Evaluation of the Effect of Fungatol and Gamma-T-ol on the Emergence and Adult Parasitoid Survival of Mummies of Cotton Aphids Parasitized by Aphidius colemani

Beneficial insects play a major role in controlling pest populations. In sustainable agricultural production systems, control methods compatible with integrated pest management (IPM) are preferred over broad-spectrum pesticides. EOs from aromatic plants may provide a new and safe alternative to synthetic chemicals. In this research, the efficacy of Fungatol, Gamma-T-ol, Fungatol plus neem, and Gamma-T-ol plus neem was evaluated against Aphidius colemani Viereck (Hymenoptera: Braconidae; Aphidiidae), the parasitoid of the cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae). Under laboratory and greenhouse conditions, five different concentrations of each formulation were applied to parasitized mummies and adult parasitoids. Results for parasitoid emergence from aphid mummies sprayed with different concentrations of Fungatol, Gamma-T-ol, Fungatol plus neem, and Gamma-T-ol plus neem in the laboratory and glasshouse showed that the formulations did not adversely affect adult emergence as rates above 60% were observed. For residual toxicity tests done by exposing adult parasitoids to a fresh, dry biopesticide film sprayed on glass plates, less than 20% mortality was observed after 48 h of exposure. Adult longevity tests revealed that the highest concentrations of some of the formulations evaluated were slightly toxic to A. colemani. According to the IOBC rating, our results indicated that most of the tested concentrations for each formulation were harmless to A. colemani. Based on the above results, it may be proposed that the formulations evaluated in this study are potential botanical pesticide candidates for incorporation into an IPM program.

Biocontrol in practice in Canadian floricultural greenhouses

The environment inside Canadian prairie greenhouses differs from greenhouses built in other northern latitude locations in terms of lighting, temperature, humidity, and photoperiod. Since the performance of biocontrol agents depends upon several interactive environmental variables, their effectiveness to control pests in a particular crop growing under certain climatic conditions does not directly translate to another crop or location. So, we analyzed research trials assessing the efficacy and compatibility of various biocontrol agents (Amblyseius cucumeris, Amblyseius cucumeris, Phytoseiulus persimilis, Encarsia formosa, Aphidius colemani, Aphidius ervi, and Steinernema feltiae) on key pests (Western flower thrips, two-spotted spider mites, greenhouse whiteflies, and aphids) of spring bedding plants grown in a commercial floricultural greenhouse. Were analyzed several compatible combinations of biocontrol agents and observed a significant reduction in pest densities and plant damage symptoms as compared to untreated control plants. The results demonstrate that P. persimilis controlled two-spotted spider mites successfully in calibrachoa crop. The combination of Amblyseius cucumeris and S. feltiae resulted in significantly better control of Western flower thrips than the use of Amblyseius cucumeris alone in sweet potato vine plants. The application of E. formosa and Amblyseius cucumeris individually reduced greenhouse whiteflies on calibrachoa plants as compared to control, but their combination performed better resulting in a significantly lower number of whiteflies on plants. Another combination of Aphidius colemani and Aphidius ervi controlled green peach aphids and foxglove aphids effectively on the pansy crop. The biocontrol agents were effective for managing a variety of pests in a commercial greenhouse setting.

Developmental Temperature Affects Life-History Traits and Heat Tolerance in the Aphid Parasitoid Aphidius colemani

Developmental temperature plays important roles in the expression of insect traits through thermal developmental plasticity. We exposed the aphid parasitoid Aphidius colemani to different temperature regimes (10, 20, or 28 °C) throughout larval development and studied the expression of morphological and physiological traits indicator of fitness and heat tolerance in the adult. We showed that the mass decreased and the surface to volume ratio of parasitoids increased with the development temperature. Water content was not affected by rearing temperature, but parasitoids accumulated more lipids when reared at 20 °C. Egg content was not affected by developmental temperature, but adult survival was better for parasitoids reared at 20 °C. Finally, parasitoids developed at 20 °C showed the highest heat stupor threshold, whereas parasitoids developed at 28 °C showed the highest heat coma threshold (better heat tolerance CTmax1 and CTmax2, respectively), therefore only partly supporting the beneficial acclimation hypothesis. From a fundamental point of view, our study highlights the role of thermal plasticity (adaptive or not) on the expression of different life history traits in insects and the possible correlations that exist between these traits. From an applied perspective, these results are important in the context of biological control through mass release techniques of parasitoids in hot environments.

