Cowpea seed beelte, Callosobruchus maculatus Fabricius (Coleoptera: Chrysomelidae) is a key pest of stored cowpea in the tropics. The seed is highly susceptible to the attacks of this beetle mainly between the period of harvest, processing and storage. The beetle is known to cause qualitative and quantitative losses which are manifested by seed perforations, reduction in weight, reduction in seed germination and all these have resulted into farmers’ low income from the crop. This work is therefore designed to evaluate the use of the extracts of the leaf, stem bark and root bark of Cleistopholis patens (Benth) on Callosobruchus maculatus (Fab.) for mortality, oviposition and adult emergence effects. The extracts of the plant parts were obtained using n-hexane solvent in the Soxhlet apparatus. The extracts of the plant parts were tested at 1, 2, 3, 4 and 5% v/g treatment levels respectively. Control experiments were also set up. Adult mortality and repellent test were monitored daily for 96 h while result of ovicidal test was recorded at 35 days after treatment. All the three extracts applied were able to cause significant (P < 0.05) adult mortality of the cowpea beetle. The root bark extract achieved the highest mortality of 77.50% at the dosage rate of 5% v/g within 24 h of application and its effect was significantly different (P < 0.05) from others. Also, lethal doses (LD50 and LD95) revealed that lower doses of the root bark extracts were required to achieve 50 and 95% insect mortalities when compared to leaf and stem bark extracts after 96 h of application. All the plant extracts significantly reduced oviposition and adult emergence when compared with control. The root bark extract at 5% v/g recorded the lowest seed damage and weight loss. The result obtained showed that extract of root bark of C. patens was effective in controlling C. maculatus and could serve as an alternative to synthetic insecticides.

中文翻译：

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Cleistopholis patens (Benth) 提取物对豇豆种子甲虫的影响，Callosobruchus maculatus (Fab.)（鞘翅目：Chrysomelidae）在储存中侵染豇豆种子

豇豆，Callosobruchus maculatus Fabricius（鞘翅目：Chrysomelidae）是热带豇豆的主要害虫。种子很容易受到这种甲虫的攻击，主要是在收获、加工和储存期间。众所周知，甲虫会造成质量和数量上的损失，表现为种子穿孔、重量减轻、种子发芽减少，所有这些都导致农民从作物中获得低收入。因此，这项工作旨在评估 Cleistopholis patens (Benth) 的叶、茎皮和根皮提取物对 Callosobruchus maculatus (Fab.) 的死亡率、产卵和成虫羽化的影响。在索氏装置中使用正己烷溶剂获得植物部分的提取物。植物部分的提取物在 1、2、3、分别为 4% 和 5% v/g 处理水平。还设置了对照实验。每天监测成虫死亡率和驱虫试验，持续 96 小时，而在治疗后 35 天记录杀卵试验结果。应用的所有三种提取物都能够导致豇豆甲虫的显着（P < 0.05）成年死亡率。根皮提取物在施用24 h内以5% v/g的剂量达到77.50%的最高死亡率，其效果与其他有显着差异（P < 0.05）。此外，致死剂量（LD50 和 LD95）表明，在施用 96 小时后，与叶和茎皮提取物相比，需要较低剂量的根皮提取物才能达到 50% 和 95% 的昆虫死亡率。与对照相比，所有植物提取物都显着减少了产卵和成虫出现。5% v/g 的根皮提取物记录了最低的种子损伤和重量损失。所得结果表明，苍蝇的根皮提取物可有效防治斑马蝇，可作为合成杀虫剂的替代品。