The Japanese pine sawyer beetle, Monochamus alternatus Hope (Coleoptera: Cerambycidae) is currently the most destructive forest pest as it transmits the pine wilt nematode Bursaphelenchus xylophilus. Morphological, optical features and dark/light adaptational changes of the compound eyes of M. alternatus adults were examined by light, scanning and transmission electron microscopy. The eye of M. alternatus is apposition type and contains 489–712 ommatidia, depending on the beetle’s body size. Each ommatidium features a large corneal lens, composed of a thick inner lens (ILU) and a thin outer lens unit (OLU); an acone-type of cone of four cone cells, a semi-fused type of rhabdom formed by eight retinular cells (two central cells: R7-R8 surrounded by six peripheral cells: R1-R6). Dark/light adaptational changes affect size and shape of the cones as well as the rhabdom’s cross-sectional area and outline, to optimize the amount of light that reaches the photopigment. The compound eyes of M. alternatus have an F-number of 0.94, an interommatidial angle of 5.34°, an eye parameter P of 4.98 μm rad and a ratio of acceptance to interommatidial angle of 0.45. The eye is characterized by relatively poor spatial resolution, but can be expected to exhibit high absolute sensitivity and contrast in dim light.

日本松树锯甲甲虫Monochamus alternatus Hope（Coleoptera：Cerambycidae）目前是最具破坏性的森林害虫，因为它传播了松树枯萎线虫Bursaphelenchus xylophilus。通过光镜，扫描电镜和透射电镜观察了松墨天牛成虫复眼的形态，光学特征和暗/光适应性变化。松墨天牛的眼睛是并置类型，包含489–712眼象，这取决于甲虫的体型。每个眼孔都有一个大的角膜透镜，由厚的内透镜（ILU）和薄的外透镜单元（OLU）组成。由四个视锥细胞组成的圆锥形圆锥体，由八个网状细胞（两个中央细胞：R7-R8，被六个外围细胞：R1-R6围绕）形成的半融合型横纹。暗/光适应性变化会影响视锥细胞的大小和形状以及横纹肌的横截面和轮廓，以优化到达光色素的光量。松墨天牛的复眼F数为0.94，眼间角为5.34°，眼参数P为4.98μmrad，接受度与眼间角之比为0.45。眼睛的特征是相对较差的空间分辨率，但可以预期它在昏暗的光线下显示出很高的绝对灵敏度和对比度。