The occurrence of Xyleborus perforans (Woll.) and X. similis in Java (Coleoptera, Scolytidae)

In 1898 a shot-hole borer, identified as X. perforans (Woll.) appeared in an experimental plantation of sugar-cane varieties at Kagok, near Tegal, West Java. Zehntner, the Swiss entomologist on the staff of the Sugar-cane Experimental Station at Kagok, used the opportunity to study the borer extensively in the laboratory as well as in the field. The borer was already notorious at the time by its boring into the bung and staves of wine-casks in Madeira and beercasks in India, which caused leakages ²). Zehntner published the very important results of his investigations in an extensive paper written for the planters in the Dutch language, in 1900. A summary of this paper on ”De riet-schorskever” (the cane bark-borer) was inserted in an annual report for 1900. An excerpt of the paper, quoting some parts verbatim but wanting several of the most interesting biological details, appeared in 1906 in VAN DEVENTER’S volume on „De dierlijke vijanden van het suikerriet en hunne parasieten” (= The enemies of sugar-cane and their parasites).