NEW DATA ON ENTOMOFAUNA HARMFUL TO RAPESEED CROPS AND THE ESTABLISHMENT OF MEASURES TO PREVENT AND REDUCE ATTACKS

"Rapeseed, the first crop established in autumn, is a species that attracts a large number of pests, from emergence to the siliquae formation and seed. Decreased production due to the attack of harmful insects can vary between 30-50%, in certain years, they can completely compromise crops. This paper presents data on the entomofauna harmful to rapeseed crops and the influence of measures to prevent and combat attacks, under specific conditions in the Central area of Moldova. The results obtained between 2017 and 2020 showed that the harmful entomofauna of rapeseed was composed of 23 species of insects, classified in five systematic orders: Coleoptera, Lepidoptera, Heteroptera, Hymenoptera and Homoptera. According to the number of species and the number of specimens collected, the order Coleoptera had the maximum share of 73.9% and respectively 88.9%. Within the order Coleoptera, the most abundant species were Phyllotreta atra (41.4%), Meligethes aeneus (27.8%), Ceuthorynchus assimilis (9.6%) and Phyllotreta nemorum (7.3%). Out of the total pest entomofauna, it was found that 30% affect rapeseed crops in the period between seed germination-plant emergence-leaf rosette formation, 9.1% in budding phase, 38% in flowering and 1.8% up to 2.8% in the phenophases of siliquae formation and seed. To prevent the attacks of soil pests (P. atra, P. nemorum, Psylliodes sp., Athalia rosae) was achieved by chemical treatment of the seed with Imidacloprid, Clothianidin and Thiamethoxam. The product Lumiposa 625FS-11.4 l/t seed was experimented with good results in seed treatment. To reduce the attacks of the pests during the flowering period (M. aeneus, A. rosae, Epicometis hirta, Ceuthorynchus assimilis) three treatments were applied on vegetation as follows: Decis Mega-0.075l/ha; Biscaya-0.3 l/ha; Mavrik-0.2 l/ha. This work was carried out within ADER 4.1.5 and 2.2.1 projects."

Efficiency of chemical protection of spring rape and mustard from rape blossom beetle

One of the most dangerous pests of cabbage crops which can damage plants in the budding and flowering phases in all areas of their cultivation is a rape blossom beetle (Meligethes aeneus Fabricius, 1775). The pest is widespread throughout Ukraine; it causes significant damage to the crops every year and reduces the seed yields. It should be noted that the rape blossom beetle is not new to our country and as a pest of rape and other crops from the cabbage family has been mentioned since 1845, and a detailed description of its morphology, biology and ecology can be found in the works of the nineteenth century. It is established that in the Eastern Forest-Steppe of Ukraine the first individuals of the rape blossom beetle appear on the flowering wild growing plants (first of all on dandelion and buttercup) when the average daily temperature exceeds 8 °C, it is the middle of the first decade of April and the beginning of the third decade of April. The mass emergence of the rape blossom beetles takes place when the daily average temperatures are at the range of 9–13 °C and the sum of the effective temperatures above 5 °C is at the range of 100–113 °C, it is the middle of the second decade of April and the end of the third decade of April. The females of the rape blossom beetle usually lay 2–3 eggs into one bud of spring rape or mustard. When protecting the crops from the rape blossom beetle the highest technical efficiency was noted when applying the binary mixture of the microbiological preparation Actophyte, 0.25 % of emulsion concentrate in the dose of 4.8 L/ha and systemic insecticide Biscaya, 24 % of oily dispersion (0.25 L/ha) and in 14 days after spraying it was 76.6 % on white mustard, 74.3 % on Chinese mustard and 76.2 % on spring rape. The highest growth increase in the yield capacity was observed in the same variant; for white mustard it was 0.431 t/ha, for Chinese mustard it was 0.265 t/ha and for spring rape the growth increase amounted to 0.277 t/ha. As a result of the researches it is established that the weight of 1000 healthy seeds is 2,6996 g, and the weight of the seeds damaged by the larvae of the rape blossom beetle is 0.4213 g, so it is reduced by 84.4 %. The filling of the damaged seeds is 6.8 times more, which indicates that they are smaller in diameter and frail. The undamaged seeds of spring rape contain 35.92 % of fat, and the damaged seeds contain only 17.48 %, which is 2.05 times less. The protein content in the undamaged seeds was 30.97 % and in the damaged ones it was 32.23 %, that is 1.04 times more. The germination rate of the undamaged seeds of spring rape under the laboratory conditions on the eighth day was 90.0 %, and the germination rate of the damaged ones amounted to 58.0 % and was lower by 32.0 %.

