Hopper Control Research Articles

Insecticide Use against Desert Locust in the Horn of Africa 2019–2021 Reveals a Pressing Need for Change

The desert locust upsurge in the Horn of Africa over 2019–2021 led to a total of 1.6 million ha being treated with broad-spectrum organophosphate and pyrethroid insecticides in Ethiopia and Kenya, while insect growth regulators and the entomopathogenic fungus Metarhizium acridum were applied in Somalia. Environmental monitoring was largely absent, with limited surveys conducted in Kenya and Ethiopia. Overdosing of fenitrothion of a 960 g/L formulation in Kenya led to non-target mortality, including birds and honeybees. In Ethiopia, chlorpyrifos and malathion applications coincided with a honey production decline of 78% in 2020 compared to pre-upsurge levels. The use of M. acridum on nearly 253,000 ha was a breakaway from previous campaigns, in which its successful application in Somalia against both hopper bands and swarms shows that the persistent and pervasive use of organophosphate insecticides can no longer be justified. Furthermore, future procurement of organophosphate insecticides and possibly insect growth regulators could become increasingly problematic due to measures enacted by the European Union. It is recommended that the complementary impact of M. acridum and bird predation on locusts should be considered in an integrated management approach for both swarm and hopper control.

Comparative evaluation of some sprayers in control of leaf hoppers and aphids of cotton crop

An experiment was conducted to study the deposition characteristics and biological efficacy of some commonly used sprayers like manual gun sprayer, automatic gun sprayer and tractor operated boom sprayer to control some commonly found pests (leaf hopper and aphids) in cotton crop. Spray droplets were collected on water sensitive paper and analysed using DepositScan software to determine the size of droplets and droplet density. The field trials showed that, tractor operated boom sprayer provided better droplet deposition on the upper and underside of leaves with the largest droplet VMD (224 μm) and higher droplet densities (107.2 no's/cm2). However, its operating cost (Rs. 250.5/h) was higher than any of the other sprayers. The automatic gun sprayer produced more droplet densities and small droplets size (VMD) when compared to a manual gun sprayer. In the present study, tractor operated boom sprayer gave significantly better aphids (83.42%) and leaf hopper (85.61%) control than the gun sprayers. The least effective treatment was with the manual gun sprayer had 72.36 and 67.28% population reduction of leaf hopper and aphids.

Linear Quadratic Tracking With Reinforcement Learning Based Reference Trajectory Optimization for the Lunar Hopper in Simulated Environment

In this work, we provide a novel optimal guidance and control strategy for lunar hopper obstacle-avoidance, descent, and landing problem and demonstrate its behavior using numerical simulations. More specifically, the major contributions of this paper are three-fold: 1) proposed a feedback-based reference trajectory design for lunar hopper guidance, 2) developed the mathematical models and equations of linear quadratic tracking (LQT) controller for lunar hopper control, and 3) developed a method using reinforcement learning to optimize the designed reference trajectory in conjunction with the designed LQT controller, the so-called linear quadratic tracking with reinforcement learning based reference trajectory optimization (LQT-RTO). We demonstrated the LQT-RTO under a 2-dimensional (2D) lunar hopper simulation environment with 1) the LQT with heuristic reference trajectory design (LQT-HTD) and 2) reinforcement learning (reinforcement learning based controller, or RLC). We confirmed by numerical simulation that the LTQ-RTO outperformed the LQT-HTD in terms of fuel consumption, and outperformed the RLC in terms of landing success rate. Lastly, we provided theoretical interpretation to the simulation results.

The spider diversity and plant hopper control potential in the long-term organic paddy fields in sub-tropical area, China

Previous studies showed that organic farming augmented natural enemies and enhanced pest control in the agroecosystem, but the effect may change over time, as long-term application of different cultivation methods would gradually affect the agricultural systems. In this paper, spider diversity and its plant hopper control potential were assessed in paddy fields cultivated organically for 5 (OR5), 10 (OR10) and 15 (OR15) years and in conventional paddy fields (CR). The results showed that the abundance, richness and Pilou evenness of spiders in organic paddy fields were significantly higher than those in conventional paddy fields were, but no significant difference found between OR5, OR10 and OR15. There was no significant difference between Shannon Wiener index (H') of spiders in organic and conventional paddy fields. There was no distinct difference in spider assemblage composition between conventional and organic paddy fields, and a considerable overlap between the organic paddy fields with different organic farming period. Plant hopper was less abundant in organic paddy fields than conventional ones in rice blooming stage, but there was no difference in other rice growth stages. A higher number of the spider species in organic paddy fields had large temporal overlap with plant hopper than that in conventional fields. Adopting organic practices in paddy fields can maintain a high diversity of spiders across rice paddy ecosystems, although there was not significant increase of spider diversity over time after five years since transition.

