) values of the benthic algal community (0.1–1.2 mg C mg chl. a ⁻¹ h⁻¹) obtained from photosynthesis–irradiance (P–I) curves were lower than those of the planktonic algal community (2.4–11.5 mg C mg chl. a ⁻¹ h⁻¹). This is apparently a result of the high degree of self shading in the benthic algal community and its low turnover as compared with that of the planktonic algal community.
3. Relatively high I_k values (150–200 μmol photon m⁻² s⁻¹) were observed in the benthic algal community only in June–July when a FGA, Spirogyra sp., was abundant. This reflected a photosynthetic characteristic of the Spirogyra itself, in which photosynthesis was saturated at high light intensity.
4. The FGA community established in the layer between planktonic and sessile (benthic algae except for FGA) algal communities. It brought about extraordinarily high organic matter production in the littoral zone at the expense of production in the sessile algal community.     

Growth performance, mortality and carotenoid pigmentation of fry offspring as affected by dietary supplementation of astaxanthin to female rainbow trout (Oncorhynchus mykiss) broodstock

Growth performance, mortality and carotenoid pigmentation were studied in triplicate groups each with 1000 swim-up larvae of rainbow trout ( Oncorhynchus mykiss ), derived from five groups of female broodstock fed diets with 0.07, 12.5, 33.3, 65.1 or 92.9 mg astaxanthin kg⁻¹, respectively. The first feeding fry (initial weight range from 113 to 148 mg) were fed a diet not supplemented with carotenoids in an experiment lasting 45 days. Fry were initially sampled for astaxanthin content and initial weight, and in subsequent 15-day intervals to determine weights, condition factors (CF), specific growth rates (SGR) and thermal growth coefficients (TGC). Total carotenoid concentration of the larvae was highly linearly correlated to that of the eggs ( r ² = 0.97, P = 0.002). About 59–67% of fry carotenoids consisted of esterified astaxanthin, and on average 39.7% of the egg carotenoids were recovered in the fry. Overall (0–45 days) SGRs and TGCs were significantly higher (P < 0.05) in the offspring of the four groups of females fed supplemented diets (12.5–92.9 mg astaxanthin kg⁻¹) than in offspring of females fed the non-supplemented diet. TGCs (0–45 days) within groups derived from broodstock supplemented with astaxanthin were similar (P > 0.05), but higher than in the group derived from females fed the diet not supplemented with astaxanthin (P < 0.05). Mortality (average 0.76%) was not significantly affected by treatment. The study indicates that dietary supplement of astaxanthin (>12.5 mg kg⁻¹) to maternal broodstock diets improves offspring SGR and TGC with up to 33 and 38%, respectively.     

Effect of feeding level and feeding frequency on specific dynamic action in Silurus meridionalis

The effect of feeding level ( F _L; 0·5 to 4% dry diet mass per wet fish body mass) and feeding frequency (once every 4 days to twice per day) on postprandial metabolic response was investigated in southern catfish Silurus meridionalis at 27·5° C. The results showed that there was no significant difference in the specific dynamic action (SDA) coefficient among the groups of different feeding levels ( P  > 0·05). The duration increased from 26·0 to 40·0 h and the peak metabolic rate increased from 207·8 to 378·8 mg O₂ kg⁻¹ h⁻¹ when the feeding level was increased from 0·5 to 4%. The relationship between the peak metabolic rate ( R _P, mg O₂ kg⁻¹ h⁻¹) and F _L could be described as: R _P = 175·4 + 47·3 F _L( r ² = 0·943, n  = 40, P  < 0·001). The relationship between the SDA duration ( D , h) and F _L could be described as D =30·97 F _L^0·248 ( r ²=0·729, n =40, P  < 0·001).     

