IMPACT OF CUCUMBER GENOTYPE ON THE DAMAGES CAUSED BY TWOSPOTTED SPIDER MITE AND EFFICIENCY OF BIOLOGICAL SPECIMENS

Due to the growing variety of vegetables, the impact of genotypic parameters of plants on pest resistance and efficiency of biological specimens is of high importance when selecting and creating new varieties and hybrids. The researchers found out the significant differences in stability of parental forms, hybrids and cucumber varieties of the Siberian selection in relation to twospotted spider mite. The paper finds out relatively resistant parental forms - ZhL-4 and GP-61/b, and also samples of the paternal form - GF-7 and a maternal line - ZhL-9 damaged by a phytophage in a strong degree have been defined rather steady against a phytophage. High acaricidal effect of Phytoverm was found on all studied varietal samples, however the most effective biospecimen restrained development of the pest on plants of relatively resistant to phytophage of female line ZL-4. Reproduction of the twospotted spider phytoseiulus did not depend on genotypic features of parental forms, varieties and hybrids of cucumbers. The number of acarifages increased by 7.8-8.2 times in two weeks after appearance on the plants inhabited by spider mite in comparison with the initial number, as a result of which the damage rate of plants by the pest of most cultivars decreased, and in male forms practically did not change (GF-19) or slightly increased (GF-7). According to biochemical parameters, cucumber varieties with different degree of resistance to phytophage differed in dry matter content. Non-resistant to twospotted spider mite female forms LL-9, LL-12/1 and Nadezhda variety contained the lowest concentration of dry matter (5.4%), the highest amount of dry matter was observed in female line LL-4, which has the highest pest resistance (6.0%). Since the inherited traits are predominantly transmitted by the maternal component and the paternal form enhances these properties, it is important to assess not only the yield and flavour qualities but also the degree of resistance of parental forms to pests when selecting cucumber varieties and hybrids.

Stability and Resiliency of Biological Control of the Twospotted Spider Mite (Acari: Tetranychidae) in Hop

The twospotted spider mite (Tetranychus urticae Koch) is a common pest in agricultural and ornamental crops. This pest can be controlled by resident predatory arthropods in certain situations. This research quantified the stability and resiliency of established conservation biological control of the twospotted spider mite in hop over a 5-yr period associated with nitrogen fertilization rate and use of a broad-spectrum insecticide. Biological control generally was stable and resilient over a sixfold range of nitrogen fertilization rates, and in only 1 of 5 yr did elevated nitrogen rates significantly affect populations of spider mites. In contrast, one application of the insecticide bifenthrin was associated with disruption of biological control and a severe outbreak of spider mites. The complex of natural enemies suppressed the outbreak during the same year in which bifenthrin was applied, but only after populations of spider mites exceeded levels associated with economic damage. However, in the following year the system returned to an equilibrium state where spider mites were suppressed below economically damaging levels. Therefore, conservation biological control in hop appears stable and robust to factors such as nitrogen fertilization that increase reproductive rates of spider mites but may be sensitive to factors such as nonselective insecticides that are lethal to natural enemies. Conservation biological control can be considered resilient to a single use of a nonselective insecticide in the year following the application, but not within the year of application.

Predatory Mite, Neoseiulus californicus (McGregor) (Arachnida: Acari: Phytoseiidae)

The predatory mite Neoseiulus californicus (McGregor) has characteristics of both type II specialist predatory mites and type III generalist predatory mites. N. californicus prefers Tetranychid mites as food, but will also consume other mite species, small insects, such as thrips, and even pollen when the primary prey is unavailable. N. californicus is often used to control the twospotted spider mite, Tetranychus urticae Koch, and other phytophagous mites on various crops in temperate and subtropical regions around the world. This document is EENY-359, one of a series of the Entomology and Nematology Department, UF/IFAS Extension. Original publication date November 2005. EENY-359/IN639: Predatory Mite, Neoseiulus californicus (McGregor) (Arachnida: Acari: Phytoseiidae) (ufl.edu)

Insect Management for Carrots

There are no major insect pests on carrot in Florida. The greatest concern for growers has been root damage from soil pests, particularly wireworms (southern potato and tobacco), cutworms (variegated, granulate, black), and mole crickets, all of which are sporadic. Occasional minor pests include leafminers (especially the vegetable leafminer), aphids (green peach and melon), and weevils (especially vegetable weevils). Other arthropods that may occasionally cause minimal damage to carrots in Florida include armyworms (fall, beet, and southern), field crickets, mites (especially twospotted spider mite), and plant bugs (including tarnished plant bug). This document is ENY-462, one of a series of the Entomology & Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: July 2002. Revised: August 2005. ENY-462/IG148: Insect Management for Carrots (ufl.edu)

The predating activity and prey impact on life cycle and development of predatory mite (amblysieus swirskii)

