Oviposition selection in spotted lanternfly: impact of habitat and substrate on egg mass size and hatchability

Diploid chromosome-level genome assembly and annotation for Lycorma delicatula

The spotted lanternfly (Lycorma delicatula) is a planthopper species (Hemiptera: Fulgoridae) native to China but invasive in South Korea, Japan, and the United States where it is a significant threat to agriculture. Genomic resources are critical to both management of this species and understanding the genomic characteristics of successful invaders. We report an annotated, haplotype-phased, chromosome-level genome assembly for the spotted lanternfly using PacBio long-read sequencing, Hi-C technology, and RNA-seq. The 2.2 Gbp genome comprises 13 chromosomes, and whole genome resequencing of eighty-two adults indicated chromosome four as the sex chromosome and a corresponding XO sex-determination system. We identified over 12,000 protein-coding genes and performed functional annotation, facilitating the identification of candidate genes that may hold importance for spotted lanternfly control. The assemblies and annotations were highly complete with over 96% of BUSCO genes complete regardless of the database (i.e., Eukaryota, Arthropoda, Insecta). This reference-quality genome will serve as an important resource for development and optimization of management practices for the spotted lanternfly and invasive species genomics as a whole.

Host Plants for the Lanternfly Saiva formosana Kato, 1929 (Hemiptera, Fulgoridae) Endemic to Taiwan, and Parasitism of Its Eggs by Wasps

Since Saiva formosana Kato, 1929 was first reported as a new species in Taiwan; there have been few published reports on its ecology, and fundamental knowledge of this species is still lacking. The objectives of this study are to (1) determine the preferred plants of adults, egg-laying, and nymphs, (2) analyze the change in host plants with time and development, and (3) explore the relationship between the survival of eggs and parasitism by their wasps. We detected the adults of this species between May and September 2023, and again in April 2024, mainly on Elaeocarpus decipiens F. B. Forbes & Hemsl. During our investigation, we frequently observed parasitic wasps ovipositing on the egg masses. We established that most egg masses produced only Saiva nymphs or Anastatus adults. This lanternfly might better survive parasitic pressure by laying lower numbers of eggs per mass across a broader range of plant species. The first batch of hatching nymphs was found on Magnolia compresssa Maxim. on 20 June 2023; however, most nymphs in the second and third instars were detected on Ficus fistulosa Reinw. ex Blume, between August and October 2023. After the autumn, the occurrences of nymphs increased on Heptapleurum heptaphyllum (L.) Y. F. Deng which probably served as a shelter for overwintering.

N-mixture models for population estimation: Application in spotted lanternfly egg mass survey

Population density and structure are critical to nature conservation and pest management. Traditional sampling methods such as capture-mark-recapture and catch-effort can't be used in situations where catching, marking, or removing individuals are not feasible. N-mixture models use repeated count data to estimate population abundance based on detection probability. They are widely adopted in wildlife surveys in recent years to account for imperfect detection. However, its application in entomology is relatively new. In this paper, we describe the general procedures of N-mixture models in population studies from data collection to model fitting and evaluation. Using Lycorma delicatula egg mass survey data at 28 plots in seven sites from the field, we found that detection probability (p) was negatively correlated with tree diameter at breast height (DBH), ranged from 0.516 [95 % CI: 0.470-0.561] to 0.614 [95 % CI: 0.566-0.660] between the 1st and the 3rd sample period. Furthermore, egg mass abundance (λ) was positively associated with basal area (BA) for the sample unit (single tree), with more egg masses on tree of heaven (TOH) trees. More egg masses were also expected on trees of other species in TOH plots. Predicted egg mass density (masses/100 m2) ranged from 5.0 (95 % CI: 3.0-16.0) (Gordon) to 276.9 (95 % CI: 255.0-303.0) (Susquehannock) for TOH plots, and 11.0 (95 % CI: 9.00-15.33) (Gordon) to 228.3 (95 % CI: 209.7-248.3) (Burlington) for nonTOH plots. Site-specific abundance estimates from N-mixture models were generally higher compared to observed maximum counts. N-mixture models could have great potential in insect population surveys in agriculture and forestry in the future.