Christos I. Rumbos

Management of the Pine Processionary Moth, Thaumetopoea pityocampa (Lepidoptera: Thaumetopoeidae), in Urban and Suburban Areas: Trials With Trunk Barrier and Adhesive Barrier Trap Devices

Abstract In urban and suburban areas larvae of the pine processionary moth, Thaumetopoea pityocampa (Denis and Schiffermüller), cause serious defoliation to Cedrus, Pinus, and Pseudotsuga trees and health problems to humans and domestic or farm animals by their urticating setae. In this study, we present the results of biennial trials (2015–2016) on the management of T. pityocampa infestations using commercial or LIFE-PISA prototype trunk barrier and adhesive trap devices in Greece (Attica and Volos), Spain (Valencia), and Italy (Molise). In Attica, for both 2015 and 2016, the commercial trunk barrier trap devices captured significantly more T. pityocampa wintering migrant larvae compared to the adhesive barrier trap devices, indicating their high capture capacity. The total performance of the trunk barriers trap devices was 99.8% in 2015 and 99.6% in 2016. In Volos and Valencia, no significant differences were recorded between captures in commercial and LIFE-PISA prototype trunk barrier trap devices. In the tests that were conducted in Molise, the commercial trunk barrier trap devices exhibited high effectiveness in capturing the wintering migrant larvae during their procession, before they reach the ground for pupation. Moreover, significantly fewer male adults were captured by pheromone trap devices during summer 2016 in comparison with 2015 in the experimental area. Similarly, significantly fewer nests were formed on the experimental area trees in winter 2016 and 2017 compared with 2015. Our results show the potential of the trunk barrier trap devices in the management of T. pityocampa numbers after long-term application in urban and suburban areas.

Delivering Beauveria bassiana with electrostatic powder for the control of stored-product beetles

BACKGROUND The efficacy of a Beauveria bassiana-based formulation (Bb38) with Entostat, an electrostatically charged powder, was investigated as a surface treatment against Cryptolestes ferrugineus, Oryzaephilus surinamensis and Sitophilus granarius adults. In lab bioassays, the efficacy of Bb38 against the aforementioned species was examined on concrete, plywood, steel and ceramic, whereas its residual efficacy against the same species was assessed on concrete and steel in the presence or absence of illumination. Finally, the efficacy of Bb38 against O. surinamensis and S. granarius adults was assessed in a commercial grain storage facility under realistic field conditions. RESULTS In the lab trials, O. surinamensis and C. ferrugineus were much more susceptible to Bb38 than S. granarius on all types of surfaces. Moreover, Bb38 was, at least for O. surinamensis and C. ferrugineus, as effective as the chemical standard (deltamethrin) for at least 2 months after the application, regardless of the presence or absence of illumination. Finally, in the field trial Bb38 provided a satisfactory level of control against O. surinamensis. CONCLUSION Bb38 is an effective surface treatment, but its efficacy varies according to the target species, the type of surface and the time post-application. This is the first published report that examines the efficacy of Bb38 as a surface treatment for wider uses in empty warehouses and related storage facilities.

The use of entomopathogenic nematodes in the control of stored-product insects

This review highlights the latest findings regarding the use of entomopathogenic nematodes against post-harvest insects. Due to their requirements for moisture, entomopathogenic nematodes had received, until lately, limited attention for application to the dry storage environment. Recent improvements of their formulation and application approaches, as well as the discovery of new, more virulent strains have enhanced the efficacy of entomopathogenic nematodes and renewed interest in using entomopathogenic nematodes in the stored-product environment. The nematode species tested against storage insects belong exclusively to the genera Steinernema and Heterhorhabditis. The virulence of entomopathogenic nematodes against post-harvest insects varies depending on the nematode species and strain. Usually, only a single-nematode species or strain is not equally effective against all major stored-product insect pests; therefore, one nematode strain or species cannot be suitable for controlling all species present in the storage environment, where several insect species coexist. The successful application of entomopathogenic nematodes in storage environments for controlling post-harvest insects is highly dependent on several biotic and abiotic factors, such as the host life stage, temperature, and relative humidity. Entomopathogenic nematodes have still to overcome substantial hurdles to become a reliable alternative for commercial applications in warehouses and storage facilities. However, the use of innovative, enhanced methods of formulation and application, such as encapsulation or bait traps, could boost the exploitation of entomopathogenic nematodes in storage facilities against post-harvest insects.

Use of entomopathogenic fungi for the control of stored-product insects: can fungi protect durable commodities?

