Nigerian Journal of Entomology
ISSN : 0331-0094
Published by: Lujosh Ventures Limited (10.36108)
Total articles ≅ 52
Latest articles in this journal
Nigerian Journal of Entomology, Volume 36, pp 96-102; https://doi.org/10.36108/nje/0202/63.01.11
The study evaluatrd the effect of Baobab, Adansonia digitata pod extract on larvae of Culex quinquefaciatus. The plant material was sun-dried for two weeks and pulverized using mortar and pestle and stored at room temperature for further processes. Powdered plant material was extracted using aqueous cold extraction method. The condensed extract was screened for phytochemicals. Indoor resting adult blood-fed female Culex mosquitoes were collected and introduced into Entomological Cages in the Laboratory and oviposited on water in the bowls. The third instar larvae were confirmed as Cx. quinquefasciatus using Hopkins keys for Culicinae. Triplicates of twenty-five late third instar larvae were tested in pod extract concentrations of 0.5mg/L, 1.0mg/L, 1.5mg/L, 2.0mg/L and 2.50mg/L. Mortality was recorded after 24hr of exposure. The LC50 was determined using probit analysis, while one-way ANOVA was used to establish significant differences in larval mean mortality. Phytochemical constituents such as carbohydrate, cardiac glycosides, steroids, triterpenes, tannins, flavonoids and alkaloids were present. The mean mortality of test concentrations differed significantly (p≤0.05) from control. However, the concentrations: 0.5mg/L and 8.0mg/L had 49% and 71% mortalities, respectively with LC50 of 0.6mg/L. It can be concluded that, the aqueous pod extract of Adansonia digitata demonstrated good activity against Cx. quinquefasciatus. Adansonia digitata pod extracts has potential for controlling larvae of Culex mosquitoes and can be incorporated into integrated mosquito management programme.
Nigerian Journal of Entomology, Volume 36, pp 139-145; https://doi.org/10.36108/nje/0202/63.01.61
Seasonal differences in the abundance of tsetse flies in Pantaki was investigated between July and August, 2016 and January and February, 2017 in Kagarko. Standard bioconical trapping method was used to collect the insects. A total of 208 tsetse flies were caught of which 139 (66.8%) were Glossina palpalis palpalis while 69 (33.2%) were Glossina tachinoides revealing an overall apparent density of 3.7T/T/D. The results indicate a significant difference (p<0.05) in abundance of tsetse flies in the wet compared to the dry seasons. Also, both species were relatively more abundant during wet (G. palpalis palpalis 75.5%, G. tachinoides 84.1%) than dry (G. palpalis palpalis 24%, G. tachinoides 15.9%) seasons. The differences in abundance observed could be due to the favourable climatic condition. This call for deployment of tsetse fly control measures (during the wet season) in the area.
Nigerian Journal of Entomology, Volume 36, pp 88-95; https://doi.org/10.36108/nje/0202/63.01.01
In the 21st century climate change has been recognized globally as the most impending, and critical issue that affects all animals including insects. In particular, temperature plays an important role in the development, reproduction, host searching, survival, pathogenicity, sex ratio and insect death. The Nipa palm hispid, Octodonta nipae (Maulik) is an important invasive pest of palm trees in Sothern China. Knowledge of how this beetle can be controlled with entomopathogenic nematodes under different environmental temperature is scarce. Therefore, the aims of this study were to test the efficacy of two entomopathogenic nematodes (Steinernema carpocapsae and Heterorhabditis bacteriophora) at different development temperatures. The pathogenicity was tested at concentration of 100 IJs larva-1 and treatment are kept at four temperatures of 20, 25, 30 and 36°C, 80 ± 5% RH. The results showed that, both nematodes species caused larval mortalities at all the tested temperatures except at 36°C. The highest larval mortalities of 85.3% and 40.6% were obtained at 30°C for both S. carpocapsae and H. bacteriophora respectively. Furthermore, both nematodes penetrated O. nipae larvae at all temperature conditions except at 36°C. Similarly, the highest penetrations of nematodes infective juveniles were recorded at 30°C for S. carpocapsae and H. bacteriophora. The study demonstrated that, warmer temperature enhanced the pathogenicity of nematodes, which in turns trade well with the unprecedented increase in environmental temperature under climate change, for integrated management of this beetle.
