Psyche: A Journal of Entomology

From April to July 2019, an experiment was conducted in Khumaltar, Lalitpur (27°39.312′N, 85° 19.586′E, and 1322 m above sea level) to assess the effectiveness of plant materials on maize weevil (Sitophilus zeamais Motsch.) control under laboratory conditions (maintained room temperature of 28.5 ± 2°C, and relative humidity of 72 ± 5%) treatments were Acorus calamus (rhizome powder) @ 5 g·kg⁻¹, Melia azadirach (rhizome powder) seed) @ 5 g·kg⁻¹, Curcuma domestica (rhizome powder) @ 5 g·kg⁻¹, mustard oil @ 2 mL·kg⁻¹, Gingiber officinalis (rhizome powder) @ 5 g·kg⁻¹, rice husk ash @ 5 g·kg⁻¹, and an untreated control. These treatments were evaluated in a completely randomized design (CRD) with three replications. At four months, the grains treated with Acorus calamus had the least weight loss (6.66%), and grain damage (1.23%). Grain damage (18%), and weight loss (62.33%) were the highest in the control treatment. Similarly, grains treated with Acorus calamus had the fewest number of exit holes (3.10 per 100 g of maize seed), while the control treatment had the largest number of exit holes (45.10 per 100 g of maize seed). There was a significantly higher number of weevils in the control treatment (55.80 per 250 g maize grains), but only a few numbers of weevils in the Acorus calamus-treated grains (2.50 per 250 g maize grains). In contrast with other plant materials treated grains, the maize weevil showed a reduced preference for Acorus calamus- treated grains with low weight loss, and grain damage. These findings can be used to promote locally accessible botanicals for maize weevil control in Nepal.

The quality of feed plays an important role in the growth and development of silkworms and eventually in the economic traits of cocoons. This study was conducted to evaluate ten castors (Ricinus communis L.) genotypes and their feeding values on the rearing performance of Eri Silkworm (Samia cynthia ricini Boisduval) (Lepidoptera: Saturniidae) at Tepi, southwest Ethiopia. A total of ten castor genotypes were evaluated in a randomized complete block design (RCBD), and the suitability of castor genotypes as feed for a mixed strain of Eri-silkworm was also evaluated in a completely randomized design (CRD) under laboratory conditions. A hundred worms were used in each replication. Castor genotypes showed significant differences in fresh leaf yield. Among the castor genotypes tested, genotype 219645 recorded 439 g of ten fresh leaf yields. Results of Eri-silkworm rearing performance depict that a shorter larval period (22 days), a higher effective rate of rearing (94.54%), and a shorter life cycle (58 days) were observed in Eri-silkworm fed on leaves of the 200390 genotype, while a higher larval weight (6.16 g) was recorded in the Abaro genotype. However, higher cocoon weight (3.26 g), pupal weight (2.46 g), shell weight (0.45 g), and silk ratio (13.80%) were found in Eri-silkworms fed on leaves of genotype 219645. Hence, based on silkworm rearing performance, genotype 219645 showed relatively superior results and is recommended for future development work. Further studies should continue giving more emphasis to the multilocation study of genotype 219645 to understand its performance in the diverse growing environment.

The use of larvicides, especially in endemic regions, is recommended for malaria control. However, due to the excessive use of synthetic larvicides, resistance in mosquitoes and environmental pollution have been challenges. In the current study, nanoliposome containing clove and cinnamon essential oils and their major ingredients, i.e., eugenol and cinnamaldehyde, were first prepared; particle size and successful loading were investigated using DLS (Dynamic Light Scattering) and ATR-FTIR (Attenuated Total Reflection-Fourier Transform InfraRed) analysis. Larvicidal effects of the nanoliposomes and nonformulated samples were then investigated against Anopheles stephensi. The best-observed efficacy (LC₅₀ 5.4 μg/mL) was related to nanoliposomes containing eugenol with a particle size of 109 ± 4 nm. However, LC₅₀ values of the other three nanoformulations were also around 10 μg/mL; all four prepared nanoformulations were thus introduced as natural larvicides for further investigations in the field conditions.

