Vega Fernando E, Simpkins Ann, Bauchan Gary, Infante Francisco, Kramer Matthew, Land Michael F
Sustainable Perennial Crops Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville, Maryland, United States of America.
Electron and Confocal Microscopy Unit, United States Department of Agriculture, Agricultural Research Service, Beltsville, Maryland, United States of America.
PLoS One. 2014 Jan 20;9(1):e85860. doi: 10.1371/journal.pone.0085860. eCollection 2014.
The coffee berry borer, Hypothenemus hampei, is the most damaging insect pest of coffee worldwide. Like males in other species in the genus, male coffee berry borers have a lower number of facets in the compound eyes than females. The rudimentary eyes in male coffee berry borers could be an evolutionary response to their cryptic life habit, whereby they are born inside a coffee berry and never leave the berry. The main objective of the study was to determine if the differences in the number of facets translates into differences in visual acuity. We used low-temperature scanning electron microscopy to visualize and quantify the number of facets in the compound eyes. There was a significantly lower (p<0.0001) number of facets in males (19.1 ± 4.10) than in females (127.5 ± 3.88). To assess visual acuity, we conducted optomotor response experiments, which indicate that females respond to movement, while males did not respond under the conditions tested. The coffee berry borer is an example of an insect whereby disuse of an organ has led to a rudimentary compound eye. This is the first study that has experimentally tested responses to movement in bark beetles.
咖啡果小蠹（Hypothenemus hampei）是全球对咖啡危害最大的害虫。与该属其他物种的雄性一样，雄性咖啡果小蠹复眼中的小眼面数量比雌性少。雄性咖啡果小蠹的退化眼睛可能是对其隐匿生活习性的一种进化反应，它们在咖啡果内出生，从不离开果实。该研究的主要目的是确定小眼面数量的差异是否转化为视敏度的差异。我们使用低温扫描电子显微镜来观察和量化复眼中的小眼面数量。雄性（19.1 ± 4.10）的小眼面数量显著低于雌性（127.5 ± 3.88）（p<0.0001）。为了评估视敏度，我们进行了视动反应实验，结果表明雌性对运动有反应，而在测试条件下雄性没有反应。咖啡果小蠹是一个器官废用导致复眼退化的昆虫实例。这是第一项对小蠹虫运动反应进行实验测试的研究。
