Efforts to control balsam woolly adelgids (BWA) with conventional pesticides have failed, and natural enemy populations are too sparse to effectively control BWA, an exotic pest destroying natural and cultivated firs in the US, including Fraser firs in Christmas tree plantations. We propose to develop the technology for a diet-based mass rearing system for brown lacewings to control BWA in Fraser fir Christmas tree plantations. Efforts at control by cutting infested trees, applying pesticides and classical biological control have failed. In all of the failures of augmentation the problems were from errors in techniques (not enough predators applied, not matching seasons or life cycle, etc.) rather than inherent weaknesses of the augmentation model. Fraser fir is a native U.S. species, being ravaged by the balsam woolly adelgid (BWA) an exotic pest, and the adelgid, both in its natural range and in the extensive Christmas tree farming industry, which brings in nearly $100 million per year in North Carolina alone (Potter et al. 2005). Several million dollars per year are lost to BWA damage and cost of control, and more are threatened as this insect spreads (Potter et al. 2005). Old growth Fraser fir has been almost entirely destroyed (Dull 1988). It is the only fir species native to the Southern U.S. and a dominant species of the spruce-fir ecotype of the Southern Appalachians (Burns and Honkala 1990). These unique forests are popular recreational areas, including the Great Smoky Mountains National Park. In Christmas tree plantations, even light infestations can cause a loss of apical dominance, rendering the tree useless as a Christmas tree. Fraser fir is economically important to the people of the Southern Appalachians. In North Carolina, 5.5 to 6.0 million Christmas trees (over 98% Fraser fir) are harvested annually, which is the second largest Christmas tree harvest in the nation (Potter et al. 2005). PURPOSE: If brown lacewings could be mass-reared and made abundant enough for inoculation of individual infested trees, at a rate of 5-10 lacewing eggs per tree, BWA could be reduced in plantations below damaging threshold. To make such releases possible, a mass-rearing system based on a low cost artificial diet must be developed, and with such a diet, cost of reducing BWA populations could be less than pennies per tree. Such control would translate into prevention of loses of millions of dollars worth of trees per year. This Phase I will determine feasibility for developing a low cost diet and rearing technology and testing the laboratory reared predators on BWA infested Fraser firs in a greenhouse setting. Green and brown lacewings (Chysopidae and Hemerobiidae) in the natural habitats of BWA (European forests) have been shown to be quite effective in suppression of Adelges piceae (Szentkiralyi 2001), so there is a strong basis for optimism about the chances of large scale releases of lacewings being a key factor in BWA suppression. In contrast with natural forests Christmas tree plantations are, in all respects, parallel to orchards where augmentation biological control has been successful. OBJECTIVES: The goals and objectives of the Phase I project are to develop artificial diet based rearing systems for brown lacewings, Hemerobius spp. or Micromus spp. (Neuroptera: Hemerobiidae), which are excellent biological control agents, especially of small Homoptera such as aphids and adelgids (New 1975), but for which artificial diet-based rearing systems have not been developed. While our primary goal is to protect Fraser fir farms, we believe that the mass-rearing system for brown lacewings would be applicable to several other problems and would enhance management of forest and agricultural pests for which excellent predators are not available. Demonstration of the feasibility of a mass rearing system for rearing brown lacewings would meet a great demand and a pre-made market in Christmas tree farms and other agricultural industry and forest management. We will 1)develop rearing systems that will produce large numbers of high quality predators 2)use brown lacewings, which are known to match the preys biological characteristics in terms of search strategy fitted to a non-moving prey such as BWA, along with releases timed with the preys reproductive timing (especially in winter) 3) use the native brown lacewings found in the target habitats, and therefore preadapted to planned release environments. If successful, we would expect: 1) Our company IDRR, would patent the diet and packaging technology. 2) A producer such as Beneficial Insectary and its owner Sinthya Penn would adopt and license the rearing system technology. 3) Christmas tree plantations will see higher profits by having fewer losses 4) Higher employment in Christmas tree farm areas 5) A low cost (a few cents rather than few dollars each) biological control predator (brown lacewings) will be made available to control agricultural pests. 6) Millions of dollars saved in lost crops and trees 7) Positive ecological and aesthetic outcomes; technology will spill over from the Christmas tree plantations, to the eastern US forests being decimated by BWA. 8)Major advances in protecting forest ecosystems from adelgids and other forest pests that the USDA Forest Service and various state organizations have targeted for protection. 9) Use of mass reared predator of BWA would buy more time for long-term development of host-plant resistance or genetically modified plants. The benefits of a successful Phase I & II (costing <$500,000) could be far reaching, not only for the Christmas tree industry where losses are >$20,000,000 over 10 years, but losses in agricultural settings, for which the brown lacewing could be effective. The social value comes from saving jobs in Appalachian areas where they are associated with the Christmas tree industry. Ecologically, success of this project would reduce the spread of the woolly adelgid in forests and give researchers a chance to protect the forests. APPROACH: Objective 1: Establish a colony of brown lacewings (5/1-7/15) using conventional colonization methods for living prey. Do feeding tests on factitious prey and test natural oviposition substrates. Objective 2: Develop artificial diet, starting with established diets for other lacewing species and making adjustments in base materials (5/15-8/31). Use standards of diet development established by Cohen (2004, described on p. 59), including bioassays of consumption, rates of development, growth and reproduction, continually making improvements based on bioassay results. Several of the intended diets are proprietary materials that we have been using successfully with other predators of adelgids. Objective 3: Design functional components to be palatable and nutritious while preventing microbial and oxidative deterioration (5/15-9/15). Test texturizing agents, antimicrobial agents, optimize vitamins and antioxidants. Objective 4: Optimizing the diet presentation system (coatings or alginate encapsulation) that is most suitable to the brown lacewings (9/1-11/30). Develop optimum diet packaging and presentation system. We will use a combination of conventional bioassays along with novel methods of rheological testing derived from the food science and food technology industry. Despite years of research on diet packaging for predators with small mouthparts, diet presentation systems remain a major obstacle to predator mass rearing. Brown lacewings are among the predators with the smallest mouthparts; therefore we must focus on techniques that stretch, thin, and weaken the diet packaging. We will start with the package-stretching and filling techniques developed by the PI, and we will use a combination of pressure and vacuum along with weakening of laboratory film with selected solvent systems. The details of this work are proprietary. Our recent work with specialist predators of adelgids has led to development of a proprietary product that is at once an optimal base nutrient composite and an absorbing matrix for other nutrients. We found that this substance, imbued with key nutrients, is an excellent feeding stimulant and carrier for lipid soluble and water soluble nutrients. Objective 5: Test consumption of BWA by lab-reared brown lacewings in the laboratory and on Fraser fir in the Hain greenhouse setting to demonstrate feasibility of using mass-reared brown lacewings to effectively control balsam woolly adelgids in Fraser fir Christmas tree plantations(9/1-12/15). The evaluation of brown lacewings that have been laboratory reared is unique in systems of Fraser fir production. Also, using brown lacewings in an augmentation biological control setting is unique, and should prove to be applicable to many other cropping and natural plant systems. Test in vivo feasibility of lab-reared brown lacewings on live, infested tree parts. In every case, insect
