Azrag A G A, Yusuf A A, Pirk C W W, Niassy S, Mbugua K K, Babin R
International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya.
Department of Zoology and Entomology, Social Insect Research Group, University of Pretoria, Private Bag X20, Hatfield, Pretoria0028, South Africa.
Bull Entomol Res. 2020 Apr;110(2):207-218. doi: 10.1017/S0007485319000476. Epub 2019 Aug 23.
Although the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae) is the most destructive insect pest of coffee worldwide, there is much to learn about its thermal biology. This study aimed to develop temperature-based models for H. hampei development and to provide the thermal requirements of immature stages in the laboratory. Using a new observation method, larval development and survival were monitored daily on fresh Arabica coffee seeds, under seven constant temperatures in the range 15-35°C, with 80 ± 5% RH and 12:12 L:D photoperiod. Linear and non-linear functions were fitted to the development data plotted against temperature, using Insect Life Cycle Modelling software (ILCYM). Temperature significantly affected the development time of all immature stages. Egg incubation period ranged 4.6-16.8 days, under temperature between 30 and 15°C. No development occurred at 35°C and the larval stage did not develop to pupa at 15°C. The minimum temperature threshold (Tmin) estimated from linear regression was 10.5, 13.0, 15.0 and 13.0°C, for egg, larva, pupa and the total development from egg to adult, respectively. The maximum temperature threshold (Tmax) estimated from the Sharpe and DeMichele function was 32°C for egg to adult development. The thermal constant (k) was estimated at 78.1, 188.7, 36.5 and 312.5 degree days, for egg, larva, pupa and for egg to adult, respectively. Our results will help understand and predict the pest population dynamics and distribution in coffee plantations as impacted by temperature, and as such, will contribute to a more efficient management of the pest.
尽管咖啡果小蠹（Hypothenemus hampei (Ferrari)，鞘翅目：象甲科：小蠹亚科）是全球咖啡最具毁灭性的害虫，但关于其热生物学仍有许多有待了解之处。本研究旨在建立基于温度的咖啡果小蠹发育模型，并提供其未成熟阶段在实验室中的热需求。采用一种新的观察方法，在15 - 35°C的七个恒温条件下，相对湿度80 ± 5%，光周期12:12 L:D，每天监测新鲜阿拉比卡咖啡种子上幼虫的发育和存活情况。使用昆虫生命周期建模软件（ILCYM），将发育数据与温度作图，并拟合线性和非线性函数。温度显著影响所有未成熟阶段的发育时间。在30至15°C的温度下，卵的孵化期为4.6 - 16.8天。在35°C时不发生发育，在15°C时幼虫阶段不能发育为蛹。通过线性回归估计的最低温度阈值（Tmin），卵、幼虫、蛹以及从卵到成虫的总发育分别为10.5、13.0、15.0和13.0°C。根据夏普和德米歇勒函数估计的最高温度阈值（Tmax），卵到成虫发育为32°C。热常数（k）估计分别为78.1、188.7、36.5和312.5度日，分别对应卵、幼虫、蛹以及从卵到成虫。我们的结果将有助于理解和预测受温度影响的咖啡种植园中害虫种群动态和分布，因此将有助于更有效地管理该害虫。
