Wpływ suszu z mięty pieprzowej (Mentha piperita L.) na rozwój i płodność wołka zbożowego

W prezentowanej pracy oceniano potencjalne możliwości wykorzystywania jednego z alternatywnych sposobów obniżania liczebności szkodników magazynowych, jakim jest bezpośrednie dodawanie naturalnych substancji roślinnych do przechowywanego ziarna zbóż. Podjęto problem dotyczący oddziaływania produktu pochodzenia roślinnego - proszku z mięty pieprzowej (Mentha piperita L.) na populację wołka zbożowego. Doświadczenia prowadzono w klimatyzowanym pomieszczeniu, na ziarnie pszenicy konsumpcyjnej. Proszek stosowano w dwóch dawkach (1,0 i 0,5 g na 100 g pszenicy) oraz w dwóch formach: zmieszany z ziarnem i zamknięty w osłonce z gazy młyńskiej. Na podstawie uzyskanych wyników stwierdzono zależność długości cyklu rozwojowego szkodnika i jego płodności od wysokości dawki suszu oraz sposobu jego aplikacji. Notowano większą efektywność proszku zmieszanego z ziarnem. Wraz ze wzrostem dawki testowanego suszu z mięty pieprzowej obserwowano: wydłużenie czasu rozwoju pokolenia, skracanie trwania pojawu chrząszczy i spadek płodności szkodnika.

Combating the storage pests has been a serious economic problem for years. So far pest control involved mostly chemical fumigation of storage places. Today, since January 1, 2014 we have been obliged to obey the legal regulations of the European Parliament and the Council of the European Union which order a blanket application of integrated methods, with the priority of the use of non-chemical and natural methods, which is connected with limiting the application of chemicals to those with a selective effect and demonstrating a lack of negative effect on the human and animal health and on the environment. The present paper provides an analysis of one of the alternative methods of decreasing the number of storage pests; direct adding natural plant substances (i.e. dried and plant parts crushed to powder) to the grain stored. There has been investigated the problem of the effect of the product of plant origin: powder from peppermint (Mentha piperita L.) on the population of grain weevil. The experiments were performed in an air-conditioned room, at the moisture of 70-80%, at the temperature of 25°C, and involved milling grain. The powder, made from peppermint, was tested at two rates (1.0 and 0.5 g per 100 g) of wheat as well as in two forms: mixed with grain and closed in a mill gauze cover. Each series consisted of 10 replications. One replication corresponded to one glass flask 250 ml in capacity filled with 100 g of wheat, in which 10 males and 10 females at the age of 2-5 days were placed. To monitor the after-effect of the plant dried material tested, the second experiment was performed, without peppermint added, which involved the use of weevils derived from respective series of the first experiment. For each series the following were calculated: the generation development time, hatching time as well as the fertility rate which was determined based on the ratio of the number of F1 individuals to the number of P generation females. The results demonstrated a varied reaction of grain weevil to the dried peppermint material. There was shown the dependence of the pest development cycle time and the pest fertility on the rate of the dose of dried material as well as its application method. In the experiments analyzing a direct effect, with increasein of the dose of the dried peppermint material tested, the following were observed: a prolonged generation development time, shortening of the period of beetle hatching and a decreased pest fertility. There was noted a higher effectiveness of dried material mixed with grain, as compared with that added in covers of mill gauze. However, no significant after-effect was reported.