THE ROLE OF MULTI-MEDIA APPROACH INI NARROWING THE KAP-GAPS AMONG THE FARMERS OF THE STRATEGIC EXTENSION CAMPAIGN IN MUDA IRRIGATION SCHEME

The purpose of the study was to determine whether the multi-media approach in the brown plant hopper (BPH) control management Strategic Extension Campaign (SEC) has narrowed the knowledge, attitude, and practice (KAP)-gaps among the farmers with low and high socio-economic status (SES) in the MADA area, Malaysia. The research was designed as the before and after campaign study.The KAP-survey results as the secondary data of the study, was the benchmark data of the before campaign study. Data of the after campaign study were gathered by means of personal interview with 189 farmers using the structured questionnaire.Findings reveal that KAP-level of both farmers with low and high-SES farmers on the technology of BPH control management had increased after the multi-media campaign. However, the multi-media approach of SEC had narrowed the KAP-gaps of these farmers. Therefore, the study found that the multi-media approach of the SEC is the appropriate approach in narrowing the KAP-gaps among the farmers.

Semi‐field evaluation of the effects of sub‐lethal doses of pesticides, with and without adult Schistocerca gregaria pheromone, on hoppers

AbstractPreviously, we reported a chain of effects induced by phenylacetonitrile, the gregarious‐phase adult cohesion pheromone of the desert locust, Schistocerca gregaria (Forskål) (Orthoptera: Acrididae), on conspecific hoppers. Specifically, the nymphs became hyperactive and displayed high levels of intraspecific predation, as surviving individuals gradually shifted to the solitary phase. The findings suggested that the pheromone could induce a significant level of mortality of the nymphs and predispose them to greater sensitivity to lower doses of insecticides. In this study, we compared the effects of the pheromone and various doses of three pesticides (fipronil, malathion, and carbosulfan) to pheromone‐exposed and unexposed crowd‐reared hoppers in semi‐field enclosures. The pheromone on its own displayed a high level of cumulative mortality of the nymphs (89%). Although combinations with fractional pesticide doses gave control efficiencies that were, in most cases, higher than with individual pesticides, pheromonal and pesticidal effects were only partially complementary, probably because of the feeding‐deterrent effects of the pesticides and the resulting reduction in cannibalism. However, our results demonstrate the possibility of significantly reducing the levels of pesticides used in hopper control and, thus, their negative environmental effects.

Development and Performance Evaluation of an Automatic Fish Feeder

Aquaculture, the process of raising aquatic animals in ponds, is gaining more attention in recent times. The feeding system is an important aspect of aquacultural practice. A simple, relatively inexpensive automatic fish feeder was designed, constructed and evaluated. The operation of the feeder does not require highly technical expertise. This paper reports the design considerations, materials used and the effectiveness of the device, based on analysis of manual feeding and automatic feeding. The main features of the device are: hopper (stainless steel), bi-directional motor, feed platform and electrical control box. The design was based on specific parameters which included capacity of culture tank, stocking density, fish biomass, diameter of the feed, angle of repose and bulk density (of the feed). The total cost of the device was 17,000 naira (approx. 106 U.S. dollars). The device was tested under two culture tanks (0.75 m3 each) with 10 kg-33 juvenile cat fish (Clarias gariepinus) placed in each tank with one feeding automatically and the other, manually. The feeder evaluation was based on feed conversion ratio (FCR) and feeding efficiency (FE). The total average gain in weight per fish was higher in the automatic feeding (89.50 g) than in manual (78.50 g). An FE of 20.9% was obtained in the automatic feeding and 18.6% in manual, in relation to their FCRs. A t-test, conducted at 5% significance level, indicated a significant difference in the two feeding methods.

