Complete Genome Analysis of a Novel Picorna-Like Virus From a Ladybird Beetle, Cheilomenes Sexmaculata

The ladybird beetle Cheilomenes sexmaculata (family Coccinellidae, order Coleoptera), is a common insect predator of agricultural pests. In this study, the full genome sequence of a novel picorna-like virus, temporarily named “Cheilomenes sexmaculata picorna-like virus 1” (CSPLV1), was identified from C. sexmaculata. The full-length sequence of CSPLV1 was 11,384 nucleotide (nt) in length (excluding the polyA tail) with one predicted open reading frame (ORF) encoding 3727 amino acids, a 13 nt 5' untranslated region (UTR) and a 187 nt 3' UTR. The ORF of CSPLV1 consisted of four distinct domains including an RNA virus helicase domain (3029-3319 nt), a peptidase domain (5555-6121 nt), an RNA-dependent RNA polymerase domain (7154-8101 nt) and a picorna-like coat protein domain (8606-9283nt). Phylogenetic analysis based on the conserved RdRP sequence showed that CSPLV1, together with Wuhan house centipede virus 3, Hypera postica associated virus 1 and Diabrotica undecimpunctata virus 1, formed as an unclassified group which is closely related to the clade Solinviviridae. To the best of our knowledge, CSPLV1 is the first picorna-like virus revealed in C. sexmaculata.

PENGARUH VARIETAS DAN POLA TANAM KAPAS TERHADAP KELIMPAHAN POPULASI PREDATOR HAMA PENGISAP DAUN Amrasca biguttula (ISHIDA)

ABSTRAK<br />Penanaman varietas tahan hama adalah salah satu cara pengendalian<br />serangga hama pengisap daun, A. biguttula, yang telah diadopsi petani<br />kapas di Indonesia. Penggunaan varietas tahan hama cukup efektif<br />menekan serangan hama pengisap ini. Namun demikian, peluang adanya<br />cara pengendalian alternatif patut dipertimbangkan, misalnya memanfaat-<br />kan faktor mortalitas biotik A. biguttula, seperti musuh alami. Penelitian<br />pengaruh varietas dan pola tanam kapas terhadap perkembangan populasi<br />predator hama pengisap daun A. biguttula telah dilakukan di Kebun<br />Percobaan Asembagus, Situbondo, dan di laboratorium Entomologi Balai<br />Penelitian Tanaman Tembakau dan Serat di Malang, mulai Januari sampai<br />Desember 2005. Penelitian ini bertujuan untuk mempelajari pengaruh<br />perbedaan varietas dan pola tanam kapas terhadap perkembangan predator<br />A. biguttula. Perlakuan terdiri atas dua faktor, yaitu faktor I adalah varietas<br />kapas dengan tingkat ketahanan terhadap A. biguttula berbeda-beda, yaitu:<br />(1) TAMCOT SP37 (peka), (2) Kanesia 7 (moderat), dan (3) LRA 5166<br />(tahan). Faktor II adalah pola tanam kapas, yaitu: (1) monokultur, dan (2)<br />tumpangsari dengan kedelai. Setiap perlakuan disusun secara faktorial<br />dengan rancangan petak terbagi (Split Plot) dengan tiga kali ulangan.<br />Parameter pengamatannya adalah populasi nimfa A. biguttula dan<br />predator. Di laboratorium dilakukan uji pemangsaan terhadap predator<br />terpilih dengan cara memberi umpan nimfa A. biguttula untuk mengetahui<br />kemampuannya memangsa per hari. Hasil penelitian menunjukkan bahwa<br />perbedaan tingkat ketahanan varietas terhadap A. biguttula mempengaruhi<br />perkembangan populasi kompleks predator. Lebih banyak predator<br />ditemukan pada TAMCOT SP37 dan Kanesia 7 dibanding pada LRA<br />5166. Sedangkan perbedaan pola tanam tidak menyebabkan perbedaan<br />populasi predator. Kapas monokultur maupun tumpangsari dapat<br />menyediakan lingkungan ideal bagi perkembangan kompleks predator.<br />Laba-laba dan Paederus sp. adalah predator yang populasinya lebih<br />dominan dibanding predator lainnya. Pada uji pemangsaan di<br />laboratorium, Paederus sp. mampu memangsa 15-25 nimfa A. biguttula<br />instar kecil dan 10-20 instar besar, sedangkan laba-laba per hari<br />memangsa 2-12 nimfa A. biguttula instar kecil dan besar.<br />Kata kunci: Kapas, Gossypium hirsutum, hama, Amrasca biguttula,<br />Paederus sp., nimfa, mortalitas biotik, varietas, pola tanam,<br />Jawa Timur<br />ABSTRACT<br />Effect of variety and cropping pattern of cotton on<br />population density of insect predator Amrasca biguttula<br />(Ishida)<br />Planting resistant variety of cotton is one of cultural method for<br />controlling sucking insect pest, A. biguttula. This method has widely been<br />applied by cotton farmers in Indonesia. Nevertheless, alternative control<br />should also be found to obtain better control of this pest, e.g. biological<br />control by using parasitoids and predators. Study on effect of variety and<br />cropping pattern of cotton to population density of insect predator of A.<br />biguttula was carried out at Asembagus Experimental Station and in<br />Entomology Laboratory of Indonesian Tobacco and Fiber Crops Institute<br />in Malang from January to December 2005. The objective of study was to<br />study the effect of variety and cropping pattern of cotton to population<br />density of insect predators. Treatment consists of two factors. The first<br />factor was cotton variety based on resistance to A. biguttula, viz.<br />TAMCOT SP37, Kanesia 7, and LRA 5166 known susceptible,<br />intermediate, and resistant to A. biguttula, respectively. The second factor<br />was cropping system with monoculture and intercropping with soybean.<br />Each treatments was arranged in Split Plot Design with three replications.<br />Parameter observed in field study were population of A. biguttula and its<br />predators. While, the laboratory study was to find out the daily prey<br />ability of selected predator by baiting nymph of A. biguttula.<br />The result showed that difference resistance of cotton variety<br />influenced the population density of insect predator. More insect predators<br />were found on TAMCOT SP37 and Kanesia 7 compared to LRA 5166,<br />while the density of insect predator was not affected by different cropping<br />pattern and it was due to the patterns provided better environment for<br />insect predator development. Spider and Paederus sp. were the dominant<br />insect predators found in the field because their population higher than<br />those other predators. Laboratory study showed that Paederus sp. preyed<br />15-25 younger and 10-20 older instar of nymph per day, while spider ate<br />2-12 nymphs of both age of A. biguttula per day.<br />Key words: Cotton, Gossypium hirsutum, pest, Amrasca biguttula,<br />Paederus sp., nymph, biotic mortality, variety, cropping<br />pattern, East Java

Influence of colour on oviposition behaviour in green lacewing Chrysoperla zastrowi sillemi (Esben - Petersen) (Neuroptera: Chrysopidae)

The Green lacewing, Chrysoperla zastrowi silleni (Esben-Peterson), also known as “aphidlion” is a beneficial insect predator of various insect pests. The laboratory experiment was conducted during 2018-19 to evaluate the substrate colour preference for egg laying by C. zastrowi sillemi. Egg receiving sheets were pasted with white, black, green, indigo blue, yellow, brown, violet, sky blue, pink, red and orange colour papers. Among all colours C. z. sillemi females preferred orange colour as a substrate for egg laying with maximum number of eggs (43.13/female/day) followed by red colour substrate (25.50 eggs/female/day). White and black were least preferred.