Notch Signaling in Insect Development: A Simple Pathway with Diverse Functions.

Notch signaling is an evolutionarily conserved pathway which functions between adjacent cells to establish their distinct identities. Despite operating in a simple mechanism, Notch signaling plays remarkably diverse roles in development to regulate cell fate determination, organ growth and tissue patterning. While initially discovered and characterized in the model insect Drosophila melanogaster, recent studies across various insect species have revealed the broad involvement of Notch signaling in shaping insect tissues. This review focuses on providing a comprehensive picture regarding the roles of the Notch pathway in insect development. The roles of Notch in the formation and patterning of the insect embryo, wing, leg, ovary and several specific structures, as well as in physiological responses, are summarized. These results are discussed within the developmental context, aiming to deepen our understanding of the diversified functions of the Notch signaling pathway in different insect species.

Role of the Hox Genes, Sex combs reduced, Fushi tarazu and Antennapedia, in Leg Development of the Spider Mite Tetranychus urticae.

Mites, the second largest arthropod group, exhibit rich phenotypic diversity in the development of appendages (legs). For example, the fourth pair of legs (L4) does not form until the second postembryonic developmental stage, namely the protonymph stage. These leg developmental diversities drive body plan diversity in mites. However, little is known about the mechanisms of leg development in mites. Hox genes, homeotic genes, can regulate the development of appendages in arthropods. Three Hox genes, Sex combs reduced (Scr), Fushi tarazu (Ftz) and Antennapedia (Antp), have previously been shown to be expressed in the leg segments of mites. Here, the quantitative real-time reverse transcription PCR shows that three Hox genes are significantly increased in the first molt stage. RNA interference results in a set of abnormalities, including L3 curl and L4 loss. These results suggest that these Hox genes are required for normal leg development. Furthermore, the loss of single Hox genes results in downregulating the expression of the appendage marker Distal-less (Dll), suggesting that the three Hox genes can work together with Dll to maintain leg development in Tetranychus urticae. This study will be essential to understanding the diversity of leg development in mites and changes in Hox gene function.

Potential of a winterschmidtiid prey mite for the production of the predatory mite Neoseiulus californicus (Acari: Phytoseiidae).

Mass rearing of the predatory mite Neoseiulus californicus (McGregor) (Acari: Phytoseiidae) using natural (prey) methods is costly and laborious, limiting its application in the biological control of pests. A high-production, low-cost method using a prey substitute would help to relieve this problem. Oulenziella bakeri Hughes (Acari: Winterschmidtiidae) could be an alternative prey source, but studies on the reproductive parameters of N. californicus under rearing conditions are lacking. This study evaluated the potential of O. bakeri as an alternative prey in N. californicus rearing by comparing developmental parameters among N. californicus reared on three diets based on an age-stage two-sex life table. We found that the preoviposition period and developmental time of N. californicus did not vary based on diet. The fecundity of N. californicus adults reared on O. bakeri was 29.8 eggs per female, which was lower than that of adults reared on Tetranychus urticae Koch (Acari: Tetranychidae) (42.9 eggs per female); there was no significant difference between O. bakeri and apple pollen (30.2 eggs per female). The oviposition rate of mites fed on O. bakeri was 69% of that fed on T. urticae. Neoseiulus californicus reared on O. bakeri and apple pollen showed the same intrinsic rate of increase (0.25 per day), which was 86% of the rate of those fed on T. urticae. Compared with predatory mites reared on natural prey, N. californicus reared on O. bakeri had a high survival rate and good oviposition and population growth parameters, suggesting that O. bakeri is suitable for the rearing of N. californicus.

Efficient CRISPR/Cas9-mediated ebony gene editing in the greater wax moth Galleria mellonella.

The greater wax moth, Galleria mellonella (Lepidoptera, Pyralidae), is a major bee pest that inflicts considerable harm on beehives, leading to economic losses. It also serves as a valuable resource insect and a model organism. The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system plays a crucial role in improving economic insect breeding and developing efficient agricultural pest management systems in Lepidoptera. However, the CRISPR/Cas9 protocols have not been developed for G. mellonella. Here, the Gmebony knockout (KO) strain was established using the CRISPR/Cas9 genome editing system. We obtained Gmebony KO strain in the G4 generation, which took approximately 10 months. When compared with wild-type, the head, notum, and the terminal abdominal surface of 1st to 4th instar larvae in the KO strain changed from yellow to brown, and these regions of the KO strain gradually transformed into a black color from the 5th instar larvae, and the body color of the adult moth in the KO strain changed to black. The developmental period of the early larval and the following larval instars extended. The embryonic hatchability of the Gmebony KO strain was significantly decreased. The pupal body weight of the Gmebony KO strain was not affected. The feasibility of the CRISPR/Cas9 methodology was validated by single-target editing of Gmebony. Our findings provide the first evidence that the ebony gene can serve as a pigmentation reference gene for genetic modifications of G. mellonella. Meanwhile, it can be utilized in the development of genome editing control strategies and for gene function analyses in G. mellonella.

