Study on the biology of groundnut bruchid, Caryedon serratus Olivier [Coleoptera: Bruchidae] on stored groundnut in Ganye area, Adamawa State, Nigeria

Study on the biology of groundnut bruchid, Caryedon serratus Olivier was carried out in the Laboratory of the Department of Agricultural Technology, Adamawa State College of Agriculture, Ganye, Adamawa State from June to September, 2015. The sex of the bruchid (male and female) was assigned the sub-treatment while the period of development was the main treatment and was replicated three times. The work considered the pre-oviposition stage, incubation stage, larval stage, pupal stage, adult stage and the total life cycle of the bruchid (male and female). The experiment was carried out under Laboratory conditions at 30-35°C temperature and 70-90% relative humidity. After the experiment was established, weekly counting of the total number of eggs laid was carried out at intervals. The results showed that, the mean developmental stages in both female and male bruchids were: 6.50 and 6.00 days; 17.00 and 18.00 days; 13.50 and 13.50 days; 12.00 and 13.50 days; 48.00 and 50.00 days for incubation stage, larval stage, pupal stage, adult stage and total life cycle of the bruchids, respectively. Moreover, the mean pre-oviposition and oviposition stages in female adult bruchid were 1.50 and 5.50 days, respectively.

Infestation and Damage by Caryedon serratus (Olivier) Weevil on Stored Tamarindus indica (Linneaus) Fruits in Kano State, Nigeria

A survey was conducted on the infestation and damage of Caryedon serratus on stored tamarind pods from September to November, 2014 in three local government areas (Doguwa, Gezawa and Kano Municipal) of Kano State in Nigeria. Structured questionnaires were randomly administered to 60 respondents. A total of 27 samples of tamarind pods were purchased for damage analysis. Descriptive statistics were used to analyze the collected data while ordinary least square Regression was used on damage data. Results obtained indicated that un-elevated room storage (in woven sacks) was the preferred (48.3%) form of tamarind storage practiced (91.7%), mostly for a period of 1 – 3 months (60%) of storage before being sold out. More so, about 98.3% of the respondents were aware of C. serratus as pest of tamarind pods. The pods are commonly attacked by such pest (48.3%) from inception to about 3 months of storage leading to highest damage levels (36.7%). The regression analysis revealed that the number of perforations were highly significant (P<.001) in relation to the total number of tamarind pods, however the effect observed on pods was insignificant on weight loss in any of the three locations. The combined models analysis shows Gezawa recorded significantly higher number of perforations (P<.001) compared to others which are similar. On the control measures, 46.7% have reported the application of a control method against C. serratus and that dried pepper (20%) was the most prevalent. Solarization and airtight polythene storage bags were found statistically similar. Only 5% of the respondents use synthetic chemicals although very effective. The present study revealed that C. serratus is a widespread and damaging pest of tamarind in the study areas. Therefore, there is need for a more advanced, cost effective and safe alternative means of control especially from the first three to six months of storage.

Phytophagous insects in tamarind crop (Tamarindus indica L.), with emphasis on the greatest damage to the fruit, in five farms from the nearby Western of Antioquia

El tamarindo es un fruto importante para los pequeños productores del occidente cercano antioqueño, en cuanto a que se ofrece en diversas presentaciones a los turistas que visitan esta región. Sin embargo, algunos problemas de calidad, relacionados con la presencia de insectos en este fruto generan dificultades para su comercialización. El objetivo de este trabajo fue determinar los insectos fitófagos de los árboles de tamarindo, con énfasis en los que causan mayor daño al fruto. En cinco fincas de Santa Fe de Antioquia y Sopetrán, se recolectaron los insectos asociados a cada órgano, de seis árboles por finca, se describió su daño y se identificaron hasta el nivel más detallado posible. Tres insectos causantes del mayor daño en el fruto tuvieron prioridad, determinándose su porcentaje de infestación (PI). Para ello, se diseñó una escala de daño y se evaluaron 30 frutos por árbol. Se encontraron once insectos fitófagos asociados al tamarindo, de los cuales cinco registros son nuevos para el tamarindo en Colombia: H. obscurus, Toxoptera aurantii, Trigona sp., Ectomyelois ceratoniae y Acromyrmex octospinosus. Cinco insectos atacan al fruto: Caryedon serratus, dos polillas Phycitinae, Sitophilus linearis e Hypothenemus obscurus. El PI promedio para C. serratus, las dos polillas Phycitinae y S. linearis fue de 19,5%, 8% y 2,5%, respectivamente. Los tres primeros afectan la pulpa y S. linearis ataca a la semilla. El daño más frecuente (43% - 52%) fue de grado 1 y los grados 4 y 5 se presentaron en menores porcentajes (0% - 4%).