Supplemental feeding of insect larvae increases mass of nestling Eastern Bluebirds, but not nestling Black‐capped Chickadees

To date, vaccination has become one of the most effective strategies to control and reduce infectious diseases, preventing millions of deaths worldwide. The earliest vaccines were developed as live-attenuated or inactivated pathogens, and, although they still represent the most extended human vaccine types, they also face some issues, such as the potential to revert to a pathogenic form of live-attenuated formulations or the weaker immune response associated with inactivated vaccines. Advances in genetic engineering have enabled improvements in vaccine design and strategies, such as recombinant subunit vaccines, have emerged, expanding the number of diseases that can be prevented. Moreover, antigen display systems such as VLPs or those designed by nanotechnology have improved the efficacy of subunit vaccines. Platforms for the production of recombinant vaccines have also evolved from the first hosts, Escherichia coli and Saccharomyces cerevisiae, to insect or mammalian cells. Traditional bacterial and yeast systems have been improved by engineering and new systems based on plants or insect larvae have emerged as alternative, low-cost platforms. Vaccine development is still time-consuming and costly, and alternative systems that can offer cost-effective and faster processes are demanding to address infectious diseases that still do not have a treatment and to face possible future pandemics.

Download Full-text

Need for growing non-Bt cotton refugia to overcome Bt resistance problem in targeted larvae of the cotton bollworms, Helicoverpa armigera and Pectinophora gossypiella

Egyptian Journal of Biological Pest Control ◽

10.1186/s41938-021-00384-8 ◽

2021 ◽

Vol 31 (1) ◽

Author(s):

Muhammad Rafiq Shahid ◽

Muhammad Farooq ◽

Muhammad Shakeel ◽

Misbah Ashraf ◽

Zia Ullah Zia ◽

...

Keyword(s):

Helicoverpa Armigera ◽

Larval Mortality ◽

Pectinophora Gossypiella ◽

Bt Cotton ◽

Insect Larvae ◽

Plant Parts ◽

Arthropod Species ◽

Bt Resistance ◽

American Bollworm ◽

Helicoverpa Armígera

Abstract Background The effectiveness of Bacillus thuringiensis (Bt) cotton against target arthropod larvae is decreasing day by day. The comparative effect of Bt expression among Bt cotton varieties and different plant parts was observed against the cotton bollworms: Helicoverpa armigera and Pectinophora gossypiella larvae. Results In the present study, larval mortality of H. armigera was higher than P. gossypiella among selected Bt cultivars. Median lethal concentration (LC50) values were 8.91, 13.4, 14.0, and 36.4 for P. gossypiella, while 5.91, 4.04, 2.37, and 8.26 for H. armigera of FH-142, MNH-886, IR-3701, and FH-Lalazar, respectively. These values depicted that P. gossypiella had more Bt resistance problem than H. armigera larvae. The host range of both targeted insect larvae was different from each other due to the polyphagous feeding nature of the larvae of H. armigera that feed on different host plants, but P. gossypiella attacked only cotton with monophagous feeding habit. It was also notable from results that Bt expression in reproductive parts where the attacked pink bollworm was lower than the American bollworm, so the former had the maximum chance of resistance due to repeated exposure to Bt. Conclusions It was concluded that farmers be advised to follow the practice of growing non-Bt as a refuge crop to reduce the problem of Bt resistance in the target arthropod species.

Download Full-text

Juvenile hormone esterase activity repressive factor in the plasma of parasitized insect larvae.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)38517-5 ◽

1990 ◽

Vol 265 (19) ◽

pp. 10813-10816

Author(s):

Y Hayakawa

Keyword(s):

Juvenile Hormone ◽

Esterase Activity ◽

Insect Larvae ◽

Juvenile Hormone Esterase

Download Full-text

Florivory by the occupants of phytotelmata in flower parts can decrease host plant fecundity

Current Zoology ◽

10.1093/cz/zoab015 ◽

2021 ◽

Author(s):

Caio C C Missagia ◽

Maria Alice S Alves

Keyword(s):

Host Plant ◽

Negative Influence ◽

Female Fitness ◽

Insect Larvae ◽

Floral Tissue ◽

Trophic Effects ◽

Plant Fecundity ◽

Ephemeral Habitats ◽

Neutral Effect

Abstract Some types of plant accumulate liquid in their inflorescences creating phytotelmata. These environments protect the flowers against florivory, although they may be colonized by aquatic or semi-aquatic florivorous insect larvae, whose effects on the fitness of the plants remain unclear. We tested the hypothesis of floral antagonism by the occupants of phytotelmata, which predicts that florivory by the occupants of the phytotelmata represents a cost to the female fitness of the plant, reducing its fecundity. We manipulated experimentally the infestation by three florivores larvae species occupants of phytotelmata in inflorescences of Heliconia spathocircinata (Heliconiaceae) to test for negative direct trophic effects on the fecundity of the flowering and fruiting bracts. We found that the foraging of the hoverfly (Syrphidae) and moth (Lepidoptera) larvae in the inflorescences contributed to a decline in the fecundity of the plant. While the lepidopteran impacted fecundity when foraging in both flowering and fruiting bracts, the syrphid only affected the fruiting bracts, which indicates that the nectar and floral tissue are the principal resource exploited by the hoverfly. By contrast, soldier fly (Stratiomyidae) had a neutral effect on fecundity, while foraging in flowering or fruiting bracts. These findings corroborate our hypothesis, that herbivory by the larval occupants represents cost to the host plant having phytotelmata. The negative influence of this foraging on plant fecundity will nevertheless depend on the consequences of the exploitation of resources, which vary considerably in ephemeral habitats such as the phytotalmanta of flower parts.

Download Full-text