The periodic occurrence of biological population is affected by several biological and environmental factors and ancient literature survey offers insight into ecological process related to the cyclicity. The periodic occurrence of a Lepidopteran species, the pine caterpillar (Dendrolimus spectabilis), was estimated based on ancient literature survey. The pine caterpillar was one of the most injurious defoliators of pine trees in northeast Asia, especially Korea during 1960s and 1970s. Outbreaks of this species have long history in Korea. Since about 900 years ago, damages of pine forest by this species and its control were recorded both in History of Corea dynasty which cover 475 years (918-1392) of the history of the Corea Dynasty and in the Annals of Joseon Dynasty (Joseon Wangjo Shillok) which cover 472 years (1392-1863) of the history of the Joseon Dynasty, respectively. At least over 20 and 30 occurrences of pine caterpillar were recorded during Corea dynasty and Joseon Dynasty, respectively. These results showed that the pine caterpillar had been one of the most severe forest pests during Corea and Joseon Dynasty. Our result showed that the ancient literature survey is useful to understand the long-term periodic occurrence of the pine caterpillar.
Most ectotherms mature at a larger body size in colder conditions. This negative relationship between developmental temperature and final body size is termed the temperature-size rule. In this study, we investigated how dietary protein:carbohydrate (P:C) balance modulates the fundamental relationship between temperature and body size in the final-instar caterpillars of Spodoptera litura. The magnitude and sign of the thermal reaction norm for body size were altered by the dietary P:C balance of the food eaten by caterpillars. The slope of the reaction norm was flat for caterpillars raised on a nutritionally balanced food (P:C = 1:1) but was negative for those on imbalanced foods (1:5 or 5:1). When allowed to self-compose their preferred diet, caterpillars preferred carbohydrate-rich food at higher temperatures. The negative impact of high temperature on body size was mitigated by such a temperature-driven shift in nutrient preference. This study highlights the importance of macronutrient balance as a key factor modulating the relationship between temperature and body size in insects.
나비목 종 다양성이 높은 지리산 온대 낙엽수림의 0.1 ha (33 m × 33 m) 방형구에서 나비목 애벌레와 기주식물의 다양성을 조사하였다. 방형구에 있는 식물의 종 및 개체수를 확인하고 이들 식물에서 먹이활동을 하는 애벌레를 채집하였다. 조사결과 14과 16종 141개체의 기주식물과, 11과 70종 159개체의 나비목 애벌레가 조사되었다. 나비목 애벌레는 졸참나무에서 가장 많이 채집되어 조사지역에서 선호 기주식물로 조사되었다. 채집된 애벌레의 종 다양성과 종 균등도는 자나방과와 밤나방과에서 가장 높게 나타났다. 이 연구를 통해 나비목 애벌레와 기주식물과의관계를 알 수 있었으며, 나아가 온대림의 나비목 애벌레의 종 다양성을 추정할 수 있을 것이다.
The mulberry white caterpillar, Rondotia menciana, belongs to the lepidopteran family Bombycidae, in which the domestic silkworm, Bombyx mori is included. In this study, we describe the complete mitochondrial genome (mitogenome) sequences of the species in terms of general genomic features and characteristic features found in the A+T-rich region. The 15,364-bp long genome consisted of a typical set of genes (13 protein-coding genes, two rRNA genes and 22 tRNA genes) and one major non-coding A+T-rich region, with the typical arrangement found in Lepidoptera. Twelve of the 13 PCGs start with typical ATN codons, except for the COI, which begins with CGA. Twelve of the 13 PCGs have complete stop codon, except for COII, which ends up with a single T. The 360-bp long A+T-rich region harbored the conserved sequence blocks that are typically found in lepidopteran insects. Additionally, the A+T-rich region of R. menciana contained one tRNAMet-like structure, which has a proper anticodon and secondary structure.
Temperature and nutrition are the two most important environmental factors influencing growth and survival in immature insects. There is ample evidence of interactions between these two factors but still little is known how changes in thermal environment affect feeding and nutrient utilization insect ectotherms. The aim of this study is to investigate the potential effects of ambient temperature on food selection and post-ingestive nutritional physiology in a generalist-feeding caterpillar of Spodorptera litura. Two separate experiments were performed. The first was a food choice experiment in which caterpillars were maintained through their final larval stadium under one of three constant temperatures(20,25,30°) and given a choice between two nutritionally unbalanced diets that differed in protein(p) and carbohydrate(c) content (p42:c0 vs p7:c35 and p35:c7 vs p7:c35). In the second experiment, caterpillars were kept at the same thermal conditions as the first experiment but received a single diet from three no-choice feeding treatments(p35:c7,p21:c21and p7:c35). When raised at the highest temperature (30C), caterpillars from the choice experiment selected significantly more carbohydrate than those on lower temperatures whereas protein intake did not differ significantly between caterpillars across three test temperatures. Results from the no-choice experiment showed that lipid storage efficiency was reduced when caterpillars were maintained at the highest temperature(30C). In both experiments, growth rate increased progressively with rising temperature. However, there was a significant temperature-by-diet interaction, with growth rates increasing more rapidly on p21:c21 diet than on the other diets(p35:c7 and p7:c35). Our results demonstrate that caterpillars adjust their nutrient preference to meet the increased energetic demand at high ambient temperature.