Capsella bursa-pastoris Is a Key Overwintering Plant for Aphids in the Mediterranean Region

The reproduction of aphids depends to a great extent on their host plants, an integration that impacts on the successful expansion of overwintering populations. Therefore, a survey was conducted to evaluate the globally distributed Capsella bursa-pastoris as an overwintering host of economically important aphid species, their parasitoids and hyperparasitoids in the southern and western regions of Turkey from November to March in 2006 to 2013. During this survey, 395 samples of C. bursa-pastoris were collected with 25 aphid species recorded. Among aphids that feed on this host, Myzus persicae, Aphis gossypii, Rhopalosiphum padi, Aphis fabae, Aphis craccivora, Lipaphis erysimi, and Brevicoryne brassicae were the most frequently recorded. In total, 10,761 individual parasitoids were identified. Binodoxys angelicae, Aphidius colemani, Aphidius matricariae, Diaeretiella rapae, Ephedrus persicae, and Lysiphlebus confusus were the most abundant aphidiines that emerged from the aphids collected from C. bursa-pastoris. Alloxysta spp. (Hymenoptera: Cynipoidea), Chalcidoidea (unidentified at genus level), and Dendrocerus spp. (Hymenoptera: Ceraphronoidea) were identified as hyperparasitoids on the parasitoids. These findings indicate that C. bursa-pastoris is a key non-agricultural plant that significantly contributes to the overwintering of numerous aphids and their parasitoids, which should be given serious consideration when biological control strategies are designed.

Biological Control May Fail on Pests Applied with High Doses of Insecticides: Effects of Sub-Lethal Concentrations of a Pyrethroid on the Host-Searching Behavior of the Aphid Parasitoid Aphidius colemani (Hymenoptera, Braconidae) on Aphid Pests

The use of synthetic insecticides may cause failures in the biological control of insect pests due to undesired side effects on natural enemies and the rapid evolution of insecticide resistance in agroecosystems. Residues of neurotoxic insecticides can interfere with the recognition of chemical cues used by natural enemies to find pests. We investigated the effects of sub-lethal concentrations of the pyrethroid lambda-cyhalothrin on the interaction between the aphid parasitoid wasp Aphidius colemani and the peach potato aphid Myzus persicae. We studied changes in host-searching and oviposition behavior through laboratory bioassays when susceptible and kdr-resistant aphids are offered to parasitoid females, evaluating the effect of applying insecticides on the interacting species. The patch residence time, exploration, oviposition, and grooming were significantly disturbed when the parasitoids were offered resistant aphids sprayed with sub-lethal doses, but not when the parasitoids were offered susceptible M. persicae exposed to sub-lethal doses. We discuss how the effects of insecticides on parasitism behavior may result in failures of biological control if natural enemy populations are not adequately managed, particularly for the management of insecticide-resistant pest populations. Efforts to introduce biological control in integrated pest management (IPM) programs are also discussed.

Standardised arthropod (Arthropoda) inventory across natural and anthropogenic impacted habitats in the Azores archipelago

