|Stoeva, Atanaska -|
|Harizanova, Vili -|
Submitted to: Experimental and Applied Acarology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 7, 2011
Publication Date: May 3, 2011
Citation: Stoeva, A., Rector, B.G., Harizanova, V. 2011. Biology of Leipothrix dipsacivagus (Acari: Eriophyidae), a candidate for biological control of invasive teasels (Dipsacus spp.). Experimental and Applied Acarology. 55:225-232. Interpretive Summary: Several species of teasels (Dipsacus spp.), which are native to Europe, have become invasive in the USA. They are present in 43 states and listed as noxious is CO, IA, MO, NM, and OR. The eriophyid mite Leipothrix dipsacivagus is a candidate for classical biological control of invasive teasels. The biology and life cycle of this mite was investigated in this study to gain information about its suitability as a biological control candidate. The mite was shown to have a brief life-cycle and high fecundity, suggesting a high potential for rapid population growth. The results of this study demonstrate that L. dipsacivagus can be reared easily on potted plants under laboratory/greenhouse conditions and that this mite is worthy of further testing as a candidate biological control agent.
Technical Abstract: The present study describes key aspects of the biology of Leipothrix dipsacivagus, an eriophyid mite that was recently described as a new species from Dipsacus fullonum and D. laciniatus (Dipsacaceae). Preliminary host-specificity tests have shown that it can develop and reproduce only on Dipsacus spp. (teasels) and therefore the mite is being studied as a candidate biological control agent against invasive teasels. Studies were conducted in a laboratory at 24-28°C with 16 h of light per day. Mites for the stock colony for this study were collected from D. laciniatus in Klokotnitsa, Bulgaria and reared on rosettes of D. laciniatus in the laboratory. This mite can reproduce either sexually or by parthenogenesis (arrhenotoky). Unfertilized females produced male offspring only, while progeny of fertilized females were of both sexes. Experiments were designed to compare male progeny from fertilized eggs to males from unfertilized eggs and to compare males and females from fertilized eggs. The incubation period of unfertilized eggs was 6.3 days, while that of fertilized eggs was 5.8 days for male offspring and 6.9 days for female offspring. Development time for active immature instars (larvae and nymphs) hatching from unfertilized females was 4.0 days, compared to 3.4 days and 5.3 days for males and females hatching from fertilized eggs, respectively. The life cycle (egg to adult) was 10.4 days for progeny of unfertilized females compared to 9.6 days for male progeny of fertilized females and 11.4 days for females. Fecundity of fertilized and unfertilized females was also measured. The total egg production per female averaged 18.3 eggs, and the daily egg production was about 1.6 eggs per female. Adult longevity for males and females averaged 9.9 and 15.1 days respectively. The results suggest that L. dipsacivagus could be successfully mass-produced in the laboratory for potential use as a biological control agent against invasive teasels.