evaluating-the-effect-of-pesticides-on-the-larvae-of-the-solitary-bees

Evaluating the Effect of Pesticides on the Larvae of the Solitary Bees

Current ecological risk assessments of pesticides on pollinators have primarily considered only laboratory conditions. For the larvae of solitary bees, ...

dissection-grading-ovarian-development-wild-type-female

Dissection and Grading of Ovarian Development in Wild-Type Female Insects

Migratory insect pests pose serious challenges to food production and security all over the world. The migratory pests can be monitored and captured using ...

Shandong Academy of Agricultural Sciences

Botryosphaeria dothidea, the causal agent of apple ring rot, is an important fungal plant pathogen that can cause serious reductions in crop yield, and fungicides still play a crucial role in management. In the present study, the sensitivity of B. dothidea to fludioxonil, fluazinam, and pyrisoxazole was assessed in 162 isolates. Moreover, the protective and curative activity of the three fungicides on detached apple fruit as well as the control efficacy in the field were determined. The results showed that the mean 50% effective concentration (EC) values (± standard deviation) were 0.01 ± 0.008, 0.04 ± 0.03, and 0.02 ± 0.01 μg ml, with individual EC values of 0.002 to 0.05, 0.003 to 0.19, and 0.005 to 0.26 μg ml for fludioxonil, fluazinam, and pyrisoxazole, respectively. In addition, the frequency distributions of EC values were both unimodal curves. However, significant correlations (P < 0.05) were found between fludioxonil and iprodione, between fluazinam and iprodione, as well as between pyrisoxazole and difenoconazole. In field trials conducted during 2016 and 2017, the control efficacy ranged from 75.91 to 87.41% when fludioxonil was applied at 100 to 150 mg active ingredient (a.i.) kg, 81.90 to 85.13% when fluazinam was applied at 400 mg a.i. kg, and 77.43 to 80.97% when pyrisoxazole was applied at 400 mg a.i. kg. The control efficacy of the fungicides in storage was higher than 60%, with the exception of fluazinam. These results demonstrated that fludioxonil, fluazinam, and pyrisoxazole have considerable potential to control apple ring rot.

Evaluating the Sensitivity and Efficacy of Fungicides with Different Modes of Action Against Botryosphaeria dothidea.

The bird cherry-oat aphid, Rhopalosiphum padi (L.), is a major insect pest of cereal crops in many countries. Imidacloprid has been widely used for controlling piercing-sucking insect pests worldwide, but its sublethal effects on R. padi have not been well addressed. In this study, we investigated the sublethal effects of imidacloprid on biological parameters and five enzyme activities of R. padi. The LC10, LC20, and LC25 of imidacloprid to adult aphids were 0.0053, 0.0329 and 0.0659 mg L-1, respectively. These concentrations significantly decreased pre-adult survival rate, but prolonged the development duration of 1st instar nymphs, pre-oviposition period, and adult longevity. Adult oviposition period was also extended by LC20. The intrinsic rate of increase (r), net reproductive rate (R0), and finite rate (λ) decreased at all three concentrations, whereas mean generation time (T) increased. Moreover, LC20 and LC25 significantly inhibited superoxide dismutase (SOD) activity, but increased catalase (CAT) activity. Acetylcholinesterase (AChE) activity also increased at LC20. However, cytochrome P450 enzyme and peroxidase (POD) activity did not differ between imidacloprid treatments and the control. In conclusion, the imidacloprid concentrations tested here have negative impacts on the performance of R. padi by reducing its nymphal survival, extending the development duration of some stages, decreasing the rate of population growth, and altering enzyme activities.

Sublethal effects of imidacloprid on the performance of the bird cherry-oat aphid Rhopalosiphum padi.

Host genetic backgrounds affect gene functions. The genetic backgrounds of genetically engineered organisms must be identified to confirm their genetic backgrounds identity with those of recipients. Marker-assisted backcrossing (MAB), transgenesis and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (CRISPR/Cas9) editing are three commonly used genetic engineering techniques. However, methods for genetic background screening between genetically engineered organisms and corresponding recipients suffer from low efficiency, low accuracy or high cost.

Application of high-throughput amplicon sequencing-based SSR genotyping in genetic background screening.

