도토리거위벌레는 큰턱을 이용하여 도토리에 구멍을 뚫고 가지를 자르는 독특한 행동을 한다. 이러한 행동을 이해하기 위해 다양한 현미경을 이용하여 구기의 해부학적 특징을 관찰하였다. 실체현미경을 이용한 연구에서는 도토리거위벌레 수컷의 평균 내전건과 외전건의 두께는 각각 32.87 μm, 53.83 μm이었고, 암컷의 평균 내전건과 외 전건의 두께는 각각 40.81 μm, 75.55 μm이었다. 내전건과 외전건의 유의한 두께 차이로 인해 큰턱을 닫는 힘보다 벌리는 힘이 더 강하다는 것을 유추할 수 있다. 광학현미경을 이용한 관찰에서는 주둥이 안쪽에 위치한 내전건과 외 전건의 너비 차이와 큰턱 쪽에서는 원형으로 위치하며 두부로 갈수록 납작해져 두부 외피 안쪽에 근육으로 연결된다는 것을 확인할 수 있었고, 내전건의 위치와 모양의 변화에 대한 관찰을 수행하였다. 전자현미경을 통한 연구에서는 외전건이 내전건보다 더 굵으며 이로 인해 큰턱을 안쪽으로 당기는 힘보다 바깥쪽으로 밀어내는 힘이 더 크다는 것을 확인하였다. 관찰 결과를 바탕으로, 도토리거위벌레, 밤바구미, 왕거위벌레의 큰턱의 형태와 이빨의 위치 그리고 큰턱의 움직임에 대해 비교 분석하였고, 도토리거위 벌레가 보여주는 특징적인 행동은 해부학적/형태적 특징과 연관되어 있음을 확인할 수 있었다.

Heavy metals resulted from the increase of human industrial activity are introduced into the environment through rainfall and wastewater, and have harmful effects on inhabitants. In this study, we investigated biological responses such as survival rate, growth rate, emergence rate and sex ratio, and morphological effects of mentum deformity in Chironomus plumosus, an indicator organism to evaluate pollutions on aquatic ecosystem. The survival rate of C. plumosus showed time- and dose-dependent decrease after chromium and copper exposures. Growth rate decreased at 4th day after chromium exposure and significantly reduced at exposure to relatively high concentration (copper 1000 mg L-1) for all exposure times. In addition, we observed that the emergence rate by exposure to copper 1000 mg L-1 was significantly lower than that of the control group. The imbalance of sex ratios showed at relatively low concentrations (chromium 10 and 50 mg L-1) with the high proportion of female and at the relative high concentration (copper 1000 mg L-1) with the high proportion of male. Furthermore, the morphological mentum deformities of C. plumosus observed in the exposed group according to chromium and copper exposure. These results suggest that the heavy metal exposure in environment may influence biosynthetic and morphological stresses of benthic invertebrate C. plumosus, and aquatic midge C. plumosus are potential indicators for toxicity assessment of heavy metals such as chromium and copper.

Sexual dimorphism of the mouthpart, antenna and mandible of the Cyllorhynchites ursulus in South Korea was studied with linear measurements. The mouthpart and antenna measurements were conducted with a stereoscopic microscope using 122 specimens (72 males and 50 females). Microscopic observation of the mandible were conducted with a Field Emission Scanning Electron Microscope (FE-SEM) using 103 specimens (73 males and 30 females). Results showed that the size difference between males and females was significant in the size of the mouthpart and antenna. On the other hand, we could not detect sexual size dimorphism in the microstructure of the mandible. The bivariate plots made by the result of Principal Component Analysis (PCA) and Discriminant Analysis (DA) showed a size dimorphism in the size of the mouthpart and the antenna between males and females. Based on our study, sexual dimorphism in the mouthpart and antenna exists in C. ursulus from the South Korean population, and this difference seems to be related to the behavioral differences between males and females.