Tenuisvalvae notata preys upon several mealybug species (Hemiptera: Pseudococcidae), a group of worldwide pests including Planococcus citri and Ferrisia dasyrilii. Although the consequences of variation in temperature for the development and reproduction of insects are generally appreciated, the consequences of potential interactions between temperature and prey for predatory insects are not. Thermal requirements and predation rates were determined for T. notata at different constant temperatures with both prey species. T. notata larvae developed to adults in experimental conditions > 18 to <38 °C. The upper thermal limit for egg hatch was 34 °C and for pupation was 33 °C. Adults reared at ≥32 °C did not lay eggs and survived less than 1 week. Prey species did not affect lower temperature thresholds or thermal constants for development from egg to adult. Furthermore, prey did not affect a number of reproductive traits, but the interaction between temperature and prey affected changes in developmental times and oviposition rate with age. Predation rate of T. notata increased as a function of temperature, and T. notata adults generally consumed more nymphs of P. citri than F. dasyrilii. These findings indicate that T. notata is well adapted to the tropical and sub‐tropical temperatures and may prove useful for the biological control of some native and non‐native mealybugs.

Tenuisvalvae notata (Mulsant) (Coccinellidae) is a predatory ladybird beetle native to South America. It specializes in mealybugs prey (Pseudococcidae), but relatively little is known about its ecology. In contrast, the ladybird beetle Cryptolaemus montrouzieri Mulsant (Coccinellidae) is indigenous to Australia and has been introduced to many countries worldwide including Brazil for biological control of mealybugs. The potential impacts of these introductions to native coccinellids have rarely been considered. The software CLIMEX estimated the climate suitability for both species as reflected in the Ecoclimatic Index (EI). Much of South America, Africa, and Australia can be considered climatically suitable for both species, but in most cases, the climate is considerably more favorable for C. montrouzieri than T. notata, especially in South America. The CLIMEX model also suggests seasonal differences in growth conditions (e.g. rainfall and temperature) that could affect the phenology of both species. These models suggest that few locations in South America would be expected to provide T. notata climatic refugia from C. montrouzieri. Although other ecological factors will also be important, such as prey availability, this analysis suggests a strong potential for displacement of a native coccinellid throughout most of its range as a consequence of the invasion by an alien competitor.

The survivorship of social insects is known to increase with group size, even in situations of stress, such as starvation and exposure to insecticides. However, in termites, studies have been undertaken only with workers, disregarding the possible effect of soldiers. The role of soldiers in the termite colonies goes beyond defense, mainly in Nasutitermes species. It is already known that soldiers initiate the foraging as well as improve the decision‐making of food resources. Here, we evaluated the effect of group size and the presence of soldiers on exposure to sublethal doses of the insecticide imidacloprid in Nasutitermes corniger (Termitidae: Nasutitermitinae). To do so, toxicity bioassays were undertaken initially to determine the dose of the insecticide required to kill 50% of the N. corniger population (LD50) to be used in the main experiments. Survival bioassays were then carried out with termite groups, with and without soldiers, in different sizes (6, 10, 14, 22, 26, 30 and 60), exposed and nonexposed to insecticide. In general, the mean time to death of termites increases linearly with group size. However, the mean time to death in groups with soldiers was significantly longer only in groups exposed to the insecticide. Our results indicate that soldiers can help to increase the tolerance of nasute termite groups to insecticides, in addition to the group size, as already shown in the previous study. The size of the group and social context could, therefore, modulate behavioral and/or physiological responses that enhance the ability to survive under stressful situations.

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