A new species of the genus Sonotetranychus (Acari: Tetranychidae) from New Zealand.

The genus Sonotetranychus consisted of seven species prior to this study. Sonotetranychus menziesii sp. nov., collected on Nothofagus menziesii and N. fusca from New Zealand, is described based on females, protonymphs, deutonymphs and a male. An updated key to the species of Sonotetranychus is provided.

Ontogenetic development and redescription of Tribolonychus collyerae (Acari: Tetranychidae).

Tribolonychus collyerae Zhang & Martin is redescribed based on the larva, protonymph, deutonymph and adult male and female specimens from New Zealand. The ontogenetic development of chaetotaxy in Tribolonychus and the number and position of solenidia on tibia I are discussed. Patterns of setal addition on leg III and IV from larva to adult in Trilobonychus are different from the basic pattern of the Tetranychinae and allied genus Neonidulus.

Hotspots of new species discovery: new mite species described during 2007 to 2012.

The type localities of new mite species described in two journals (Systematic & Applied Acarology and Zootaxa) during the last six years (2007­2012) were surveyed to detect hotspots of new mite species discovery. Among the 642 papers examined, 71% of them contain new species, with 148 new species in 2007, 207 in 2008, 234 in 2009, 208 in 2010, 333 in 2011 and 249 in 2012. Systematic & Applied Acarology published about 3% of the total new species indexed by Zoological Record during 2007­2012, whereas Zootaxa published about 35% of the total. The 1379 new species are distributed unevenly among 150 mite families; the top 15 families accounted for 55% of all the species, and 86 of the 150 families have 1­3 species each. The top family is the Eriophyidae, which alone accounted for nearly 15% of the total new species. Geographically, the new species were described from 92 countries and their distribution among these countries is highly uneven. The top 10 countries accounted for 62% of all the new species and the top country, China, alone accounted for 18% of the total. The average number of new species per country is 15 and no more than a fifth of the countries are above the average, and 40% of the countries have only 1­3 new species each. The top country for each continent is China (248 species) for Asia, Australia (166 species) for Oceania, Brazil (76 species) for South America, Kenya (51 species) for Africa, USA (51 species) for North America and Russia (42 species) for Europe. Increased efforts in discovering and describing new species are much needed for biodiversity-rich countries in South America, Southeast Asia and Africa.

Redescription of three species of Aponychus from China with ontogenetic development and morphological variations of A. corpuzae (Acariformes: Tetranychidae).

Ontogenetic development of leg chaetotaxy, stylophore and striae of the dorsal integument, and variations of leg setal counts and length of idiosomal setae in Aponychus corpuzae are discussed. The following changes were observed during the ontogenetic development of A. corpuzae: the depth of the depression in stylophore increases; the dorsal striae gradually reduce in number and prominence; the length of dorsal setae sc1, c12, d12 and e1 reduce in size; adult dorsal setae much thicker than those of immature stages. There are a significant number of setae suppressed in A. corpuzae, often resulting in unique patterns and sexual dimorphism. The adult males and females of Aponychus firmianae and A. taishanicus from mainland China are redecribed, and a key to all Aponychus from mainland China is provided.

Revision of Neotrichobia Tuttle & Baker (Acari, Tetranychidae) with ontogenetic development and redescription of N. arizonensis.

The genus Neotrichobia Tuttle & Baker is redescribed with a revised diagnosis. The type species Neotrichobia arizonensis Tuttle & Baker, 1968 is redescribed based on larvae, protonymphs, deutonymphs and adults including the paratype male and deutonymph.

Genomics, transcriptomics, and peptidomics of the greater wax moth Galleria mellonella neuropeptides and their expression in response to lead stress.

