Effects of adult emergence timing on susceptibility and fitness of Cry3Bb1-resistant western corn rootworms

2016 ◽  
Vol 141 (5) ◽  
pp. 372-383 ◽  
Author(s):  
D. S. Wangila ◽  
L. J. Meinke
Keyword(s):  
Adult Emergence ◽  
Corn Rootworms

Rotation-Resistant Corn Rootworms 2006

2006 ◽  
Author(s):  
Jon Tollefson ◽  
Patricia Prasifka ◽  
Benjamin Kaeb
Keyword(s):  
Corn Rootworms

scholarly journals Evaluation of indigenous the nucleopolyhedrovirus (NPV) of Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) in combination with chlorantraniliprole against Spodoptera species

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Ghulam Sarwar ◽  
Naeem Arshad Maan ◽  
Muhammad Ahsin Ayub ◽  
Muhammad Rafiq Shahid ◽  
Mubasher Ahmad Malik ◽  
...  
Keyword(s):  
Larval Mortality ◽  
Adult Emergence ◽  
Lethal Concentration ◽  
Pest Species ◽  
Vegetable Crops ◽  
Chemical Insecticide ◽  
Larval Instars ◽  
Novel Method ◽  
High Larval Mortality ◽  
Lepidoptera Noctuidae

Abstract Background The armyworms, Spodoptera exigua (Hübner), and S. litura (Fabricius) (Lepidoptera: Noctuidae) are polyphagous pests of many cash crops. Heavy crop losses have been reported for the fruit and vegetable crops each year owing to the diverse impact on global economies. The present study was aimed to sort out a novel method of pest control using the insect’s own nucleopolyhedrosis virus (NPV) alone and in combination with a new chemistry insecticide chlorantraniliprole. Results In the study, the effect of indigenous isolated nucleopolyhedrovirus (NPV) and the chemical insecticide (chlorantraniliprole) formulations against the 2nd and 4th larval instars of S. litura and S. exigua, collected from the different geographical region of Punjab (Pakistan) province, was evaluated. Three concentrations of the NPV isolate, sub-lethal (1 × 104, 6 × 104 POB ml−1), lethal (3 × 105 POB ml−1), and chlorantraniliprole 0.01 μl l−1, were applied alone and in combination against the 2nd and 4th larval instars of both pest species. The lethal concentration of NPV + chlorantraniliprole exhibited synergistic interaction and caused high larval mortality against both instars, while in all other combinations, additive effect was observed. Moreover, NPV + chlorantraniliprole at lethal concentration exhibited decreased pupation, adult emergence, and egg eclosion. Conclusion The implications of using NPV alone and in combination with an insecticide are discussed briefly in this study.

scholarly journals Laboratory and microcosm experiments reveal contrasted adaptive responses to ammonia and water mineralisation in aquatic stages of the sibling species Anopheles gambiae (sensu stricto) and Anopheles coluzzii

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Nwamaka Oluchukwu Akpodiete ◽  
Frédéric Tripet
Keyword(s):  
West Africa ◽  
Anopheles Gambiae ◽  
Emerging Adults ◽  
Sibling Species ◽  
Adult Emergence ◽  
Ecological Speciation ◽  
Sensu Stricto ◽  
Rice Fields ◽  
Anopheles Coluzzii ◽  
Phenotypic Quality

Abstract Background The sibling species of the malaria mosquito, Anopheles gambiae (sensu stricto) and Anopheles coluzzii co-exist in many parts of West Africa and are thought to have recently diverged through a process of ecological speciation with gene flow. Divergent larval ecological adaptations, resulting in Genotype-by-Environment (G × E) interactions, have been proposed as important drivers of speciation in these species. In West Africa, An. coluzzii tends to be associated with permanent man-made larval habitats such as irrigated rice fields, which are typically more eutrophic and mineral and ammonia-rich than the temporary rain pools exploited by An. gambiae (s.s.) Methods To highlight G × E interactions at the larval stage and their possible role in ecological speciation of these species, we first investigated the effect of exposure to ammonium hydroxide and water mineralisation on larval developmental success. Mosquito larvae were exposed to two water sources and increasing ammonia concentrations in small containers until adult emergence. In a second experiment, larval developmental success was compared across two contrasted microcosms to highlight G × E interactions under conditions such as those found in the natural environment. Results The first experiment revealed significant G × E interactions in developmental success and phenotypic quality for both species in response to increasing ammonia concentrations and water mineralisation. The An. coluzzii strain outperformed the An. gambiae (s.s.) strain under limited conditions that were closer to more eutrophic habitats. The second experiment revealed divergent crisscrossing reaction norms in the developmental success of the sibling species in the two contrasted larval environments. As expected, An. coluzzii had higher emergence rates in the rice paddy environment with emerging adults of superior phenotypic quality compared to An. gambiae (s.s.), and vice versa, in the rain puddle environment. Conclusions Evidence for such G × E interactions lends support to the hypothesis that divergent larval adaptations to the environmental conditions found in man-made habitats such as rice fields in An. coluzzii may have been an important driver of its ecological speciation.