The mirid bug, Apolygus lucorum, has become a major pest of many crops and fruit trees since the widespread adoption of Bt cotton in northern China. Neonicotinoid insecticides, such as dinotefuran, applied to control this pest may show sublethal effects, but evidence for such effects is lacking. Here, we investigated the sublethal and transgenerational effects of dinotefuran on biological parameters and feeding behavioural traits of A. lucorum using the age-stage, two-sex life table and electrical penetration graphs (EPGs), respectively. The LC and LC of dinotefuran against 3-instar nymphs of A. lucorum were 14.72 and 62.95 mg L, respectively. These two concentrations significantly extended the development duration from 3-instar nymph to adult in parent generation (F0). LC also increased the oviposition period and male adult longevity and reduced nymphal survival rate in the F0. For offspring generation (F1), the egg duration, preadult duration, and total preoviposition period were significantly lower at LC than in the control, and the egg duration, duration of 4-instar nymphs, preadult duration, oviposition period, and fecundity were also decreased at LC. However, the four demographic parameters of F1 generation, namely, net reproductive rate (R), intrinsic rate of increase (r), finite rate of increase (λ), and mean generation time (T), were not affected by dinotefuran. The significant differences in the number of probes and duration of each of four feeding waveforms failed to be detected when A. lucorum nymphs treated by dinotefuran feed on Bt cotton plants without insecticide exposure. Overall, the dinotefuran concentrations tested here have sublethal, but no transgenerational impacts on A. lucorum.

Sublethal and transgenerational effects of dinotefuran on biological parameters and behavioural traits of the mirid bug Apolygus lucorum.

Agricultural expansion at the cost of natural or semi-natural habitats is simplifying human-dominated landscapes. As croplands provide a large resource of food to herbivores, pest damage may increase, but such large-scale patterns across regions are little known. Here, we used two years of maize field data from 102 counties (each 1318 km on average) across Shandong Province in China to study the spatial distribution of two major co-occurring maize pests: the putative habitat specialist the Asian Corn Borer (Ostrinia furnacalis) (ACB) and the generalist Yellow Peach Moth (Conogethes punctiferalis) (YPM). We used Spatial Analysis by Distance Indices (SADIE) to assess the spatial distribution patterns of these pests and their relation to landscape factors. In both 2016 and 2017, the aggregation and abundance of the ACB was positively correlated with the proportion of maize on the county level, whereas the YPM exhibited the opposite pattern, i.e., a negative correlation with maize proportion. The ACB abundance was below the economic threshold level when maize was <31% in 2017, whereas the YPM abundance was below the threshold when maize was >27% (in 2016) or 23% (in 2017). Maize plant presence was the main determinant of the abundance of the ACB, while the YPM appeared to benefit from further resources in non-crop habitats. These contrasting distribution patterns suggest that the two pests are driven by their different resource requirements. In more diversified landscapes, pest control may need to focus primarily on the generalist consumer, the YPM, whereas in maize-dominated landscapes, the specialist consumer, the ACB, is dominant and needs attention.

Landscape agricultural simplification correlates positively with the spatial distribution of a specialist yet negatively with a generalist pest.

Sulfoxaflor, the first commercially available sulfoximine insecticide, has been used for the control of sap-feeding insect pests such as plant bugs and aphids on a variety of crops. However, its sublethal effects on the mirid bug Apolygus lucorum, one of the key insect pests of Bt cotton and fruit trees in China, have not been fully examined. Here, we evaluated the demography and feeding behaviour of A. lucorum exposed to sulfoxaflor. The leaf-dipping bioassay showed that the LC10 and LC30 of sulfoxaflor against 3rd-instar nymphs of this insect were 1.23 and 8.37 mg L-1, respectively. The LC10 significantly extended the nymphal duration and decreased the oviposition period by 5.29 days and female fecundity by 56.99% in the parent generation (F0). The longer duration of egg, 5th-instar nymphs, preadult, and male adult longevity were observed in the F1 generation (F1) at LC10. At the LC30, the duration of egg and 1st-instar nymph, female adult longevity, and oviposition period of the F1 were significantly shorter, while the nymphal duration in the F0 and duration of 5th-instar nymphs, preadult survival rate, and male adult longevity in the F1 significantly increased. The net reproductive rate (R0), intrinsic rate of increase (r), and finite rate of increase (λ) in the F1 were not significantly affected by these two concentrations, whereas the mean generation time (T) was lower at the LC30. Additionally, the probe counts and cells mixture feeding time were markedly lengthened by the LC10 and LC30, respectively, when A. lucorum nymphs exposed to sulfoxaflor fed on Bt cotton plants without insecticides. These results clearly indicate that sulfoxaflor causes sublethal effects on A. lucorum and the transgenerational effects depend on the tested concentrations.

