Entomological studies on hemp (Cannabis sativa L.) [Entomologische Untersuchungen an Hanf]

In two years' investigations, the entomofauna in growing hemp was recorded. Hemp attracts numerous arthropods to live there. It was predominated by potentially harmful organisms as compared to beneficial and indifferent organisms. A new harmful species found has been the cicada Eupteryx atropunctata H. (Goeze). It showed relatively high density. In the first trial year, the gamma moth Scotia gamma L. occured at remarkable population density but was parasitized up to 80% by the parasitic wasp Copidosoma ( = Litomastix) truncatellum (Dalman). As a result it was considerably impaired. Late infestation in August and September was caused by the tarnish plant bug Lygus rugulipennis Poppius and the hemp aphid Phorodon cannabis Passerini, which is the only aphid specific to hemp. Antagonists worth mentioning are parasitoids and beneficial bugs. The bug Orius minutes Wolff. occured at relatively high density. In both trial years, neither of the pests occured at an incidence that made it necessary to apply insecticides. In the light of the present knowledge it is not necessary to specifically apply plant protection products against pests to growing hemp.