scholarly journals Effect of gallic acid on the larvae of Spodoptera litura and its parasitoid Bracon hebetor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abhay Punia ◽  
Nalini Singh Chauhan ◽  
Drishtant Singh ◽  
Anup Kumar Kesavan ◽  
Sanehdeep Kaur ◽  
...  
Keyword(s):  
Gallic Acid ◽  
Spodoptera Litura ◽  
Negative Impact ◽  
Larval Mortality ◽  
Adult Emergence ◽  
Egg Hatching ◽  
Bracon Hebetor ◽  
Total Hemocyte Count ◽  
Glutathione S Transferases ◽  
Immense Potential

AbstractThe antibiosis effect of gallic acid on Spodoptera litura F. (Lepidoptera: Noctuidae) and its parasitoid evaluated by feeding six days old larvae on artificial diet incorporated with different concentrations (5 ppm, 25 ppm, 125 ppm, 625 ppm, 3125 ppm) of the phenolic compound revealed higher concentration (LC50) of gallic acid had a negative impact on the survival and physiology of S. litura and its parasitoid Bracon hebetor (Say) (Hymenoptera:Braconidae). The mortality of S. litura larvae was increased whereas adult emergence declined with increasing concentration of gallic acid. The developmental period was delayed significantly and all the nutritional indices were reduced significantly with increase in concentration. Higher concentration (LC50) of gallic acid adversely affected egg hatching, larval mortality, adult emergence and total development period of B. hebetor. At lower concentration (LC30) the effect on B. hebetor adults and larvae was non-significant with respect to control. Gene expression for the enzymes viz., Superoxide dismutase, Glutathione peroxidase, Peroxidase, Esterases and Glutathione S transferases increased while the total hemocyte count of S. litura larvae decreased with treatment. Our findings suggest that gallic acid even at lower concentration (LC30) can impair the growth of S. litura larvae without causing any significant harm to its parasitoid B. hebetor and has immense potential to be used as biopesticides.

scholarly journals Perforation index assessment of cowpea seeds against cowpea bruchid, Callosobruchus maculatus (Fabricius) [Coleoptera: Chrysomelidae], infestation using Piper guineense

2020 ◽  
Vol 81 (1) ◽  
Author(s):  
Kayode David Ileke ◽  
Jacobs Mobolade Adesina ◽  
Luke Chinaru Nwosu ◽  
Abimbola Olagunju
Keyword(s):  
Callosobruchus Maculatus ◽  
Adult Emergence ◽  
Adult Mortality ◽  
Contact Toxicity ◽  
Toxicity Assay ◽  
Piper Guineense ◽  
Cowpea Seeds ◽  
Leaf Powder ◽  
Human Use ◽  
Seed Extracts

Abstract Background Powders and extracts of Piper guineense seeds and leaves were assessed for insecticidal activities against Callosobruchus maculatus in the laboratory at temperature and relative humidity of 29.6 °C and 75.9%, respectively. Bioactive compounds in P. guineense leaves and seeds were also investigated. The powders were tested at rates 1.0, 2.0 and 4.0 g/20 g cowpea seeds while extracts were tested at 1.0, 2.0 and 3.0%. Results Results of contact toxicity assay of the seed powder caused 100% adult mortality at 96 h post-treatment period whereas leaf powder evoked 90% adult mortality within the same period at concentration of 1.0 g/20 g cowpea seeds. Low adult emergence was observed on cowpea seeds treated with 1 g of seed powder with percentage adult emergence of 10.0% and inhibition rate (IR) of 97.5%. Beetle Perforation Index (BPI) obtained from treated cowpea seeds was significantly different (P < 0.05) from BPI of untreated seeds. Extracts of P. guineense seed were more toxic than seed powder. Piper guineense seed extract caused 87.5% adult mortality of C. maculatus while leaf extract caused 70.0% adult mortality within 24 h of infestation at concentration of 1%. Progeny development of C. maculatus was completely inhibited in cowpea treated with 2% and 3% leaf and seed extracts of P. guineense. β-Pinene was the most abundant active compound in P. guineense seed (55.6%) and leaf (48.4%). β-Phellandrene occurred 38.2% in seeds while Ocimene had the least value of 0.2% in seed and 0.5% in leaf. Conclusion The study showed that P. guineense seed powder and extracts were more effective than leaf powder and extract. Utilization of plant products as alternative to synthetic insecticides in protecting cowpea seeds against C. maculatus should be encouraged for enhanced food safety and security. Piper guineense is used as spice and medicine and interestingly safe for human use.