Neuropeptides are crucial in regulation of a rich variety of developmental, physiological, and behavioral functions throughout the life cycle of insects. Using an integrated approach of multiomics, we identified neuropeptide precursors in the greater wax moth Galleria mellonella, which is a harmful pest of honeybee hives with a worldwide distribution. Here, a total of 63 and 67 neuropeptide precursors were predicted and annotated in the G. mellonella genome and transcriptome, in which 40 neuropeptide precursors were confirmed in the G. mellonella peptidome. Interestingly, we identified 12 neuropeptide precursor genes present in G. mellonella but absent in honeybees, which may be potential novel pesticide target sites. Honeybee hives were contaminated with heavy metals such as lead, enabling its bioaccumulation in G. mellonella bodies through the food chain, we performed transcriptome sequencing to analyze the effects of Pb stress on the mRNA expression level of G. mellonella neuropeptide precursors. After treatment by Pb, the expression of neuropeptide F1 was found to be significantly downregulated, implying that this neuropeptide might be associated with responding to the heavy metal stress in G. mellonella. This study comprehensively identified neuropeptide precursors in G. mellonella, and discussed the effects of heavy metals on insect neuropeptides, with the example of G. mellonella. The results are valuable for future elucidation of how neuropeptides regulate physiological functions in G. mellonella and contribute to our understanding of the insect's environmental plasticity and identify potential new biomarkers to assess heavy metal toxicity in insects.

A new species of Aponychus (Acariformes, Tetranychidae) from China.

Aponychus mai sp. nov. is the fourth reported species of Aponychus collected from bamboo in Baoshan City, Yunnan Province in Mainland China. We described this new species based on a larva, three deutonymphs and ten adults, and also explored the ontogenetic development, especially the discussion of the development in leg chaetotaxy.

Two New Species and a New Combination of the Subfamily Erythraeinae Based on Larval Stage (Acari: Trombidiformes: Erythraeidae) from China.

The species Eatoniana yangshuonicus (Haitlinger) comb. nov. is transferred from the genus Erythraeus to Eatoniana based on the basifemoral setal formula 2-2-1. Two new species, Eatoniana nanlingensis Xu and Jin sp. nov. and Erythraeus (Erythraeus) kunyuensis Xu and Jin sp. nov. are described and illustrated based on larvae. Eatoniana nanlingensis sp. nov. from the Oriental region (Guangdong Province), Er. (Er.) kunyuensis sp. nov. from the Palaearctic region (Shandong Province). An updated key to larval species of the genus Eatoniana of the world is presented.

Morphological changes and ontogenetic development of Amblyseius eharai Amitai & Swirski (Acari: Phytoseiidae).

This paper describes the immature and mature characteristics of Amblyseius eharai Amitai & Swirski in detail to determine its morphological ontogeny based on laboratory-reared specimens. The main changes during ontogeny are as follows: the pronotal shield extends to j6 level and opisthosoma is unsclerotized in the larva; the dorsum has two shields in the protonymph, pronotal shield slightly expended comparing to that of the larva, and the opisthonotal shield smooth and weakly sclerotized. The podonotal and opisthonotal shields in the deutonymph are partially fused, and the dorsal shield is complete, covering almost the entire opisthonotum in adults in both sexes. There are nine pairs of dorsal setae in the larva, 14 pairs in the protonymph, and 19 pairs in both deutonymph and adult. In deutonymphs, gender could be distinguished by the number of setae in the area around the anal valves. In protonymphs, all dorsal, hypostomal setae, and the macrosetae of leg IV appear and are consistent with the subsequent stages. The development of morphological traits in the ontogeny of A. eharai may provide some basic knowledge to distinguish it from closely related species.

Redescription and new record of Odontoscirus nipponicus Shiba, 1985 (Bdellidae: Odontoscirinae) from China with a description of its ontogeny.

Odontoscirus nipponicus Shiba, 1985 is recorded from China and is redescribed; male, tritonymph, deutonymph, protonymph, and larva are described and illustrated for the first time. Morphological observations on the ontogeny of this species are also provided.

Four New Species of Larval Charletonia and Leptus (Acari: Trombidiformes: Erythraeidae), with a Checklist of the Two Genera and Their Hosts from China.

Four new species, Charletonia rectangia Xu and Jin sp. nov., Leptus (Leptus) bomiensis Xu and Jin sp. nov., Leptus (Leptus) longisolenidionus Xu and Jin sp. nov., and Leptus (Leptus) striatus Xu and Jin sp. nov. are described and illustrated based on larvae. All four new species are from biodiversity hotspots, L. (L.) bomiensissp. nov. from the Eastern Himalayas biodiversity hotspot, while the other three species from the Indo-Burma biodiversity hotspot.

The Effects of Alternative Foods on Life History and Cannibalism of Amblyseius herbicolus (Acari: Phytoseiidae).

