Importance of Nutritional and Physical Characteristics of Diets for Mass Rearing Screwworm & Pink Bollworm Norman C. Leppla, Muhammad F. Chaudhury &Fred D. Stewart University of Florida and USDA Norman C. Leppla, Muhammad F. Chaudhury & Fred D. Stewart University of Florida and USDA

New World Screwworm Cochliomyia hominivorax (Diptera:Calliphoridae)

Eggs on wound Adults ScrewwormLife Cycle Screwworm Life Cycle Pupae in ground Larvae in wound

Myiasis in Livestock

Screwworm Larval Media Nutria Whale

Tuxtla Gutierrez Screwworm “Factories” Mission

Diet preparation Mixer IngredientFeeder WaterFeeder

Pumping diet into trays

Tray with larval diet

Larvae falling from trays

Screwworm pupae

Cotton Linter Rearing System

Composition of Larval Diet Composition of Larval Diet Spray-dried bovine blood 6% Spray-dried egg 4% Milk substitute 4% Gelling agent(or 6% Cellulose) 2% Water (or 79.9% with cellulose) 83.9% Formalin 0.1%

Spray Dried Whole Bovine Blood Protein 85% Protein 85% Fat 1% Fat 1% Ash 4.5% Ash 4.5% Fiber 1% Fiber 1% Moisture 6% Moisture 6%

Egg Powder Protein 50-58% Protein 50-58% Fat 25-30% Fat 25-30% Moisture 5% or less Moisture 5% or less Cholesterol trace Cholesterol trace Vitamins A, B 1,2,6,12, D,E, Vitamins A, B 1,2,6,12, D,E, Folate, Biotin Folate, Biotin Minerals Na, K, Ca, P, Mg, Minerals Na, K, Ca, P, Mg, Fe, Cu, Cl, I, Zn Fe, Cu, Cl, I, Zn

Milk Powder Substitute Protein 20 g Fat 28 g Carbohydrate 42 g Moisture 3 g Ash 3 g Total Vitamins ~1 g A, B 1, B 2, B 3, B 6, B 12, Biotin A, B 1, B 2, B 3, B 6, B 12, Biotin C, D, E, Folate, Pantothenic acid C, D, E, Folate, Pantothenic acid Minerals ~2.5 g Calcium, Copper, Iodine, Iron Calcium, Copper, Iodine, Iron Magnesium, Phosphorous Magnesium, Phosphorous Potassium, Sodium, Zinc Potassium, Sodium, Zinc

Physical Characteristics Role of gelling agent (or cellulose fiber) Role of gelling agent (or cellulose fiber) - Provide texture and matrix to diet - Provide texture and matrix to diet - Gel polymer is not bio-degradable - Gel polymer is not bio-degradable - Cellulose is biodegradable - Cellulose is biodegradable Importance of viscosity Importance of viscosity - Larval mobility and growth - Larval mobility and growth - Proper functioning of equipment - Proper functioning of equipment Importance of pH Importance of pH - pH change occurs during feeding - pH change occurs during feeding - Feeding not effected between 6.8 & Feeding not effected between 6.8 & 5.5

Pink Bollworm Pectinophora gossypiella (Lepidoptera: Gelechiidae)

Pink Bollworm Life Cycle

Pink Bollworm Rearing Facility

Diet Preparation

Diet Extrusion

Larval Development and Cutout

Collection of Pupae

Larval Diet Composition Wheat germ Wheat germ Sugar Sugar Soy flour Soy flour Yeast Yeast Anti-microbials (3) Anti-microbials (3) Vitamins(8) Vitamins(8) Choline chloride Choline chloride Red dye Red dye

Successful Diet Characteristics Stimulate and enable feeding Stimulate and enable feeding Contain essential nutrients Contain essential nutrients Organize ingredients in a matrix Organize ingredients in a matrix Nutrients biologically available Nutrients biologically available

Chemically stable & clean Chemically stable & clean Eliminate anti-nutrients Eliminate anti-nutrients Easy to prepare Easy to prepare Easy to discard (biodegradable) Easy to discard (biodegradable) Provides a “happy” home Provides a “happy” home Successful Diet Characteristics

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