Nigerian Journal of Entomology
Latest articles in this journal
Nigerian Journal of Entomology, Volume 35; https://doi.org/10.36108/nje/9102/53.01.51
Nigerian Journal of Entomology, Volume 35, pp 19-30; https://doi.org/10.36108/nje/9102/53.01.30
The reproductive performance, damage and weight loss of the Larger Grain Borer (LGB), Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) on three food hosts namely cassava (TMS 30572, TME 419 and TMS98/0505), maize (SUWAN-1-SR-Y, BR 9943-DMR-SR and 2009 TZEWDT STR) and wood (Albizia glaberrima, Gmelina arborea and Tectona grandis) were investigated. Samples of 100g of the food host were weighed in four replicates into 250ml Kilner® jar and infested with 10 pairs of 1-5 day old LGB. The developmental period of LGB on each of the food host was noted and recorded. Similarly, weight loss and weight of damaged grains was determined as basis for determining the susceptibility of the food hosts to LGB infestation. Proximate composition of infested and un- infested food hosts of LGB were determined following the analytical procedures. Maize was the most preferred host, followed by cassava as indicated by the high number of adult LGB and grain damage recorded on them. The development of LGB was completed on all maize and cassava varieties but not on any of the wood species examined. Percent damage, weight loss, and percent dust were significantly (P
Nigerian Journal of Entomology, Volume 35, pp 135-143; https://doi.org/10.36108/nje/9102/53.01.21
Papaya mealybug, Paracoccus marginatus is an invasive polyphagous hemipteran that causes enormous damage to different host plants in Nigeria. However, information on the pest’s damage potential and host range is scanty; therefore, the host preference and life cycle of P. marginatus were investigated. Six economic plants: Carica papaya (Caricaceae), Solanum lycopersicum (Soalnaceae), Manihot esculenta (Euphorbiaceae), Abelmoschus esculentus (Malvaceae), Psidium guajava (Myrtaceae) and Tectona grandis (Lamiaceae) were evaluated as food hosts to P. marginatus using free-choice and no-choice tests in screen cages (1.80×0.60×1.50m). The developmental biology was investigated following standard procedures at ambient conditions of 27±20C; 70±5% RH and 12:12 hour photoperiod. Significantly more P. marginatus migrated to and utilized C. papaya (27.5±2.9) and M. esculenta (20.75±1.3) as food host. This pest occurred on other plants in decreasing order; S. lycopersicon (17.0±1.3) > P. guajava (12.5±0.4) > A. esculentus (11.8±1.2) and T. grandis (10.00±1.4) appeared to be the least preferred. The duration of development from egg to adult ranged from 23.52±0.1 to 25.76±0.4 days in the females and 25.91±0.6 to 30.62±0.8 in the males, which passed through more nymphal instars (4) than in females (3). The life cycle of P. marginatus was completed in shorter time on C. papaya than on any other host plants. The differences between male and female adult weights (2.98±0.4mg and 3.90±0.6mg) were not significant. Paracoccus marginatus preferred pawpaw and cassava to the other crops. This information is useful for development of appropriate integrated management programme for the pest.
Nigerian Journal of Entomology, Volume 35, pp 45-59; https://doi.org/10.36108/nje/9102/53.01.50
Damage to stored maize grains by Sitophilus zeamais and Prostephanus truncatus is enormous and could be total if the insects are not controlled timely and appropriately. Control of the insects with host plant resistance has advantages over other control measures because of its lasting effect, friendliness to the environment and safety to natural enemies among others. This study assessed host resistance of 11 maize varieties to infestation and damage by S. zeamais and P. truncatus. One hundred gram maize grains each of the maize varieties were weighed into 250 cm3 glass jars and separately infested with twenty, 1-5 days old S. zeamais or P. truncatus. Percentage grain damage, weight loss, adult mortality, grain dust and number of insects were determined and integrated to define the resistance of the maize varieties to the insects. Eight of the 11 maize varieties were either resistant or moderately resistant to damage by S. zeamais and P. truncatus, while three were susceptible. The basis of resistance is antibiosis conferred by the ash, carbohydrate and fat content of the maize grains. The resistance varieties could be planted to mitigate infestation and damage by the insects. The factors conferring resistance can be used as environmentally friendly source of resistance to breed maize grains for resistance to the insects.
