Exploratory Analysis of Color Forms’ Variability in the Invasive Asian Lady Beetle Harmonia axyridis (Pallas 1773)

The Asian ladybird (Harmonia axyridis Pallas), native to Asia, is one of the 100 most invasive species in the world and has spread worldwide. This study aimed to characterize color forms of H. axyridis in Croatia and to analyze the variability of wing shape between populations and indicated forms. Geometric morphometric methods were used to analyze a total of 129 left and right wings in males and 126 left and right wings in females of H. axyridis collected from four different sites in Croatia. The results show a significant difference in wing shapes between the studied forms. Each form had its own specific morphotype that likely originated under the influence of genetic changes in the species. This study demonstrates that the use of geometric morphometric analysis is effective in studying the variability in H. axyridis populations. As this study is the first of its kind, for further clarity, it is necessary to conduct additional studies on a larger number of sites and an equal number of individuals of all forms.

Evaluation of compounds for repellency of the multicoloured Asian lady beetle (Coleoptera: Coccinellidae) in vineyards

The multicoloured Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), has become a pest in North American vineyards during harvest due to its adverse effects on wine quality. This study evaluated alternative products that may be suitable for use in vineyards as repellents to the beetle. Products were screened as repellent for multicoloured Asian lady beetle in short-term laboratory trials. Thirteen products significantly reduced the number of beetles on grapes, Vitis vinifera (Vitaceae). Products that showed a 50% or greater repellency were evaluated for residual repellency 24, 48, and 72 hours after application. In these trials, pine oil was highly repellent at each testing period, whereas the repellency of most other products decreased over time. Eight repellent compounds were evaluated in field trials in commercial vineyards that had high multicoloured Asian lady beetle populations. The number of beetles on vines was counted 2–6 and 24–28 hours after application. In the field, the most effective repellents overall were Biobenton and Buran, which reduced the number of multicoloured Asian lady beetles by 39 and 34%, respectively. The discovery of new repellents of multicoloured Asian lady beetle provides an opportunity to improve management of the pest in vineyards and to reduce risk of wine taint without using broad-spectrum insecticides.

THE FEATURES OF BIOLOGY OF HARMONIA AXYRIDIS PALL. AND THE MOST COMMON SPECIES OF COCCINELLIDS IN UKRAINE AGROCOENOSIS

The research was conducted in 2017–2019 years in the Institute of Plant Protection of The National Academy of Agrarian Sciences of Ukraine in the Laboratory of entomology and resistance of agricultural crops against pests (Kyiv, Ukraine). The objective of the research is investigation of particular biology features of Harmonia axyridis Pall. in comparison with the main species of coccinellids in typical agrocoenosis. The research methods are the following: laboratory method that means laboratory maintenance of coccinellids; mathematical-statistical method that means statistical processing of the obtained results. The Coccinellidae family (Latreille, 1807) has an important economic value in the human business activities. Most species are predators of aphids, scale insects, thrips, spider mites, leafhoppers, whiteflies, eggs and larvae of other small arthropods. Coccinellids are marked by their high gluttony, polyphagous, fertility. Beetles and larvae of ladybirds play a significant role in the quantity control of pests of agricultural, forest and ornamental plants. Since 2009 researchers in Ukraine have devoted great attention to identification and distribution of invasive species of Asian lady beetle, or Multicolored Asian lady beetle, Harlequin ladybird, Halloween ladybeetle (Harmonia axyridis Pallas, 1773). H. axyridis Pall. is characterized by its wide ecological plasticity, trophic specialization, greater gluttony, fertility and number of generations leading to the gradual displacement of local species of coccinellids. The comparative results of researches of some biology features of H. axyridis Pall. and the most common species of ladybirds are presented. The survival of coccinellids imago during the wintering, in the active period in the absence of feed, their gluttony for different species of aphids is examined. Features of oviposition and duration of various stages of coccinellids development are presented. In the laboratory the Asian lady beetle was marked among other species by the number of its laid eggs, oviposition period, duration of various stages of its development, survival and gluttony

Comparison of the Sex Pheromone Composition of Harmonia axyridis Originating from Native and Invaded Areas

The multicolored Asian lady beetle, Harmonia axyridis (Coleoptera: Coccinellidae), originates from South-East Asia and is now considered as an invasive species at a worldwide scale, with populations encountered in North and South America, Africa, and Europe. Several previous studies suggested that invasive populations display different behavioral and physiological traits, leading to a better fitness than native individuals. H. axyridis sex pheromone was identified recently, but only from individuals established in Europe. In this study, we compare the composition of the female sex pheromone of H. axyridis from two populations: (i) an invasive population in North America, and (ii) a native population in South-East China. We found the females originating from both populations to release in similar proportions the same five pheromonal compounds, namely β-caryophyllene, β-elemene, methyl-eugenol, α-humulene, and α-bulnesene. However, females from the North American strain release all five compounds in larger amount than the Chinese ones. Whether invasive individuals were selected during the process of invasion through their capacity to better call and find sexual partners remains to be confirmed.

Compatibility of selected biorational pesticides with the predatory arthropods in brinjal ecosystem

Susceptibility of three predatory arthropods namely Asian lady beetle, Harmonia axyridis (Pallas), lynx spider, Lycosa pseudoannulata (Boescriberg and Strand), and wolf spider, Oxyopes javanus (Thorell) to four commonly used biorational molecules viz. buprofezin, spinosad, emamectin benzoate and abamectin were determined in a brinjal ecosystem. Biorational pesticides were applied singly and in some selected combinations and their toxicity on the predators was recorded up to three sprayings in a confined habitat. Buprofezin caused no significant mortality of predators (2.87%, 0.32%, 0.96% mean mortality per spray of Asian lady beetle, lynx spider, and wolf spider respectively) and was found most compatible among the biorational molecules. However, other three tested molecules were found highly toxic for all predatory natural enemies when applied singly or in combination with buprofezin. Spinosad was most toxic for Asian lady beetles (21.84% mean mortality per spray) and lynx spiders (15.32 % mean mortality per spray) whereas abamectin (17.78% mean mortality per spray) for wolf spiders. It was observed that the number of spraying was very crucial and had a proportionate relationship with the mortality percentage of predators. Based on this study it is suggested that buprofezin could be considered to incorporate safely in the IPM program for brinjal pest management.J. Bangladesh Agril. Univ. 15(2): 234-238, December 2017