Field evaluation for bio-efficacy of fenpyroximate 5 EC against leaf hopper and spider mite infesting cotton and their safety to natural enemies

Fenpyroximate 5 EC at two different doses viz., 25 and 37.5 g a.i. /ha along with imidacloprid 17.8 SL (20 g a.i. / ha) and dicofol 18.5 EC (500 g a.i. /ha) as standard checks for leaf hoppers and spider mites, respectively, were evaluated for bio-efficacy under field condition during Kharif 2012-13 and 2013-14. After three rounds of spraying initiating at ETL of leaf hopper (> 6 / 3 leaves) at 15 days interval, fenpyroximate 5 EC at both the doses @ 25 g a.i. /ha and 37.5 g a.i. / ha were found as effective as standard check imidacloprid 17.8 SL in leaf hopper control. For spider mites, fenpyroximate @ 37.5 g a.i. / ha was found as effective as standard check dicofol 18.5 EC sprayed twice at 15 days interval when mite populations was moderate (>10 mites/ leaf) during later stage of the crop. Between the two doses of fenpyroximate, lower dose (25 g a.i. / ha) was better for predator populations. Maximum seed cotton yield was obtained in fenpyroximate 5 EC @ 25 g a.i. / ha. No phytotoxicity symptoms were formed at higher dose viz., 37.5, 75 and 150 g a.i. /ha.

The Study of the Lock Hopper Control System

This thesis is the introduction of a certain Petro-chemical factory about the locked block hopper control system of reforming equipment. The equipment is controlled by the American TRICON control system completes together by American Honneywell DCS. installment's hard core - The catalyst regeneration unit and the unit interconnection part's control is completes in the TRICON control system, the data passes to the DCS control system through the serial port, the operators can monitor the situation. This design concept is applicable in the complex programmed control and operation in refinery.

Can Fish Control Planthopper and Leafhopper Populations in Intensive Rice Culture?

Planthoppers and leafhoppers are important rice pests. We tried to find out whether a polyculture of silver barb, common carp and Nile tilapia could control hoppers in intensively cropped rice fields. We used the data of five rice-fish experiments conducted between 1995 and 1998 at the Co Do rice-fish research station, Can Tho province, Mekong Delta, Vietnam. Our results showed that the number of Nilaparvata lugens (Stål), Sogatella furcifera (Horváth), Nephotettix virescens (Distant) and Recilia dorsalis (Motschulsky) was the same in fields with and without stocked fish. We concluded that the three stocked fish species are not able to control hopper numbers. Other, predatory fish species might be more effective in hopper control.

Automated wet feeding of weaner pigs versus conventional dry diet feeding -effects on growth rate and feed consumption

Poor feed intake of conventional dry diets in the immediate post-weaning period can be a major factor limiting potential growth rate in the young pig. Feeding systems based on the automatic dispensing of liquid milk -substitute have been developed over the last 10-15 years but they have not achieved widespread usage within the U.K. industry for various reasons. Several studies have shown, however, the potential benefit of offering liquid or slurry diets over this critical period around weaning (eg. English, Maclean and MacPherson 1988; Anon 1991). Deprez et a] (1987) also demonstrated its beneficial effects on the morphology of the small intestine post-weaning. The present study examined the use of an experimental automated feeder (‘Autofeeder’, patent applied for) which could dispense a conventional pelleted starter diet plus water (1:1 ratio) 6, 8, 12 or 24 times throughout the day in varying quantities. It was compared against a conventional dry hopper (control) with ad libitum feeding.

Insecticide Treatments for Bollworm and Cotton Flea Hopper Control, 1983

Abstract Cotton was planted 5 May on beds with 40-in. centers in plots three beds wide by 110 ft long. The experiment was designed and analyzed as a complete randomized block with three blocks and 10 treatments. Pesticides were applied with a self-propelled high clearance sprayer at 4 mph and a boom pressure of 30 lb/in2. Flat-fan nozzles ca. 12 in. above the plants were directed downward, spraying a broadcast pattern at a rate of 5.5 gaal per acre. Insecticides were applied on 6, and 27 July and 3 Aug. Three beat sheet samples (3 ft by 3 ft) were taken from one row per plot on 11 July and 1 and 8 Aug. Heliothis larval damage to squares was monitored on the same dates by examining 10 terminal squares per plot. Data for each variable were combined over the 3 dates and subjected to ANOV and means separation test (Bonferroni t tests).