Фітосанітарний стан посівів ріпаку ярого в умовах північно-східного лісостепу України

Динаміку розповсюдженості шкідників ріпаку ярого вивчено в умовах північно-східного Лісостепу України у 2005‒2018 рр. Методика досліджень була загальноприйнятою. У посівах ріпаку ярого найбільш розповсюдженими шкідниками були квіткоїд ріпаковий (Meligethes aeneus F.), блішки хрестоцвіті (Phyllotreta spp.) та пильщик ріпаковий (Athalia rosae L.). Блішки заселяли 100 % площ хрестоцвітих у фазу сходів культури. На посівах ріпаку блішки пошкодили 12,0 ‒ 35,0 % рослин. Найбільша пошкодженість шкідниками становила 67,0 % у 2006 р. і 66,0 % – у 2005 р. Чисельність блішок на хрестоцвітих складала 3,0‒5,0 екз./м2. Найвищою(18,0 екз./м2) вона була у 2006 р. Квіткоїд ріпаковий заселяв 100,0 % посівів, а у 2006 р. – 85,0 %, у 2010 р. – 91,0 % посівів у фазу бутонізації‒цвітіння. У посівах ріпаку ярого квіткоїд пошкодив 17,0‒37,0 % рослин. Найбільша пошкодженість шкідниками була у 2006 р. і складала 74,0 %, у 2005 р. ‒ 69,0 %, у 2007 р. – 63,0 %. Чисельність квіткоїда ріпакового становила у середньому 2,0‒6,0 екз./рослину. Найвищою вона була у 2006 р. (30,0 екз./рослину). Розповсюдженість пильщика ріпакового була найменшою зі спеціалізованих шкідників ріпаку ярого. Він заселяв 100,0 % посівів лише у 2005 р., а у 2008 р. – тільки 64,0 % посівів. За роки досліджень пильщик ріпаковий заселяв, в основному, в межах 14,0‒50,0 % посівів. Комахами було пошкоджено 3,0‒8,0 % рослин. Чисельність пильщика ріпакового становила 0,9‒2,0 екз./рослину. Найвища чисельність шкідників 7,0 екз./рослину була у 2006 р., дещо меншою ‒ у 2007 р. (4,0 екз./рослину). В Сумській області за період 2005‒2018 рр. площі посівів ріпаку ярого змінювалися в межах 1,1‒22,2 тис. га, валовий збір насіння – 1,9‒22,3 тис. т. Заходи захисту посівів ріпаку ярого від шкідників включають профілактичні і винищувальні методи. Для захисту посівів від блішок хрестоцвітих у фазу сходів використовують інсектицидні протруйники. У період вегетації проти блішок хрестоцвітих (3‒5 жуків на м2), квіткоїда ріпакового (5‒6 жуків на рослину), ріпакового пильщика посіви обприскують інсектицидами.

OBSERVATIONS CONCERNING THE HARMFUL ENTOMOFAUNA FROM WINTER RAPESEED CROPS IN THE CONDITIONS OF CENTRAL OF MOLDAVA, BETWEEN YEARS 2014-2017

<p>During 2014-2017, 22 species were identified in the yellow bowl trap type installed in winter rapeseed crops established at A.R.S.D. Secuieni. Of these, 11 species are specific to winter rapeseed crops and 11 species were accidental identified because of the proximity with different agricultural crops (maize. sunflower. grain cereals). The highest abundance was registered by <em>Epicometis hirta</em> Poda species which accounted 914 specimens collected during the analyzed period. The species were integrated into classes of dominance ((D1 - subrecedent species. D2 - recedent species. D3 - subdominant species. D4 - dominant species and D5 - eudominant species). <em>Meligethes aeneus</em> F., <em>Ceuthorrhyncus napi</em> Gyll. and <em>Epicometis hirta</em> Poda. being considered eudominant species belonging to the D5 class. The <em>Ceuthorrhynchus napi </em>Gyll.,<em> Meligethes aeneus </em>F.,<em> Epicomites hirta </em>Poda.,<em> Psylliodes chrysocephala</em> L.,<em> Subcoccinella 24 punctata L., Oulema melanopa </em>L. species were classified in the constancy class - C4 - euconstant species. <em>Meligethes aeneus</em> F., <em>Epicometis hirta </em>Poda<em> </em>and <em>Ceuthorrhynchus napi </em>Gyll. species recorded the highest values for the index of ecological significance (W %) and were classified in the W5 class - characteristic species. The collected entomofauna belongs to five orders:<em> </em><em>Coleoptera, Heteroptera, Lepidoptera,. Diptera </em>and<em> Hymenoptera. </em>The highest number of species (17 species) and the highest number of collected speciemens (3246 specimens) belonged to the <em>Coleoptera</em> order.</p>

