Dactylopius opuntiae (Hemiptera: Dactylopiidae) as a Diet Source for Mass Rearing Cryptolaemus montrouzieri (Coleoptera: Coccinelidae).

Although natural enemies play an important role in most integrated pest management programs, biological control agents remain poorly adopted in food production systems primarily due to the high costs associated with their implementation. Cryptolaemus montrouzieri (Mulsant, 1853) is a very promising candidate for the biological control of mealybugs. However, mass rearing of this predator is critical to provide sufficient numbers so that effective control of mealybugs can be achieved. Thus, this work focuses on mass rearing of this biological control agent under controlled conditions at T = 28 ± 1 °C, RH = 70 ± 5%, and 12:12-h photoperiod L:D. This experiment was based on feeding this predator three diets: a freeze-dried artificial food source, the cactus cochineal-Dactylopius opuntiae (Cockerell, 1929), and a combination of the two diets. The fecundity recorded in the freeze-dried artificial food, D. opuntiae, and mixed diet was 2.73, 8.79, and 8.78 larvae/female, respectively. The sex ratios (male:female) of the cochineal adults that emerged on the three diets were 1:1.35, 1:1.23, and 1:1.11, respectively, for the freeze-dried artificial food, D. opuntiae, and mixed diet. The emerged adults had an average weight of 9.2 mg when fed the artificial diet, 13.8 mg for the D. opuntiae diet, and 9.5 mg for the mixed diet, while the life cycle duration for each diet was 50.1, 43.5, and 42.3 d, respectively. At the beginning of the C. montrouzieri rearing process with 40 adults, our results indicated that an average of 1031.1 adults can be produced using D. opuntiae as the diet in a volume of 1 m3. The D. opuntiae diet is recommended due to its overall lower costs. Additionally, this study indicates that mass-rearing of C. montrouzieri can be achieved with cheaper and more readily available materials for diets, instead of purchasing a freeze-dried artificial food source.

Evaluation of Rearing Parameters of a Self-Limiting Strain of the Mediterranean Fruit Fly, Ceratitis capitata (Diptera: Tephritidae).

The Mediterranean fruit fly (medfly), Ceratitis capitata, is a significant pest of stone and pome fruit that causes considerable economic losses worldwide. Current control is primarily based on insecticides, which are often mixed with protein baits. Oxitec has developed a self-limiting medfly strain (OX3864A) that demonstrates conditional female-specific mortality in the early life stages. Sustained release of OX3864A males offers medfly control, which should lead to substantial economic benefits in area-wide programmes. In the current study, the optimum quantities of mature and immature stages of the strain are assessed under semi-mass production. Moreover, the rearing and quality control limitations related to the production of this strain are provided. The data here demonstrate that the egg hatch rate can reach >85% under optimum rearing conditions. However, this depends on the number of pupae loaded in a cage and their ages. The suggested pupal density ranges between 14,000 and 18,000 pupae per cage to provide optimum egg production. In parallel, the embryo densities of 1.25-1.5 mL/kg larval Tet+ diet are recommended for strain propagation, while embryo densities of 1.25-2.0 mL/kg larval Tet- diet are suggested for male-only pupal production.