Seasonal Changes in Sugar and Amino Acid Preference in Red Wood Ants of The Formica rufa Group

Red wood ants of the Formica rufa group are important ecosystem engineers throughout the Northern Hemisphere with potential to be commercially produced and used as predatory agents in biological control programs. However, in order to do that, their mutualistic relationship with aphids needs to be disrupted. This may be achieved by developing artificial sugar-based solutions with a composition that makes them more attractive than aphid honeydew. The present field study investigated Formica rufa’s preference for several sugar and amino acid sources, as well as potential seasonal changes in these preferences. Red wood ants consistently preferred sucrose to monosaccharides and were most attracted to solutions containing an amino acid source, albeit seasonal differences were observed with regard to which amino acid sources were most preferred. Recruitment to offered sugar solutions was highest during July, when colony requirements were high, and during October, when alternative food sources were scarce. Since ant preference for sugar solution constituents seems to be species-specific and show seasonal dynamics, artificial food aimed at disrupting ant-aphid mutualisms should be tailored to individual species and seasons

MothStop: Skovmyrer skal sikre økologiske æbler

Folder om RDD 2.2 projektet MothSto

Myrer skal sikre bæredygtig frugtproduktion

Den danske produktion af økologiske bær og frugter må ikke bruge kemiske sprøjtemidler - derfor mangler sektoren effektive midler til at bekæmpe skadedyr og plantesygdomme

Open Field Biocontrol: Skovmyrer som et biologisk alternativ til sprøjtemidler

Baggrund: Den danske produktion af økologiske bær og frugter må ikke bruge kemiske sprøjtemidler. Derfor mangler sektoren effektive midler til at bekæmpe skadedyr og plantesygdomme. Hvis der kan findes et biologisk alternativ til de kemiske stoffer, kan økologerne stabilisere og øge deres udbytter. Resultatet kan blive en højere produktion af økologiske frugter og bær uden sprøjtemiddelrester, hvilket er en mangelvare hos forbrugerne. Samtidig kan det gøre den økologiske sektor mere attraktiv, så avlere omlægger fra konventionel til økologisk produktion. Det vil betyde færre sprøjtemidler i den danske natur, højere biodiversitet og et mindre klimaaftryk. Formål: Open Field Biocontrols formål er at undersøge, om skovmyrer kan fungere som et biologisk alternativ til sprøjtemidler, fordi de kan beskytte frugter og bær imod skadedyr og plantesygdomme. Dette skyldes, at myrerne æder andre insekter og sygdomsvæv, samt at de udskiller antibiotiske stoffer, der hæmmer plantesygdomme. I dette projekt arbejdes der med æbletræer, men metoden forventes at kunne fungere i de fleste typer flerårige plantesystemer

Skovmyrer skal bekæmpe æblernes fjender - MothStop

Skovmyrer er kendte som effektive skadedyrsbekæmpere og spiser med glæde larver. De er også tidligt aktive, men lever normalt i skoven. Myrer lever i tætte samfund, hvor sygdomssmitte er en fare, og derfor er de i stand til at producere antibiotika, som kan bekæmpe svampe-sygdomme. I MothStop er skovmyrer blevet flyttet ind i en æbleplantage. Forskerne har undersøgt, om myrerne ville etablere sig og æde af larverne. Desuden har projektet undersøgt, om myrerne ved deres udskillelse af antibiotiske stoffer på æbletræerne, kan give en give en reduktion i udbredelsen af sygdomme, herunder den frygtede sygdom skurv

Wood Ant (Formica polyctena) Services and Disservices in a Danish Apple Plantation

