Air-Fluidized Aggregates of Black Soldier fly Larvae

Black soldier fly larvae are a sustainable protein source and play a vital role in the emerging food-waste recycling industry. One of the challenges of raising larvae in dense aggregations is their rise in temperature during feeding, which, if not mitigated, can become lethal to the larvae. We propose applying air-fluidization to circumvent such overheating. However, the behavior of such a system involves complex air-larva interactions and is poorly understood. In this combined experimental and numerical study, we show that the larval activity changes the behavior of the ensemble when compared to passive particles such as dead larvae. Over a cycle of increasing and then decreasing airflow, the states (pressure and height) of the live larva aggregates are single-value functions of the flow speed. In contrast, dead larva aggregates exhibit hysteresis characteristic of traditional fluidized beds, becoming more porous during the ramp down of airflow. This history-dependence for passive particles is supported by simulations that couple agent-based dynamics and computational fluid dynamics. We show that the hysteresis in height and pressure of the aggregates decreases as the activity of simulated larvae increases. To test if air fluidization can increase larval food intake, we performed feeding trials in a fluidization chamber and visualized the food consumption via x-ray imaging. Although the food mixes more rapidly in faster airflow, the consumption rate decreases. Our findings suggest that providing moderate airflow to larval aggregations may alleviate overheating of larval aggregations and evenly distribute the food without reducing feeding rates.

Antixenosis, Antibiosis, and Potential Yield Compensatory Response in Barley Cultivars Exposed to Wheat Stem Sawfly (Hymenoptera: Cephidae) Under Field Conditions

Wheat stem sawfly, Cephus cinctus Norton, is an economically serious pest of cereals grown in North America. Barley cultivars were previously planted as resistant crops in rotations to manage C. cinctus, but due to increasing levels of injury to this crop, this is no longer a valid management tactic in Montana. Therefore, we aimed to understand antixenosis (behavioral preference), antibiosis (mortality), and potential yield compensation (increased productivity in response to stem injuries) in barley exposed to C. cinctus. We examined these traits in eight barley cultivars. Antixenosis was assessed by counting number of eggs per stem and antibiosis was assessed by counting infested stems, dead larvae, and stems cut by mature larvae. Potential yield compensation was evaluated by comparing grain yield from three categories of stem infestation: 1) uninfested, 2) infested with dead larva, and 3) infested cut by mature larva at crop maturity. We found the greatest number of eggs per infested stem (1.80 ± 0.04), the highest proportion of infested stems (0.63 ± 0.01), and the highest proportion of cut stems (0.33 ± 0.01) in ‘Hockett’. Seven out of eight cultivars had greater grain weight for infested stems than for uninfested stems. These cultivars may have compensatory responses to larval feeding injury. Overall, these barley cultivars contain varying levels of antixenosis, antibiosis, and differing levels of yield compensation. Our results provide foundational knowledge on barley traits that will provide a framework to further develop C. cinctus resistant or tolerant barley cultivars.

Syzygium Polyanthum Wight Leaf Extract Evaluation On Aedes Spp Instar III-IV Larvae

Aedes spp mosquitos are the vectors that most cause diseases. The rise of insecticide resistance is related to the increasing of vectorial capacity. Plant can be used as an alternative source for controlling these vectors, one of which is Syzygyium polyanthum (Wight). The present study was conducted to investigate the larvasidal properties of S. polyanthum leaf on Aedes spp instar III-IV. Ethanolic extract of S. polyanthum (EESP) was prepared by maceration using ethanol 70%. Larvae were divided into 7 groups (n=25, respectively). Group I to V consisted of different concentrations of EESP (100 (CI);150 (CII);200 (CIII);250 (CIV);300ppm (CV)); VI: Water (W) and VII : Temephos 1% (T). Larvacidal activity was evaluated by calculating the dead larva at 180. 360, 1440 and 2880 minutes to obtain Lethal Concentration 50% (LC50) and Lethal Time 50% (LT50) using Statistical Product and Service Solution (SPSS). The result showed that no larva found dead in W-treated group. Otherwise, the mortality of larva was increased with increasing of EESP concentration (CI to CV). LC50 and LT50 showed 213 ppm and 2410 minutes, respectively. We conclude that EESP has larvicidal activity on Aedes spp instar III-IV. Keywords: Aedes spp, extract, larvicidal, Syzygium polyanthum

Biological activities of spores and metabolites of some fungal isolates on certain aspects of the spiny bollworms Earias insulana (Boisd.) (Lepidoptera: Noctuidae)

Biological activities of spores and metabolites of some fungi isolated from dead larva of the spiny bollworms (SBW), Earias insulana (Boisd.) (Lepidoptera: Noctuidae), against the newly hatched larvae of the pest were carried out. Results showed that the fungi Metarhizium anisopliae, Acremonium sp., and Paecilomyces variotii had affected the newly hatched larvae of (SBW). Acremonium sp. was the most potent one as it had the highest newly hatched larval mortality percentage (65 and 58.33%) for its spore suspension and metabolites, respectively, while the lowest one (41%) was for P. variotii metabolites. Also, spore suspensions of the all fungal isolates had the highest larval mortality than fungal metabolites. Studying the enzymatic activity showed that Acremonium sp. produced protease enzyme on media containing gelatin, which caused the highest larval mortality (72.22%).These isolates showed different effects on all stages of the pest and decreased pupal weight, adult emergence percentages, deposited eggs, and hatchability percentages than the control. Identification of Acremonium sp. EZ1 was confirmed using 18 s rRNA and its accession number MN25101.

Cerebral sparganosis caused by Spirometra mansonoides

✓ Cerebral sparganosis is an uncommon parasitic zoonosis caused by the migrating larva of the genus Spirometra mansonoides. The clinical and computerized tomography presentation, as well as the operative and histopathological findings, of the first known case in Mexico are detailed. The dead larva elicited intense acute inflammation resulting in focal encephalitis. Surgical removal of the larva yielded excellent results.

A New Species of Paraprosalpia Villeneuve (Diptera: Anthomyiidae) Reared From a Beetle Larva

Paraprosalpia dytisci new species is described from a larva, puparia, and adults reared from a dead larva of Dytiscus fasciventris Say, collected in southern Ontario.