Insecticide Treatments for Tarnished Plant Bug and Cotton Flea Hopper Control, 1982

Abstract Two insecticide evaluation studies were conducted at the Red River Valley Agricultural Experiment Station, Bossier City, LA, to examine the efficacy of various insecticides in controlling tarnished plant bugs and cotton flea hoppers on cotton. The effect of the various insecticides on beneficials was also examined. The first test was conducted on ‘DPL 61’ variety cotton planted May 5 on a combination Norwood loam and Norwood very fine sandy loam soil. The second test was conducted on ‘DPL 55’ variety cotton planted May 12 on a Latanier silty clay loam soil. Plots in both tests were 8 rows x 30.5 m (1.02 m centers) arranged in a randomized block design with 4 replications. Insecticides were applied with a high clearance sprayer equipped with a CO2 system for spraying small plots. Insecticides were applied in 11.4 liters of water with TX-3 hollow cone nozzles spaced 50.8 cm apart (2/row). Insecticides were applied Jun 14 in the first test and Jun 24 in the second test. Yields were taken Oct 10 only in the first test. Single 50-sweep samples/plot were taken in the first test to determine both pretreatment and post-treatment insect levels. In the second test, the pretreatment count was based on a single -50-sweep sample/plot while the 2 post-treatment counts were based on single 100-sweep samples/plot.

Bean Leaf Beetle and Threecornered Alfalfa Hopper Control on Soybeans in Alabama, 1982

Abstract This field test was conducted in soybeans planted on Vaiden soil at the Auburn Univ., Blackbelt Substation, Marion Jet., AL. Ten treatments and an untreated check were replicated 4 times in a randomized complete block design. Each of the .01-acre plots was 4 rows wide (36-in row spacing) and 37 ft long. Treatments were applied on Aug 31 with a CO2-pressurized sprayer equipped with 3 D-2 nozzles per row, operating at 30 psi, and delivering 22 gal/acre. Insect populations were sampled by placing a standard 3-ft beatsheet between the rows and beating the plants on both sides. Insects were identified, counted and recorded. Immature threecornered alfalfa hoppers (3CAH) were rated as small, medium, and large. Two samples from each plot were taken prespray (Aug 31) and 24 h, 72 h and 1 wk post spray (Sep 1, 3 and 7).

Strategies, systems, value judgements and dieldrin in control of locust hoppers.

The physiology and field biology of locusts have been extensively studied, and ecological control of Red Locusts has been investigated by field experiment. No fruitful or even promising non-insecticidal method of control has emerged. An effective and economical system requires an insecticide that is: (i) effective at very small area dosages, as a stomach poison placed on the natural vegetation can be, if it is also cumulative; (ii) persistent enough in sunshine and rain to retain effectiveness over the locust's non-feeding periods; (iii) capable of being well distributed by well-tried methods; and (iv) not dangerous to users or consumers and posing a minimal overall risk. Only one insecticide, dieldrin, satisfies all these requirements. Dieldrin is not in the small class of insecticides that are dangerous to man by skin absorption (such as parathion, arsenicals, DNC) and, at the area dosages needed for locust control, is not dangerous to stock. The Sayer exhaust sprayer in a Land Rover, with work rates of the order of square kilometres per hour is excellent for many situations; aircraft spraying at he rate of square kilometres per minute is quicker and less subject to difficulties of terrain, but requires trained and appropriately directed aircrew. Apart from checking, aircraft methods require no party on the ground to find, assess and control locust hoppers. Several ideas about dieldrin are found to be based on insufficient evidence and are probably not true: for example that dieldrin in the atmosphere at a few parts in a million million (10(12)) becomes concentrated in a food web and harmful to man, or that dieldrin is carcinogenic in man. It is noteworthy, however, that one species of antelope in South Africa is exceptionally susceptible to dieldrin poisoning, though harm occurs at area dosages considerably greater than are required in the method of aircraft spraying of Courshee & McDonald (1963). To attack tsetse flies, emissions two orders of magnitude greater have been used. Care must be taken with any insecticide, but the risks of using dieldrin as properly used in locust hopper control have been exaggerated by propaganda. If harm is to be expected, then a quantitative comparison of that with the undoubted benefits of locust control is required to enable one to make a value judgement.

Significant Developments in Rice Stem Borer and Leaf Hopper Control

(1967). Significant Developments in Rice Stem Borer and Leaf Hopper Control. Pest Articles & News Summaries. Section A. Insect Control: Vol. 13, No. 1, pp. 45-60.

