The assumption that the invertebrate immune system lacks memory and specificity has changed over time: many studies now indicate that a primary exposure of the host to a pathogen increases its resistance to a subsequent lethal challenge, a phenomenon known as immune priming. One group of insects in which immune priming has been little investigated is the hematophagous triatomine bugs. Herein, we tested the capability of the kissing bug Rhodnius pallescens Barber (Hemiptera: Reduviidae; hereafter kissing bugs), the vector of Chagas disease, to resist entomopathogenic fungi. Laboratory kissing bugs free of Wolbachia and Trypanosoma spp. as well as kissing bugs collected from the wild were used for tests with the entomopathogen Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae). Against laboratory kissing bugs, the fungus remained virulent for 94 d, indicating long-term viability. Kissing bugs collected from the wild that were exposed to a nonlethal dose of the fungus did not show increased survival against a lethal dose compared with controls inoculated with the lethal dose. However, kissing bugs inoculated with a nonlethal dose had higher levels of total phenoloxidase than control kissing bugs. Although the fungus activates the immune system of the kissing bugs, other variables may influence survival in the face of infection. Moreover, the lethality of the same strain was lower against wild kissing bugs, suggesting that the presence of symbionts or parasites influence the fungus–triatome (host) interaction. This work is one of the few studies that have investigated the fungus–host interaction in terms of immune priming in a hematophagous insect of public health importance. Implications are discussed.

In Mexico, a large number of insects are used by indigenous groups for food, medicine, and the arts. The objective of this research was to review and identify edible insects in communities in the municipality of Escarcega, state of Campeche, Mexico. We conducted a literature review and interviewed residents of 12 communities in Escarcega. The interview consisted of questions about insects that they or others may have consumed, the location of collection of those insects, the times of the year when the insects appear, the methods of capture, and the ways that they were used. We determined that 25 insect species are consumed by humans in the 12 communities studied. In the communities of Constitución and Ej. Km. 74, Brachygastra mellifica Say (Hymenoptera: Vespidae) larvae are consumed year-round. Our results serve as a foundation for future research on the use and production of insects for food in rural and indigenous communities in southern Campeche and represent an initial approach to acquiring knowledge for the use of insects as a food source in Campeche to guarantee food security in such communities.

Chemosensory proteins (CSPs) are widely distributed in insect tissues and are involved in olfactory and non-olfactory functions. In this study, based on the transcriptome data of Agrilus zanthoxylumi Hou (Coleoptera: Buprestidae), the AzanCSP4 of was cloned by RT-PCR and bioinformatically analyzed, and RT-qPCR was conducted to analyze their expression levels of AzanCSP4 in different genders and tissues (head, thorax, abdomen, leg and wing). Sequence analysis showed that AzanCSP4 had an open reading frame (ORF) length of 366 bp, encoding 121 amino acids with an estimated molecular weight 13.96 kD. The encoded protein had no transmembrane domain, and the signal peptide was located in the position 1–15 at the N-terminal of the amino acid sequence. Sequence alignment revealed that AzanCSP4 had four conserved cysteines. Phylogenetic analysis revealed that the AzanCSP4 and AmalCSP6 from Agrilus mali Matsumura (Coleoptera: Buprestidae) were closely clustered into the same clade. RT-qPCR results showed that AzanCSP4 of A. zanthoxylumi was expressed in different tissues of both male and female adults, and the expression in the same tissue was greater in female adults than in male adults. The expression of AzanCSP4 in the head of female adults was significantly higher than that in other tissues of male and female adults. This study provides a theoretical basis for further research on the function of AzanCSP4, especially on the chemical communication mechanism in A. zanthoxylumi.

The cotton aphid (Aphis gossypii Glover) (Hemiptera: Aphididae) is a major pest of cotton (Gossypium hirsutum L.) grown in Xinjiang and is an agricultural pest found worldwide. With the extensive use of insecticides, A. gossypii in Xinjiang has developed high levels of resistance to a variety of insecticides. Afidopyropen is a new biogenic insecticide that is effective against insects with piercing-sucking mouthparts and has no cross-resistance with any commonly used insecticides in cotton fields. However, to our knowledge, the risk and stability of resistance of A. gossypii to afidopyropen and its detoxification enzymes under high selection pressure have not yet been elucidated. In this study, resistant A. gossypii specimens were selected with the cotton leaf-dipping method under laboratory conditions, and the realized heritability of A. gossypii resistance to afidopyropen was calculated using domain trait analysis. After 18 successive generations of selection for afidopyropen resistance, a resistant population with a median lethal dose (LC₅₀) of 9.006 mg/L was obtained; the resistance ratios had increased 23.033 times. The realized heritability was 0.063, and a 10-fold increase in resistance required only 20–26 generations when mortality was 60–80%. The 15th generation of the resistant strain had some resistance instability, and glutathione S-transferases played an important role in the detoxification metabolism of afidopyropen. The results of this study provide a basis for application of afidopyropen and management of A. gossypii resistance.

