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BIOLOGICAL pest control agents, BIOLOGICAL pest control, PEST control, PESTS, TOMATOES, and SPECIES pools

Tuta absoluta (Meyrick), a key pest of tomato, is quickly spreading over the world and biological control is considered as one of the control options. Worldwide more than 160 species of natural enemies are associated with this pest, and an important challenge is to quickly find an effective biocontrol agent from this pool of candidate species. Evaluation criteria for control agents are presented, with the advantages they offer for separating potentially useful natural enemies from less promising ones. Next, an aggregate parameter for ranking agents is proposed: the pest kill rate k m. We explain why the predator's intrinsic rate of increase cannot be used for comparing the control potential of predators or parasitoids, while k m can be used to compare both types of natural enemies. As an example, kill rates for males, females and both sexes combined of three Neotropical mirid species (Campyloneuropsis infumatus (Carvalho), Engytatus varians (Distant) and Macrolophus basicornis (Stål)) were determined, taking all life-history data (developmental times, survival rates, total nymphal and adult predation, sex ratios and adult lifespan) into account. Based on the value for the intrinsic rate of increase (r m) for T. absoluta and for the kill rate k m of the predators, we predict that all three predators are potentially able to control the pest, because their k m values are all higher than the r m of the pest. Using only k m values, we conclude that E. varians is the best candidate for control of T. absoluta on tomato, with C. infumatus ranking second and M. basicornis last. [ABSTRACT FROM AUTHOR]

MIRIDAE, EGGS as food, PREDATORY animals, TEMPERATURE effect, and MEDITERRANEAN flour moth

Three Neotropical predators Campyloneuropsis infumatus (Carvalho), Engytatus varians (Distant) and Macrolophus basicornis (Stål) (Hemiptera: Miridae) are considered in Brazil as potential biological control agents of Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) and other tomato pests. This study evaluated the effect of five constant temperatures (16, 20, 24, 28 and 32°C, all ±1°C) on the reproduction, population growth and longevity of these predatory mirids. Adults freshly emerged from nymphs reared at each temperature, were separated in couples and kept in 1.7 l glass pots with tobacco plant seedlings (Nicotiana tabacum L., cv. TNN) as oviposition substrate and ad libitum Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) eggs as food. The shortest pre-oviposition and the longest oviposition periods were observed at 24°C and 28°C in all three mirid species. At 24°C all three species showed the highest daily and total fecundities. The population growth parameters represented by the intrinsic rate of increase (rm) and the finite rate of increase (λ) were highest at 24°C and 28°C, and the net reproductive rate (R0) was highest at 24°C for all three species. Longevities of both males and females were longest at 24°C and 28°C in all three mirids. The size of tibia and adult weight in the three species were greatest at 20°C and 28°C, respectively. Differences in values for all above variables were small and often statistically non-significant for the three mirid species at the same temperature. Also, not a single significant difference was found for any of the growth parameters at each of the temperatures, including rm. The results indicate that temperatures in the range from 24-28°C are best for reproduction and population growth of C. infumatus, E. varians and M. basicornis. The factitious prey E. kuehniella is an excellent food source and tobacco plants provide a good rearing substrate for these mirids. The obtained results may assist in developing a mass rearing method for C. infumatus, E. varians and M. basicornis, in determining optimal timing and frequency of mirid releases in the crop, and in determining whether they are active at the temperature spectrum observed during tomato production in the field or greenhouse. [ABSTRACT FROM AUTHOR]

MIRIDAE, ATMOSPHERIC temperature, MEDITERRANEAN flour moth, TOBACCO, and INSECT rearing

Effects of temperature (16, 20, 24, 28 and 32 ± 1 °C), host plant (Nicotiana tabacum L.) and factitious prey (eggs of Ephestia kuehniella Zeller) on immature development of three recently found Neotropical mirids, Campyloneuropsis infumatus (Carvalho), Engytatus varians (Distant) and Macrolophus basicornis (Stal) were studied at RH 70 ± 10% and 12h photophase in climate cabinets. These mirids are being evaluated for biological control of the South American tomato borer Tuta absoluta (Meyrick) and other pests on tomato. Survival of eggs of the three mirid species on tobacco was high (> 80%) at 16-28 °C, but lower (< 80%) at 32 °C. Development times decreased with increasing temperature from 16-28 °C. Nymphal survival was higher (84-96%) at 20, 24 and 28 °C than at 16 and 32 °C (46-83%). The sex ratio of C. infumatus was strongly female biased at all temperatures, whereas it was 1:1 for the other two species. The lower temperature thresholds for egg-adult development of C. infumatus, E. varians and M. basicornis were 9.4, 9.4 and 7.9 °C, and their thermal constants were 384.6, 384.6 and 476.2 DD, respectively. Temperatures between 24 to 28 °C are best for immature performance and for rearing of these mirids species. Eggs of the factitious host E. kuehniella provide adequate food for their mass production. Optimal temperatures for best mirid predator performance are similar to those for the pest T. absoluta, indicating good climate matching. [ABSTRACT FROM AUTHOR]