Plant viruses induce plant volatiles that are detected by aphid parasitoids.

Aphis gossypii (Sternorrhyncha: Aphididae) aphids are vectors of important plant viruses among which cucumber mosaic virus (CMV) and potato virus Y (PVY). Virus-infected plants attract aphid vectors and affect their behavior and growth performance either positively or negatively depending on mode of transmission. Viruses cause changes in the composition and the amount of volatile organic compounds (VOCs) released by the plant that attract aphids. The aphid parasitoid Aphidius colemani (Hymenoptera: Aphelinidae) has been shown to have higher parasitism and survival rates on aphids fed on virus-infected than aphids fed on non-infected plants. We hypothesized that parasitoids distinguish virus-infected plants and are attracted to them regardless of the presence of their aphid hosts. Herein, we examined the attraction of the A. colemani parasitoid to infected pepper plants with each of CMV or PVY without the presence of aphids. The dynamic headspace technique was used to collect VOCs from non-infected and CMV or PVY-infected pepper plants. Identification was performed with gas chromatography-mass spectrometry (GC-MS). The response of the parasitoids on virus-infected vs non-infected pepper plants was tested by Y-tube olfactometer assays. The results revealed that parasitoids displayed a preference to CMV and PVY infected plants compared to those that were not infected.

Oviposition-Induced Volatiles Affect Electrophysiological and Behavioral Responses of Egg Parasitoids.

In response to an attack by herbivores, plants emit a variety of compounds that may act as semiochemicals. Oviposition-induced volatiles (OIPVs) have been shown to mediate interactions between plants and natural enemies. Here, we investigated the role of OIPVs by Tuta absoluta towards two egg parasitoids, Trichogramma cordubense and T. achaeae. We collected headspace volatiles from tomato plants at 24, 48, and 72 h after oviposition by T. absoluta females and tested the antennographic response of Trichogramma parasitoids to them by means of gas chromatography- electro-antennographical detection (GC-EAD). The response of the parasitoids was also tested in behavioral experiments using a Y-tube olfactometer. Oviposition by T. absoluta females induced qualitative and quantitative changes in the volatiles emitted by tomato plants. Antennae of Trichogramma parasitoids responded to several of the induced volatiles in GC-EAD. T. cordubense females were attracted to tomato plants with T. absoluta eggs 24 h after oviposition. The elucidation of the behavior of egg parasitoids towards OIPVs enhances the development of sustainable management strategies either by selecting species that exploit OIPVs or by manipulating their foraging behavior by utilizing specific OIPVs that are used by parasitoids as a host location.

Data on the scale insect (Hemiptera: Coccomorpha) fauna of Greece, with description of two new species.

Surveys of the scale insect (Hemiptera: Coccomorpha) fauna of Greece were carried out in 2013 and 2014. Altogether 93 scale insect species were collected, belonging to 11 families. Thirty-eight species (41%) proved to be new to the Greek fauna, including two species new to science (Anophococcus hellenicus Kaydan & Szita sp. n. (Acanthococcidae) and Iberococcus attikus Szita & Fetykó sp. n. (Pseudococcidae)), and two introduced invasive species (Phenacoccus graminicola Leonardi and Pseudococcus comstocki (Kuwana), both Pseudococcidae). The rest of the species seem to be native to the Greek fauna. The total number of scale insect species recorded from Greece is increased to 253.

Sublethal effects of the insecticidal fusion protein ω-ACTX-Hv1a/GNA on the parasitoid Eulophus pennicornis via its host Lacanobia oleracea.

BACKGROUND: The neurotoxin peptide ω-ACTX-Hv1a, fused to the carrier molecule GNA, presents potential for insect control as a biopesticide, being orally toxic to insect pests from different orders. However, thorough evaluation is required to assure its safety towards non-target invertebrates. Effects of this novel biopesticide on the parasitoid Eulophus pennicornis via its host Lacanobia oleracea are presented. RESULTS: Hv1a/GNA did not cause mortality when injected or fed to fifth-stage L. oleracea, but caused up to 39% reduction in mean larval weight (P < 0.05) and increased developmental time when injected. When fed, GNA, but not Hv1a/GNA, caused ∼35% reduction in larval weight, indicating that host quality was not affected by the fusion protein. Although GNA and Hv1a/GNA were internalised by the hosts following ingestion, and thus were available to higher trophic levels, no significant changes in the rate of E. pennicornis parasitism occurred. Number of parasitoid pupae per host, adult emergence and sex ratio were unaffected by GNA- or Hv1a/GNA-treated hosts (P > 0.05). The fusion protein was degraded by parasitoid larvae, rendering it non-toxic. CONCLUSION: Hv1a/GNA has negligible effects on the parasitoid, even under worst-case scenarios. This low toxicity to these insects is of interest in terms of biopesticide specificity and safety to non-target organisms.