Biological Control and Spatial Ecology Laboratory

Brussels, Belgium

Biological Control and Spatial Ecology Laboratory

Brussels, Belgium

Time filter

Source Type

Maes S.,Ghent University | Massart X.,Biological Control and Spatial Ecology Laboratory | Gregoire J.-C.,Biological Control and Spatial Ecology Laboratory | De Clercq P.,Ghent University
BioControl | Year: 2014

The performance of three species of predatory ladybirds was compared in a flight mill and the effect of diet on their flight parameters was tested. The invasive ladybird Harmonia axyridis Pallas (Coleoptera: Coccinellidae) outperformed Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) and Adalia bipunctata (L.) (Coleoptera: Coccinellidae) in terms of flight distance, duration and velocity. Harmonia axyridis flew at least two times further, needed three times less breaks and flew two times faster than C. montrouzieri and A. bipunctata fed the same diet. Ladybirds reared on eggs of Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) performed better than their counterparts reared on natural prey (aphids for H. axyridis and A. bipunctata, mealybugs for C. montrouzieri). The findings of this study indicate that comparative flight studies can be useful to identify candidate biocontrol agents with pronounced dispersal abilities and thus can yield significant evidence to be used in an environmental risk assessment. However, it also demonstrates that variability related to mass rearing conditions should not be ignored when standardizing a risk assessment procedure for candidate biocontrol agents. © 2014 International Organization for Biological Control (IOBC).


Maes S.,Ghent University | Gregoire J.-C.,Biological Control and Spatial Ecology Laboratory | De Clercq P.,Ghent University
BioControl | Year: 2014

The prey range of Cryptolaemus montrouzieri was studied in the laboratory to investigate whether the mealybug destroyer can contribute to the suppression of other pest insects besides mealybugs and to assess its potential impact on non-mealybug populations as part of an environmental risk assessment for its use in biological control. Prey tested in these experiments were: tobacco aphid Myzus persicae nicotianae (Sulzer)(Hemiptera: Aphididae), pea aphid Acyrthosiphon pisum (Harris)(Hemiptera: Aphididae), tobacco whitefly Bemisia tabaci (Gennadius)(Hemiptera: Aleyrodidae), southern green stinkbug Nezara viridula (L.)(Hemiptera: Pentatomidae) eggs, western flower thrips Frankliniellaoccidentalis (Pergande)(Thysanoptera: Thripidae), two-spotted ladybird Adalia bipunctata (L.)(Coleoptera: Coccinellidae) eggs and eggs of the greater wax moth Galleria mellonella L. (Lepidoptera: Pyralidae). Larval survival was high to moderate when C. montrouzieri was provided with hemipteran prey and poor to zero when the ladybirds were provided with non-hemipteran prey. Females reared on M. persicae and A. pisum produced similar numbers of eggs as their counterparts fed the citrus mealybug Planococcus citri (Risso)(Hemiptera: Pseudococcidae), but fecundity was significantly lower when the ladybirds were reared on B. tabaci nymphs or on A. bipunctata eggs. Prey species that were found to be less suitable for immature development of C. montrouzieri could still be an adequate food source for reproduction and survival of adult ladybirds. For example, only 8 % of the predator larvae reached the adult stage when provided with A. bipunctata eggs, but females that had developed on eggs of the Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) and that were supplied with A. bipunctata eggs from adult emergence on, were only 35 % less fecund than females provided with mealybugs in their adult life. The results are discussed in relation to the development of a suitable methodology for prey/host range testing in the framework of an environmental risk assessment for arthropod natural enemies. © 2014, International Organization for Biological Control (IOBC).


Maes S.,Ghent University | Machtelinckx T.,Ghent University | Moens M.,Belgium Institute for Agricultural and Fisheries Research | Gregoire J.-C.,Biological Control and Spatial Ecology Laboratory | De Clercq P.,Ghent University
BioControl | Year: 2012

The generalist predator Macrolophus pygmaeus Rambur (Hemiptera: Miridae) is a key biological control agent in European greenhouses. The influence of acclimation, infection with endosymbiotic bacteria and diet on the cold tolerance of the Mediterranean biocontrol population was assessed by determining the supercooling point, i. e. the temperature at which the insect's body fluids freeze. This parameter provides a first indication of an insect's establishment potential in a new region and of its possible geographical range. Allowing the predatory bugs to adapt to lower temperatures resulted in an increase in supercooling ability. Macrolophus pygmaeus bugs exposed to antibiotics in their artificial diet and hence cured from their infection with the endosymbiotic bacteria Wolbachia pipientis, Rickettsia bellii and R. limoniae were more tolerant to freezing than infected bugs. The diet of the predators also affected the freezing temperature of the body fluids. Predators fed an artificial diet based on egg yolk were less resistant to freezing than those fed Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs. These findings illustrate that several factors may affect the cold hardiness of a biocontrol agent and may thus complicate the evaluation of its establishment potential in the framework of an environmental risk assessment. © 2012 International Organization for Biological Control (IOBC).


Maes S.,Ghent University | Gregoire J.-C.,Biological Control and Spatial Ecology Laboratory | De Clercq P.,Ghent University
BioControl | Year: 2015

The effect of low temperature acclimation and diet on the supercooling point (SCP, the temperature at which the insect’s body fluids freeze) and lethal time (LTime, time required to kill 50 % of the population at a temperature of 5 °C) of the mealybug destroyer, Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae), was assessed in the laboratory. The SCP of acclimated adult ladybirds which were allowed to complete development to adulthood at 18 °C and a 8:16(L:D)h photoperiod, or at 25 °C and a 16:8(L:D)h photoperiod, and which were subsequently kept at 10 °C and a 12:12(L:D)h photoperiod for seven days, was −17.4 and −16.8 °C, respectively. These SCP-values were approximately 7 °C lower than the value of −9.9 °C for non-acclimated ladybirds maintained at a temperature of 25 °C and a photoperiod of 16:8(L:D)h throughout development and in the first week of their adult life. Also food source had a significant effect on the freezing temperature of C. montrouzieri: the SCP of ladybirds fed the citrus mealybug, Planococcus citri (Risso)(Hemiptera: Pseudococcidae), was 1.6 °C higher than the value of −17.2 °C observed for ladybirds provided with eggs of the flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae). However, neither cold acclimation nor diet had a significant effect on the lethal times of C. montrouzieri. Overall, the time required to kill 50 % of the population at a temperature of 5 °C ranged from 12.8 days for ladybirds fed P. citri mealybugs to 14.4 days for ladybirds fed E. kuehniella eggs. All individuals exposed to a constant 5 °C had died by day 24. Based on the results from this laboratory study, it is deemed unlikely that C. montrouzieri could establish outdoors in western Europe, and it is therefore expected to pose little risk to non-target species in this area when used as an augmentative biological control agent. © 2014, International Organization for Biological Control (IOBC).

Loading Biological Control and Spatial Ecology Laboratory collaborators
Loading Biological Control and Spatial Ecology Laboratory collaborators