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ABSTRACT Anthropogenic activities result in global change, including climate change, landscape degradation and pollution, that can alter insect physiology and immune defences. These changes may have contributed to global insect decline and the dynamics of insect‐transmitted diseases. The ability of insects to mount immune responses upon infection is crucial for defence against pathogens and parasites. Suppressed immune defences reduce fitness by causing disease‐driven mortality and elevated immune responses reduce energy available to invest in other fitness traits such as reproduction. Understanding the impact of anthropogenic factors on insect–pathogen interactions is therefore key to determining the contribution of anthropogenic global change to pathogen‐driven global insect decline and the emergence and transmission of insect‐borne diseases. Here, we synthesise evidence of the impact of anthropogenic factors on insect immunity. We found evidence that anthropogenic factors, such as insecticides and heavy metals, directly impacting insect immune responses by inhibiting immune activation pathways. Alternatively, factors such as global warming, heatwaves, elevated CO2 and landscape degradation can indirectly reduce insect immune responses via reducing the energy available for immune function. We further review how anthropogenic factors impact pathogen clearance and contribute to an increase in vector‐borne diseases. We discuss the fitness cost of anthropogenic factors via pathogen‐driven mortality and reduced reproductive output and how this can contribute to species extinction. We found that most research has determined the impact of a single anthropogenic factor on insect immune responses or pathogen resistance. We recommend studying the combined impact of multiple stressors on immune response and pathogen resistance to understand better how anthropogenic factors affect insect immunity. We conclude by highlighting the importance of initiatives to mitigate the impact of anthropogenic factors on insect immunity, to reduce the spread of vector‐borne diseases, and to protect vulnerable ecosystems from emerging diseases. [ABSTRACT FROM AUTHOR]

The colours of insects function in intraspecific communication such as sexual signalling, interspecific communication such as protection from predators, and in physiological processes, such as thermoregulation. The expression of melanin‐based colours is temperature‐dependent and thus likely to be impacted by a changing climate. However, it is unclear how climate change drives changes in body and wing colour may impact insect physiology and their interactions with conspecifics (e.g. mates) or heterospecific (e.g. predators or prey). The aim of this review is to synthesise the current knowledge of the consequences of climate‐driven colour change on insects. Here, we discuss the environmental factors that affect insect colours, and then we outline the adaptive mechanisms in terms of phenotypic plasticity and microevolutionary response. Throughout we discuss the impact of climate‐related colour change on insect physiology, and interactions with con‐and‐heterospecifics. [ABSTRACT FROM AUTHOR]

Conspicuous colouration increases male reproductive success through female preferences and/or male–male competition. Despite the advantages of conspicuous colouration, inconspicuous male morphs can exist simultaneously in a population due to genetic diversity, condition dependence or developmental constraints. We are interested in explaining the male dichromatism in Xanthagrion erythroneurum damselflies. We reared these damselflies in outdoor insectaries under natural conditions and showed that this species undergoes ontogenetic colour changes. The younger males are yellow and change colour to red 6–7 days after their emergence. We took red and yellow male reflectance spectra and found that red males are brighter than yellow males. Next, we aimed to determine whether ontogenetic colour change signals sexual maturity with field observations and laboratory experiments. Our field observational data showed that red males are in higher abundance in the breeding territory, and they have a higher mating frequency than yellow males. We confirmed these field observations by enclosing a red and a yellow male with two females and found that yellow males do not mate in presence of red males. To determine whether colour change signals sexual maturity, we measured mating success of males before and after colour changes by enclosing a single male at different age (day 3‐day 7) and colour (yellow, intermediate and red) with a single female in a mating cage. Males did not mate when yellow but the same male mated after it changed colour to red, suggesting the ontogenetic colour change signals sexual maturity in this species. Our study shows that male dichromatism can be age‐dependent and ontogenetic colour change can signal age and sexual readiness in non‐territorial insects. [ABSTRACT FROM AUTHOR]

Rice-based vaccines do not require high-cost purification. They are stable at room temperature, can eliminate the risk of attenuated vaccine strains, and are resistant to gastrointestinal degradation. We tested the applicability of an oral delivery system for tuberculosis (TB) and cholera antigens in transgenic rice for induction of immune responses in the mucosal compartment as well as in the systemic circulation. For vaccine development, we selected mycobacterial Ag85B antigen and immunoprotective P4 epitope of TcpA fused to the nontoxic cholera toxin B (CTB) subunit for immunization against TB and cholera, respectively, in independent constructs. The expression levels of CTB, CTB-TcpA, and CTB-Ag85B in transgenic lines containing stably integrated, chimeric genes showed up to 0.64%, 0.34%, and 0.02% of total rice seed protein, respectively. Oral immunization of mice with each of the three seed lines resulted in significantly increased levels of both anti-CTB IgG and IgA responses in the serum and IgA responses in the bronchoalveolar lavage (BAL) fluid. This indicated the capacity for oral immunization to elicit immune responses in the respiratory mucosal compartment. Plant-expressed TcpA could be detected in immunoblot analysis by using TcpA-specific commercial antibody, while there was no recognition of rice-expressed Ag85B by the commercial antibody raised against the latter antigen, where both antibodies were produced against the antigens expressed in the bacterial system. This study focused on identifying antigens resistant to both posttranslational modifications in plants and immunogenic under the proposed delivery system in animals for boosting the mucosal and systemic humoral immune response against enteric as well as respiratory pathogens. [ABSTRACT FROM AUTHOR]

Many animals use self-built structures (extended phenotypes) to enhance body functions, such as thermoregulation, prey capture or defence. Yet, it is unclear whether the evolution of animal constructions supplements or substitutes body functions-with disparate feedbacks on trait evolution. Here, using brown spiders (Araneae: marronoid clade), we explored if the evolutionary loss and gain of silken webs as extended prey capture devices correlates with alterations in traits known to play an important role in predatory strikes-locomotor performance (sprint speed) and leg spination (expression of capture spines on front legs). We found that in this group high locomotor performance, with running speeds of over 100 body lengths per second, evolved repeatedly-both in web-building and cursorial spiders. There was no correlation with running speed, and leg spination only poorly correlated, relative to the use of extended phenotypes, indicating that web use does not reduce selective pressures on body functions involved in prey capture and defence per se . Consequently, extended prey capture devices serve as supplements rather than substitutions to body traits and may only be beneficial in conjunction with certain life-history traits, possibly explaining the rare evolution and repeated loss of trapping strategies in predatory animals.