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To date, direct interactions between pests and natural enemies are often considered in biocontrol programs. Recently there has been an increase of evidence for the importance of third-party mediated indirect interactions in determining the population dynamics of insects. Predicting the strength of such interactions remains a central challenge in biocontrol assessments. Here, two field experiments were performed in two years to investigate to which extent Dysaphis plantaginea Passerini, Aphis pomi De Geer, and Myzus cerasi Fabricius might indirectly interact through shared natural enemies and ants. We first studied the population dynamics of target insects in isolated orchards of apples and cherries. Secondly, we investigated how the spatial coexistence of aphid-infested cherries can indirectly affect the population dynamics of apple aphids via natural enemies and ants. In the first experiment, nine parasitoid species were recorded on apple and cherry aphids, among them were three species in common. Six predatory families were found on cherry and apple aphids, while only one ant species, Lasius niger L., was found associating with these aphids. In the second experiment, temporal variation in the natural enemy-mediated apparent competition between M. cerasi and apple aphids was found. The cherry aphid is likely to be an important source of natural enemies that attack apple aphids early in the season. Significantly reduced numbers of ants associating with apple aphids in the intercropping habitat were found. Our results emphasize the importance of considering indirect interactions in the designing of pest management strategies. [ABSTRACT FROM AUTHOR]

Background: Spotted wing drosophila (SWD), Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), is a pest of stone and small fruits causing considerable economic losses. Current management strategies rely primarily on calendar‐based spraying, owing to the poor relationship between monitoring data and damage levels, and the lack of success of mass‐trapping tools. The aim of this study was to evaluate different trap models for SWD, with an emphasis on their fly‐retention capacity. To this end, we examined and quantified the added value of two fly‐retaining trap features; tunnel entries to impede escape and an insecticide‐coated inner surface as a killing agent. Results: An insecticide‐coated inner surface resulted in significantly higher trap retention after 24 h in the laboratory (4.9‐ to 7.4‐fold greater, depending on trap type) compared to a noncoated trap. Trapping efficacy was significantly improved in field trials by such a killing agent in the trap (1.2‐ to 4.5‐fold greater). Tunnel entries significantly improved trap retention in the laboratory and field (by 1.5‐fold). Conclusion: The outcomes of this study clearly reveal the substantial impact of the fly‐retention capacity of SWD traps on their overall capture performances. It was demonstrated for the first time that an insecticide‐coated inner surface as a killing agent significantly improves trap efficacy for SWD. This finding can readily be implemented in any trap model to improve monitoring and mass trapping of SWD. Also tunnel entries were shown to have a significant influence on the fly retention and, hence, substantially enhance trapping efficacy. [ABSTRACT FROM AUTHOR]

During the purification of trypsin­modulating oostatic factor (TMOF) of the grey fleshfly Neobellieria bullata, a new factor with oostatic activity was discovered. We report herein its purification, primary structure and effects on oocyte development. Its amino acid sequence was determined as H-SIVPLGLPV-PIGPIVVGPR-OH. Due to structural sequence similarities with parts of several known collagens and its oostatic activity, we named it Neb­colloostatin. The synthetic peptide inhibits yolk uptake by previtellogenic oocytes and might have a role in the absence of yolk deposition in penultimate oocytes. Nebcolloostatin does not inhibit trypsin biosynthesis in the gut or ecdysone biosynthesis by larval ring glands. It decreases vitetlogenin concentrations in the hemolymph by an unknown mode of action. The role of extracellular matrix proteins in the feedback control of growth is discussed. [ABSTRACT FROM AUTHOR]

Trypsin mRNA from the grey fleshfly (Neobellieria bullata) was reverse transcribed and amplified by means of PCR. Two cDNA species of 600 bp and 800 bp were cloned and sequenced. The 3' end of the gene (300 bp) was amplified by means of the rapid-amplification-of-cDNA-ends method, cloned and sequenced. The deduced protein sequence of 254 amino acids exhibited 46% identity to Drosophila trypsin and 32% identity to Anophiline trypsin and Aedes trypsin. Three-dimensional models of Neobellieria trypsin and Drosophila trypsin were built and compared. Both models contain two domains of β-barrel sheets as was shown by means of X-ray crystallography of mammalian trypsin. The catalytic active site is composed of the canonical triad of His42, Asp87 and Serl 82 whereas Aspl 76 sits at the bottom of the specificity pocket. Southern blot analysis suggested that Neobellieria trypsin is encoded by one gene. Northern blot analysis showed that an early trypsin transcript is found in the midgut of sugarfed females. This message disappeared after a liver meal, and was replaced by a late transcript. Injection of trypsin-modulating oostatic factor (TMOF) at 10-9M prevented the disappearance and the translation of the early transcript. TMOF did not prevent the appearance of the late transcript. However, in the presence of the hormone the late transcript was not translated. Thus, TMOF is the biological signal that terminates the translation of trypsin mRNA in the fleshfly gut and probably in the mosquito gut. [ABSTRACT FROM AUTHOR]

Background: Spotted wing drosophila (SWD), Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), is a pest of stone and small fruits causing considerable economic losses. Current management strategies rely primarily on calendar-based spraying, owing to the poor relationship between monitoring data and damage levels, and the lack of success of mass-trapping tools. The aim of this study was to evaluate different trap models for SWD, with an emphasis on their fly-retention capacity. To this end, we examined and quantified the added value of two fly-retaining trap features; tunnel entries to impede escape and an insecticide-coated inner surface as a killing agent., Results: An insecticide-coated inner surface resulted in significantly higher trap retention after 24 h in the laboratory (4.9- to 7.4-fold greater, depending on trap type) compared to a noncoated trap. Trapping efficacy was significantly improved in field trials by such a killing agent in the trap (1.2- to 4.5-fold greater). Tunnel entries significantly improved trap retention in the laboratory and field (by 1.5-fold)., Conclusion: The outcomes of this study clearly reveal the substantial impact of the fly-retention capacity of SWD traps on their overall capture performances. It was demonstrated for the first time that an insecticide-coated inner surface as a killing agent significantly improves trap efficacy for SWD. This finding can readily be implemented in any trap model to improve monitoring and mass trapping of SWD. Also tunnel entries were shown to have a significant influence on the fly retention and, hence, substantially enhance trapping efficacy., (© 2020 Society of Chemical Industry.)