Quality assessment of entomophagous arthropods used in augmentative biological control is one of the main concerns after their mass production. The quality-testing procedures for natural enemies reared on artificial diets largely remain to be defined. As a first approach, comparisons of some relevant parameters between in vivo- and in vitro-reared entomophages are presented in this chapter. Results from experiments with different kinds of diets with or without insect components, developed for parasitoids and predators, are examined. Morphological traits as well as development and reproduction parameters used for comparisons between in vivo- and in vitro-grown arthropods are discussed. Morphological characters include body size and weight and the occurrence of abnormalities. Immature development is assessed by measuring duration and survival rates of the different stages. Sex ratio and symbiont association, fecundity-fertility and longevity are compared as reproduction parameters. It is important to consider biochemical parameters, such as protein, lipid and carbohydrate content, for quality control. These parameters may also indicate the deficiency or excess in a particular nutritional component. Behavioural and genetic parameters are considered as well. The establishment of relationships between certain parameters, e.g. between body size and fecundity or longevity, may help in simplifying quality control procedures. The ultimate quality criterion for an artificially reared natural enemy is its capacity to reduce pest populations, which can be evaluated by measuring the predation efficiency or the parasitization rate under laboratory or field conditions.

No abstract

No abstract

The susceptibility of the predatory pentatomid Podisus maculiventris (Say) to the insect growth regulators (IGRs) diflubenzuron and pyriproxyfen was investigated in the laboratory. Fifth‐instar nymphs were exposed to formulated materials of each compound via direct contact, residual contact and ingestion. Diflubenzuron was harmless to P. maculiventris by direct and residual contact, but was highly toxic when ingested via drinking water. Pyriproxyfen caused severe deformities at ecdysis whatever the method of exposure. Exposure of fifth instars to sublethal concentrations (around LC10) of both compounds had no adverse effects on reproduction of emerging adults. The data suggest that the use of these IGRs in the integrated management of insect pests should be evaluated with caution.

No abstract

No abstract

Development and survival of the predatory pentatomids Podisus maculiventris (Say) and Podisus sagitta (Fab.) were studied at six constant temperatures ranging from 19 to 35 °C. Time required for development from egg to adult ranged from 48.9 days (19 °C) to 18.9 days (30 °C) for P. maculiventris and from 51.9 days (19 °C) to 16.9 days (33 °C) for P. sagitta. At 33 °C, eggs of P. maculiventris did not hatch and development of nymphs that had emerged at 23 °C was retarded; none of the first-instar nymphs incubated at 35 °C survived the next moult. A constant temperature of 35 °C was fatal to P. sagitta eggs and extended the developmental period of nymphs from 23 °C. Egg hatch ranged from 47% (19 °C) to 57% (27 °C) for P. maculiventris and from 54% (33 °C) to 71% (27 °C) for P. sagitta. Nymphal survival was high at moderate temperatures, with 63–78% and 65–82% of the first-instar nymphs of the respective species reaching adulthood. Mortality during the nymphal stage was significantly increased at high temperatures, but was considerably lower for P. sagitta than for P. maculiventris. Lower threshold temperatures for egg and nymphal development were estimated to be 10.7 and 11.7 °C for P. maculiventris, and 13.3 and 12.2 °C for P. sagitta. Thermal requirements for these stages were 78.2 and 275.5 degree-days, and 60.9 and 265.5 degree-days, respectively. These observations suggest that P. sagitta is somewhat better adapted to high temperatures than is P. maculiventris.

No abstract