scholarly journals Interspecific Competition and Grain-Hosts Selection of Maize Weevil, <i>Sitophilus zeamais</i> (Motsch.) (Coleoptera; Dryophtoridae) and Larger Grain Borer, <i>Prostephanus truncatus</i> (Horn) (Coleoptera; Bostrichidae)

2020 ◽  
Vol 08 (01) ◽  
pp. 34-45
Author(s):  
Déthié Ngom ◽  
Cheikh Thiaw ◽  
Mbacké Sembène
2019 ◽  
Vol 49 (1) ◽  
pp. 255-264 ◽  
Author(s):  
Hannah Quellhorst ◽  
Christos G Athanassiou ◽  
Alexander Bruce ◽  
Erin D Scully ◽  
William R Morrison

Abstract Interspecific competition between agricultural pests may affect the species that can establish, and may also affect food production. Prostephanus truncatus (Horn), the larger grain borer, is endemic to Central America, but invaded Africa with disastrous consequences for maize production. Its main competitor is Sitophilus zeamais Motschulsky, the maize weevil, which is cosmopolitan. These insects co-occur in many regions of the world and both are threats to maize. However, the impact of competition between these two species is not well-understood, nor is its effect on grain quality or potential to limit P. truncatus invasion in new areas. The aims of our study were to evaluate the outcome of interspecific competition between P. truncatus and S. zeamais at four different temperatures on a fixed quantity of grain, and determine effects on progeny production, grain damage, and mold growth. We found that coexistence may be possible at a range of 25–30°C, but mixed colonies experienced a direct competitive cost compared to single-species colonies. Prostephanus truncatus performed better at warmer temperatures, while S. zeamais favored cooler temperatures. The majority of grain damage was the result of P. truncatus activity as opposed to S. zeamais. Finally, mold growth was greater where both species were present, and species of mold that produce aflatoxin were identified. Although there are an increasing number of areas where both of these species occur, our results suggest P. truncatus will be capable of destroying much more maize in a shorter period compared to S. zeamais at temperatures greater than 25°C.


2020 ◽  
Vol 42 (2) ◽  
Author(s):  
Nguyen Van Dzuong ◽  
Khuat Dang Long

The instintive behaviour exhibited by insects in the selecting  food is always a matter of  interests to entomologists, and it is one of the fundamental principles underlining the application of entomology to agriculture, horticulture and forestry. Food seclection is an important characteristic of insects that help them survive in periods with insufficient foods.Three grain types of food, maize grain, long-grain rice and soybean grain, were used in this sudy for detecting food selection behaviours of maize weevil, Sitophilus zeamais. Grains were kept in box traps put in the different stores in Son La during 90 days. The result showed that maize weevil, Sitophilus zeamais, prefered traps with maize grains (71.4%) considerably more than ones with long-grain rice (14.3%) and soybean grain (14.3%). Meanwhile, the cornsap beetle, Carpophilus dimidiatus, was mostly observed in maize grain (98.5%) and to a lesser degree, in soybean grain (1.5%); and the dried-fruit beetle, Carpophilus hemipterus, was abundantly observed in maize grain (93.1%) and less in soybean grain (6.9%). The red flour, Tribolium castaneum, also tended to select all the three food grain, i.e. maize grain: 53.5%, long-rice grain: 35.2%, and soybean grain: 11.3%.Comparing f beetle individuals captured on three types of food grains showed that the maize weevil, Sitophilus zeamais, is the most abundant species. The percentage this store beetle among all beetles observed in maize, soybean grains and long-rice grains were 57.0%, 84.9% and 27.6%, respectively. Interestingly, Ahasverus advena, foreign grain beetle, occurred abundantly on long-rice gain (61.7%), i.e. this grain is a suitable food for the development of this beetle. 


2013 ◽  
Vol 36 (3-S3-A) ◽  
pp. 347
Author(s):  
Silverio García-Lara ◽  
David J. Bergvinson

The maize weevil (MW) (Sitophilus zeamais), and the larger grain borer (LGB) (Prostephanus truncatus) are major storage pests causing serious losses in maize (Zea mays L.) in developing countries of Latin America (LA). This study identified maize landraces with high levels of resistance to MW and LGB by screening 1171 genotypes collected from 24 LA countries in 38 sampling areas. Maize grain weight losses (GWL), total dust production (TDP) and number of adult progeny (NAP) were measured for LGB and MW attack in each genotype. Susceptibility traits to MW and LGB were related to specific geographical location. Range of resistance for MW was from 0.6 to 51 %, while for LGB from 0.1 to 66 %. Approximately 28 % of the analyzed genotypes showed high level of resistance to MW, with Antilles region offering the most resistant accessions with races of EarCar, Chande, Haitye, Nal-Tel, Tuson, and Canill. Resistance to LGB was observed in 22 % of genotypes analyzed with accessions from Southern México with races of Cónico, Nal-Tel, Vandeño, Elotes Occidentales, Cubano, Tuxpeño, and Tepecintle. Low correlation (r = 0.28; P < 0.01) between maize resistance to MW and LGB indicated a divergent adaptive response of maize grain to these two pest. Geographic data showed a negative correlation between latitude and longitude with MW resistance traits being significant only for longitude (r = -0.253; P < 0.05). Opposite trend of correlations, positive but not significant, was observed for LGB resistance traits. These results indicate an influence of geographic location in local varieties being selected for storage pest resistance over time. Genotypes with excellent postharvest insect resistance have now been identified for maize breeders to use in developing improved cultivars for use in LA.The maize weevil (MW) (Sitophilus zeamais), and the larger grain borer (LGB) (Prostephanus truncatus) are major storage pests causing serious losses in maize (Zea mays L.) in developing countries of Latin America (LA). This study identified maize landraces with high levels of resistance to MW and LGB by screening 1171 genotypes collected from 24 LA countries in 38 sampling areas. Maize grain weight losses (GWL), total dust production (TDP) and number of adult progeny (NAP) were measured for LGB and MW attack in each genotype. Susceptibility traits to MW and LGB were related to specific geographical location. Range of resistance for MW was from 0.6 to 51 %, while for LGB from 0.1 to 66 %. Approximately 28 % of the analyzed genotypes showed high level of resistance to MW, with Antilles region offering the most resistant accessions with races of EarCar, Chande, Haitye, Nal-Tel, Tuson, and Canill. Resistance to LGB was observed in 22 % of genotypes analyzed with accessions from Southern México with races of Cónico, Nal-Tel, Vandeño, Elotes Occidentales, Cubano, Tuxpeño, and Tepecintle. Low correlation (r = 0.28; P < 0.01) between maize resistance to MW and LGB indicated a divergent adaptive response of maize grain to these two pest. Geographic data showed a negative correlation between latitude and longitude with MW resistance traits being significant only for longitude (r = -0.253; P < 0.05). Opposite trend of correlations, positive but not significant, was observed for LGB resistance traits. These results indicate an influence of geographic location in local varieties being selected for storage pest resistance over time. Genotypes with excellent postharvest insect resistance have now been identified for maize breeders to use in developing improved cultivars for use in LA.


2019 ◽  
Vol 35 (1) ◽  
pp. 45-59
Author(s):  
T. J Adebowale ◽  
A. A Osipitan

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.


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