Compatibility between chemical insecticides and nematodes against Drosophila

07 Nov 2024
2682

The productivity of small fruits, such as cherries (but not only), is greatly reduced by the insect Drosophila suzukii (Diptera: Drosophilidae). This pest can be controlled either by chemical insecticides or by the use of entomopathogenic nematodes. These nematodes are easy to apply because they can be mixed in tanks together with other plant protection products (chemical, natural and biological), fertilisers and soil conditioners. 

Obviously, the action of pesticides on entomopathogenic organisms varies depending on the species and lineage of the nematodes and the chemical nature and concentrations of the products used. This is why the compatibility of the two methods requires further investigation. 

The aim of the study carried out in collaboration between Brazilian and Argentinian research institutes was to assess the compatibility of Steinernema brazilense (IBCBn 06), S. carpocapsae (IBCBn 02), Heterorhabditis amazonensis (IBCBn 24) and H. bacteriophora (HB) with different chemical insecticides for the control of D. suzukii pupae, as well as to monitor the longevity of surviving adult insects.

Longevity of Drosophila suzukii adults exposed to a combination of insecticides and H. amazonensis IBCBn 24 or H. bacteriophora HB. Source: Sergio da Costa Dias et al., 2024 

In contrast, S. carpocapsae was more sensitive to exposure to Malathion, Abamectin, Azadirachtin, Deltamethrin, Lambda-cyhalothrin and Spinetoram. Fosmet was compatible with all nematode species during infectivity bioassays, with minimal changes in infectivity and efficiency compared to treatment with nematodes alone. In contrast, Lambda-cyhalothrin generally reduced nematode infectivity on D. suzukii pupae, with a reduction in efficiency of up to 75 %. 

The second study compared pupae mortality induced by the two most compatible nematode species and five insecticides in different combinations. When used alone, both Heterorhabditis species caused 78-79% mortality of D. suzukii pupae. They were also tested in combination with Spinetoram, Malathion, Azadirachtin, Fosmet or Novaluron at a dose of one quarter. Importantly, H. bacteriophora showed an additive effect on D. suzukii pupae, resulting in a 79% mortality rate when used alone and 89% when combined with Spinetoram. 

Combined with Novaluron, however, the number of infectious nematodes was significantly reduced to 270 in H. amazonensis and 218 with H. bacteriophora. The lifespan of adult flies emerging from pupae treated with entomopathogenic nematodes was significantly shorter than that of untreated pupae. The combined use of Heterorhabditis and compatible chemical insecticides was promising, with the exception of Novaluron. 

In conclusion, most of the nematode-insecticide combinations evaluated did not compromise the viability of the nematodes, which remained viable with high infectivity rates. In an integrated pest management approach, the use of insecticides in combination with some Brazilian entomopathogenic nematode isolates is promising against D. suzukii.

Sourcee: Dias, S.d.C.; de Brida, A.L.; Jean-Baptiste, M.C.; Leite, L.G.; Ovruski, S.M.; Lee, J.C.; Garcia, F.R.M. Compatibility of Entomopathogenic Nematodes with Chemical Insecticides for the Control of Drosophila suzukii (Diptera: Drosophilidae). Plants 2024, 13, 632. https://doi.org/10.3390/plants13050632

Melissa Venturi
University of Bologna (IT)


Cherry Times - All rights reserved

What to read next

Dark-skinned cherries: a boon for gut and brain health

Health

03 Apr 2026

Dark sweet cherries improve gut microbiota, reduce inflammation, and support memory and focus. Scientific studies highlight benefits for metabolism and cognitive health, especially in higher-risk individuals and widespread metabolic conditions, with growing scientific validation.

Tree training in narrow orchard systems: the NOS project in Australia

Planting systems

23 Sep 2025

Advanced tree training techniques in narrow orchard systems: shoot removal, horizontal cordons and vertical leaders for cherry, plum, apple, pear and nectarine. The NOS project operates in Victoria, South Australia, Western Australia and NSW with multiple trial sites.

In evidenza

The Chilean cherry season has started early, but with a 50 per cent drop in the earliest-ripening areas

Processed

02 Oct 2026

In Coquimbo, Chile, the cherry harvest could begin between October 10 and 15, one of the earliest dates ever recorded in the region. Production is expected to fall by 50%, while larger fruit, higher sugar levels and access to new markets could support growers this season.

How real-time tracking maintains and protects the quality of cherries

Post-harvest​

02 Oct 2026

In New Zealand, real-time monitoring with IoT sensors helps cherry growers track temperature and humidity during transport, prevent spoilage, reduce food waste and preserve quality and freshness from the orchard to the market throughout the entire cold-chain journey.

Tag Popolari