The spatial distribution and seasonal dynamics of the spotted lanternfly (Lycorma delicatula) on tree of heaven (Ailanthus altissima) were studied in Pennsylvania through weekly sampling of 30 trees (6 sites, 5 trees/site) from 27 July to 8 November 2020. Adults found on each tree were separated into six within-tree positions (lower trunk, middle trunk, upper trunk, first branch, second branch, and above second branch) by four directions (East, South, West, and North). In total, 78,796 adults were counted at the six study sites during the 15-week period. Significant differences in total adult count were found among trees, with a mean of 2,627 (254–12,023) adults/tree. Study site, tree diameter, and cardinal direction had no significant impact on adult spatial distribution. However, significantly more adults were found on the middle (1077), the lower (865), and the upper trunk (337) compared with the first (194), the second (93), and above second branches (60). Most adults were congregated on the lower and middle trunks. Seasonal dynamics followed adult development and migration patterns in the field, with peak populations observed in weeks 35 (24–30 August) and 37 (7–13 September) before declining. Female-based sex ratios ranged from 77.3 to 100% according to weekly monitoring of the lower 1 m trunk of 10 trees at 2 sites (5 trees/site) for 12 weeks from 17 August to 8 November, with 7,356 females and 197 males counted, respectively. Impact factors such as attack patterns, intraspecific congregation, adult seasonality, and sexual dimorphism in host selection are discussed.

In a symbiosis, each participant gains more fitness benefits than is paid in maintenance costs for the symbiosis. The mugwort aphid, Macrosiphoniella yomogicola, is ant-associated, and the host mugwort Artemisia montana is a genet-producing plant that has clonal aboveground shoots. M. yomogicola infests most A. montana shoots from spring to midsummer, and attending ants also repel leaf-eaters of the host plant. However, most aphid colonies become extinct after budding of A. montana inflorescence after early August. A few surviving aphid colonies (1∼3 per genet) produce sexuparae in mid-October. The shoots on which the sexuparae emerged lost most of their fitness because the aphids strongly suppress budding and growth of inflorescence. However, as the shoots are genetic clones of each other, the appearance of stem mothers in the next spring may result in early spreading of the aphids and attending ants to clonal shoots, which would protect the host from leaf-eaters. Here, we show that all shoots on a genet with stem mothers are occupied by aphids and ants much faster than those on a genet without stem mothers. The attending ants repel leaf-eaters to unimportant leaves for the host. Our results suggest that, as the shoots of a genet are all clones, sustaining the aphids on a few shoots may be beneficial to a genet as a whole through kin selection.

West Nile (WN) virus has been detected in Morocco in 1996, 2003, and 2010. One WN human case and 94 equine cases with 42 deaths were reported in the first outbreak. The second and the last epizootics were in Kénitra and Mohammedia regions, respectively. Culex pipiens mosquitoes were strongly suspected as WN vectors during these epizootics in Morocco. To help propose the first insecticide resistance management strategy in Morocco, we provide baseline data on the resistance status of C. pipiens mosquitoes to insecticides most used in public health in Morocco. We investigated the resistance intensity of C. pipiens and the role of monooxygenases in pyrethroids resistance using the synergist piperonyl butoxide (PBO) in three prefectures of central Morocco: Mohammedia, Benslimane, and Skhirate. Bioassays were carried out using WHO (World Health Organization) diagnostic test kits for adult mosquitoes, with DDT 4%; deltamethrin 0.05%, 0.25%, and 0.5%; bendiocarb 0.1%, 0.5%, and 1%; and malathion 5%. The synergist PBO 4% was used to check for the involvement of detoxification enzymes in pyrethroids resistant populations. Mosquito populations tested displayed high resistance intensity to pyrethroids and carbamates in Mohammedia and moderate resistance intensity in Skhirate. In Benslimane, the resistance intensity of C. pipiens was high to carbamate and moderate to pyrethroids. The pre-exposure to PBO restored full or partial susceptibility to pyrethroids in the different regions. According to our finding, Mohammedia and Benslimane are at risk level 3 of control failure, while Skhirate is at risk level 2 of it. The employment of IRM is therefore imperative in all study sites.