scholarly journals Is High Whitefly Abundance on Cassava in Sub-Saharan Africa Driven by Biological Traits of a Specific, Cryptic Bemisia tabaci Species?

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 260
Author(s):  
Habibu Mugerwa ◽  
Peter Sseruwagi ◽  
John Colvin ◽  
Susan Seal
Keyword(s):  
Food Security ◽  
Bemisia Tabaci ◽  
Development Time ◽  
Adult Emergence ◽  
Sub Saharan Africa ◽  
Biological Traits ◽  
Population Development ◽  
Species Classification ◽  
First Instar ◽  
Sub Saharan

In East Africa, the prevalent Bemisia tabaci whiteflies on the food security crop cassava are classified as sub-Saharan Africa (SSA) species. Economically damaging cassava whitefly populations were associated with the SSA2 species in the 1990s, but more recently, it has been to SSA1 species. To investigate whether biological traits (number of first instar nymphs, emerged adults, proportion of females in progeny and development time) of the cassava whitefly species are significant drivers of the observed field abundance, our study determined the development of SSA1 sub-group (SG) 1 (5 populations), SG2 (5 populations), SG3 (1 population) and SSA2 (1 population) on cassava and eggplant under laboratory conditions. SSA1-(SG1-SG2) and SSA2 populations’ development traits were similar. Regardless of the host plant, SSA1-SG2 populations had the highest number of first instar nymphs (60.6 ± 3.4) and emerged adults (50.9 ± 3.6), followed by SSA1-SG1 (55.5 ± 3.2 and 44.6 ± 3.3), SSA2 (45.8 ± 5.7 and 32.6 ± 5.1) and the lowest were SSA1-SG3 (34.2 ± 6.1 and 32.0 ± 7.1) populations. SSA1-SG3 population had the shortest egg–adult emergence development time (26.7 days), followed by SSA1-SG1 (29.1 days), SSA1-SG2 (29.6 days) and SSA2 (32.2 days). Regardless of the whitefly population, development time was significantly shorter on eggplant (25.1 ± 0.9 days) than cassava (34.6 ± 1.0 days). These results support that SSA1-(SG1-SG2) and SSA2 B. tabaci can become highly abundant on cassava, with their species classification alone not correlating with observed abundance and prevalence.

scholarly journals Impact of conventional insecticides on two bollworms and their indirect effects on the ectoparasitoid, Bracon brevicornis (Wesmael) (Hymenoptera: Braconidae)

2019 ◽  
Vol 43 (1) ◽  
Author(s):  
Mervat A. Kandil ◽  
Hemat Z. Moustafa
Keyword(s):  
Indirect Effects ◽  
Larval Mortality ◽  
Adult Emergence ◽  
Immature Stage ◽  
Pectinophora Gossypiella ◽  
Earias Insulana ◽  
Pupal Development ◽  
Percentage Mortality ◽  
Biological Aspects ◽  
Newly Hatched Larvae

