Abundance Dynamics of Selected Arthropods in Relationship with Rice Plant Growth, Pests and their Natural Enemies (original) (raw)
Related papers
International Journal of Tropical Insect Science, 2019
Ecological intensification through organic farming is known to have an influence on plant communities and diversity of insects associated with them. The comparative abundance of natural enemies was studied in organically as well as conventionally (chemical control) grown aromatic rice at farmer's field during 2015-2016 and 2016-2017. Different life stages, i.e., egg, larvae and pupae of rice stem borer, and leaf folder, were collected and brought to the laboratory to record natural parasitism in both organic and conventional fields. The population of predators was recorded through sweep nets. The population of spiders was recorded using pitfall traps and sweep net. A total of nine parasitoid species including 3 egg parasitoids (T. chilonis, T. japonicum, and Telenomus sp.), 3 larval parasitoids (Stenobracon nicevillei, Bracon sp., and Cotesia sp.), and 3 pupal parasitoids (Tetrastichus sp., Brachymeria sp., and Xanthopimpla sp.) were recorded. However, the natural parasitism by these parasitoids was significantly higher in organic than conventional rice. Similarly, the population of predators like spiders, dragonflies, and damselflies was significantly higher in organic fields than in conventional fields. The study highlights the significance of conservation of these natural enemies for a sustainable system of rice insect pest management.
Population dynamics of insect pests in rice ecosystem
Indian Journal Of Entomology, 2021
Investigations on major insect pests in rice was carried out at the Agricultural Research Farm, Banaras Hindu University, Varanasi during kharif 2017-18 and 2018-19. Observations on Scirpophaga incertulas incidence revealed that deadhearts and white ears were observed to be maximum during 1 st week of October (40 th SMW) and 3 rd week of November (47 th SMW), respectively. Likewise, Cnaphalocrocis medinalis was observed during 1 st week of August (31 st SMW) with maximum incidence being in the 1 st week of October (40 th SMW) with 11.39% damaged leaves/ 10 hills. Nilapravata lugens appeared from 2 nd week of August (33 rd SMW) and attained its peak in 1 st week of October (40 th SMW) as 17.33/ 10 hills. The maximum incidence of Nephotettix virescens was observed in the 4 th week of October (43 rd SMW)-15.67 insects/ 10 hills. The activity of Leptocorisa acuta commenced from 3 rd week of October (42 nd SMW) and reached its peak during 3 rd week of November (47 th SMW-14.67/ 10 sweeps in nets). Correlation analysis revealed that the rainfall and evening RH exhibited a negative impact on S. incertulas, C. medinalis, N. lugens, N. virescens and L. acuta; minimum and maximum temperature, and morning RH, showed both positive and a negative impact on these insect pests of rice.
The Diversity of Arthropods Predator on Wild Plant of Rice Field with and without Pesticides
Biosaintifika: Journal of Biology & Biology Education, 2017
Contaminated-agro ecosystem influences abundance and diversity of arthropods. The aims of this study were to analyze the diversity and abundance of pre-planting arthropod predators on wild plants in rice field with and without application of pesticides. The survey and direct observation of wild plants at the rice filed were conducted from January to March 2015, at 1 ha in Pemulutan and 1 ha in Musi 2 Palembang. Sampling of arthropod predator was conducted 8 times before the rice was grown, using insect nets. On the land without pesticide application was found 14 arthropod families which consists of 28 species and 15 families of wild plant consists of 25 species. On the land with pesticide application was found 8 arthropod families consists of 16 species and 15 wild plant families with 23 species. On the land without pesticide application was found High index of diversity (H'=3.121) and low dominance (D=0.095), while on the land with pesticide application low index of diversity (H'=2.602) and high dominance (D=0.171). It is the indicators of arthropods predator more varieties at the land without pesticide application compare to the land with pesticide application. This finding is very important for biological pest management in South Sumatra.
