Effects of sugar beet cultivar on development and reproductive capacity of Aphis fabae

Abstract Black been aphid, Aphis fabae Scopoli (Homoptera Aphididae) is recognized as a serious pest of sugar beet with worldwide distribution. Development and fecundity rates of this aphid were evaluated on six commonly growing cultivars under laboratory conditions in Ardabil County, Iran. The results obviously clarified significant differences in biology and life history characteristics of A. fabae reared on different sugar beet cultivars. The shortest developmental time for the immature stages was observed to be 11.32 days on 'Polyrave' and the longest 13.23 days on '7233'. There was the highest fecundity (14.33, nymphs/female) of A. fabae on 'Polyrave' and the lowest (7.32, nymphs/female) on '7233' cultivar. The r m values of the aphid ranged from 0.1336 on '7233' to 0.2202 (nymphs/female/day) on 'Polyrave'. In general, Jackknife estimates of this aphid population parameters on cultivars examined showed the highest development and fecundity rates on 'Polyrave' and the lowest on '7233' cultivar

Data from: Climate effects on life cycle variation and population genetic architecture of the black bean aphid, Aphis fabae

Aphid species commonly have different reproductive modes ranging from cyclical to obligate parthenogenesis. The distribution of life cycle variation in aphids is generally determined by ecological forces, mainly climate, because only sexually produced diapausing eggs can survive harsh winters. Aphids are thus interesting models to investigate intrinsic and environmental factors shaping the competition among sexual and asexual lineages. We conducted a Europe-wide sampling of black bean aphids, Aphis fabae, and combined population genetic analyses based on microsatellite data with an experimental determination of life cycle strategies. Aphids were collected from broad beans (Vicia faba) as well as some Chenopodiaceae, but we detected no genetic differentiation between aphids from different host plants. Consistent with model predictions, life cycle variation was related to climate, with aphids from areas with cold winters investing more in sexual reproduction than aphids from areas with mild winters. Accordingly, only populations from mild areas exhibited a clear genetic signature of clonal reproduction. These differences arise despite substantial gene flow over large distances, which was evident from a very low geographic population structure and a lack of isolation-by-distance among 18 sites across distances of more than 1000 kilometres. There was virtually no genetic differentiation between aphids with different reproductive modes, suggesting that new asexual lineages are formed continuously. Indeed, a surprising number of A. fabae genotypes even from colder climates produced some parthenogenetic offspring under simulated winter conditions. From this we predict that a shift to predominantly asexual reproduction could take place rapidly in under climate warming

Chemical Composition and Acaricidal Effects of Essential Oils of Foeniculum vulgare Mill. (Apiales: Apiaceae) and Lavandula angustifolia Miller (Lamiales: Lamiaceae) against Tetranychus urticae Koch (Acari: Tetranychidae)

Utilization of synthetic acaricides causes negative side-effects on nontarget organisms and environment and most of the mite species such as two spotted spider mite, Tetranychus urticae Koch, are becoming resistant to these chemicals. In the present study, essential oils of fennel, Foeniculum vulgare Mill., and lavender, Lavandula angustifolia Miller, were hydrodistilled using Clevenger apparatus and chemical composition of these oils was analyzed by GC-MS. Anethole (46.73%), limonene (13.65%), and α-fenchone (8.27%) in the fennel essential oil and linalool (28.63%), 1,8-cineole (18.65%), and 1-borneol (15.94%) in the lavender essential oil were found as main components. Contact and fumigant toxicity of essential oils was assessed against adult females of T. urticae after 24 h exposure time. The essential oils revealed strong toxicity in both contact and fumigant bioassays and the activity dependeds on essential oil concentrations. Lethal concentration 50% for the population of mite (LC50) was found as 0.557% (0.445–0.716) and 0.792% (0.598–1.091) in the contact toxicity and 1.876 μL/L air (1.786–1.982) and 1.971 μL/L air (1.628–2.478) in the fumigant toxicity for fennel and lavender oils, respectively. Results indicated that F. vulgare and L. angustifolia essential oils might be useful for managing of two spotted spider mite, T. urticae

Life table parameters of Callosobruchus maculatus on cowpea seeds (Vigna unguiculata) treated with some biological and chemical fertilizers

The cowpea weevil, Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae), a destructive insect pest of cowpea, Vigna unguiculata (L.), in the field and storage, causes significant losses in seed weight, germination ability, and the market value. The effect of cowpea (Mashhad cultivar) fertilization with chemical fertilizers (triple superphosphate (TSP) and urea) and some biofertilizers (Bradyrhizobium japonicum, Pseudomonas putida, mycorrhizal fungi) was studied on biology and life table parameters of C. maculatus at 28 ± 1°C, relative humidity of 65 ± 5%, and complete darkness. The highest immature survival (%) was on the grains treated with P. putida and control (97.75 and 95.69%, respectively), and the lowest survival was on the grains fertilized with TSP and B. japonicum (65.06 and 75%, respectively). Although the developmental time of C. maculatus reared on TSP- and B. japonicum-treated grains was longer than the control, the intrinsic rate of increase (0.124 day-1) and net reproductive rate (34.34 offspring) on the grains treated with TSP were lower than the control (0.143 day-1 and 51.07 offspring, respectively). Results of this research showed that the nutritional value of the grains obtained from TSP and B. japonicum treatments were lower than those obtained from other fertilizer treatments

