Behavioral effects induced by organic insecticides can be exploited for a sustainable control of the Orange Spiny Whitefly Aleurocanthus spiniferus

The Orange Spiny Whitefly (OSW) Aleurocanthus spiniferus (Hemiptera: Aleyrodidae) represents a new serious threat to Citrus spp., grapevine and ornamental plants in the whole Mediterranean area. Such threat urgently calls for the development of a sustainable control strategy, including insecticides compatible with biological control, and applicable also in organic citrus farming that represent an essential part of Mediterranean agricultural economy. Therefore, we evaluated the toxicity and the effects on host searching, oviposition, and probing and feeding behavior exerted on OSW by organic insecticides supposed to have limited side effects on environment and ecosystem services, i.e. sweet orange essential oil (EO), extract of Clitoria ternatea (CT), mineral oil, pyrethrin and azadirachtin. Despite none of the compounds caused a significant mortality of any of the OSW instars, we observed interesting effects on whitefly behavior: (i) EO and pyrethrin showed a relevant repellent effect, with impairment of both adults landing and oviposition on treated plants; (ii) CT and pyrethrin strongly affected probing behavior. Here, in the light of our findings, we discuss possible OSW sustainable control strategies and further research perspectives.

Comparative Efficacy of Common Active Ingredients in Organic Insecticides Against Difficult to Control Insect Pests

There exists a lack of control efficacy information to enable decision-making about which organic insecticide product works best for a given insect pest. Here, we summarize results of 153 field trials on the control efficacy of common active ingredients in organic insecticides against 12 groups of the most difficult to control insect pests. These trials evaluated primarily the organic products Entrust (spinosad), Azera (pyrethrin and azadirachtin), PyGanic (pyrethrin) and Neemix (azadirachtin), which reduced pest infestations by an overall 73.9%, 61.7%, 48.6% and 46.1% respectively, averaged across all trials. Entrust was the most effective control option for many insect pests, particularly providing >75% control of flea beetles, Colorado potato beetle, cabbageworms and alfalfa weevil, but was relatively ineffective against true bugs and aphids. Azera provided >75% control of green peach aphid, flea beetles, Japanese beetle, Mexican bean beetle, potato leafhopper and cabbageworms. PyGanic was less effective than Entrust and Azera but still provided >75% control of green peach aphid, flea beetles and potato leafhopper. The growth inhibition effects of azadirachtin in Neemix were particularly effective against larvae of Mexican bean beetle and Colorado potato beetle but was generally less effective in trials with insect infestations consisting mainly of adult stages. Those insect pests that were particularly difficult to control included thrips, stinkbugs, cucumber beetles and fruitworms. Several caveats pertaining to the application of the results are discussed.

Economic Effect of Insect Pest Management Strategies on Small-scale Tomato Production in Mississippi

Due to difficulty in monitoring insect pests, applications of insecticides are frequently conducted on a calendar schedule. However, seasonal variability in pest populations leads to these calendar schedules sometimes being inaccurate. Threshold-based insect management strategies, including use of thresholds with conventional pesticides and with use of organic pesticides only, were compared with a conventional calendar approach for yield, management cost, and production value of tomato (Solanum lycopersicum). Effect of cultivar was considered by inclusion of the long season cultivar Celebrity and the short season cultivar Early Girl Bush. These factors were compared for spring and fall seasons during two production years. Greatest total and marketable yields were obtained from use of conventional pesticides according to action thresholds. Use of organic insecticides according to thresholds did not affect yields in comparison with a calendar-based approach. Proportion of fruit rated unmarketable was greater with use of organic insecticides due to reduced efficacy and residual of control. Production costs for the organic threshold-based approach were greater due to increased number of insecticide applications required. Gross margin for both conventional and organic threshold-based insect pest management was greater than for the conventional calendar method. Increased economic return for conventional threshold-based management was due to increased yields. Increase in return for organic threshold management was based on premiums received for organically grown tomatoes. Adoption of conventional threshold-based insect pest management by small-scale producers has the potential to increase production efficiency and value, as well as increase environmental sustainability of production. Economic feasibility of organic production requires access to markets willing to pay significant premiums for organic produce. Further research to evaluate economic and yield impacts of production practices for small-scale farms is needed.

INORGANIC SUBSTANCES AND THEIR EFFECTS ON INSECTS

The return of interest in the use of inorganic substances as insecticides is associated with the development of resistance to traditional organic insecticides from the classes of organophosphorus compounds (OPs), carbamates and pyrethroids in populations of insect vectors of pathogens. In this regard, we have developed an insecticide based on a mixture of diatomaceous powder (DP) with silica gel, which is recommended primarily for controlling resistant populations of bed bugs, as well as German cockroaches, fleas, and crickets, and a special insecticide (a mixture of DP with boric acid) for controlling German and black cockroaches and crickets.

Novel nicotinoid structures for covalent modification of wood: an environmentally friendly way for its protection against insects

A novel and eco-friendly procedure for durable wood protection applying covalently bound organic insecticides is presented. Biological tests confirmed the effectiveness of the method, which also reduces the environmental impact.

Management of Eulophid Seed Borer, Anselmella kerrichi (Narayanan et al.) (Hymenoptera : Chalcidoidea : Eulophidae) on Jamun

A field experiment was conducted at ICAR-Indian Institute of Horticultural Research, Bengaluru during 2019 to evaluate certain insecticides and botanicals against jamun seed borer, Anselmella keriichi (Naryananet al.). The results revealed that the seed borer infestation was significantly low in –λ cyhalothrin (4.20%) and cypermethrin (5.77%) treatments followed by spinosad (6.36%), deltamethrin (6.40%) and imidacloprid (6.71%) (F=7.9; df=11; P<0.0001). Among the organic insecticides viz., spinosad @ 0.2 mL/L showed significant reduction in jamun seed borer infestation.