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.


Introduction
Among representatives of the Coccinellidae (Coleoptera) family during the last 20 years special attention has been devoted to Asian lady beetle. The original habitat of this insect is located in Central and Southeast Asia. Today H. axyridis Pall. is recognized as the «most aggressive ladybird on Earth», mass eurytopic species-invader, that exists on four continents [1].
For a long time, Asian lady beetle was successfully bred and used against aphids and scale insects, pests of agriculture and forestry. In the USSR this began in 1927 (Georgia, Belarus, Kazakhstan [2]; in Ukraine -since the 1960s. [3]), in Western Europe -since 1982. Gradually H. axyridis Pall. acclimatized in nature and started to form stable, rapidly growing populations. Since 1991 in Western Europe were single exemplars of Asian lady beetle (France, Greece, Germany, Belgium, the Netherlands). Since 2002 mass reproduction and displacement across Europe has begun [2,[4][5][6][7][8].
Besides the useful value in biological plant protection, the Asian lady beetle invasion has negative consequences. H. axyridis Pall. destroys harmless insects in agrocoenosis and natural communities, displaces local species of ladybirds, becomes a pest of fruit-growing and winemaking, as it damages apples, pears, citrus fruits, grapes [22]. Imagines form masses, swarmed in residential buildings in the autumn-winter period. Beetles can bite people and cause allergic reactions. In the USA Harlequin ladybird is recognized as a new pest of bee-keeping [23].
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.

Materials and Methods
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).

Results and Discussion
There were examined features of oviposition, duration of development of various stages, imago survival during the wintering and in the period of active development in the absence of feed, as well as feeding females, males and fourth instar larvae with different species of aphids.
The oviposition of seven spot ladybird started on May 18 and terminated on July 15; its duration was 34-56 days. The pause between separate ovipositions reached up to four days. The number of eggs in one cluster amounted to 6-86. The fertility within the whole period was 608-1381 eggs, the number of clusters was 20-38.
The oviposition of variegated lady beetle lasted 25-43 days, its beginning was marked on May 27, the end was on July 13. The fertility of one female was 282-566 eggs; the number of clusters ranged from 17 to 28, the number of eggs in one cluster was between 5 and 51. The egg-laying interval was from one to five days.
The oviposition of fourteen spot ladybird was marked from May 21 to July 13. During 32-54 days females laid from 358 up to 574 eggs. The number of eggs in one cluster ranged from 6 to 45; the number of clusters was 20-33, with an interval between ovipositions from one to four days.
The fertility of Asian lady beetle was 811-1645 eggs, the minimum number of eggs laid was 8 and the maximum was 67. The number of clusters was 20-42, pause between ovipositions was from one to three days. The beginning of oviposition was marked on May 18, the end -on July 17, its duration was 39-56 days.
The oviposition dynamics of coccinellids of overwintered generation is presented in Table 1. Among all ladybirds species, H. axyridis Pall. differed by its fertility and mean number of eggs in one cluster. At the same time the mean number of its clusters and duration of oviposition were similar to C. septempunctata L.. The lowest fertility, number of clusters and duration of oviposition were observed in case of H. variegate Gz., but the mean quantity of its eggs in one cluster prevailed P. quatuordecimpunctata L..
For ladybirds breeding each oviposition was placed in a separate container, where hatching of eggs larvae was kept together. And then from each container one larva was transferred to another separate container for its individual keeping. Thus, at the same time and conditions larvae developed both in common and separate containers. A noteworthy detail was that ladybirds in case of individual breeding passed the full cycle of development faster.
The mean duration of the developmental stages of coccinellids of the overwintered generation (general maintenance) is presented in Table 2. In case of general maintenance all species of coccinellids had the similar duration of their egg stage, the larval stage was similar for seven spot ladybird and Asian lady beetle, variegated lady beetle and fourteen spot ladybird. C. septempunctata L. differed among others by duration of pupa stages. In general, the full development cycle was similar for C. septempunctata L. and H. axyridis Pall., in H. variegata Gz. and P. quatuordecimpunctata L.. Individual maintenance. The first instar larvae of seven spot ladybird developed in 2-3 days, the second -in 1-3 days, the third -in 2-3 days, the fourth -in 3-5 days; pupae -in 3-5 days. The The mean duration of the developmental stages of ladybirds of overwintered generation is presented in Table 3 (individual maintenance). In case of individual maintenance the first instar larvae of C. septempunctata L. developed most rapidly, the second instar larvae of all species developed similarly, the third instar larvae of H. variegata Gz. differed by duration, the fourth instar larvae of H. axyridis Pall. was slightly prevalent by its period of larvae development. The pupa stage lasted longer for Asian lady beetle, a little less for seven spot ladybird and it was almost identical for variegated lady beetle and fourteen spot ladybird. The full cycle of development was marked as similar for C. septempunctata L. and H. variegate Gz., faster for P. quatuordecimpunctata L. and the longest for H. axyridis Pall..
During 2017-2019 years in the wintering period were annually kept 200 exemplars of coccinellids imago ( Table 4). The diapausing lasted from the first decade of November to the third decade of March.
In the wintering period of 2017-2019 among the researched species of coccinellids, Asian lady beetle was marked by its highest survival with percentage of mortality on the level of 25.3. The mortality of other species was on the following levels: seven spot ladybird -38.7 %, fourteen spot ladybird -53.3 %, variegated lady beetle -70.0 %.
To determine the ability of ladybirds to tolerate adverse conditions, in particular absence of food, beetles were kept in containers until complete death. The percentage of mortality is presented in Table 5.
In the absence of food the highest survival was observed for H. axyridis This feature of H. axyridis Pall. biology allows it to withstand periods of insufficient feed or absence of food. And therefore this helps to hold the quantity of the population and promotes its rapid growth after feeding (because of the high fertility of Asian lady beetle).
The mean numbers of aphids, eaten per day by females, males and fourth instar larvae, are presented in Table 6. Agricultural and biological sciences Table 4 The wintering of coccinellids in the laboratory  Table 5 The mortality of coccinellids imago in the absence of food Among investigated species of ladybirds, the Asian lady beetle was characterized by the greatest gluttony, that was close to the quantity of aphids, eaten by the seven spot ladybird. The quantity of feed, eaten by the variegated lady beetle and the fourteen spot ladybird, was marked as similar, with some excess in case of the males of the latter one. Similarly larvae were fed with aphids, but H. variegata Gz. prevailed P. quatuordecimpunctata L. by the quantity of eaten food.