Sublethal and transgenerational effects of sulfoxaflor on the demography and feeding behaviour of the mirid bug Apolygus lucorum.

In this study, the complete mitogenome sequence of  was described. The assembled mitogenome is 15,241 bp in length with an extreme bias of high AT content (80.9%) (GenBank accession no. MN747041). The mitochondrial genome contains 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (12S rRNA and 16S rRNA) genes, and a control region (D-loop region). The mitochondrial gene order was identical to that observed in most lepidopteran genomes, nine PCGs were located on the H-strand, others were located on the L-strand. 12 PCGs were initiated by typical ATN codons, except for  with CGA instead. 21 tRNAs had the typical cloverleaf structure, while the DHU arm of the  gene did not form a stable stem-loop structure. The 'ATAGT(A)'-like motif and a 19 bp poly-T stretch at the down-stream of the  gene were observed in the A + T-rich region. The phylogenetic analysis showed that the relationship of  is very close to the three species in the subfamily Pyraustinae: ,  and , and all the subfamilies of Spilomelinae, Pyraustinae, Crambinae and Nymphulinae within Crambidae formed monophyletic groups with the highest bootstrap value support.

Characterization of the complete mitochondrial genome of Asia Corn Borer,  (Lepidoptera: Crambidae).

In this study, the complete mitochondrial genome of orange swift, , was recovered through Illumina sequencing data. This complete mitochondrial genome of  is 15,040 bp in length and has a base composition of A (41.0%), T (41.2%), C (10.4%), G (7.5%), demonstrating an extreme bias of high AT content (82.2%). The mitochondrial genome contains a typically conserved structure among moth mitogenomes, encoding 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, two ribosomal RNA (12S rRNA and 16S rRNA) genes and a control region (D-loop region). Seven PCGs were located on the H-strand, others were located on the L-strand.  gene and  gene were overlapped by 6 bp.  gene and  gene were overlapped by 9 bp. The whole mt genome of  and other moth and butterfly mitogenomes (100 species, in total) were used for phylogenetic analysis. The result indicated  represents a distinct genus, which separated far from genus .

Characterization of the complete mitochondrial genome of the orange swift, .

Osmia excavata is an important pollinator in commercial fruit orchards. Little information has been published about ecotoxicity to O. excavata, especially the larvae. To clarify the risk of commonly used insecticides with different modes of action to the larvae of O. excavata, six insecticides (clothianidin, acetamiprid, sulfoxaflor, lambda-cyhalothrin, chlorfenapyr and abamectin) were selected for evaluation of their acute lethal toxicity and sublethal effects. Clothianidin and abamectin were the two most toxic insecticides to the larvae of O. excavata with LD values of 0.007 (0.006-0.008) and 0.0004 (0.0003-0.0006) μg active ingredient (a.i.) bee, respectively. And their ecological risks were high according to the hazard quotient values (HQ > 2500). Sulfoxaflor was identified as the only safe insecticide for O. excavata (HQ < 50) under field conditions. Sublethal toxicity tests showed that larval weight was significantly decreased by ingesting food treated with clothianidin, lambda-cyhalothrin and abamectin (less than the maximum field registered concentrations on fruit trees) due to interference with consumption per larva and reduction of the efficiency of conversion of ingested food. Additionally, above three insecticides significantly prolonged larval developmental duration before cocooning and decreased eclosion rate. Overall, there results suggested that clothianidin and abamectin should not be applied, especially during the flowering phase, the application frequency of lambda-cyhalothrin should be minimized for the purpose of conserving O. excavata. Our results provided important evidences for selecting appropriate insecticides for use in fruit orchards.

Comparative ecotoxicity of insecticides with different modes of action to Osmia excavata (Hymenoptera: Megachilidae).