Foraging is fundamental to animal survival and reproduction, and animals often require more than one nutrient to maximize their evolutionary fitness. Here, we test whether caterpillars of Spodoptera exigua (Hübner) balance the intake of multiple nutrients to meet their nutrient requirement. In the choice test, final-instar larvae were offered a choice of two nutritionally complementary diets [1) p42:c0 vs. p0:c42, 2) p42:c0 vs. p7:c35, 3) p35:c7 vs. p0:c42, 4) p35:c7 vs. p7:c35, 5) p35:c7 vs. p5.6:c28, 6) p28:c5.6 vs. p7:c35 and 7) p28:c5.6 vs. p5.6:c28]. Caterpillars tightly regulated their intake of protein (P) and carbohydrate (C) to defend a specific nutrient composition, which was slightly carbohydrate-biased (P:C=1:1.2). In the no-choice test, larvae were restricted to feed on one of 42 diets that varied both in P:C mixtures (1:0, 5:1, 2:1, 1:1, 1:2 and 1:5) and in total nutrient concentration(P+C=67.2%, 58.8%, 50.4%, 42%, 33.6%, 25.2% and 16.8%). Fitness landscapes fitted for key larval fitness variables (e.g., growth rate) over these range of diets revealed that the larval performance was optimized at the regulated position of nutrient intake in this caterpillar.
The aim of this research was to demonstrate whether generalist-feeding caterpillars of Spodoptera exigua (Hübner) regulate their nutrient intake when faced with nutritionally variable food conditions. Six, chemically-defined diets were prepared that differed in the composition of protein and digestible carbohyrate:42% protein with 0% carbohydrate by dry mass(p42:c0), p35:c7, p28:c5.6, p7:c35, p5.6:c28 and p0:42. A total of 288 newly-ecdysed final instar(5th) caterpillars were collected and assigned randomly into 7 food pairing treatments, in which they were allowed to choose between two diet block:one with high P:C ratio and the other with low ratio [1) p42:c0 vs. p0:c42, 2) p42:c0 vs. p7:c35, 3) p35:c7 vs. p0:c42, 4) p35:c7 vs. p7:c35, 5) p35:c7 vs. p5.6:c28, 6) p28:c5.6 vs. p7:c35 and 7) p28:c5.6 vs. p5.6:c28]. Various aspects of food intake and larval performance variables were measured for each insect, including larval survival, stadium duration, pupal mass and body lipid composition. Results showed that the intake of protein and carbohydrate self-composed by caterpillars in all treatments converged to a point in a bivariate nutrient plot and the ratio of protein to carbohydrate averaged over these converging intake points was close to 1:1. This indicates that S. exigua caterpillars have capacity to balance their nutrient intake by defending their species-specific ‘intake target’ despite the differences in amount and proportion of nutrients available in each food choice treatment.
This study was carried out to investigate the effect of each single component of the synthetic sex pheromone in the rice green caterpillar, Naranga aenescens and rice leaf roller, Cnaphalocrocis medinalis. Trap catches with each single component or binary mixtures of the sex pheromone in N. aenescens were significantly lower than that with an optimum mixture (2: 1: 4) of Z9-14:Ac, Z9-16:Ac and Z11-16:Ac. But only few number of C. medinalis male was caught in trap baited with each component of the sex pheromone excepting Z13-18:Ald. In an optimum composition of the sex pheromone in C. medinalis, trap catches baited with an 11: 100: 11 mixture of Z11-18:Ald, Z13-18:Ald, and Z13-18:Ac without two alcohol components (Z11-18:OH and Z13-18:OH) was higher than that baited with an optimum mixture of Z11-18:Ald, Z13-18:Ald, Z11-18:OH, Z13-18:OH, and Z13-18:Ac. The efficacy of the sex pheromone lure of N. aenescens kept over 4 weeks. The occurrence of N. aenescens caught in trap baited with sex pheromone gave three peaks and C. medinalis showed two distinct peaks throughout the flight season. Therefore, it can be expected that pheromone-baited trap provides a simple tool for monitoring N. aenescens and C. medinalis in Korea.
This study was carried out to investigate the optimum composition of sex pheromone of the rice green caterpillar Naranga aenescens and its efficacy was examined in a paddy field. The mating rate of N. aenescens tended to be increased with age, showing the highest rate of mating at age 2. The highest mating showed within 1 h after the scotophase, and also mating took place even during the photophase. A GC-EAD analysis of virgin female extracts showed two EAG-active components. Their chromatographic behavior was coincident with that of an authentic sample of Z9-14:Ac and Z11-16:Ac, respectively. The mass spectrum of two EAG-active components was almost identical to that of the authentic samples. The EAG response to two compounds, Z9-14:Ac and Z11-16:Ac, was significantly dose-dependent, but response to Z9-16:Ac was not dose-dependent. A 2: 1: 4 mixture of Z9-14:Ac, Z9-16:Ac, and Z11-16:Ac was the most effective composition for attracting N. aenescens. The male moths increased in proportion to the pheromone amount impregnated. The sticky-typed wing trap baited with sex pheromone captured significantly more males than the other two type of trap examined. Trap catches within a paddy field were much more than those in perimeter trap. The trap-baited with sex pheromone gave three or four distinct fluctuation peaks of male catches throughout the flight seasons.