A new species of a staphylinid beetle, Paleothius mckayi sp. n. is described using a single fossil from the Orapa Diamond Mine in Botswana. Paleothius is placed in the extant subfamily Staphylininae based on its general symmetrical habitus, typical sub-limuloid and elongated medium-to-large body form, elongated head, remarkably long antennomere 1, antennal density increasing apically, antennal insertions closer to the eye than to each other, tapering abdomen with two pairs of paratergites, and intersegmental membranes with ‘brick-wall’ pattern. It is separated from its sister clade Paederinae by having exposed antennal insertions and a small post-coxal process. It can be distinguished from all other Staphylininae by its significantly curved temples and large subtriangular pro-, meta- and meso-coxae. The specimen is preserved with flexed, distally-sharpened, extended or protruding scissor-like mouthparts. It is possible that it was primarily using these extended or protruding scissor-like mouthparts to actively hunt prey in leaf litter and other microhabitats in and around the crater lake at Orapa. This fossil further confirms the widespread distribution of staphylinines during the Cretaceous. Moreover, similarly to other previously described fossil staphylinine staphylinid beetles, it portrays morphological stasis, or morphological conservatism. This is also known as arrested evolution. Therefore, it provides evidence for punctuated evolution dating back to the Cretaceous. Moreover, it highlights that morphological similarities between Staphylininae and Paederine date back to the Jurassic period.

We investigated the effectiveness and biochemical impact of the insecticides flubendiamide and flonicamid compared with azadirachtin and acetamiprid against the whitefly Bemisia tabaci (Grennadius) (Hemiptera: Aleyrodidae) infesting cherry tomato (Solanum lycopersicum var. cerasiforme L.) grown under greenhouse conditions. The dissipation of both insecticides in the plants and in the soil also was determined using the QuEChERS (quick, easy, cheap, effective, rugged, and safe) and liquid chromatography–electrospray ionization–mass spectrometry methods. Both insecticides were more effective for reducing B. tabaci populations than were either acetamiprid or azadirachtin. Biochemical analysis revealed that esterase may play an important role in whitefly adaptation to flubendiamide and flonicamid. The QuEChERS method was determined suitable for quickly detecting residues of flubendiamide and flonicamid in complex matrices. The recovery rates on tomato fruit samples were 92.8–106.0%, with a relative standard deviation (RSD) range of 0.46–2.65%. For soil samples, the recovery rates were 81.3–95.7% with RSDs of 1.20–3.86%. We further determined that flubendiamide had dissipation half-lives of 3.13, 3.63, and 3.68 d in tomato fruit, tomato leaves, and soil, respectively. Flonicamid had half-lives of 4.25, 3.54, and 2.60 d in fruit, leaves, and soil, respectively. These results suggest that preharvest intervals of 3 and 7 d are appropriate for flubendiamide and flonicamid, respectively, in cherry tomato production. The risk quotient was >1 by the day 5 after application; however, that value declined to <1 on day 7 after application, indicating little long-term risk to human health.

The maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), is a major pest of stored grains that feeds on and develops inside the grain. The trehalose analog validamycin has a strong inhibitory effect on insect trehalase. Studies have found that validamycin affects several insects; however, no information is available on its inhibitory and physiological effects on these insects. In this study, validamycin's inhibitory effect on trehalase was examined by incorporating it into artificial seeds and feeding them to S. zeamais. Trehalase activity was recorded throughout the developmental stages of the exposed weevils and was highest in the larval followed by adult, pupal, and egg stages. We found that feeding adult S. zeamais artificial seeds containing validamycin resulted in a significant reduction of trehalase activity in both males and females, although the primary source of trehalase was in the intestinal tract rather than in the reproductive organs. The validamycin treatment also had a concentration-dependent lethal effect, resulting in approximately 90% mortality, with females being more susceptible than males. In addition, the validamycin treatment caused a significant reduction in the number of first-generation progeny and S. zeamais demonstrated delayed development in a concentration-dependent manner. These data show that validamycin influences trehalase enzyme activity, reproductive success, and development of S. zeamais. The results obtained from this research will be valuable tools for designing a control strategy.

Maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), is a major insect pest of stored grain products, causing extensive damage to both grain quantity and quality. The application of synthetic insecticides to control this insect has a negative impact on human health and the environment. Essential oils derived from natural plants are recognized as user- and environmentally friendly alternatives. The use of essential oils from Lamiaceae, which exhibit toxic properties through contact, fumigation, and repellency, provides another option for protecting stored products from various insect pests. The aim of this research was to study the chemical constituents and insecticidal activity of essential oil extracted from the leaves of Indian borage, Plectranthus amboinicus (Lour.) (Lamiales: Lamiaceae), against S. zeamais adults.The chemical composition of the essential oil was analyzed using gas chromatography–mass spectrometry, and the insecticidal activity against adult maize weevils was investigated in the laboratory. The experimental plan followed a completely randomized design with five replications of seven treatments or concentrations of the essential oil: 0, 0.5, 1, 1.5, 2, 2.5, and 3 ml/ml air. The results revealed that the essential oil from the leaves of P. amboinicus contained 23 chemical constituents (97.51%). Thymol (49.96%) was identified as the main compound followed by caryophyllene, trans-α-bergamotene, 3-methyl-4-isopropyl-phenol, γ-terpinene, p-cymene, caryophyllene oxide, humulene, 4-hydroxy-2-methylacetophenone, 2-hydroxy-2-phenylbutyramide, (2-oxazolidinylidene)malononitrile, hexestrol, terpinen-4-ol, 1-octen-3-ol, (1R,7S,E)-7-isopropyl-4,10-dimethylenecyclodec-5-enol, α-bisabolene, isoaromadendrene epoxide, α-farnesene, 4-carene, α-muurolene, 3-hexen-1-ol, ledene oxide-(II), and α-myrcene, respectively. The fumigation toxicity (median lethal concentration) to maize weevil adults at 48 h was 292.53 ml/ml air. The essential oil from the leaves of P. amboinicus, when applied at a concentration of 2 ml/ml air for 144 and 168 h, resulted in adult maize weevil mortality exceeding 90%. The highest concentration tested (3 ml/ml air) led to exceptionally high mortality rates, with 99–100% of the maize weevils succumbing to the treatment. These findings demonstrate that essential oil from P. amboinicus leaves holds promise as a fumigation insecticide for reducing the population of maize weevils, a significant pest in stored products.

Oligonychus afrasiaticus (McGregor) (Acari: Tetranychidae) is a major pest that causes significant economic losses to date palm, Phoenix dactylifera L. (Arecales: Arecaceae), fruit in southern Tunisia and Algeria, where climatic conditions are highly conducive to development of this insect. In our efforts to develop sustainable management alternatives for O. afrasiaticus, essential oils extracted from Lantana camara L. and Ruta chalepensis L. were tested against O. afrasiaticus adult females. Both essential oils exhibited acaricidal activity against O. afrasiaticus in laboratory bioassays of concentration–mortality responses. At 96 h after exposure, the median lethal concentrations were 5,259 µl/ml for the L. camara extract and 3,329 µl/ml for the R. chalepensis extract. Based on median lethal times, the acute toxicity of the extracts against O. afrasiaticus was higher with L. camara than with R. chalepensis at a concentration of 50 ml/ml. Gas chromatography–mass spectrometry analysis revealed that the primary constituents of the essential oil extracted from L. camara were humulene (26.65%), caryophyllene (26.33%), and γ-muurolene (14.22%). The predominant compounds in the essential oil obtained from R. chalepensis were 2-undecanone (50.52%), 2-nonanone (11.27%), and 2-octanol, acetate (9.17%). These two essential oils have potential for development as botanical acaricides for the management of O. afrasiaticus in date palm production in this region.

Evidence is accumulating that insect epsilon class glutathione S-transferases (GSTs) play an important role in the resistance to xenobiotics such as insecticides. A Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) epsilon class GST gene, TcGSTe17, was previously found to be significantly induced following exposure to the plant derivative eucalyptol. However, whether TcGSTe17 is involved in resistance to eucalyptol remains unclear. In this study, TcGSTe17 was cloned from the T. castaneum. Development stage expression profiling revealed that TcGSTe17 was expressed at all development stages of T. castaneum but was highly expressed in late-stage larvae. Subsequent expression profiling of tissues showed that TcGSTe17 was highly expressed in the gut of larvae and the fat body of adults, and also revealed gender-specific expression patterns. In addition, the transcripts of TcGSTe17 were significantly increased following exposure to eucalyptol, and RNAi increased the susceptibility of the beetles to eucalyptol. Collectively, these results suggest that TcGSTe17 contributes to the susceptibility of T. castaneum to eucalyptol. These findings provide new data for the prevention of pest resistance.