Many obscure points remain to be resolved with respect to the transport of photosynthates from source to sink through sieve tubes. It is very important to be able to collect and analyze the phloem sap if an attempt is to be made to explain the phloem transport system. The insect laser technique (Kawabe et al. 1980) has been shown to be useful method for the study of this problem. The insect las...

We revise the large Neotropical genus Operclipygus Marseul, in the histerid tribe Exosternini (Histeridae: Histerinae). We synonymize 3 species, move 14 species from other genera, sink the genus Tribalister Horn into Operclipygus, and describe 138 species as new, bringing the total to 177 species of Operclipygus. Keys are provided for the identification of all species, and the majority of the s...