Abstract Background Cotton bollworms such as Pectinophora gossypiella and Earias insulana are serious pests which destroy the cotton plant, and Bracon brevicornis is a parasitoid which attacked the larvae of bollworms. Results In this study, experiments were performed to investigate and evaluate the toxicity of etofenprox and chlorpyrifos insecticides against newly hatched larvae of Pectinophora gossypiella and Earias insulana. Some biological aspects of compound effects on larval and pupal duration, percentage of mortality, and percentage of adult emergence which resulted from treated newly hatched larvae were studied. The results revealed that LC50 was 0.7 and 0.87 ppm when P. gossypiella was treated with etofenprox and chlorpyrifos, respectively, while LC50 was 0.09 and 0.73 ppm when E. insulana was treated with etofenprox and chlorpyrifos, respectively. The obtained results showed that the percentage of mean larval mortality was 65.0 and 63.0% for treated P. gossypiella, while it was 71.0 and 66.0% for treated E. insulana. The corresponding figure for pupal percentage mortality was 8.0 and 10.0% for treated P. gossypiella, but it was 5.0 and 2.0% for treated E. insulana, with etofenprox and chlorpyrifos, and a prolongation effect in larval and pupal development (total immature stage) resulted from treated both bollworms as follows: 35.5 and 32.4 days for treated P. gossypiella compared with 21.9 days in control and 34.7 and 23.2 days for treated E. insulana compared with 23.1 days in control. The indirect effect of etofenprox and chlorpyrifos on the total immature stage of Bracon brevicornis was 18.2 and 19.5 days compared with 14.3 days in control when B. brevicornis parasitized on P. gossypiella larvae while it was 19.8 and 20.6 days compared with 15.2 days when B. brevicornis parasitized on E. insulana larvae. Conclusion The life cycle of B. brevicornis after parasitism on P. gossypiella and E. insulana larvae treated with etofenprox and chlorpyrifos were increased than the control larvae.

scholarly journals Biological activities of spores and metabolites of some fungal isolates on certain aspects of the spiny bollworms Earias insulana (Boisd.) (Lepidoptera: Noctuidae)

2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Eman Mohammed Abd-ElAzeem ◽  
Warda Ahmed Zaki El-Medany ◽  
Hend Mohammed Sabry
Keyword(s):  
Biological Activities ◽  
Larval Mortality ◽  
Adult Emergence ◽  
Pupal Weight ◽  
Earias Insulana ◽  
Dead Larva ◽  
Fungal Isolates ◽  
Protease Enzyme ◽  
Newly Hatched Larvae ◽  
Lepidoptera Noctuidae

AbstractBiological activities of spores and metabolites of some fungi isolated from dead larva of the spiny bollworms (SBW), Earias insulana (Boisd.) (Lepidoptera: Noctuidae), against the newly hatched larvae of the pest were carried out. Results showed that the fungi Metarhizium anisopliae, Acremonium sp., and Paecilomyces variotii had affected the newly hatched larvae of (SBW). Acremonium sp. was the most potent one as it had the highest newly hatched larval mortality percentage (65 and 58.33%) for its spore suspension and metabolites, respectively, while the lowest one (41%) was for P. variotii metabolites. Also, spore suspensions of the all fungal isolates had the highest larval mortality than fungal metabolites. Studying the enzymatic activity showed that Acremonium sp. produced protease enzyme on media containing gelatin, which caused the highest larval mortality (72.22%).These isolates showed different effects on all stages of the pest and decreased pupal weight, adult emergence percentages, deposited eggs, and hatchability percentages than the control. Identification of Acremonium sp. EZ1 was confirmed using 18 s rRNA and its accession number MN25101.

EFFECTS OF ECDYSONES, JUVENILE HORMONE ANALOGS, AND 6-OXOOCTANOIC ACID ON THE DEVELOPMENT OF THE MOSQUITO, CULEX TARSALIS (DIPTERA: CULICIDAE)

1974 ◽  
Vol 106 (1) ◽  
pp. 79-85 ◽  
Author(s):  
P. I. Ittycheriah ◽  
M. S. Quraishi ◽  
E. P. Marks
Keyword(s):  
Juvenile Hormone ◽  
Topical Treatment ◽  
Adult Emergence ◽  
Fourth Instar ◽  
Culex Tarsalis ◽  
Juvenile Hormone Analog ◽  
Hormone Analog ◽  
High Doses ◽  
Hormone Analogs ◽  
Very High

AbstractEggs, larvae, and pupae of Culex tarsalis Coquillett were treated with ecdysones, juvenile hormone analogs, and 6-oxooctanoic acid. Effects of these agents on mortality, induction of supernumerary stages, and adult emergence were determined. Topical treatment of eggs with CRD9499 (a juvenile hormone analog), β-ecdysone, and 22-isoecdysone caused a reduction in adult emergence. Treatment of fourth-instar larvae with these chemicals not only induced mortality but also caused the formation of supernumerary intermediate stages. Larvae of C. tarsalis were very susceptible to CRD9499, but pupae were resistant. The ecdysones caused some mortality but only at very high doses and would thus be of little use as larvicides. 6-Oxooctanoic acid caused high rates of mortality at 0.001 M concentrations.

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