Zur Unterscheidung der Puppen der Kiefernspanner Bupalus piniarius L. und Semiothisa liturata Cl

For better determination of the pupae of Bupalus piniarius L. and Semiothisa liturata Cl. German pine forests are irregularly threatened by defoliation due to some noted insect pests, particularly the pine looper and the pine beauty. The densities of the larval stages of these insects are predicted annually by making rough estimates of the numbers of their pupae hibernating in the forest floor. A usable prognosis requires that the species involved are distinguished correctly. This presents difficulties in two geometrids, Bupalus piniarius L. and Semiothisa liturata Cl., the pupae of which may differ with respect to some morphological characteristics, such as weight, size, colour, gloss, mobility of the abdomen, and shape and structure of the cremaster. However, all of these characteristics overlap in some cases to a considerable extent. An absolutely reliable identification has to be based on the surface texture of the caudal parts of the fifth and sixth body segments, the specific differences of which are described and illustrated in the fig. 3 and 4. Zusammenfassung Es konnte deutlich gezeigt werden, das eine zuverlassige Determination der Puppen von B. piniarius und S. liturata auf Grund der Differenzen in der Form und Struktur des Cremasters, in Puppengewicht, Puppendurchmesser, Farbe, Glanz und Beweglichkeit der Puppen unmoglich ist. Eine Unterscheidung der Puppen der beiden Arten ist jedoch moglich an Hand der Unterschiede, die in der kutikularen Struktur der kaudalen Teile des funften und sechsten Abdominalsegmentes bestehen (Abb. 3 und 4).