Structure of Anther Epidermis and Endothecium, Production of Pollen, and Content of Selected Nutrients in Pollen Grains from Six Rubus idaeus L. Cultivars

Poland is the largest European Union producer of Rubus idaeus. This species provides insects with nectar and pollen from June to September. The rationale behind the present research is the increasing commercial production and the use of food attractants for pollinators increasing fruit yields. The intensive search for phytochemicals applicable in industry and phytotherapy together with the unavailability of data on anther epidermis and endothecium structure justify undertaking these investigations. The pollen mass, the content of elements, protein, and fat, as well as the composition of amino acids and fatty acids in the pollen of six R. idaeus cultivars were compared. In terms of pollen production, the cultivars ranked as follows: ’Pokusa’ < ‘Polana’ < ‘Glen Ample’ < ‘Polka’ < ‘Radziejowa’ < ‘Laszka’. The protein content (26–31%) in the pollen indicates its good quality and high attractiveness. Exogenous amino acids, including those with dietary importance, constituted a substantial proportion (33–39%). The content of MUFAs and PUFAs was 32–47% and 3.7–9.1%, respectively. The presence of elements that determine the nutritional value and proper development of pollen was detected in the mineral composition of the exine. The data on the epidermis and endothecium structure provide new information about the micromorphology, anatomy, ultrastructure of and generative organs and auxiliary criteria in the taxonomy of related species.

Boric acid-based baits against pharaoh ants

For control of the Pharaoh ant, liquid baits based on 5–6 % boric acid or sodium tetraborate, with a high content of food attractant and an agent that prevents drying, are effective. The death of workers, queens and brood occurs within 2–4 weeks. In laboratory conditions, when colonies of the Pharaoh ant feed with such baits, depletion of the colony was noted by the 4th week of the experiment (death of queen was 75–100 %, and critical decrease in the number of live workers and brood was occured). Dry boric baits do not significantly affect the viability of ant colonies. Solutions of sodium tetraborate in glycerol are ineffective due to the lack of food attractants, the death of workers is comparable to that obtained in the variant with starving control. The mechanism of action and sterilizing properties of boric acid and sodium tetraborate for insects are discussed.

Does Ammonia Released from Protein-Based Attractants Modulate the Capture of Anastrepha obliqua (Diptera: Tephritidae)?

Tephritid fly responses to food-based attractants involve a complex range of food-derived semiochemicals, including ammonia. We performed laboratory and field experiments to compare the attraction of Anastrepha obliqua (Macquart) to ammonia with the attraction to commercial food attractants and torula yeast at a range of pHs. A positive correlation was established between the concentration of ammonia in solution (1.5–150 mM ammonium solution) and gaseous ammonia released by bottle-type traps. This resulted in an asymptotic response in captures of A. obliqua flies in traps that released 99–295 µg ammonia/h. Pairwise comparisons in laboratory cages revealed that traps baited with 150 mM ammonia solution captured similar numbers of A. obliqua as traps baited with Biolure 2C, CeraTrap, and hydrolyzed protein products (Captor, Winner, and Flyral) plus borax, despite the low quantities of ammonia (11–56 µg/h) released from these attractants. Subsequent choice experiment captures in traps containing ammonia solution were similar or higher than those of commercial attractants, with the exception of Winner + borax, but were not correlated with the ammonia released from attractants. Captures of flies in traps containing ammonia solution were increased by the addition of 1% torula yeast or torula yeast alkalized with sodium hydroxide or borax despite differences in the quantities of ammonia released. Fly captures generally increased with increasing alkalization of torula yeast (pH 7.5–9.5). In the field, torula yeast in ammonia solution captured similar numbers of A. obliqua flies as Captor + borax when traps were evaluated after 24 h but not after a 7-day trapping period. Traps baited with ammonia solution or Winner + borax were significantly less attractive than Captor + borax in both field experiments. We conclude that A. obliqua flies are attracted to ammonia solutions of increasing concentration, up to 150 mM, in the absence of other stimuli, whereas attraction to commercial attractants or alkalized torula yeast is not correlated with the release of ammonia.

Necrobia rufipes (De Geer) Infestation in Pet Food Packaging and Setup of a Monitoring Trap

Necrobia rufipes (De Geer) (Coleoptera: Cleridae), also known as the red-legged ham beetle, is a newly emerging pest of pet food stores, causing apprehension among producers worldwide. Concerns about this pest are exacerbated by the lack of information about infestation modalities in pet food, while specific monitoring tools are missing. Considering that adequate pet food packaging could limit N. rufipes infestations, information about the penetration modalities in commonly used pet food packaging is needed. Moreover, the development of appropriate monitoring instruments is urgent to detect pest presence early and to reduce chemical treatments for its control. In this paper, the adults’ and larvae’s ability to enter into pet food packaging was evaluated. Furthermore, to develop monitoring traps, behavioral bioassays were done: (1) testing two different commercial adhesive surfaces, one generally used in mouse glue traps (MG), and the other used in cockroach glue traps (CG), to evaluate their different abilities in avoiding insects’ escape; (2) screening different molecules, typical of the substrates attacked by N. rufipes, as candidate food attractants for this pest: methyl cyclopentenolone (MCP), squalene (SQ), and stearic acid (SA). The results show that N. rufipes adults and larvae enter into packaging through the air vent valves on the bottom, suggesting that a way to improve the packaging to prevent insect infestation would be to modify these points of weakness. Laboratory tests show that the different bioassayed glues have strong differences in the ability to retain the caught insects, with MG being more effective than CG. The behavioral bioassay indicated that MCP and SQ attract N. rufipes adults in olfactometer. Finally, the results of dual-choice arena bioassays show that among the candidate attractant tested, a mixture of pet food (PF) and MCP elicited the strongest attraction in N. rufipes adults. These results encourage further experiments with the use of an MG adhesive trap loaded with a mixture of PF+MCP to test the effectiveness of such a tool for monitoring N.rufipes in pet food industries and warehouses.

Effect of Food Attractants and Insecticide Toxicity for the Control of Spodoptera frugiperda (Lepidoptera: Noctuidae) Adults

An alternative for the population suppression of Spodoptera frugiperda is the use of toxic baits. The objective of this study was to evaluate the dietary preference and toxic effect of insecticides associated with the attractiveness of S. frugiperda adults as a pest management method. The following attractions were tested: 1) 5% sucrose solution, 2) 10% sugarcane syrup, 3) 10% honey, 4) 5% hydrolyzed protein, 5) Noctovi&reg; 43sb, 6) Noctovi&reg; OVI PLU 1-3, 7) Noctovi&reg; OVI PHE/PAL 50-50 in the study with choice. Attractions: 1) sugarcane syrup 10%, 2) Noctovi&reg; 43sb, 3) Noctovi&reg; 43sb + sugarcane syrup 10%, 4) Noctovi&reg; OVI PLU 1-3 in the study with no chance of choice. For the toxicity study, the food attraction associated with insecticides was used: methomyl 2%, lambda-cyhalothrin 1%, chlorpyriphos 2%, spinosad 1%, chlorantraniliprole 2% and chlorfenapyr 2%. The experimental design was the completely randomized design (CRD) with chance of choice, without chance of choice and toxicity. The following parameters were evaluated: number of insects that fed; time in minutes that remained in the attractive food and mortality. The molasses (10%) and Noctovi&reg; 43sb food attractiveness were significantly more efficient in relation to feeding time and the highest number of landings was observed in the Noctovi&reg; 43sb treatment, both in females and total adults. Methomyl, lambda-cyhalothrin and spinosad insecticides associated with food attractiveness are promising toxic baits for the management of S. frugiperda.