The effect of sowing time on pest spreading in spring oilseed rape crop

The field experiments were conducted at the Experimental Station of Aleksandras Stulginskis University in 2015–2017. The aim of the experiment was to evaluate the influence of sowing time on spreading of pests and diseases in spring oilseed rape crop. The first sowing occurred when soil reached physical maturity, the other sowing dates were every 5 days in 2015–2016 and every 7 days in 2017. In 2015, the sowing time did not have a significant effect on the distribution of Alternaria brassicae. Meteorological conditions strongly influenced the severity of the disease. The sowing date had a significant influence on the distribution of Verticillium dahliae: in the spring rape crop sown in May, the stems were damaged by 6.4%, less compared to the crop sown in April. In 2016–2017, the rape seedlings in the plots of the latest sowing were significantly more damaged compared with those of earlier sowing dates. In 2016, spreading of Verticillium longisporum significantly increased by 3.7 times in the crop of spring rape sown on 10 May compared to other sowing dates. In 2017, the spreading of Verticillium dahliae in spring rape crops was more influenced by a colder than usual vegetation period and an abundant rainfall than the sowing time. In 2015, the intensity of Phyllotreta spp. damage in the rape seedling period (BBCH 10-19) significantly increased by 2.7 times with the sowing date from 30 April to 20 May. The spreading of Meligethes aeneus was the least in the spring oilseed rape sown at the optimal time (30 April and 5 May). In 2016–2017, Phyllotreta spp. were more intensively spread in the crops sown in April, and rape seedlings were significantly more damaged. In 2016, Meligethes aeneus were most widely spread in the spring rape crop of the earliest sowing (4 October). A significant decrease in the number of pests was detected in the rape crops sown in May compared to that sown in April. In 2017, the highest number of Meligethes aeneus was evaluated in the rape crop sown on 2 June, significantly by 3.9 times more compared with that in the earlier sown crop and by 2.9 times in the crop sown one week later. It is believed that the other generation of Meligethes aeneus from winter rape crops went to the spring rape crops. In 2016, there was a very strong statistically significant correlation between the sum of positive temperatures for the 10-day period up to the sowing of rapeseed and the prevalence of Phyllotreta spp. in crops: r = 0.98, P ≤ 0.05, and the damage intensity of rape seedlings by Phyllotreta spp. of (BBCH 10-19): r = 0.92, P ≤ 0.05. The warmer the weather was before rape sowing, the more active Phyllotreta spp. were. In 2017, strong correlations were established between the number of Phyllotreta spp. and the intensity of crop damage by Phyllotreta spp. and the crop density 3 days after the emergence: r = –0.82, P ≤ 0.05; r = –0.89, P ≤ 0.01, and 7 days after the emergence of spring rape: r = –0.81, P ≤ 0.05; r = –0.88, P ≤ 0.01.

OBSERVATIONS CONCERNING THE HARMFUL ENTOMOFAUNA FROM WINTER RAPESEED CROPS IN THE CONDITIONS OF CENTRAL OF MOLDAVA, BETWEEN YEARS 2014-2017

During 2014-2017, 22 species were identified in the yellow bowl trap type installed in winter rapeseed crops established at A.R.S.D. Secuieni. Of these, 11 species are specific to winter rapeseed crops and 11 species were accidental identified because of the proximity with different agricultural crops (maize. sunflower. grain cereals). The highest abundance was registered by Epicometis hirta Poda species which accounted 914 specimens collected during the analyzed period. The species were integrated into classes of dominance ((D1 - subrecedent species. D2 - recedent species. D3 - subdominant species. D4 - dominant species and D5 - eudominant species). Meligethes aeneus F., Ceuthorrhyncus napi Gyll. and Epicometis hirta Poda. being considered eudominant species belonging to the D5 class. The Ceuthorrhynchus napi Gyll., Meligethes aeneus F., Epicomites hirta Poda., Psylliodes chrysocephala L., Subcoccinella 24 punctata L., Oulema melanopa L. species were classified in the constancy class - C4 - euconstant species. Meligethes aeneus F., Epicometis hirta Poda and Ceuthorrhynchus napi Gyll. species recorded the highest values for the index of ecological significance (W %) and were classified in the W5 class - characteristic species. The collected entomofauna belongs to five orders: Coleoptera, Heteroptera, Lepidoptera,. Diptera and Hymenoptera. The highest number of species (17 species) and the highest number of collected speciemens (3246 specimens) belonged to the Coleoptera order.