Phytosanitary monitoring in the Arboretum of the Nikita Botanical Gardens in 2020

According to the results of phytosanitary monitoring in the Arboretum of the NBG, 26 pest species were identified on 97 tree introduced species (1039 foci). In the Arboretum of the NBG in 2020, 27 species of phytopathogenic fungi (186 foci) were identified on 65 species of woody plants. Of these, 18 species are wood-destroying fungi that cause root and trunk rot in 57 species of tree introduced species (159 foci). In the Arboretum, 5 types of powdery mildew fungi (9 foci) and 4 types of fungi that cause rust (18 foci) were identified. The results of phytosanitary monitoring for the period 2015-2020 were summed up. The number of pest species increased by 8 species and amounted to 26 species of phytophagans, the number of pest foci increased by 32%. The number of foci of phytopathogenic bracket fungi that cause root and trunk rot increased from 103 to 159 units, the increase in foci of pathogens was 56 units. Currently, the number of bracket fungi that cause root rot is 7 species (135 foci), bracket fungi that cause trunk rot - 11 species (24 foci). The number of powdery mildew and rust fungi did not change during the studies. The biology and ecology of cottony-cushion scale ( Icerya purchasi ) was studied.

Sex, males, and hermaphrodites in the scale insect Icerya purchasi

Androdioecy (the coexistence of males and hermaphrodites) is a rare mating system for which the evolutionary dynamics are poorly understood. Here we study the only presumed case of androdioecy in insects, found in the cottony cushion scale, Icerya purchasi. In this species, female-like hermaphrodites have been shown to produce sperm and self-fertilize. However, rare males are sometimes observed too. In a large population-genetic analysis, we show for the first time that although self-fertilization appears to be the primary mode of reproduction, rare outbreeding events between males and hermaphrodites do occur, and we thereby confirm androdioecy as the mating system of I. purchasi. Thus, this insect appears to have the colonization advantages of a selfing organism while also benefitting from periodic reintroduction of genetic variation through outbreeding with males.

The abundance and mechanical control of Icerya purchasi (Maskell, 1878) (Hemiptera: Monophlebidae) on Mangifera indica in Dhaka, Bangladesh

The cottony cushion scale, Icerya purchasi, one of the devastating pests of citrus and ornamentals distributed all over the world. A study was conducted on the biology, abundance and mechanical control of this pest on mango plants from at two locations of Dhaka, Bangladesh. Simple linear regression lines were produced on the lengths and widths of different nymphal instars and adult of this pest. It was proved that body lengths and widths were highly correlated with the successive changing of the nymphal instars from 1st, 2nd and 3rd to adults. The maximum abundance of the I. purchasi on mango leaves was 310 ± 21 in March, 2016. The results of the mechanical control method by hand crushing showed that it was highly effective to control this insect. Abundances of this insect before and after treatment were significantly different (p < 0.05). Abundances of insects in different sampling times were showed different by Tukey’s HSD test (p < 0.05). Bangladesh J. Zool. 47(1): 89-96, 2019

Análise Faunística de Insetos Associados à Cultura do Quiabeiro [Abelmoschus esculentus (L.) Moench] em Plantio Comercial, no Município de Canindé de São Francisco, SE, Brasil

Resumo. A presente pesquisa objetivou estudar a entomofauna associada ao cultivo comercial de quiabo, no Município de Canindé do São Francisco (SE), por meio de análise faunística. As espécies Bemisia tabaci (Gennadius) biótipo B, Aphis gossypii (Glover), Phenacoccus sp., Icerya purchasi (Maskell) e Lagria villosa (Fabricius) foram as principais pragas do quiabeiro neste estudo. Diabrotica speciosa (Germar) e Gryllus assimilis (Fabricius) foram pragas de importância secundária. Leptoglossus zonatus (Dallas), Nezara viridula L., Pachycoris torridus (Scopoli) e Oxycarenus hyalinipennis (Costa) foram pragas esporádicas. Foram encontradas quatro espécies de insetos predadores, sendo uma constante e dominante (Cycloneda sanguinea L.), uma dispersa, mas constante (Eriopis connexa German) e duas raras (Hippodamia convergens Guérin-Méneville e Psyllobora confluens F.). Insect Faunal Analysis Associated with the Commercial Cultivation of Okra [Abelmoschus esculentus (L.) Moench] in Canindé do São Francisco, SE, BrazilAbstract. This research aims to study the entomofauna associated with the commercial cultivation of okra in municipality of Canindé do São Francisco, Sergipe State, Brazil, through faunal analysis. The species Bemisia tabaci (Gennadius) biotype B, Aphis gossypii (Glover), Phenacoccus sp., Icerya purchasi (Maskell) and Lagria villosa (Fabricius) were the okra key pests. Diabrotica speciosa (Germar) and Gryllus assimilis (Fabricius) were plagues of secondary importance. And Leptoglossus zonatus (Dallas), Nezaraviridula L., Pachycoris torridus (Scopoli) and Oxycarenus hyalinipennis (Costa) were sporadic pests. Four species of predatory insects were found, a constant and dominant (Cycloneda sanguinea L.) a dispersed, but constant (Eriopis connexa German) and two rare (Hippodamia convergens Guérin-Méneville and Psyllobora confluens F.).