Aphis_fabae_microsatellite_and_sampling_data

Sampling details (locations, dates and host plants) of 655 European Aphis fabae specimens and the corresponding data for eight microsatellite loci

Comparative life table analysis of Tetranychus urticae Koch (Acari: Tetranychidae) on ten rose cultivars

International audienceLife history parameters of plant feeders are useful tools to evaluate resistance or susceptibility of host plants including different cultivars. This study compared population growth parameters of Tetranychus urticae Koch on 10 rose cultivars, including Bella Vita, Cool Water, Dolce Vita, Maroussia, Orange Juice, Pink Promise, Roulette, Tea, Valentine, and Persian yellow in laboratory conditions at 24+/-1°C, 65+/-5% relative humidity, and a photoperiod of 16:8 (L:D) h. The results revealed that mite survival rate varied from 66.5% on Bella Vita to 85.9% on Persian yellow. The immature development time was different among the tested rose cultivars and ranged from 9.35 days on Orange Juice to 12.30 days on Bella Vita. The highest fecundity rate was recorded on Pink Promise. Consequently, population growth parameters were also significantly affected. The lowest intrinsic rate of increase (rm) was recorded on Roulette and this parameter was relatively higher on Cool Water, Orange Juice, and Persian yellow. In addition, the highest net reproductive rate (R0) was observed on Pink Promise, which was significantly higher than Roulette, Tea, and Valentine cultivars. The longest mean generation time (T) was calculated on Roulette and the shortest on Cool Water, Tea, and Orange Juice. The lowest performance of the two-spotted mite on Roulette could indicate that this is a suitable cultivar against mite infestation. Differences in mite susceptibility of tested rose cultivars here highlighted have the potential to be used for integrated pest management of T. urticae in ornamental rosa cultivations

Water ferns Azolla spp. (Azollaceae) as new host plants for the small China-mark moth, Cataclysta lemnata (Linnaeus, 1758) (Lepidoptera, Crambidae, Acentropinae)

Water ferns (Azolla spp., Azollaceae) are reported for the first time as host plants for the larvae of the small China-mark moth Cataclysta lemnata (Linnaeus) (Lepidoptera: Crambidae: Acentropinae) in rice fields and waterways of northern Iran. Cataclysta lemnata is a semi-aquatic species that has been recorded to feed on Lemnaceae and a few other aquatic plants. However, it has not been reported before on Azolla spp. Larvae use water fern as food source and shelter and, at high population density in the laboratory, they completely wiped water fern from the water surface. Feeding was confirmed after rearing more than eight continual generations of C. lemnata on water fern in the laboratory. Adults obtained this way are darker and have darker fuscous markings in both sexes compared with specimens previously reported and the pattern remains unchanged after several generations

Distance genetic matrix (above diagonal) and population pairwise FST of 7 tested regions comparison by 4 microsatellites loci (below diagonal).

<p>Genetic distance and pair-wise FST values between regions are shown in Table 5. The minimum genetic distance was found between the Moghan-Zarghan pair (0.116) and the maximum between the Esfahan-Sabzvar pair (0.722). Computed FST values ranged from 0.102 for the Kalposh-Miandoab to 0.349 for the Moghan-Esfahan. FST values were significant for all paired combinations (P < 0.05).<br></p

AMOVA of 7 tested geographic populations of Spodoptera exigua using 4 microsatellites loci.

<p>Analysis of molecular variance (AMOVA) was performed using ARLEQUEIN version 3.11 (Excoffier et al. 2005). A two-part AMOVA analysis was conducted to check genetic divergence (FST) as a factor of variation between individuals within a given population and between populations. Molecular variance analysis showed significant variations among and within populations, 21 and 71 percent, respectively </p

Results from the Bayesian clustering analysis in STRUCTURE, using k=2. Each population represented by a vertical line with different colors representing the assignments probabilities to each of the clusters.

<p>We inferred population structure using a Bayesian clustering algorithm as implemented in the software STRUCTURE (Pritchard et al. 2000, Falush et al. 2003). The most probable number of genetic clusters based on the log probability of the data was inferred following the method of Evanno et al. (2005). We varied the number of genetic clusters (K) from 1 to 10 and ran 10 independent simulations for each k with a burn-in period of 50,000 iterations, followed by 50,000 Markov chain Monte Carlo steps. For all simulations, the admixture model was used. The distribution of log- likelihoods for the number of genetic clusters (K) from the Bayesian clustering analysis with STRUCTURE peaked at estimates of k=2. In this k, 52.9 % of individuals could be assigned to one of the clusters with more than 50% probability. The ∆k method by Evanno et al (2005) favored k=2 than the others, with a seven–fold higher value of ∆k. The assignment of this cluster with respect to population is illustrated in Fig. 3. The most individuals collected from Gonbad and Esfahan regions were assigned to cluster 1; whereas, individuals assigned with high probability to cluster 2 were found in Moghan, Sabzvar and Zarghan regions. Most individuals from Kalposh and Miandoab regions were assigned in cluster 2.</p><p></p><p></p