Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract Full Text

Laboratory researches on unconventional methods for control of Colorado potato beetle (Leptinotarsa decemlineata L.).


Almost all over the world as in Romania, being Holarctic species, the Colorado potato beetle, (Leptinotarsa decemlineata L.), is by far the biggest pest for potato growers. Given increasing consumer demand of products without pesticides, concept best expressed by the emergence of the term of "ecological farming" is similar terms "organic farming" or "biological farming" used in other EU Member States. There are a few methods, taking into consideration organic or that work well against potato beetle. Some organic gardeners rely on a broad-spectrum of homemade sprays for reject insects, after the Rodale encyclopaedia. From literature is known that wood ash is highly toxic to adult and larval stages of the Colorado potato beetle continuously exposed to wood ash for periods of up to 10 days but remained low in topical applications. To determine the effect of the experimental products (Dust of grinded beetles dried at 105°C; decoction from grinded beetles dried at 105°C; ash of grinded beetles burned at 250°C; decoction from the ashes of burnt bugs to 250°C; Chilli pepper powder; decoction of Chilli pepper powder; chopped fresh peppers; decoction of fresh chopped peppers; tobacco decoction; check.), potato leaves were sprayed with decoction for about 3 seconds or powdered with dust or powder, put onto the Petri dishes. In present laboratory experiment defined the effect of the 9 extracts on Colorado potato beetle feeding and survival. Colorado potato beetle put onto the Petri dishes filled with leaves, was provided with 5 Colorado potato beetles adults or 5 larvae in stage L2-L3. The experiment was 24, 48 and 72 h long and involved the replacement and supplementing of feed. The test and control combinations (untreated dry leaves) were set up in 5 replications. After 24, 48, 72 and 96 hours the CPB adults or larvae were counted. Tests have shown that the products tested did not significantly effect in combating CPB nor on adults or larvae, either powdered or decoctions, without any repellent effect. So it have been rejected different opinions, spread among potato growers, concerning the use of different products non insecticides.