The Effect of Climate and Weather on the Numbers of the Red Locust, Nomadacris septemfasciata (Serv.), in the Rukwa Valley Outbreak Area

An examination of the records from 1930 onwards shows that a very high level of Lake Rukwa is correlated with small numbers of the red locust, Nomadacris septemfasciata (Serv.), in the Rukwa Valley outbreak area in Tanganyika. When the lake level is not very high, the size of the adult locust population (taken as that present in the middle of the dry season) is correlated negatively with the total rainfall of the last but one wet season (broadly, November–May), positively with the size of the preceding parental population (taken as that present at the time of oviposition) and possibly also with the rainfall of the preceding October–December, but not significantly with the date of the drop in temperature that is thought to be associated with the start of ovarian development.Three tentative explanations of the correlation between adult population and rainfall are offered. First, if the water-table is high because of heavy rain in the previous season, the early rains may make the soil unsuitable for successful egg-laying and incubation; second, after a season of heavy rainfall the grass cover may be particularly dense at the end of the following dry season and the consequent reduction of the oviposition sites may make breeding unsuccessful; third, parental mortality may be high during a dry season following heavy rains. These possibilities are being further investigated.It is suggested that by using a multiple regression equation incorporating the correlations that have been established, the size of the adult locust population can be forecast in time for the scale of hopper control measures to be appropriately modified and economies thereby achieved.

Effectiveness of New Insecticides on the Potato Leafhopper and the Influence of Leafhopper Control and Potato Variety on Tuberworm Infestations1

In 11 experiments insecticides were screened as foliage sprays for insecticidal activity against the potato leafhopper, Empoasca fabae (Harr.), on Irish potatoes. Four weekly applications of Dc1nav@ (2, 3-p-dioxanedithiol s, s-his(O,O-diethyl phosphorodithioate). Sevin@ (l-naphthvl-N-methyl carbamate), and Thiodan @ (6,7,8,9,10,10-hexuchloro-l,5,.5a,6, 9,9a-hexahyd ro-6,9- methano-2,4,3-benzodioxathiepin-3-oxide) at dosages as low as 0.2 pound per acre were still highly effective 7 days after the last treatment, showing a 98% reduction in leaf hoppers at that time. Ethion, Guthion (O,O-dimethyl S-(4-oxo-3ll-1,2,3-benzotriazine- 3-methyl) phosphorodithioate), and Trithion@ (S-(p-chlorophenylthio) methyl O,O-diethyl phosphorodithioute) gave good results at 0.5 pound actual per acre. Diazinon@ (O,O- diethyl O-(2-isopropyl-4-lnethyl-6-pyrimidinyl) phosphorothioute), Dihroll@ (O,O-dimethyl-O-(l, 2,-dibromo-2,2-dichloroethyl phosphate), Dipterex@ (O,O-dimethyl 2,2,2-trichloro-l-hydroxy-ethylphosphonate), parathion, and Phosdrin'@ (l-methyloxycarhonyl- I-propen-2-yl dimethyl phosphate, 60% technical) applied at 0.5 pound actual per acre produced a high initial mortality but afforded only a limited residual action. DDT at 0.5 pound actual was quite effective but was inferior to Sevin, Thiodan, and a DDT-Dibrom combination. Aldrin, dieldrin, ami heptachlor did not give adequate leafhopper control. Observations in commercial plantings showed that damage by the potato tuber worm, Gnorimoschema operculella (Zell.), to tubers in the soil was directly influeneed by the degree of potato leaf hopper control and the potato variety. '11ere poor leafhopper control was obtained 63% of the Cobbler tubers were infested with tuber worms as compared with an infestation of only 1.5% in the Pungo variety. Tuber worm damage to Cobbler tubers was very light in fields receiving adequate leaf hopper protection.

Methods of Insecticide Application Against the Desert Locust

This paper was read at the Plant Protection Second International Conference, Fernhurst, 1956. It shows that insecticides may give poor or excellent kills of the desert locust, whether applied in baits for hopper control or sprayed from aircraft against adults in settled or flying swarms. Much depends on locust density and other factors affecting pick-up, and these must be taken into account if efficiency in control is to be improved.

Cotton Flea Hopper Control in 1936

Journal Article Cotton Flea Hopper Control in 1936 Get access K. P. Ewing, K. P. Ewing U. S. Department of Agriculture, Bureau of Entomology and Plant Quarantine Search for other works by this author on: Oxford Academic PubMed Google Scholar R. L. McGarr R. L. McGarr U. S. Department of Agriculture, Bureau of Entomology and Plant Quarantine Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 30, Issue 6, 1 December 1937, Pages 850–854, https://doi.org/10.1093/jee/30.6.850 Published: 01 December 1937