Years
As these ladybirds are main representatives of coccinellids fauna in typical agrocoenosis, such gluttony of H. axyridis Pall. promotes significant competition in the food chains with local species of ladybirds.
Among the available aphids, beetles and larvae of coccinellids preferred S. graminum Rond., the least eaten was A. pisum Harr., and the quantity of eaten A. fabae Scop. and B. brassicae L. varied. Females of C. septempunctata L. preferred cabbage aphid, males and larvae -bean aphid. Imago and larvae of H. variegate Gz., P. quatuordecimpunctata L., H. axyridis Pall. (except larvae of fourteen spot ladybird.) ate more cabbage aphid.
The limitation of the study is that only three main indigenous species of ladybirds: C. septempunctata L., H. variegata Gz. and P. quatuordecimpunctata L. are presented in the article.
The further researches of the biological features of H. axyridis Pall in comparison with the other local species of coccinellids are promising. Due to which it is possible to determine the species of ladybirds, the quantity of which will be rapidly reduced in the case of mass reproduction of H. axyridis Pall. The research is useful in the biological protection of plants where H. axyridis Pall. is the most effective entomophage among coccinellids, but also has a negative effect on them.

Conclusions
In case of laboratory maintenance of coccinellids the fertility of H. axyridis Pall. was the greatest -1294.7 eggs, for other species it reached: C. septempunctata L. The greatest gluttony was observed in imago and larvae of Asian lady beetle, in particular, when fed by wheat aphid: females -142.5, males -110.8, fourth instar larvae -127.5 exemplars/day. All species of coccinellids ate less pea aphid, especially fourteen spot ladybird: females -58.5, fourth instar larvae -46.5 exemplars/day, males of variegated lady beetle -36.5 exemplars/day.
As a result of this research, Asian lady beetle was marked with its high survival both during the wintering (25.3 %) and the active period (up to 40 days).
These as well as other features of H. axyridis Pall. biology promote faster quantity recovery and even growth of its population in comparison with local species of ladybirds.