Evaluation of PCR assays for quantifying seed-borne infection by Fusarium and Microdochium seedling blight pathogens

Aims:  To evaluate competitive PCR assays for quantifying seed-borne Microdochium and Fusarium seedling blight pathogen DNA and to determine test and year repeatability and sources of variability.
Methods and Results:  Relationships between DNA and plate counts were significant for Fusarium and Microdochium seedling blight pathogens in 152 seed batches from 3 years. Coefficient of determinations, however, differed greatly ( Fusarium ; R ² = 0·25, P  =   0·029, Microdochium ; R ² = 0·73, P  <   0·001). Significant differences between years were observed in the regression slopes for Microdochium . Pathogen DNA quantified in 16 extractions after sampling was highly correlated to results following storage for 1–2 years ( R ² > 0·90). Residual maximum likelihood analysis showed that the least and greatest variance components of the testing procedure were DNA extraction subsampling and PCR assay respectively.
Conclusions:  Amount of pathogen DNA is a useful estimator of seed batch contamination for Microdochium but not Fusarium seedling blight pathogens. Although reproducible over time, improvements to the testing procedure should focus on repeated PCR amplifications to reduce assay variability.
Significance and Impact of the Study:  Replacing plate counts with competitive PCR for determining the severity of seed batch contamination is feasible in areas where Microdochium seedling blight pathogens predominate.     

Real-time quantification of Pseudomonas fluorescens cell removal from glass surfaces due to bacteriophage varphiS1 application

Aims:  To study the efficacy of the lytic phage φS1 in eliminating Pseudomonas fluorescens in the early stage of biofilm formation, using an in situ and real time methodology for cell quantification.
Methods and Results:  Cell adhesion and phage infection studies were carried out in a parallel plate flow chamber under laminar conditions. Cells were allowed to adhere until reaching 1·7–1·8 × 10⁶ cells cm⁻² and phage infection was performed with two different phage concentrations (2 × 10⁹ PFU ml⁻¹ and 1 × 10¹⁰ PFU ml⁻¹). Phage concentration clearly affects the speed of infection. The less concentrated phage solution promoted a three times slower rate of cell removal but did not affect the overall percentage of cell removal. In fact, after a longer infection period the less concentrated phage solution reached the same 93% cell removal value.
Conclusions:  Phages are efficient in the eradication of bacterial cells at the early stage of biofilm formation and their presence at the surface did not allow bacterial recolonization of the surface.
Significance and Impact of the Study:  To date, no published studies have been made concerning in situ and real time quantification of cell removal from surfaces due to phage action.     

Resting spore formation of aphid-pathogenic fungus Pandora nouryi depends on the concentration of infective inoculum

Resting spore formation of some aphid-pathogenic Entomophthorales is important for the seasonal pattern of their prevalence and survival but this process is poorly understood. To explore the possible mechanism involved in the process, Pandora nouryi (obligate aphid pathogen) interacted with green peach aphid Myzus persicae on cabbage leaves under favourable conditions. Host nymphs showered with primary conidia of an isolate (LC₅₀: 0.9–6.7 conidia mm⁻² 4–7 days post shower) from air captures in the low-latitude plateau of China produced resting spores (azygospores), primary conidia or both spore types. Surprisingly, the proportion of mycosed cadavers forming resting spores ( P _cfrs ) increased sharply within the concentrations ( C ) of 28–240 conidia mm⁻², retained high levels at 240–1760, but was zero or extremely low at 0.3–16. The P _cfrs – C relationship fit well the logistic equation P _cfrs  = 0.6774/[1 + exp(3.1229–0.0270 C )] ( r ² = 0.975). This clarified for the first time the dependence of in vivo resting spore formation of P. nouryi upon the concentration of infective inoculum. A hypothesis is thus proposed that some sort of biochemical signals may exist in the host–pathogen interaction so that the fungal pathogen perceives the signals for prompt response to forthcoming host-density changes by either producing conidia for infecting available hosts or forming resting spores for surviving host absence in situ .     