To understand the resistance risks of Frankliniella occidentalis Pergande against phoxim, this paper studied the resistance mechanisms of phoxim-resistant F. occidentalis population against phoxim and the cross-resistance of the population against other insecticides. The phoxim-resistant population had medium level cross-resistance to chlorpyrifos, lambda-cyhalothrin, and methomyl, low level cross-resistance to chlorfenapyr, imidacloprid, emamectin-benzoate, and spinosad, but no cross-resistance to acetamiprid and abamectin. The synergists piperonyl butoxide (PBO), s, s, s-tributyl phosphorotrithioate (DEF), and triphenyl phosphate (TPP) had significant synergism (P < 0.05) on the toxicity of phoxim to the resistant (XK), field (BJ), and susceptible (S) populations, while diethyl maleate (DEM) had no significant synergism to XK and S populations but had significant synergism to BJ population. As compared with S population, the XK and BJ populations had significantly increased activities of mixed-functional oxidases P450 (2.79-fold and 1.48-fold), b, (2.88-fold and 1.88-fold), O-demethylase (2.60-fold and 1.68-fold), and carboxylesterase (2.02-fold and 1.61-fold, respectively), and XK population had a significantly increased acetylcholine esterase activity (3.10-fold). Both XK and BJ population had an increased activity of glutathione S-transferases (1.11-fold and 1.20-fold, respectively), but the increment was not significant. The increased detoxification enzymes activities in F. occidentalis could play an important role in the resistance of the plant against phoxim.

[Resistance mechanisms and cross-resistance of phoxim-resistant Frankliniella occidentalis Pergande population].

Athetis dissimilis (Hampson) has emerged as a serious pest on corn in recent years in China. Understanding the population response of A. dissimilis to temperature will be beneficial for adopting control strategies for this pest. The impact of five constant temperatures (17, 21, 25, 29, and 33 °C) on the life table of A. dissimilis was studied using age-stage, two-sex life table method in the laboratory. The results showed that the developmental time of egg, larva, pupa, and adult decreased when temperature increased from 17 °C to 33 °C. The TPOP (total preoviposition period) decreased with temperature increasing from 17 °C to 29 °C, while the longest APOP (adult preoviposition period) occurred at 21 °C (3.57 d) and the shortest at 33 °C (2.15 d). The fecundity increased from 407.52 to 763.94 eggs as temperatures were raised from 17 to 25 °C, but decreased at temperatures from 25 °C to 33 °C. The intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R0) increased as temperatures increased from 17 to 25 °C, then decreased when temperatures exceeded 25 °C. In contrast, the mean generation time (T) decreased as temperatures increased from 17 to 33 °C. Based on the estimated data, the highest female age-stage-specific fecundity (fx) and age-specific fecundity (mx) were 81.91 and 45.04 eggs, respectively, at 25 °C. The age-stage life expectancy (exj) of all stages decreased as the temperature increased. The reproductive value (vxj) increased gradually with age and stage. The developmental rates of A. dissimilis between 17 to 29 °C fit the linear equation y  = -0.01315 + 0.001303x, with a coefficient of determination (R2) of 0.9314. In conclusion, our finding clearly states that A. dissimilis has the greatest population increase at 25 °C, and this may help develop appropriate pest management strategies.

Impact of Temperature on the Growth and Development of Athetis dissimilis (Lepidoptera: Noctuidae).

The nectarine is an important fruit, which is attacked by  in Europe and the United States but there are no reports of it attacking nectarines in China. Here, we determined the oviposition preference of  six on intact and sliced nectarine varieties in China and how physical and physiological indexes of the fruit correlate with these preferences.  were allowed to oviposit on two early-, two middle- and two late-maturing varieties of nectarine-Shuguang and Chunguang, Fengguang and Zhong you 4, Zhong you 7 and Zhong you 8, respectively and the number of larvae also followed the order. The firmness, soluble solids content and the nutritional components of the amino acid, protein, soluble sugar and pectin contents of each variety were measured.  preferred the early Shuguang variety, followed by the early Chunguang variety and then the middle Zhong you 4 and Fengguang varieties. Taken together, results show that  shows preferences for earlier rather than later varieties of nectarines in China and that these preferences are related to the fruit's physical and physiological traits. Results suggest that mixed cultivation of early-, middle- and late-maturing nectarine varieties should be avoided in order to prevent fly dispersal and infestation by .

Oviposition Suitability of  (Diptera: Drosophilidae) for Nectarine Varieties and Its Correlation with the Physiological Indexes.