Population dynamics of insect pests and their natural enemies in rice seed bed ecosystem
Journal of Crop and Weed, 2009
As a general principle, natural enemies consume the insect pests to sustain. Though the population densities of both the pests and natural enemies always vary, their proportional representation is generally sufficiently balanced in nature to make natural enemies as successful bio-control agents. Insecticides tend to disturb the natural equilibrium over a relatively long time (Anon., 1999). Being the staple food for more than 65% of the population, increased and sustained production of rice is fundamental to food security in India (Gour et al., 2003; Katti, 2008). Losses in grain yields due to insect pests have been estimated at 10-15 % (Krishnaiah et al., 2008). In several instances, a rich diversity of natural enemies has been reported in rice ecosystem. These natural enemies play an important role in keeping the population levels of major pests under EP (Equilibrium point) under normal conditions. Therefore, to avoid indiscriminate use of pesticides as well as associated residue problems, the natural prevalence of parasites and predators in rice seed bed should be encouraged towards eco-friendly pest management programme. Keeping this background in mind, the present investigation was undertaken to enumerate the role of naturally occurring parasites and predators in rice seed bed visà- vis their impact on BIPM (Bio-intensive pest management).
ECOLOGICAL STUDIES AND BIOLOGICAL CONTROL OF SOME RICE PESTS AT EL-BEHIERA GOVERNORATE By
Doctor of Philosophy in Agricultural Science (Economic Entomology), 2013
ABSTRACT Studies were conducted at rice fields at Rasheed District, Beheira Governorate and laboratory of Entomology, Faculty of Agricultural, Kafer El- sheikh University . during 2009 and 2010 seasons .. The studies aimed to survey arthropods. dominant in rice fields, and role of Trichogramma evanescens in suppressing infestation by Chilo agamemenon in rice fields. Twenty-one insect pest species, 36 predators, five parasitoids, 10 true spiders and three spider mites were surveyed using five techniques of sampling. The most important insect pests were Chilo agamemnon Bles.,Hydrellia prosternalis Deem. and Chironomus spp. Odonata and staphlylinids were the most important predators, while Trichogramma evanescens West. was the most efficient parasitoid Spiders of Lycosidae, Teteragnathidae and Thomisidae proved to be efficient biocontrol agents as generahist predators. Leafhoppers exhibited 5-4 peaks during rice season, while H. prosternalis appeared in 4-5 peaks of occurrence, dragon flies in 5-6 peaks, staqhlinids in 4-5 peaks , true spiders in 4-5 peaks. Because the rice stem borer, Chilo agamemnon is the most important insect pest , a trial was conducted to evaluate the role of the egg-parasitoid, Trichogramma evanescensin in suppressing the insect infestations in rice fields (Giza 178 susceptible cultivar). The parasitoid was released in two waves, 40 and 60 days after rice transplanting, each at a rate of 30,000 parasitoids/ fed. No insecticides or fungicides were applied. The insect symptoms of infestation were recorded as percentages of dead hearts and white heads. The release of the parasitoid reduced the rice stem borer infestation by 44.30-63.36% dead hearts 63.15- 65.18 % white heads. The current studies conclude the recommendation to release this egg- parasitoid to control the rice stem borer, as an alternative method to insecticides. In addition, to enhance the role of insect predators, parasitoids and true spiders, it is necessary to avoid using insecticides particularly early in the season.
Key Insect Pests and Weeds in Irrigated Rice Fields at Varying Fertilization Regimes
Zenodo (CERN European Organization for Nuclear Research), 2023
The study Key Insect Pests and Weeds in Irrigated Rice fields at Varying Fertilization Regimes was conducted during July to December 2020 cropping season. It aimed to describe the occurrence of pests and weeds along with the soil characteristics and fertilizer regimes in different rice fields in RTRomualdez, Agusan del Norte. Relative to the objectives, findings were obtained. Pests and weeds are rising at the sampling sites which are contributory factors to the poor production of rice. Pests and weeds are significantly linked to fertilizer applications such as potassium (K) and nitrogen (N). The soil characteristics such as soil PH and soil phosphorus (P) of the farm sites in RTRomualdez Agusan del Norte are in the normal range. Organic matter (OM) content is low. However, soil potassium (K) is higher which is above the normal range when farmers applied more potassium fertilizers it may cause fixation rather than availability which aggravated further the occurrence of insect pests. Rice crops have a very low nitrogen (N) concentration and marginal potassium (K) levels. Regarding pest occurrence, Rottboellia cochinchinensis (Aguingay) grows more with increasing N concentration. The occurrence of pests is positively correlated to organic matter and phosphorus (P). Further, Nitrogen (N) is positively correlated to the occurrence of weeds. These implied that soil characteristics are significant factors in the occurrence of pests and weeds. The optimal use of potassium (K) and nitrogen (N) can be studied in the occurrence of pests and weeds. The growth of plant hopper and green leaf hopper can be further investigated at varying concentrations of organic matter and phosphorous content. A deeper study on the influence of Nitrogen uptake on the growth of Rottboellia cochinchinensis (Aguingay) is also suggested. Wide sampling sites may also be considered to understand the variability of pests and weeds.