Nigerian Journal of Entomology, Volume 36, pp 103-112; https://doi.org/10.36108/nje/0202/63.01.21
The study was to assess insecticidal effectiveness of Jatropha curcas L. seed powder on Callosobruchus subinnotatus (Pic) infesting stored bambaranut, Vigna subterranea (L.) Verdcourt. The experiment was laid out in a factorial design of 4×2 levels (seed powder at the rates of 0.0, 0.5. 1.0 and 1.5 g, with and without addition of the synthetic insecticide at 0.01 g/20 g bambaranut seed) and laid out in a completely randomized design, in three replicates. Results obtained showed lowest oviposition, progeny emergence and seed damage (5.33, 1.58 and 1.83, respectively) in bambaranut seeds admixed with 1.0 g of the seed. Although, statistically similar to all other treatments, it was significantly (P≤0.001) better than the control treatment in which 33.83 eggs were laid and 24.08 adults emerged from 22.92 emergence holes. In addition, at six (6) days after treatment, highest adult mortality rate (99.17%) similar to that (99.17%) obtained in the synthetic insecticide was also recorded in seeds treated with 1.0 g seed powder. However, all other treatments were also significantly better than the control, in which 72.50% of the introduced bruchids died. Comparatively, lowest rate of seed damage (6.68%) and lasting effect was also obtained with the addition 1.0 g seed powder. In conclusion, appreciable level of protection on bambaranut seeds was achieved using seed powder of J. curcas. Therefore, it is recommended that for effective management of C. subinnotatus infesting bambaranut, farmers could use 5 Kg seed powder on 100 Kg bambaranut seeds.
Nigerian Journal of Entomology, Volume 36, pp 11-21; https://doi.org/10.36108/nje/0202/63.01.20
This paper examines diversity of insect vectors and parasites/vector-borne diseases also the successes and challenges in vector control in the 21st century and the way forward suggested. The generally accepted insect biodiversity is estimated to be 5.5 million worldwide with only about 1.5 million described. Generally, four insect orders: Coloeptera, Lepidopera, Hymenoptera and Odonata have been well studied and broadly described. Majority of insect species are known to be beneficial to man and the environment however, insect vectors which are fewer have been identified as causes of morbidity. Mosquitoes which are hematophagous insect vectors are known to be the leading vector for human infectious agents. Insecticides majorly dichloro-diphenyl-trichloroethane (DDT) were therefore used for the control of insect vectors. This succeeded only for a short while in the 19th century due to insect vector resistance and the widely condemned ecological disadvantages. This led to the development of safer and more effective insecticides such as the pyrethriods although also plagued with the tendencies of insect vector resistance. However, it has been strongly indicated that there are links between drivers of global biodiversity modification and vector-borne diseases. This is identified as the strongest reason for control programs that are all encompassing, engaging different fields and institutions, communities and individuals. The Integrated Vector Management (IVM) is therefore, advocated as the way forward for control of insect vector in the 21st century. It is encouraged to be practised putting the basic principles of biodiversity conservation which are ensuring biological diversity, ecological integrity and resilience in proper perspective.
Nigerian Journal of Entomology, Volume 36, pp 54-63; https://doi.org/10.36108/nje/0202/63.01.60
The papaya mealybug, Paracoccus marginatus is a small sized polyphagous invasive hemipteran bug that attacks several genera of host plants, causing considerable yield loss. Commonly used insecticidal control is being discouraged due to environmental and human health hazards. Information on the control of this pest with botanicals is scanty, therefore the control using selected botanicals was investigated. Aqueous and ethanolic extracts of three botanicals: Hyptis suaveolens, Eugenia aromatica and Azadirachta indica were evaluated in screen cages (1.80×0.60×1.50m) for contact toxicity following standard procedures. Cypermethrin® (100 ml a.i ha-1) was used as a standard check. The secondary metabolites in the three plants were analyzed for saponins, alkaloids, terpenoids, phenols, flavonoids and cardinolides following standard procedures. Effective concentration was determined using probit analysis. Both aqueous and ethanolic extracts of the botanicals caused adult mortality of P. marginatus. However, the difference in percentage mortality in aqueous extracts of A. indica (54.28±1.7), H. suaveolens (47.5±4.1) and E. aromatica (48.6±1.1) were not significant (P>0.05). Percentage mortality of ethanolic extracts of A. indica (87.40±4.8) was significantly higher (P<0.05) than both E. aromatica (74.40.16±2.4) and H. suaveolens (72.10.58±2.8). Concentration of the secondary metabolites varied in the botanicals with H. suaveolens having higher flavonoids (107.08mg/100g), cardinolides (46.06 mg/100g) and terpenoids (3.17mg/100g) while A. indica had higher saponins (10.33mg/100g) and phenols (1938.48mg/100g) while E. aromatica had comparatively higher alkaloids (0.59%). The LC50 ranged from 3.61mg/kg in A. indica, to 4.64mg/kg in E. aromatica and 4.52mg/kg in H. suaveolens. The ethanolic extracts of botanicals evaluated were more effective than the aqueous extracts and can serve as a substitute to the synthetic insecticides for the control of P. marginatus.