Spodoptera frugiperda is a major agricultural pest that has invaded China since January 2019. Given that most of the individuals present in China carried the diagnostic rice-strain mtDNA (COI-RS), there was no efficient method to distinguish populations of S. frugiperda. In this study, we identified and characterized two variant microsatellite alleles in the mitochondrial NAD6 gene of S. frugiperda retrieved from the National Center for Biotechnology Center GenBank. We then sequenced partial NAD6 genes containing the microsatellite region and the diagnostic COI barcoding gene (used to distinguish the corn-strain and the rice-strain) of 429 invasive S. frugiperda individuals that were collected from the main infested regions in China during 2019-2020. Our data indicates that two kinds of interrupted repeat sequences, (ATA)4T(ATA)3 and (ATA)5T(ATA)3, exist in the microsatellite region which we defined as the deletion type (NAD6-D), and the insertion type (NAD6-I) based on the repeat units' differentiation, respectively. The presence of these two microsatellite types in the mtDNA genome of S. frugiperda was further confirmed with the sequencing results in 429 samples. Moreover, NAD6-I and NAD6-D types were both present in individuals with COI-RS, while only NAD6-D type was detected in the COI-CS individuals. Interestingly, the two microsatellite types suggested a possible geographic distribution: the western migratory route (Yunan and Chongqing) was comprised exclusively of NAD6-I type, while both NAD6-I and NAD6-D types were identified in the predicted eastern migration trajectories (Hainan, Guangxi, Shandong, etc.). These results suggested that NAD6-D and NAD6-I types may be useful in distinguishing between populations, analyzing the evolutionary mechanism of mtDNA microsatellite polymorphism, inferring the migratory route of S. frugiperda in China, and developing precise and integrated control strategies for S. frugiperda.

Two Microsatellite Types Within NAD6 Gene Help to Distinguish Populations and Infer the Migratory Route of the Invasive Fall Armyworm, Spodoptera frugiperda, (Lepidoptera, Noctuidae) in China.

ArticleTotal : 2	Year
Publication title Cited by 2	2021
Publication title Cited by 2	2023

Article	Year
Evaluating the Sensitivity and Efficacy of Fungicides with Different Modes of Action Against Botryosphaeria dothidea. Plant disease\| PubMed ID: 30125189	2018
Sublethal effects of imidacloprid on the performance of the bird cherry-oat aphid Rhopalosiphum padi. PloS one\| PubMed ID: 30235260	2018
Application of high-throughput amplicon sequencing-based SSR genotyping in genetic background screening. BMC genomics\| PubMed ID: 31159719	2019
Sublethal and transgenerational effects of dinotefuran on biological parameters and behavioural traits of the mirid bug Apolygus lucorum. Scientific reports\| PubMed ID: 31937822	2020
Landscape agricultural simplification correlates positively with the spatial distribution of a specialist yet negatively with a generalist pest. Scientific reports\| PubMed ID: 31941914	2020
Sublethal and transgenerational effects of sulfoxaflor on the demography and feeding behaviour of the mirid bug Apolygus lucorum. PloS one\| PubMed ID: 32407334	2020
Characterization of the complete mitochondrial genome of Asia Corn Borer, (Lepidoptera: Crambidae). Mitochondrial DNA. Part B, Resources\| PubMed ID: 33366817	2020
Characterization of the complete mitochondrial genome of the orange swift, . Mitochondrial DNA. Part B, Resources\| PubMed ID: 33474231	2018
Comparative ecotoxicity of insecticides with different modes of action to Osmia excavata (Hymenoptera: Megachilidae). Ecotoxicology and environmental safety\| PubMed ID: 33561775	2021
[Resistance mechanisms and cross-resistance of phoxim-resistant Frankliniella occidentalis Pergande population]. Ying yong sheng tai xue bao = The journal of applied ecology / Zhongguo sheng tai xue xue hui, Zhongguo ke xue yuan Shenyang ying yong sheng tai yan jiu suo zhu ban\| PubMed ID: 23173470	2012
Impact of Temperature on the Growth and Development of Athetis dissimilis (Lepidoptera: Noctuidae). Journal of economic entomology\| PubMed ID: 28011680	2017
Oviposition Suitability of (Diptera: Drosophilidae) for Nectarine Varieties and Its Correlation with the Physiological Indexes. Insects\| PubMed ID: 31344965	2019
Two Microsatellite Types Within NAD6 Gene Help to Distinguish Populations and Infer the Migratory Route of the Invasive Fall Armyworm, Spodoptera frugiperda, (Lepidoptera, Noctuidae) in Chin... Journal of economic entomology\| PubMed ID: 35899806	2022

Lili Li

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