In this paper, we present an extensive checklist of selected arthropods and their distribution in five Islands of the Azores (Santa Maria. São Miguel, Terceira, Flores and Pico). Habitat surveys included five herbaceous and four arboreal habitat types, scaling up from native to anthropogenic managed habitats. We aimed to contribute to the ongoing effort to document the terrestrial biodiversity of the world, in particular the Portuguese archipelago of the Azores, as islands harbour a significant portion of unique terrestrial biodiversity. Selection of Arthropoda groups for the current checklist was based on their known richness and abundance (Arachnida, Collembola, Hemiptera, Neuroptera, Coleoptera, Hymenoptera), in almost all terrestrial ecosystems, as well as their importance in current Integrated Pest Management and alternative Biocontrol protocols at large (i.e. hymenopteran parasitoids and beneficial Coleoptera). In addition, we include the list of Dermaptera, Orthoptera, Psocoptera and Thysanoptera species. These assembled groups represent part of the monitoring programme EDEN Azores (2008-2014), where all Arthropod fauna, at all strata, within nine representative habitats of the abovementioned five Islands of the Azores was recorded. In this study, a total of 116,523 specimens, belonging to 483 species and subspecies of selected groups of arthropods, are reported by order, family and, when possible, genus and species. Hymenopteran, mostly parasitoids, accounted for the most represented taxa across all the monitoring and sampling phase of EDEN Azores (193 species and mophospecies), followed by Coleoptera (95 species); Collembola (89 species); and Araneae (72 species). A total of 37 non-native species are reported for the first time in the Azores. Coleoptera: Asaphidion flavipes (Linnaeus, 1761) (Carabidae); Tachyporus dispar (Paykull, 1789) (Staphylinidae). Hemiptera: Acrosternum heegeri Fieber, 1861 (Pentatomidae). Collembola: Entomobrya regularis Stach, 1963 (Entomobryidae); Lepidocyrtus lusitanicus piezoensis (Simón-Benito, 2007) (Entomobryidae); Jordanathrix articulata (Ellis, 1974) (Sminthuridae); Sminthurinus quadrimaculatus (Ryder, 1879) (Katiannidae); Himalanura sp. (Entomobryidae); Protophorura sp. (Onychiuridae). Hymenoptera, parasitoids: Aphidius colemani Viereck, 1912 (Braconidae); Aphidius ervi Haliday, 1834 (Braconidae); Aphidius matricariae Viereck, 1912 (Braconidae); Aphidius rhopalosiphi Stefani-Perez, 1902 (Braconidae); Aphidius rosae (Haliday, 1834) (Braconidae); Aphidius urticae Haliday, 1834 (Braconidae); Centistidea ectoedemiae Rohwer, 1914 (Braconidae); Meteorus unicolor (Wesmael, 1835) (Braconidae); Meteorus collaris (Spin.) Hal. – Ruschka, Fulmek, 1915 (Braconidae); Orthostigma cratospilum (Thomson, 1895) (Braconidae); Orthostigma latriventris Ratzeburg, 1844 (Braconidae); two other species of Orthostigma sp.; Pseudopezomachus bituberculatus (Marshall, 1905) (Braconidae); Tanycarpa punctata (van Achterberg, 1976) (Braconidae); Gonatopus clavipes (Thunberg, 1827) (Dryinidae). New genera not previously recorded for the Azores include: Pycnetron sp. (Chalcidoidea: Pteromalidae); four species of Aspilota sp. (Braconidae: Alysiinae); four species of Chorebus sp. (Braconidae: Aphidiinae: Alysiinae); Microgaster sp. (Braconidae: Microgastrinae); Homolobus sp. (Braconidae: Homolobinae); Lodbrokia sp. (Braconidae: Alysiinae). These 37 taxa were found in several Islands and five are new species for Flores Island, 10 species are new for Pico Island, 12 species are new for Terceira Island, 19 species are new for S. Miguel Island and five species are new for S. Maria Island. Additional species records for the Islands included: Flores (5 Collembola, 9 Araneae; 2 Hemiptera; 8 Coleoptera, 8 Hymenoptera), Pico (4 Collembola; 7 Araneae; 4 Hemiptera; 11 Coleoptera; 9 Hymenoptera), Terceira (4 Collembola; 1 Araneae; 3 Hymenoptera), S. Miguel (1 Araneae; 2 Coleoptera; 3 Hymenoptera), S. Maria (5 Collembola; 3 Araneae; 2 Hemiptera; 2 Hymenoptera).

The effects of insecticide seed treatments on green peach aphid Myzus persicae (Sulzer) (Homoptera: Aphididae) parasitism by Aphidius colemani Viereck (Hymenoptera: Aphidiidae) and predation by Mallada signatus (Schneider) (Neuroptera: Chrysopidae)

The green peach aphid, Myzus persicae (Sulzer) (Homoptera: Aphididae), is a major pest of Brassica L. species in Australia, where it can transmit >100 viruses. Globally, this species has evolved resistance to 74 insecticides from numerous chemical groups. Although Integrated Pest Management (IPM) strategies are being implemented, chemical treatment remains the predominant method used to control aphids. Insecticide seed treatments are viewed as a softer alternative to chemical sprays and are widely used in Australian canola fields. The effects of imidacloprid, thiamethoxam, and a mixture of thiamethoxam & lambda-cyhalothrin canola seed treatments were investigated on the parasitoid, Aphidius colemani Viereck (Hymenoptera: Aphidiidae) and the predator, the green lacewing Mallada signatus (Schneider) (Neuroptera: Chrysopidae); both important natural enemies of M. persicae. The number of mummies formed by A. colemani on the untreated plants was lower than those formed on the thiamethoxam & lambda-cyhalothrin and imidacloprid treated plants. The number of A. colemani reared from mummies on thiamethoxam & lambda-cyhalothrin plants was higher than those reared from thiamethoxam and untreated plants. Significant effects of insecticide seed treatments were only noted for mummies produced while the parent parasitoids were on the plants, not for those mummies produced after their removal. This suggests seed treatment effects were immediate but not long lasting. Based on cumulative parasitoid survival days for two generations, A. colemani exposed to thiamethoxam & lambda-cyhalothrin and imidacloprid treatments had a greater fitness than those exposed to the thiamethoxam and untreated controls, possibly due to the phenomenon of insecticide hormoligosis. Despite the treatment effects observed, we did not detect any behavioural differences in M. persicae or A. colemani. Mallada signatus were not negatively affected by feeding on M. persicae on insecticide seed treated plants, suggesting they are more tolerant of seed treatments than A. colemani. The findings from this study provide a useful platform for further experimentation on the effects of seed treatments on natural enemies of M. persicae.