Nigerian Journal of Entomology, Volume 35, pp 31-43; https://doi.org/10.36108/nje/9102/53.01.40
The pallid emperor moth, Cirina forda, is a prominent edible insect in Niger State but currently at great risk of extinction. The incidence, abundance and distribution of Cirina forda, was investigated for four consecutive seasons, i.e. May-June 2010, 2011, 2012 and 2013 to ascertain the effect of the depletion of its host plant, Shea butter trees, Vitellaria paradoxa. in Niger State, Nigeria. C. forda egg clusters located on the host plants were enumerated to ascertain the seasonal abundance by visual counting using hand lenses and binoculars (MARCO-model 750/8 m-988000 m). At each location, 100m2 land area in which three 10m2 portions were mapped as replicate sites, were investigated for host plant density, egg cluster abundance and distribution within three host plant canopy height ranges. The 41 locations in six Local Government Areas (LGAs) where C. forda occurred in Niger State in 2010 were investigated. The result indicated the GPS of each of the locations and showed that Niger state had a very rich but fast dwindling population of V. paradoxa. C. forda egg cluster abundance across the six LGAs showed Niger state as highly endowed but ephemeral and highly unpredictable, especially in terms of location where they occurred. The egg cluster abundance reduced drastically from 58.1± 12.1 and 56.1±24.1 egg cluster/host plant in 2010 and 2011, respectively to 41.3 ± 8.3 and 29.7 ±5.1 egg cluster/host plant in 2012 and 2013 cropping seasons, respectively. Locational similarities were observed in the trends of C. forda host plant density reduction and egg cluster abundance over the four cropping seasons and these were corroborated across the State. The decreasing densities of Shea butter trees was identified as posing serious threats to egg laying by C. forda. The possibility of the extinction of C. forda was identified as imminent and a conservation approach that stems the indiscriminate destruction of host tree, V. paradoxa (Shea butter trees) was proposed.
Nigerian Journal of Entomology, Volume 35, pp 111-120; https://doi.org/10.36108/nje/9102/53.01.01
The virulence of two Beauveria bassiana (Balsamo-Crivelli) Vuillemin and two Metarhizium spp. (Sorokin) isolates against larval and adult house fly, Musca domestica L. (Diptera: Muscidae), was assessed in the laboratory. Virulence varied significantly among the isolates but insect mortality was independent of route of exposure. Mortality was dose-dependent and stock solutions effected 79-91% and 63-70% mortality within seven days in larval and adult house fly, respectively. Generally, the fungi were more virulent against larvae than adult flies and they all showed good potential as effective biocontrol agents. However, consistently lower median lethal concentration (LC50) and lethal time (LT50) against larval and adult flies showed that M. anisopliae s.s. ARSEF 5471 was the most virulent of the four.
Nigerian Journal of Entomology, Volume 35, pp 145-153; https://doi.org/10.36108/nje/9102/53.01.31
Several studies have demonstrated the biological efficacy of leaf, stem and root powders or extracts of Chromolaena odorata (L.) King and Robinson against insect pests but those that are focused on the biological efficacy of aqueous leaf extracts against Macrotermes species are scanty. Current management of termites with synthetic insecticides is being discouraged due to human and environmental hazards. Therefore, the insecticidal effectiveness of aqueous leaf extract C. odorata against Macrotermes species was investigated. Five concentrations (0, 2.5, 5.0, 7.5 and 10.0% (w/v)) of the aqueous extract of C. odorata plant were evaluated for repellency and toxicity on the worker caste of Macrotermes species following standard procedures. The filter paper impregnation technique was used for the bioassay. Percentage repellency was monitored for 30 minutes and mortality recorded at 12, 24 and 36 hours post exposure. The leaf extract of C. odorata significantly repelled 95% of Macrotermes species at the highest concentration of 10% (w/v) after 30 minutes post treatment exposure. Mortality of Macrotermes species was independent of treatment concentration, but dependent on duration of exposure. All treatment concentrations of aqueous leaf extract of C. odorata caused significant mortality against Macrotermes species ranging between 94% and 98% compared to the control; indicating very great potential for adoption and use in the management of Macrotermes species.
Nigerian Journal of Entomology, Volume 34, pp 1-8; https://doi.org/10.36108/nje/8102/43(0110)
Nigerian Journal of Entomology, Volume 34, pp 87-98; https://doi.org/10.36108/nje/8102/43(0101)
Nigerian Journal of Entomology, Volume 34, pp 99-107; https://doi.org/10.36108/nje/8102/43(0111)