Entomopathogenic fungi are considered promising microbial control agents for the control of post-harvest insects, and their evaluation for this purpose has lately attracted a significant amount of research. They are naturally occurring, environmentally safe organisms that infect insects by contact. Insect fungal pathogens have a broad spectrum of hosts, can be mass-produced easily, rapidly and economically and can be applied with the same technical means as conventional contact insecticides. In this context, the most studied fungal species for the control of stored-product insect species are Beauveria bassiana and Metarhizium anisopliae. Both fungal species have a wide host range and have been tested against most of the major stored-product insect pests. The effect of biotic and abiotic factors on the virulence and success of entomopathogenic fungi in storage insect control, as well as the combined application of these agents with other pest control technologies, is reviewed here. Temperature and relative humidity influence the efficacy of entomopathogenic fungi, often with variable results, whereas the combined use of entomopathogenic fungi with diatomaceous earth in many cases has a synergistic or additive effect. Alternative methods of entomopathogenic fungi application, based on the lure-and-kill approach, are proposed, and future challenges for the use of entomopathogenic fungi against stored-product insects are highlighted.

Effect of the combined application of microencapsulated synthetic oviposition pheromone (MSP) with different larvicidal agents on the oviposition of Culex pipiens biotype molestus

BACKGROUND Attract-and-kill strategies, in which a behavior-modifying stimulus (e.g. a pheromone) is integrated with a pest control agent, have lately attracted increased interest for mosquito control. Previously, it was demonstrated that the polyurea microencapsulated synthetic oviposition pheromone 6-acetoxy-5-hexadecanolide (MSP) was sufficiently attractive to gravid females of Culex pipiens L. biotype molestus Førskal (Diptera: Culicidae) for a period of 40 days. Furthermore, it was shown that MSP could be effectively combined with the organophosphate temephos to achieve efficient mosquito control. In the present study, the effect of the combined application of MSP with commonly used larvicides on the oviposition response of Cx. p. biotype molestus females over time was investigated in two-choice oviposition bioassays. As larvicides, the insect growth regulator diflubenzuron and the bacterial insecticide spinosad were evaluated at their lowest recommended label dose, whereas temephos was used as a control. RESULTS When MSP was applied in combination with diflubenzuron, the attractancy of MSP to gravid females was in all cases negatively affected, as fewer egg rafts were laid in pots treated with MSP and diflubenzuron compared with MSP alone. Spinosad did not reduce, but rather increased, the attractive effect of the oviposition pheromone at the beginning of the bioassay (at 2 days of ageing) when co-applied; however, the observed attractive effect was significantly reduced after 7 days of ageing and remained stable at the same level until the termination of the bioassay. Finally, the oviposition pattern of egg rafts laid on the pot with MSP and temephos was similar to that of egg rafts laid on the pot with MSP alone, showing that temephos did not significantly affect MSP activity. CONCLUSION The results of the present study highlight the effects of the combined application of MSP with spinosad and diflubenzuron on the oviposition of gravid Cx. p. biotype molestus females, which in most cases eliminated the attractive effect of MSP.

Emerging Pests in Durable Stored Products

The term “emerging pest” has been used many times with different meanings in the pre-harvest, as well as in the post-harvest stages of agricultural production.

Influence of Temperature and Relative Humidity on the Insecticidal Efficacy of Metarhizium anisopliae against Larvae of Ephestia kuehniella (Lepidoptera: Pyralidae) on Wheat

A series of laboratory bioassays were conducted for the evaluation of the insecticidal efficacy of an isolate of Metarhizium anisopliae (Metschnikoff) Sorokin (Ascomycota: Hypocreales) against larvae of the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), under various temperature–relative humidity (r.h.) conditions. The fungus was applied at four doses (0, 8 × 106, 8 × 108, and 8 × 1010 conidia ml−1) on wheat and insect mortality was assessed after exposure of 1, 2, 7, and 14 d. Bioassays were conducted at three temperatures (20, 25, and 30 °C) and two r.h. levels (55 and 75%). Although complete control was not achieved in any case, the fungus provided a considerable level of insect control. Mortality of E. kuehniella larvae on wheat treated with M. anisopliae ranged between 41.1 and 93.3% after 14 d of exposure, whereas the respective mortality levels in control dishes never exceeded 28.3%. The increase of temperature resulted in most cases to higher efficacy, indicating that temperature is an important factor for the performance of the fungus. In contrast, in most cases r.h. did not significantly affect the efficacy of the fungus, at least for the humidity levels tested.