Amblyseius swirskii is commonly used to control whitefly and thrips, twospotted spider mite(T.urticae) in greenhouse vegetables and some ornamental crops. This study in each of three different types(two spotted spider mite feeding , pollen feeding, thrips feeding) of feeding pray, 1 females were observed to die at relative humidity 35-60% and at temperatures of 25-300С, laboratory light:dark(16:8) and characteristics of the pray were studied in the development of fertility. We studied mite’s nutritional features, and hunting activities. Amblysieus swirskii’s egg development good establish 2.18±0.17 days in environment which is pollen feeding, 2.48±0.04 days in thrips feeding environment, 2.014±0.098 in two spotted spider mite feeding environment, Growth is until Larvae turned to Nymph there is a hole day in three environments, until Nymph turned to adult tick there are 3.13±0.23 days in pollen feeding environment, 3.25±0.29 days in thrips feeding environment, 2.014±0.098 two spotted spider mite prey environment. A Generation 6.3±0.3 day’s pollen feeding environment, 6.72±0.25 days in thrips feeding environment, 6.55±0.32 days in two spotted spider mite prey environment. Therefore conclusion is feeding environment doesn’t influence their life cycle. Research shows that adult antelope feeds with 15.2 two spotted spider mite, 5.1 thrips daily, decreasing it`s population. Having observed the females egg development in three different types of feeding environment it showed highest result, 14 days, at a temperature of 29.7 1.47C and 30 3.33% moisture environment. In contrast it showed its lowest result, 6 days, in dusty feeding environment whereas in environment with thrips it lay it`s eggs in 12 days for an average. Observing Amblysieus swirskii’s laying egg and lifespan, found out that they able to lay 13±2.6 eggs in two spotted spider mite provision environment, 13.6±2.08 days survive. In thrips feeding environment laying 6.3±0.5 eggs and survive 12.3±2.08 days, in pollen feeding environment laying 4±1 eggs, 7.6±0.5 days surviving. Ангуучин амблисейус (аmblysieus swirskii) хачгийн идэш тэжээлийн онцлог, үржил хөгжил, ангуучлах идэвхийг судалсан дүн Хураангуй: Ангуучин хачиг амблисейус (Аmblysieus swirskii)ийн үржил хөгжлийг лабораторийн гэрэл: харанхуй (16:8), 25-300С дулаантай, 35-60% чийгшилтэй орчинд ургамлын тоос, шүлхий хачиг, трипс гэсэн гурван идэш тэжээлийн хувилбартайгаар үржил хөгжил, ангуучлах идэвхийг судлав.Ангуучин хачиг амблисейус (Аmblysieus swirskii)-ийн өндөгний хөгжил ургамлын тоос идэштэй орчинд 2.18±0.17 хоног, трипс идэштэй орчинд 2.48±0.04 хоног, шүлхий хачиг идэштэй орчинд 2.014±0.098 хоног авгалдайнаас нимф болох шатанд гурван орчинд бүгд 1 хоног, нимфээс бие гүйцсэн ангуучин хачиг болох шатанд тоос идэштэй орчинд 3.13±0.23 хоног, трипс идэштэй орчинд 3.25±0.29 хоног, энгийн шүлхий хачиг идэштэй орчинд 2.014±0.098 хоног тус тус бойжсон бол 1 үе удам нь тоосоор хооллосон орчинд 6.3±0.3 хоног, трипсээр хооллосон орчинд 6.72±0.25 хоног, энгийн шүлхий хачгаар хооллосон орчинд 6.55±0.32 хоног тус тус үргэлжлэв. Ангуучин бие гүйцсэн амблисейус (Аmblysieus swirskii) хачгийн ангуучлах идэвхийг судлахад өдөрт 15.2 шүлхий хачиг, 5.1 трипс дунджаар идэж тоо, толгойг бууруулж байна. Эмэгчин хачгийн төлөрхөг чанарыг дээр дурьдсан гурван идэш тэжээлийн орчинд судлахад шүлхий хачиг идэш тэжээлийн орчинд хамгийн олон хоног өндөглөсөн буюу дунджаар 14 хоног, хамгийн цөөн хоног өндөглөсөн буюу тоостой идэш тэжээлийн орчинд дунджаар 6 хоног өндөглөсөн бол трипстэй идэш тэжээлийн орчинд дунджаар 12 хоногийн турш өндөглөлт үргэжилж байна. Ангуучин хачгийн өндөглөлт ба амьдрах хугацааг тогтооход энгийн шүлхий хачиг идэш тэжээлийн орчинд 13±2.6 өндөг төрүүлж, 13.6±2.08 хоног амьдарч, трипс идэш тэжээлийн орчинд 6.3±0.5 өндөг гаргаж 12.3±2.08 хоног амьдаржилж басан бол тоостой идэш тэжээлийн орчинд 4±1 өндөг гаргаж 7.6±0.5 хоног тус тус амьдарч байгааг тогтоов. Түлхүүр үг: Биологийн хамгаалал, ангуучлах идэвх, идэш тэжээлийн онцлог