Association analysis of the catechol-o-methyltransferase (COMT), serotonin transporter (5-HTT) and serotonin 2A receptor (5HT2A) gene polymorphisms with obsessive-compulsive disorder

Family and twin studies have supported a strong genetic factor in the etiology of obsessive-compulsive disorder (OCD), although the precise mechanism of inheritance is unclear. Clinical and pharmacological studies have implicated the serotonergic and dopaminergic systems in disease pathogenesis. In this cross-sectional study, we have examined the allelic and genotypic frequencies of a Val-158-Met substitution in the COMT gene, a 44-base pair (bp) length variation in the regulatory region of the serotonin transporter gene ( 5-HTTLPR ) and the T102C and C516T variants in the serotonin receptor type 2A ( 5HT2A ) gene in 79 OCD patients and 202 control subjects. There were no observed differences in the frequencies of allele and genotype between patients and control groups for the COMT , the 5HTTLPR and the T102C 5HT2A gene polymorphisms. In contrast, a statistically significant difference between OCD patients and controls was observed on the genotypic distribution (χ² = 16.7, 2df, P  = 0.0002) and on the allelic frequencies (χ² = 15.8, 1df, P  = 0.00007) for the C516T 5HT2A gene polymorphism. The results suggest that the C516T variant of the 5HT2A gene may be one of the genetic risk factors for OCD in our sample. However, further studies using larger samples and family based methods are recommended to confirm these findings.     

Seasonal heterotrophic flagellate and bacterial plankton dynamics in a large oligotrophic lake– Loch Ness, Scotland

1. Bacterial production in the 0–30 m water column of Loch Ness was measured using a dual labelling procedure with [³H] thymidine and [¹⁴C] leucine between May 1993 and June 1994. In most cases the uptake of the two labels did not covary, suggesting unbalanced growth. Rates of bacterial production varied from undetectable to 46.2 μg C l^–1 day^–1. Highest production coincided with the period of highest primary production, but carbon derived from this source was insufficient to meet the bacterial carbon demand, which was met by allochthonous humic inputs to the system.
2. Heterotrophic flagellate (HNAN) grazing rates, measured using fluorescently labelled bacteria, ranged between 10.3 and 24.5 bacteria cell^–1 day^–1 at temperatures between 5 and 15 °C. They removed up to 27% of the bacterial production per day.
3. Heterotrophic flagellate specific growth rates ranged from 0.043 to 0.093 h^–1 between 5 and 15 °C, giving generation times of 7.4–16.1 h.
4. bacterial and HNAN abundances were not coupled, but the highest HNAN grazing impact related to a time of high bacterial productivity.     

Interspecific interactions between Bemisia tabaci (Hem., Aleyrodidae) and Liriomyza sativae (Dipt., Agromyzidae)

Abstract:  The study examines interspecific interactions between Bemisia tabaci (Hem., Aleyrodidae) and Liriomyza sativae (Dipt., Agromyzidae) feeding on pumpkins and cucumbers. L. sativae density on control pumpkins and cucumbers peaked 3 and 2 weeks after adults were seen, respectively. Compared with controls, L. sativae densities observed for weeks 3–6 and 2–6 in the B. tabaci -pre-infested plants were significantly lower, respectively ( F _2.00 = 22.66, P < 0.01). The survival of L. sativae larvae transplanted to B. tabaci -pre-infested pumpkins and cucumbers was 16.06%, 10.02% and 13.09%, 9.21%, whereas those transplanted to control plants were 52.20%, 36.06% and 48.25%, 28.22% after 5 and 10 days, respectively ( χ ² = 6.9, d.f. = 1, P < 0.01). Pupation rates of L. sativae feeding on control plants were 20.25% and 16.45%, whereas those feeding on the B. tabaci -pre-infested plants only 4.08% and 4.21%, respectively ( χ ² = 7.0, d.f. = 1, P < 0.01). The length and number of mines of L. sativae on the control pumpkins and cucumbers were 54.05%, 54.10% and 89.06%, 76.22% longer or higher than those on B. tabaci -pre-infested plants, respectively. Leaf positions of L. sativae feeding on the plants were also affected by B. tabaci -pre-infested. These results showed that B. tabaci infestations had a significantly negative effect on L. sativae when they were feeding simultaneously on the same host plant.