Ants possess properties that can be used to optimize plant production in agricultural systems. Ant services can be herbivore and pathogen protection and fertilization of their plant partners. They may, however, also harm plants by facilitating ant-attended herbivorous homopterans. To assess whether wood ants can be used in IPM-systems to improve apple production, we transplanted wood ants into a Danish apple plantation and tested whether ants (i) reduced the number of herbivores, (ii) led to higher amounts of leaf nutrients, (iii) controlled apple pathogens, (iv) increased homopteran abundance and (iv) whether these effects affected apple yields. During a two year study, we found that the wood ants significantly reduced the numbers of winter moth larvae, increased magnesium content in apple leaves (but did not affect 10 other nutrients), reduced the number of apples infected with apple brown rot and apple scab (on one apple variety) and increased aphid infections. In the first year, this led to higher apple production on ant trees, whereas ants had no effect on yields in the second year. It was evident that ants provided both services and disservices. If mutualistic ant-homopteran interactions can be disrupted, this would favor plant growth and open for the use of wood ants in sustainable plant management. We discuss how this may be accomplished. Alternatively, ants may be used short term to knock down pest outbreaks (before building up homopteran populations) or used in crops that do not host ant-attended homopterans

Experiences in Transplanting Wood Ants into Plantations for Integrated Pest Management

Ants can function efficiently as biocontrol agents in open field horticulture. Temperate wood ants can control forest pests, including species damaging forest regeneration plots and fruit plantations. Thus, they possess potential as biocontrol agents in open field horticulture, if they can persist in these systems. Here we present observationson activity and survival of wood ants transplanted from forests into different types of plantations. Mound fragments were transplanted into a conifer seedling plot, an organic and a conventional Christmas tree plantation, and into an organic apple plantation. Colonies survived at least one year in all types of plantations. In some cases, however, ants moved to new locations or migrated between mound fragments, leaving some inactive. Our compiled experiences suggest that this can be prevented by providing a minimum mound size, keeping a minimum spacing between mounds and incorporation of sand and scent marked wood pieces from donor colonies to imitate naturally occurring nests. We also observed that the ants preyed upon and significantly reduced the number of winter moth larvae (Operophtera brumata – a pest in apple and other fruit orchards) in two of four apple varieties. In conclusion, wood ants were tolerant to highly diferente habitat settings and will likely persist in most types of perennial horticultural systems, if managed properly. As they prey on winter moths and multiple other pest species, they are a potential new biocontrol agent for open agricultural systems

The use of light to enhance weaver ant Oecophylla longinoda Latreille (Hymenoptera: Formicidae) queen catches

Production of live weaver ant (Oecophylla longinoda and O. smaragdina) colonies is being developed as the ants provide several ecosystem services in agriculture and as they are used in education and research laboratories. Founding queens needed for colony production can be caught in artificial nests made of live leaves that are curled on trees. In this study we investigated if the catch rate of O. longinoda queens in artificial nests could be improved by attracting queens to trees with a light source (electric torches). We compared catch rates of 50 artificial nests on each of eight citrus trees, four of them with light and four without light. During two mating seasons covering 9 mating flights we caught a total of 178 queens. However, 3.8 times more queens were caught in the trees with light compared to trees without light. We conclude that queen catches can be highly improved by combining artificial nests with an attracting light source

Mating Behavior of the African Weaver Ant, Oecophylla longinoda(Latreille) (Hymenoptera: Formicidae)

Mating in most species of ants occurs during nuptial flights. In the African weaver ant, Oecophylla longinoda Latreille, mating has previously been hypothesized to take place within the nest before the nuptial flight. However, several researchers disagree with this supposition particularly with reference to the closely related species Oecopylla smaragdina (Fabricius) whose mating occur during nuptial flights. Understanding the mating strategy of O. longinoda is of importance for its successful application in biological control programs. We conducted field and screen house experiments during two mating seasons to determine whether the mating occur prior to the dispersal flight. We examined winged O. longinoda queens on the nest surface before taking flight, immediately after leaving the nest, up to twelve hours (12h) after leaving the nest and after settling naturally following the dispersal flights. Mating in captivity between different number of males and queens were also assessed. Only eggs produced by queens (N=65) collected after their natural settling hatched into larvae. No eggs hatched from any of the 527 winged queens that were collected prior to their dispersal flights and no mating attempts in captivity lead to viable offspring. Findings from the current study suggest that mating of O. longinoda queens take place during a nuptial flight and does not take place within the nest, as previously suggested