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The suborder Heteroptera (Hemiptera) includes zoophagous and zoophytophagous species which conform diverse natural enemies' systems with potential to control several horticultural pests. In this study, we report the assemblage structure of heteropteran bugs species inhabiting open-field and greenhouse organic tomato crops and one common adjacent non-crop solanaceous plant, Solanum sisymbriifolium, in North Buenos Aires province, Argentina, aimed to select promissory biocontrol species. Biweekly direct inspection of selected plants was carried out during a 3-year period (2017-2019) to collect hemipteran nymphs and adults. As a result, nine species and morphospecies belonging to Berytidae (zoophytophagous), Lygaeidae (phytophagous), and Miridae (phytophagous and zoophytophagous) were found, with ≥ 75% of species belonging to the latter family. The zoophytophagous mirid Tupiocoris cucurbitaceus (Spinola) was the most frequent and dominant species in all sites studied. Among the phytophagous species, Nysius simulans Stål was mostly present in greenhouse crops. The community found in greenhouse tomato crops was more diverse than that registered in open-field crops. The characterization of the heteropteran complex in organic tomato farms provides basic knowledge necessary to design pest control strategies in the region studied.

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Phytoseiid predatory mites are efficient biocontrol agents of important thrips pests, such as the western flower thrips, Frankliniella occidentalis Pergande (Thysanoptera: Thripidae). Until recently, it was believed that first instars, and to a lesser extent second instars, were the most vulnerable developmental stages of thrips to be attacked by phytoseiids. However, recent evidence showed that some phytoseiids can detect and prey upon thrips eggs inserted in the leaf tissue. As phytoseiid predatory mites often co-occur with other beneficial insects, such as mirid and anthocorid predatory bugs which also insert their eggs inside leaf material, this raises the question whether phytoseiid predatory mites may also feed on predatory bug eggs. Here we first tested the potential of Amblyseius swirskii Athias-Henriot, Transeius montdorensis Schicha, and Amblydromalus limonicus Garman and McGregor (Acari: Phytoseiidae) to kill eggs of F. occidentalis in leaf tissue. Secondly, we tested whether those phytoseiids were capable of killing eggs of Orius laevigatus Fieber (Hemiptera: Anthocoridae), Macrolophus pygmaeus Rambur and Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae), three biocontrol agents that also insert their eggs inside plant tissue. Our results showed that A. swirskii and A. limonicus could kill thrips eggs, whereas T. montdorensis could not. Furthermore, we show that the presence of phytoseiid predatory mites does not affect the hatch rate of predatory bugs that insert their eggs inside leaves.

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The invasive Drosophila suzukii feeds and reproduces on various cultivated and wild fruits and moves between agricultural and semi-natural habitats. Hedges in agricultural landscapes play a vital role in the population development of D. suzukii, but also harbor a diverse community of natural enemies. We investigated predation by repeatedly exposing cohorts of D. suzukii pupae between June and October in dry and humid hedges at five different locations in Switzerland. We sampled predator communities and analyzed their gut content for the presence of D. suzukii DNA based on the COI marker. On average, 44% of the exposed pupae were predated. Predation was higher in dry than humid hedges, but did not differ significantly between pupae exposed on the ground or on branches and among sampling periods. Earwigs, spiders, and ants were the dominant predators. Predator communities did not vary significantly between hedge types or sampling periods. DNA of D. suzukii was detected in 3.4% of the earwigs, 1.8% of the spiders, and in one predatory bug (1.6%). While the molecular gut content analysis detected only a small proportion of predators that had fed on D. suzukii, overall predation seemed sufficient to reduce D. suzukii populations, in particular in hedges that provide few host fruit resources.

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New hosts and parasitism notes for the mite Leptus (Acari: Erythraeidae) in Brazil. Larval erythraeid mites are common ectoparasites of harvestmen (Opiliones). Studies describing insects as potential hosts have received little attention. Specimens of an undescribed species of the genus Leptus were collected in association with predatory and phytophagous Heteroptera bugs in a secondary forest in Viçosa, Minas Gerais state, Brazil. New mite-host records and information on seasonality of this mite are presented.

Há novos hospedeiros e notas sobre o parasitismo do ácaro Leptus (Acari: Erythraeidae) no Brasil. As larvas de ácaros da família Erythraeidae são ectoparasitas comuns de opiliões (Opiliones). Estudos de insetos como potenciais hospedeiros de ácaros eritraídeos são escassos. Indivíduos de uma espécie nova do gênero Leptus foram coletados em associação com percevejos fitófagos e predadores (Heteroptera) em uma floresta secundária no município de Viçosa-Minas Gerais, Brasil. São apresentadas informações sobre a sazonalidade e o registro de hospedeiro desse ácaro do gênero Leptus.

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