Open Access Pub publishes peer-reviewed, free-to-read open-access articles. Showing
articles matching Larval instar — open any to read the full text,
or download the PDF or XML.
Feb 2023 DOI 10.14302/issn.2639-3166.jar-22-4389
Haroun Mohamed Adam AbubakerCorresponding author
The greater wax moth (Galleria mellonella L.) is one of the most destructive insect pests that threaten apiculture. Laboratory experiments were conducted in the Research Laboratory, College of Agricultural Studies, Sudan University of Science and Technology during the period from the 2nd_ of April to 29th_ of October 2021 to evaluate the lethal effect of Bee glue (proplis) and Bacillus thuringiensis var. Kurstaki (Btk) on the G.mellonella. Five concentrations (5%, 7.5%, 10%, 12.5% and 15%) of proplis extract and (0.62,1.25,2.5,5 and 10 mg/ml) of Bt were used for each proplis extract and Bt in a Completely Randomized Design. Powder ethanol extract of proplis at 15% concentration caused 83.3% mortality after 96 hrs of application, where as 10mg//ml concentration of Bt gave 93.3% mortality after 72 hrs of exposure. The statistical analysis revealed significant differences between all treatments and control. Additionally, all treatments (proplis/ /Bt) increased the mortality %.
Sep 2022 DOI 10.14302/issn.2639-3166.jar-22-4247
Haroun Mohamed Adam AbubakerCorresponding author
Department of Crop Science, College of Agriculture, University of Bahri- Sudan.
The greater wax moth considered one of the most worldwide-spread pests of the bee wax. This Study was designed to investigate the insecticidal activity of Carumcarvi, Eculaptus camaldulensis and Nigella sativa against 3rd larval instar of G.mellonellathrough laboratory screening. Five concentrations (5%, 7.5%, 10%, 12.5% and 15%) of each plant extract were used in this experiment. Mortality (%) was recorded after 24, 48, 72 and 96 hrs post treatment. The results showed C. carvi, E. camaldulensis and N.sativahave insecticidal activity against 3rd_ instar larvae of G. mellonella. The highest concentration (15%) caused 90% ,86.7% and 80% larval mortality after 96 hrs for C. carvi,E. camaldulensis and N.sativarespectively. The statistical analysis revealed that there is a significant difference (p< .001) between all treatments and control. The results also clearly demonstrate that the C. carvi are significantly more toxic than E. camaldulensis and N. sativa, whereas the LC50 values were 5.4% forC. carvi,6.0% for E. camaldulensis and 6.2% for N. sativa.
Jun 2021 DOI 10.14302/issn.2639-3166.jar-21-3817
Elamin Elhaj WaleedCorresponding author
Department of Plant Protection, College of Agricultural Studies, Sudan University of Science and Technology, Khartoum State, Sudan.
Helicoverpaarmigera is one of the most destructive pests of field crops worldwide. The Study was designed to investigate through laboratory screening the insecticidal activity of Ricinus communis, Cassia occidentalis and Bacillus thuringiensis var. Kurstaki (Btk) and their combinations against 2nd larval instar of H. armigera. Five concentrations (4%, 6%, 8%, 10% and 12%) of each plant extract and (0.62, 1.25, 2.5, 5, and 10 mg/ml) of Bt were used in this experiment. Mortality (%) was recorded after 24,48,72 and 96 hrs post treatment. The results showed that R. communis, C. occidentalis and Btkhave insecticidal activity against 2nd instar larvae of H. armigera. The highest concentration (12%) caused 80% and 70% larval mortality after 96 hrs for R. communis and C. occidental respectively. The statistical analysis revealed that there is a significant differences between all treatments and control. Additionally, all combinations (plant/plant or plant/Bt) increased the mortality %. The results also clearly demonstrate that the R. communis are significantly more toxic than C. occidental where the LC50 values were 6.4 % for R. communis and 8.1% for C. occidental. On the other hand LC50 value for Bt was 0.41 mg/ml. The binary mixture of R. communis and C. occidental have a potentiation effect after 48 hrs. Regarding the mixture of Bt and plant extracts the results revealed that R. communis and Bt mixture induced a potentiation effect whereas C. occidental and Bt mixture induced a an additive effects.
Jun 2019 DOI 10.14302/issn.2639-3166.jar-19-2858
Haroun Mohamed Adam AbubakerCorresponding author
Department of Crop Science, College of Agriculture, University of Bahri.
The objective of this study was to evaluate the effectiveness of endophagous Encyrtid parasitic wasp Aenasiusarizonensis (Girault) (Hymenoptera, Chalcidoidea), as a natural enemy for controlling the Mealybug, Phenacoccussolenopsis Tinsley (Hemiptera: Pseudococcidae). Where a Randomized Complete Block Design (RCBD) was adopted. Both, field survey and Laboratory experiments were conducted to study some biological characteristics of the parasitoid A. arizonensis. The results of field study revealed that, the parasitioid was available most of the year, and was highly effective on adults and last larval instar of the mealy bug, P. Solenopsis, with a total percentage of parasitism of 31.26%. While the laboratory results showed that, the duration from oviposition to adult emergence were similar for both male and female. Longevity of male was 23± 2.33 days and female 23.37±1.89 days. Mean daily fecundity in terms of number of Parasitized hosts /female / day ranged from 20 to 24. The sex ratio was 1:1.6 for the male and female in the progeny. Generally, a mass rearing of this parasitoid, with a conservation and augmentation releases could help in the application of an effective management strategy for the control of the cotton mealy bug in the field.
Feb 2019 DOI 10.14302/issn.2637-6075.jpae-19-2586
E H RadwanCorresponding author
Zoology department, Faculty of Science, Damanhour University, Egypt.
Melia azedarach extract were applied by feeding the adult female flies on diets mixed with the extracts at different doses. The concentrations of Melia azedarach utilized were 1.8, 2.4 and 3.6%. The gonotrophic cycles of length of 90, 753, 67.6 and 84, 72, 68 hours were obtained after feeding at age 24 hours with diet mixed with doses of 1.8, 2.4 and 3.6% fruit extract; respectively. 98 & 96 hours were the length of gonotrophic cycle in the control groups. The length of 86.7, 72.3, 57.3 and 89.3, 75, 61 hours were obtained after feeding adults at age 48 hours with diets mixed with different doses of fruit extract of the same plant 97.3 and 98.7 hours were the length of the control groups. Proportions of the egg hatching reached 69, 55.3, 49 and 72.9, 64.2, 52 in groups of eggs obtained from 24 hours adults feeding with diets mixed with doses of 1.8, 2.4 and 3.6% fruit extract; respectively. Also 68.7, 53.3,48 5 and 81 2, 70, 56.3 were the proportions of egg hatching obtained from groups at age 48 hours after feeding with diets mixed with the same doses. 85, 77.6, 62.2 and 92.6, 88.9, 84.9 were the proportions of the egg hatching obtained from groups feeding with diets mixed with doses of 1.8, 2.4 and 3.6% fruit extract of Melia azedarach; respectively. The pupae showed larval-pupal intermediates which failed to complete the pupal period and died after emerging from the third larval instar.