The effect of temperature on the development, survival, longevity, and fecundity of the 14-spotted ladybird beetle, Propylea quatuordecimpunctata L. (Coleoptera: Coccinellidae) reared on bean aphid, Aphis fabae Scopoli (Hemiptera: Aphididae) was determined at six constant temperatures (17, 20, 25, 30, 32.5, and 35 ± 1°C) in the laboratory. Results showed a temperature—dependent development of the coccinellid. An appropriate linear model indicated that 218.0 degree days above a threshold of 10.2°C were needed to complete immature development from egg to adult emergence. Data were fitted to the nonlinear Briere model, which for total immature period estimated the upper developmental threshold at 36.0°C, the lower threshold at 12.2°C and the temperature for maximum developmental rate at 30.3°C. Survival of immature stages varied significantly across temperatures with the lowest survival of just 14% occurring at 32.5°C and the highest (96%) at 25°C. In addition temperature showed a profound effect on female longevity over this viable range of temperatures, as it decreased from 123.06 d at 17°C to 33.53 d at 30°C. The highest fecundity (724.6 eggs/female) was recorded at 25°C. These results might be useful tools for the prediction of P. quatuordecimpunctata phenology and the interaction with its prey.

Postharvest agricultural losses constitute a major food security risk. In contrast, postharvest protection is strongly linked with food safety. The present study aims to develop novel postharvest protection tools through a bioprospecting protocol utilizing edible essential oils (EOs) as grain coatings. For this purpose, six Mediterranean culinary plants were selected for evaluation. The EOs of juniper, Juniperus phoenicea L. (Pinales: Cupressaceae), marjoram, Origanum majorana L. (Lamiales: Lamiaceae), oregano, Origanum vulgare ssp. hirtum (Link) A.Terracc. (Lamiales: Lamiaceae), bay laurel, Laurus nobilis L. (Laurales: Lauraceae) and tarhan, Echinophora tenuifolia ssp. sibthorpiana (Guss.) Tutin (Apiales: Apiaceae) were retrieved through steam distillation, while lemon, Citrus limon (L.) Osbeck (Sapindales: Rutaceae) EO was retrieved through cold press extraction. All EOs were formulated to microemulsions (MEs) and applied uniformly as a coating on wheat against larvae and adults of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and Trogoderma granarium Everts (Coleoptera: Dermestidae). All EO-based MEs have been evaluated for the first time as grain coatings. They caused moderate to high mortality to T. castaneum larvae (67.8–93.3% 14 days post-exposure) and T. granarium adults (70.0–87.8% after 7 days of exposure). Citrus limon, O. majorana and E. tenuifolia ssp. sibthorpiana EO-based MEs were the most efficient against T. castaneum larvae, by exhibiting 93.3%, 91.1% and 90.0% mortality 14 days post-exposure, respectively. Origanum majorana, L. nobilis and J. phoenicea EO-based MEs were the most efficient against T. granarium adults, exhibiting 87.8%, 84.4% and 83.3% mortality after 7 days of exposure, respectively. These results indicate that EO-based ME coating is a potent tool against the tested postharvest pests.

The invasive dermestid khapra beetle, Trogoderma granarium, is an important pest of stored products that is subject to strict phytosanitary measures. In this study, we conducted a demographic analysis of this species at 30, 35 and 40°C, combining deterministic and stochastic approaches. The net reproductive rate, the intrinsic rate of increase, the finite rate of increase and the doubling time did not differ significantly between 30 and 35°C, while at 40°C we detected negative values of the intrinsic rate of increase and the doubling time. The Briere model fit the data well with respect to the intrinsic rate of increase. Females of roughly 63, 42 and 21 days old reached their maximum reproductive potential at 30, 35 and 40°C, respectively. The stochastic models of this study allowed for checking model fit and the characterization of the most suitable distribution for each component of the process. We expect these results to have bearing on the management of T. granarium since they could be combined with models related to international trade and climatic change, alerting specialists towards early detection strategies against this species.

Mutual interference involves direct interactions between individuals of the same species that may alter their foraging success. Larvae of aphidophagous coccinellids typically stay within a patch during their lifetime, displaying remarkable aggregation to their prey. Thus, as larvae are exposed to each other, frequent encounters may affect their foraging success. A study was initiated in order to determine the effect of mutual interference in the coccinellids’ feeding rate. One to four 4^th larval instars of the fourteen-spotted ladybird beetle Propylea quatuordecimpunctata were exposed for 6 hours into plastic containers with different densities of the black bean aphid, Aphis fabae, on potted Vicia faba plants. The data were used to fit a purely prey-dependent Holling type II model and its alternatives which account for interference competition and have thus far been underutilized, i.e. the Beddington-DeAngelis, the Crowley-Martin and a modified Hassell-Varley model. The Crowley-Martin mechanistic model appeared to be slightly better among the competing models. The results showed that although the feeding rate became approximately independent of predator density at high prey density, some predator dependence in the coccinellid’s functional response was observed at the low prey—high predator density combination. It appears that at low prey densities, digestion breaks are negligible so that the predators do waste time interfering with each other, whereas at high prey densities time loss during digestion breaks may fully accommodate the cost of interference, so that the time cost may be negligible.

The dynamics of predator-prey systems are strongly affected by the predators feeding rate on increasing prey density, that is, its functional response. Holling's assumptions concerning the biological process of handling time, that is, the time a predator spends on pursuing, subduing, eating, and digesting its prey, have been debated, as digestion represents a background component of predation. Therefore, predators are characterized either as digestion or handling limited. A study was initiated to identify the mechanism that limits the coccinellids' predation ability. The 14-spotted ladybird beetle, Propylea quatuordecimpunctata (L.) (Coleoptera: Coccinellidae), and its prey, Aphisfabae Scopoli (Hemiptera: Aphididae), were used in long- and short-term functional response experiments. Results showed that P. quatuordecimpunctata adults exhibit a type II functional response. The estimated attack rates and handling times differed significantly between long- and short-term experiments, indicating that the digestion process limits predation ability of P. quatuordecimpunctata.

Predators' Functional Response: Statistical Inference, Experimental Design, and Biological Interpretation of the Handling Time