The development, survivorship, fecundity, and cannibalism of the predatory phytoseiid mite, Amblyseius herbicolus (Chant), fed six different alternative foods (Oulenziella bakeri, Tyrophagus putrescentiae, Aleuroglyphus ovatus, almond pollen (Prunus armeniaca), apple pollen (Malus pumila), maize pollen (Zea mays)), and natural prey (Tetranychus urticae) were determined in the laboratory. Our findings indicated that A. herbicolus that fed on all six alternative foods could normally complete its developmental and reproductive cycles. The shortest pre-adult developmental duration was observed when A. herbicolus fed on almond pollen (4.91 d) as well as T. urticae (4.90 d), and the longest when it fed on maize pollen (6.24 d). Pre-adult survival rates were higher when the predator fed on almond pollen (0.99), maize pollen (0.96), and O. bakeri (0.93). The highest fecundity was observed when A. herbicolus fed on apple pollen (28.55 eggs/female), almond pollen (26.06 eggs/female), and O. bakeri (26.02 eggs/female) in addition to T. urticae (48.95 eggs/female), and the lowest when it fed on maize pollen (7.84 eggs/female). The highest value of the intrinsic rate of increase (r) was obtained when A. herbicolus fed on O. bakeri (0.202 d-1) in addition to T. urticae (0.210 d-1), followed by almond pollen (0.163 d-1), and the lowest was when it fed on maize pollen (0.064 d-1). Cannibalism of conspecific eggs by adults of A. herbicolus did not occur when O. bakeri and T. urticae were provided. The cannibalism rate of the predatory mite was the lowest when fed on almond pollen, T. putrescentiae, and A. ovatus and the highest on apple pollen. Above all, when fed on O. bakeri and almond pollen, and with no or low cannibalism rate, A. herbicolus had the best development, survivorship, fecundity, and population parameters. Therefore, O. bakeri and almond pollen could be potential alternative foods for mass rearing programs of A. herbicolus or to support its population in the fields.

The first record of the water mite genus Ljania Thor, 1898 (Acari, Hydrachnidiae, Aturidae) from China, with description of two new species.

This is the first record of the genus Ljania Thor, 1898 (Axonopsinae, Aturidae, Hydrachnidiae, Acari) from China. Two new species, Ljania jini sp. nov. and Ljania guangxiensis sp. nov., are described from Guangxi Province, P. R. China. The new detections bring the total number of Chinese aturid mites to eleven species, representing seven genera.

Biology, ecology, and management of cotton mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae).

The cotton mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae), is a highly invasive and harmful pest. It causes considerable loss of cotton crops in China, India and Pakistan. Little is known about its bionomics since it was first recorded in Pakistan and India in 2005. Rapid spread of this pest worldwide has accelerated research on its biology, ecology and management. The P. solenopsis has a short life cycle, and optimal temperatures lead to an increase in the number of generations per year, which is a serious threat to cotton crop production. Cotton mealybug is native to the USA, although it has now spread to >43 countries. Insecticidal control is the primary and dominant practice for this pest, and its resistance to commonly used insecticides is increasing. Biocontrol agents have strong potential for the management of nymphal instar stages. We read >250 articles related to our review title and finally reviewed recent advances in the understanding of P. solenopsis biology, ecology and control approaches, aiming to highlight integrated and biological management practices of this pest. © 2021 Society of Chemical Industry.

Morphological changes in Neoseiulus californicus (Acari: Phytoseiidae).

This paper deals with the detailed morphological observation of larva, protonymph and deutonymph, as well as female and male adults of Neoseiulus californicus (McGregor) based on laboratory reared specimens. The main changes are as follows: larva with one dorsal shield, while protonymph with two, which fused into a holodorsal shield in deutonymph; 9 pairs of dorsal setae in larvae, 14 pairs in protonymph, and 19 pairs in deutonymph and adult; the immature stages without discernible ventrianal shield, though hypoplastic shield, a weakly sclerotized small plate around the anal pore, present in the protonymph and deutonymph. larva and protonymph each with seven pairs of ventral setae, while deutonymph and adult each with 12 pairs; movable digit with one or two teeth in larva, three teeth in protonymph, deutonymph or adult. The development of morphological traits in ontogenesis of N. californicus could provide helpful basis to identify it practically from its relatives.

Description of Cornigamasus allotritosternus sp. nov. (Mesostigmata: Parasitidae) from China, with an emphasis on the ontogenetic development of setae.

A new species, Cornigamasus allotritosternus sp. nov., is described based on the larva, protonymph, deutonymph and adult female and male collected from cow dung in Guizhou Province, China. The ontogenetic development of the gnathotectum, dorsal shields, ventral shields, and the chaetotaxy of the gnathosoma, idiosoma and legs are discussed and illustrated.