본 연구는 2002년부터 2005년까지 배추와 양배추 재배지역에 발생하는 나비나방류의 발생종과 발생소장을 시설 재배지와 노지에서 조사하였다. 노지의 배추와 양배추에 발생하여 피해를 주고 있던 나비나방류는 배추좀나방(Plutella xylostella)과 배추순나방(Hellula undalis), 도둑나방(Mamestra brassicae), 담배거세미나방(Spodoptera litura), 파밤나방(Spodoptera exigua), 검은은무늬밤나방(Autographa nigrisigna), 배추흰나비(Artogeia rapae) 등 4과 6속 7종이 확인되었다. 시설 배추와 양배추에서 주요 나비나방류 해충 발생종과 피해량 및 발생을 조사한 결과, 배추에서는 4과 6속 7종이 조사되었는데 배추좀나방의 피해가 가장 심하였으며, 배추좀나방 유충의 발생최성기는 6월 하순으로 100주당 378마리가 조사되었다. 양배추에서는 3과 4속 5종의 해충이 확인되었는데 배추좀나방이 가장 많은 피해를 주었으며, 배추좀나방 유충의 발생최성기는 6월 하순으로 100주당 756마리가 조사되었다.
The external ultrastructural morphology and distribution of antennal sensilla and hair-pencils of Palpita indica (Saunder) were examined by scanning electron microscopy. The antennal flagellum of male and female has six types of sensilla: long trichodea, short trichodea, chaetica, coeloconicum around spines, camaniformia and styloconica. There are sexual differences in antennae of P. indica. The female antenna has a coeloconicum sensillum without spines nearby the long trichodea sensilla on ninth flagellomere. Otherwise, auricillica sensilla are distribute on the basal segment of male antenna. These structures are not showed in the female antenna. There are a lot of pores on the hair tufts of the male hair-pencils.
수박 부위별 산란습성은 상위엽과 하위엽보다는 중간부위의 잎에 산란량이 많았고 잎자루와 줄기보다는 잎에, 잎의 앞면보다는 뒷면에 주로 산란하였다. 목화바둑명나방 유충의 작물 선호도는 오이, 박, 수박 등의 순이었고, 참외, 동아, 멜론, 안동오이 등은 중간정도이었고 수세미와 목화는 매우 낮은 선호도를 보였다. 수박시험장에서 수집한 유전자원과 육성중인 계통에 대한 목화바둑명나방 유충의 선호도는 품종 및 계통간의 뚜렷한 차이가 없었으며 보유중인 품종 중에서는 목화바둑명나방에 대한 저항성 계통을 발견할 수가 없었다. 목화바둑명나방의 섭식량을 추정하기 위한 일별 배설량은 유충 초기에 배설량이 매우 적었고 점차 증가하여 16~18일차에 최고에 달하며 그후 다시 급격히 감소하였다.
수박재배 하우스에서 목화바둑명나방은 유충이 10월 10일까지 높은 밀도로 유지하다가 10월 15일부터 급격히 밀도가 낮아지기 시작하고 번데기는 10월 15일 이전에는 수박잎이나 과실이 땅과 접촉하는 부위에 있으나 그 이후부터는 지하부로 이동하여 토양속에서 월동하였다. 월동 번데기는 토양의 습도가 pF 2.4정도인 토양에서 대부분이 발견되었으며, 건조한 토양이나 과습한 토양에서는 거의 발견되지 않았다. 하우스 내 월동번데기의 분포는 수박덩굴의 상위엽이 위치해 있었던 부분의 토양내에서 가장 많은 번데기가 발견되었다. 또한 토양 내 수직분포는 지중 5cm 이하에서 대부분이 발견되었으며, 지하 10cm이상에서는 전혀 발견되지 않았다 전체 월동번데기의 암수 성비는 1.09 : 1.00으로 성간에 큰 차이가 없었다. 목화바둑명나방 발생예찰을 위한 성페로몬은 (E)-11-hexadecenal과 (E, E)-10, 12-hexadecadienal을 7 : 3으로 혼합했을 때 가장 유인량이 많았다. 가장 유인효과가 좋았던 (E)-11-hexadecenal : (E, E)-10, 12-hexadecadienal 7 : 3의 페로몬을 이용한 시기별 발생소장 조사에서는 4회의 발생성기를 보였는데 7월 중하순에 처음으로 유인되었고 9월 하순에 가장 유인량이 많았다.