Nigerian Journal of Entomology, Volume 36, pp 22-31; https://doi.org/10.36108/nje/0202/63.01.30
Spiders are among the most diverse arthropod groups of organisms. This study investigated the distribution and abundance of spiders in five locations in Zaria Local Government Area of Kaduna State, Nigeria. The study was conducted for five months, from April to August, 2018. Samples were collected twice each month using vegetation beating, trapping using bottle and handpicking methods. The abundance of each species of spider identified was expressed in percentages while diversity was revealed using Shannon-Wiener diversity index. A total of 217 spiders were collected from all the study locations which belong to 14 families, 24 genera and 28 species. The study locations differ in terms of vegetation, topography and habitat structures. Family Lycosidae was found to be the dominant family which include four genera and five species, followed, by Agelenidae, Amaurobidae and Gnaphosidae which have a species proportion of 10.7% each and 3 species abundance. Area II (Tudun Serika) the most diverse, with 60 spiders collected in this area, belonging to 11 families, 18 genera and 19 species. Area IV (_________) was the least in terms of spider species diversity and abundance with only 12 spiders, belonging to four genera and four families. Cesonia bilineata had high dominance index of 1.315. There is need for proper documentation of spider species available in Nigeria.
Nigerian Journal of Entomology, Volume 36, pp 46-53; https://doi.org/10.36108/nje/0202/63.01.50
Laboratory experiment was conducted at the Department of Crop Protection Laboratory, Faculty of Agriculture, Bayero University, Kano, in order to assess the effect of oils obtained from the seeds of Jatropha curcas and Moringa oleifera on African Maize Stalk Borer (Busseola fusca Fuller). The effects of the plant seed oils on larvae mortality, pupae and adult emergence were tested on freshly cut leaves/stem of maize 3-4 cm long) and treated with the prepared plant oils at various concentrations (10, 20, and 30%) and control (0%). The experiment was laid out in a completely randomized design and replicated four times. The results showed that both plant seeds oils were lethal to the developmental stages of B. fusca, causing mortality (21%) to the larvae, and subsequently preventing and/or suppressing pupae (2.08) and adult emergence (1.95). Treatment at 30% concentration was found to be more lethal to all the developmental stages of the test insect. Based on the findings of this study, it is recommended that any of the plant seed oils at 30 % concentration could be used to manage B. fusca.
Nigerian Journal of Entomology, Volume 36, pp 81-97; https://doi.org/10.36108/nje/0202/63.01.90
Field experiment was carried out during 2018 cropping season to evaluate the effect of planting dates on incidence of legume pod borer Maruca vitrata on cowpea (Vigna unguiculata) varieties. The treatments consist of five varieties of cowpea (local variety, SAMPEA 6, SAMPEA 7, SAMPEA 8 and SAMPEA 10) which were sown at three different dates, 7th (early), 24th (Mid) August and 7th (early) September, 2018. The experiment was laid out in a Randomized Complete Block Design (RCBD) replicated three times. The number of M. vitrata larva on flowers, damaged pods and weight of grains were determined. The result showed that first sowing nearly August had less infestation by M. vitrata than those in mid August and differs significantly (P≤0.05) from those sown in September. All varieties sown in early and mid August had less M. vitrata infestation and produced higher grain yield of 533.33kg and 395.06 kg on SAMPEA 7 and SAMPEA 8, respectively compared to those sown in early September: 256.79 and 197.53 on SAMPEA 7 and SAMPEA 10, respectively. Local variety and SAMPEA 6 were the varieties with higher mean number of M. vitrata, higher pod damage and low grain yield. Therefore, SAMPEA 7 can be utilized in breeding program for the management of pod borer.
Nigerian Journal of Entomology, Volume 36, pp 1-10; https://doi.org/10.36108/nje/0202/63.01.10
Biodiversity accounts for the variability among living organisms and its conservation presents insights for mitigating the problem of depletion or exhaustion of biological resources. From the simplest level of genes, species, and ecosystems; biodiversity provides a wide range of goods and services for survival with potential direct or indirect utilization by humans. Biodiversity is key as it constitutes the rich biological resources that typically measures all variations at the genetic, species and ecosystem level and is particularly important for nutrient recycling in soil fertility maintenance; purification of water and air and detoxification of wastes as well as for mitigating pollution and moderation of floods and droughts. It is also invaluable for protecting watersheds and combating erosion; stabilization of climate; and control of pests and diseases. The diversity of insect species is unparalleled being estimated at 1.5 million species but biodiversity is generally threatened in Nigeria by high population growth rate, poverty, policy and legislation constraints as well as poor land use planning and climate change among others. The direct threats to biodiversity in Nigeria include habitat degradation, unsustainable agricultural practices and unsustainable harvesting of biological resources among others. The major approach to biodiversity conservation in Nigeria is the protected-area system and the establishment of a National Insect Museum to be domiciled in one of the Federal Universities is key.