Herbivore-Induced Rice Volatiles Attract and Affect the Predation Ability of the Wolf Spiders, Pirata subpiraticus and Pardosa pseudoannulata

Spiders are important natural enemies of rice pests. Studying the effects of herbivore-induced rice volatiles on spider attraction and predation ability may lead to safer methods for pest prevention and control. In this study, four-arm olfactometer, predation ability experiment, and field trapping experiment were used to evaluate the effects of herbivore-induced rice volatiles on Pirata subpiraticus Bösenberg et Strand (Araneae: Lycosidae) and Pardosa pseudoannulata Bösenberg et Strand (Araneae: Lycosidae). The 0.5 μg/μL linalool concentration was attractive, and also shortened the predation latency in male P. subpiraticus and female P. pseudoannulata. The 0.5 μg/μL linalool concentration increased the daily predation capacity of female P. pseudoannulata. Male P. pseudoannulata were attracted to 1.0 g/L methyl salicylate, which also shortened their predation latency. In field experiments, methyl salicylate and linalool were effective for trapping spiders. Herbivore-induced rice volatiles attract rice field spiders and affect their predatory ability. These results suggest that herbivore-induced rice volatiles can be used to attract spiders and provide improved control of rice pests.

Modest sexual size dimorphism and allometric growth: a study based on growth and gonad development in the wolf spider Pardosa pseudoannulata (Araneae: Lycosidae)

ABSTRACT Sexual size dimorphism (SSD) is a notable phenomenon in terrestrial animals, and it is correlated with unusual morphological traits. To date, the underlying sex-specific growth strategies throughout the ontogenetic stage of spiders are poorly understood. Here, we comprehensively investigated how the growth trajectories and gonad development shaped SSD in the wolf spider Pardosa pseudoannulata (Araneae: Lycosidae). We also hypothesized the potential growth allometry among the carapace, abdomen, and gonads of spiders in both sexes. By measuring the size of the carapace and abdomen, investigating developmental duration and growth rate, describing the gonadal sections, and calculating the area of gonads at all instars from hatching to maturity, we demonstrated that SSD results from sex-specific growth strategies. Our results indicated that the growth and developmental differences between both sexes appeared at early life stages, and there was allometric growth in the carapace, abdomen, and gonads between males and females.

Genomic Identification and Functional Analysis of JHAMTs in the Pond Wolf Spider, Pardosa pseudoannulata

Juvenile hormone (JH) plays a critical role in many physiological activities of Arthropoda. Juvenile hormone acid methyltransferase (JHAMT) is involved in the last steps of JH biosynthesis as an important rate-limiting enzyme. In recent studies, an increasing number of JHAMTs were identified in arthropods, but no JHAMT was reported in spiders. Herein, eight JHAMTs were identified in the pond wolf spider, Pardosa pseudoannulata, all containing the well conserved S-adenosyl-L-methionine binding motif. JHAMT-1 and the other seven JHAMTs were located at chromosome 13 and chromosome 1, respectively. Multiple alignment and phylogenetic analysis showed that JHAMT-1 was grouped together with insect JHAMTs independently and shared high similarities with insect JHAMTs compared to the other seven JHAMTs. In addition, JHAMT-1, JHAMT-2, and JHAMT-3 were highly expressed in the abdomen of spiderlings and could respond to the stimulation of exogenous farnesoic acid. Meanwhile, knockdown of these three JHAMTs caused the overweight and accelerated molting of spiderlings. These results demonstrated the cooperation of multi-JHAMTs in spider development and provided a new evolutionary perspective of the expansion of JHAMT in Arachnida.

Keanekaragaman Artropoda Predator di Agroekosistem Sawah pada Berbagai Galur Padi Politeknik Negeri Lampung

Artropoda predator dapat dioptimalkan perannya di ekosistem sawah untuk menekan populasi hama. Tujuan dari penelitian ini adalah untuk menganalisis nilai indeks keanekaragaman artropoda predator pada galur padi rakitan Politeknik Negeri Lampung. Penelitian ini telah dilaksanakan pada bulan Agustus-Desember 2020. Penelitian dilaksanakan di lahan Seed Teaching Farm Program Studi Teknologi Perbenihan, Politeknik Negeri Lampung dengan galur padi Pandan Wangi (PW), Ciherang (CH), B1, B2, B3, B4, B7, D2, D3, F3, F4, H1, H4, K, dan L2 dengan 2 varietas unggul pembanding yaitu Ciherang (CH) dan Gilirang (Gil). Pengamatan artropoda dilakukan menggunakan metode jaring dilakukan sebanyak 3 ayunan ganda. Pengambilan sampel serangga dilakukan pada pukul 06.00- 09.00 WIB. Identifikasi menggunakan makroskop binokuler di Laboratorium tanaman pangan II. Data hasil identifikasi serangga kemudian dihitung nilai indeks keanekaragaman spesies Shannon (H’), indeks dominasi spesies Berger-Parker (d) dan indeks kemerataan spesies dari Pielou (E). Hasil pengamatan menunjukkan bahwa artropoda predator yang ditemukan adalah laba-laba predator seperti Oxyopes javanus, Tetragnatha javana, T. virescens, T. maxilosa, Pardosa pseudoannulata, Athypena sp., dan serangga predator seperti Microvelia douglasi, Agriocnemis pygmaea, A. femina, A. pieris, dan Verania lineata, Menochillus sexmachulatus, Hispella atra, dan Paederus fuscipes. Nilai indeks keanekaragaman pada setiap galur padi fluktuatif dan berkisar dari rendah ke sedang.

Faunal Biodiversity of Lycosidae (Araneomorphae: Araneae: Arachnida) in India: An Updated Checklist

Faunal biodiversity of the wolf spiders (Lycosidae: Araneomorphae: Araneae: Arachnida) in different states of India and union territories is presented herewith. A total of 155 species placed under 25 genera of Lycosidae were recorded in all states and union territories of India except Nagaland, Daman and Diu and Dadra and Nagar Haveli, and Lakshdweep, out of which 91 species (58.7%) were strictly endemic. However, among them 8 species seem to be erroneous report or misidentification. Maximum number of speci es were recorded in Maharashtra followed by 65 species in West Bengal, 57 species in Gujarat, 50 species in Uttarakhand, 39 species in Madhya Pradesh, 38 species in Kerala, 36 species in Karnataka, 33 species in Jammu and Kashmir and less than 30 species are recorded in other states. Six species of Lycosidae are widely distributed, viz. Wadicosa fidelis (O. Pickard-Cambridge, 1872) (25 states, 3 union territories), Pardosa sumatrana (Thorell, 1890) (23 states, 1 union territory), Pardosa pseudoannulata (Bösenberg and Strand, 1906) (19 states, 1 union territory), Hippasa agelenoides (Simon, 1884) (17 states, 1 union territory), Hippasa greenalliae (Blackwall, 1867) (16 states, 1 union territory), and Lycosa tista Tikader, 1970 (16 states). About one-third of the species of Lycosidae reported in India are recorded only in one state or from the type locality. Hence, extensive faunistic surveys for these spiders are required.