Journal of entomology and zoology studies, 2017
Fixed plot survey carried out during Kharif season (August to December) 2013 for insect pests and natural enemies complex of paddy ecosystem in different location of Cauvery command areas of Mandya district (nearby Vishveshvaraiah canal farm, Mandya). Among the pests, yellow stem borer, plant hoppers, gall midge and leaf folder were very severe and in case of predators, mirids and spiders were most important natural enemies. The average yield loss in rice has been estimated 21-51 %. The population of yellow stem borer was significantly positively correlated to Hymenopterans, Odonata and Staphylinids, whereas BPH is positively correlated with mirids (r=+0.770**), spider spider (r=+440*), odonatan (r=+0.700**), coccinellids (r=+0.476*), carabids (r=+0.779**) and cicindelids (r=+0.417*). In the same way white backed plant hopper, skipper, caseworm, hispa, blue beetle & grass hopper recorded positive significant and positive non-significant with the predators and parasitoids.
Arthropod biodiversity and conservation biological control in rice
Indian Journal of Entomology, 2020
Rice ecosystems have a rich and diverse fauna of arthropods which varied in field in different ecological conditions. Beside the phytophages and detritivores, a large number of predators and parasitoids also exist in the rice ecosystem. Biological control has shown a great potential for reducing the dependence of crop protection on chemical control. Among the predators, spiders are highly abundant in rice fields which feed on variety of insect pests. The different organisms present in the rice ecosystem are linked by food web which can help insect pest management because they clarify the functional interaction between populations. Conservation biological control can be achieved by reducing the pesticide-induces mortality of natural enemies and habitat manipulation to improve natural enemies fitness and effectiveness in the rice fields. There is a plethora of natural enemies in rice ecosystem and conservation biological control plays a major role in reducing pests. The identification of safer chemical pesticides and supplemental food of natural enemies is still needed.
The present studies were conducted at Punjab Agricultural University Ludhiana and PAU Regional Research Station Gurdaspur during Kharif 2017-18 to determine arthropods diversity under paired row direct seeded rice with different dates of sowing and sprayed & unsprayed condition. The total 94 species of arthropods were recorded in direct seeded rice ecosystem. Among three dates of sowing, the highest arthropods diversity index was observed in the second date of sowing (first fortnight of June) due to higher evenness index and it was followed by third (second fortnight of June) and first (second fortnight of May) date of sowing. Higher diversity was recorded at Gurdaspur as compared to Ludhiana. The highest leaffolder& stem borer incidence and planthoppers population was also observed in third date (second fortnight of June) of sowing. The leaffolder incidence and planthoppers population was higher at Gurdaspur whereas stem borer incidence was higher at Ludhiana.
2018
Relationships among the population abundance of four predator groups for rice insect pests, namely: carabid beetles, staphylinid beetles, green mirid bugs, and spiders in three landscape categories were evaluated. Both rice plots and the associated bund margins of these rice plots found among three Bangladesh landscape categories were sampled by sweep net. The results revealed that the abundance significantly varied across landscapes. The rice landscape of one location harbored higher numbers of a specific predator than other location in other regions of Bangladesh. The results also showed a dependency on the width of the rice bund margins of the rice plots, where spiders populations increased with increased bund widths, but the population abundance of these predators did not depend on the diversity of the number of weed species found on the rice bund margins. The relative abundance of predator populations also significantly differed among the three landscapes, with the green mirid ...