应用雪尿分析技术评价不同类型栖息地中狍冬季的营养状况

雪尿分析技术是北方冬季有蹄类种群营养状况评价的可靠性指数。本文通过对兴隆镇小东林场和三江自然保护区1999 及2000 年冬季狍50 个雪尿、尿液样本采集及分析, 用以评价在不同类型的栖息地中狍冬季的营养状况, 结果表明: 雪尿分析可以评价狍冬季的营养状况及其变化; 雪尿中较低的尿素氮与肌酸酐的比率表明两地区狍基本上处于营养不良早期阶段, 反映了食物资源可利用性低、食物营养质量低造成外源蛋白质和能量摄入不足, 而使狍大量消耗体脂肪, 并通过对尿液化学成分的重吸收利用而保持其在尿液中排出量最低, 使机体内源蛋白质分解代谢处于较低状态; 三江1999 年冬季狍营养状况相对较差, 而2000 年情况较好; 幼体及亚成体处于营养不良中期阶段。
     

A comparative study of basal metabolism and thermoregulation in a folivorous (Colobus guereza) and an omnivorous (Cercopithecus mitis) primate species

1. Abdominal temperatures (Tab) and oxygen consumption (VO2) were measured in two males each of colobus and Sykes monkeys. 2. Tab in both species had the same range (36 38.5 C), but there were marked differences in the daily rhythms. 3. Low ambient temperatures (Ta) had little effect on Tab; at Ta = 33.5 35.5 C. however, Tab rose quickly to above 40 C. 4. The thermoneutral zone (TNZ) extended from about 5 to 28 C in both species. 5. In the colobus monkeys the basal metabolic rate (BMR) was considerably lower than in the Sykes monkeys: 85% vs 113% of the value predicted from body mass.     

中国蓝带蚊的系统发育数值分析

本文应用系统发育数值分析方法,对我国已知22种蓝带蚊的幼虫、雌蚊和雄蚊69个综合特征进行数值分析.根据修正的Wagner法计算值画出的分支图,与聚类分析法画出的矩阵图作比较,认为分支图更能反映已知种间的亲缘关系,并结合蓝带蚊属全球已知种的区系分布,计算各区的祖系比值作分析,新热带区的祖系比值特大,可能是蓝带蚊属的发源地.     

Abundance estimation of <Emphasis Type="Italic">Ixodes</Emphasis> ticks (Acari: Ixodidae) on roe deer (<Emphasis Type="Italic">Capreolus capreolus</Emphasis>)

Despite the importance of roe deer as a host for Ixodes ticks in central Europe, estimates of total tick burden on roe deer are not available to date. We aimed at providing (1) estimates of life stage and sex specific (larvae, nymphs, males and females, hereafter referred to as tick life stages) total Ixodes burden and (2) equations which can be used to predict the total life stage burden by counting the life stage on a selected body area. Within a period of 1½ years, we conducted whole body counts of ticks from 80 hunter-killed roe deer originating from a beech dominated forest area in central Germany. Averaged over the entire study period (winter 2007–summer 2009), the mean tick burden per roe deer was 64.5 (SE ± 10.6). Nymphs were the most numerous tick life stage per roe deer (23.9 ± 3.2), followed by females (21.4 ± 3.5), larvae (10.8 ± 4.2) and males (8.4 ± 1.5). The individual tick burden was highly aggregated (k = 0.46); levels of aggregation were highest in larvae (k = 0.08), followed by males (k = 0.40), females (k = 0.49) and nymphs (k = 0.71). To predict total life stage specific burdens based on counts on selected body parts, we provide linear equations. For estimating larvae abundance on the entire roe deer, counts can be restricted to the front legs. Tick counts restricted to the head are sufficient to estimate total nymph burden and counts on the neck are appropriate for estimating adult ticks (females and males). In order to estimate the combined tick burden, tick counts on the head can be used for extrapolation. The presented linear models are highly significant and explain 84.1, 77.3, 90.5, 91.3, and 65.3% (adjusted R ²) of the observed variance, respectively. Thus, these models offer a robust basis for rapid tick abundance assessment. This can be useful for studies aiming at estimating effects of abiotic and biotic factors on tick abundance, modelling tick population dynamics, modelling tick-borne pathogen transmission dynamics or assessing the efficacy of acaricides.     

Infestation of mammals by Ixodes ricinus ticks (Acari: Ixodidae) in south-central Sweden

Infestation by Ixodes ricinus ticks on rodents, hares and cervids was examined at Bogesund, 10 km north of Stockholm, in south-central Sweden during 1991-1994 and on varying hares (Lepus timidus) at Stora Karlso and Gotska Sandon in the Baltic Sea during 1992-1993. At Bogesund, there were great differences between two consecutive years in the number of I. ricinus larvae infesting bank voles (Clethrionomys glareolus). The seasonal pattern of infestation by I. ricinus larvae and nymphs on bank voles was unimodal in 1991, with peaks in June-July and bimodal in 1992, with peaks in June and August. Male bank voles, compared to females and older voles, compared to young voles, harboured greater numbers of I. ricinus ticks. Apodemus mice, compared to bank voles, harboured greater numbers of I. ricinus ticks. Ixodes ricinus larvae engorged on Apodemus mice were heavier than larvae engorged on bank voles and resulted in larger nymphs. However, there was no difference in the proportions of viable nymphs resulting from larvae engorged on mice or voles. The ranges in the numbers of I. ricinus ticks infesting individual hosts were 1-451 for rodents, 16-2374 for hares and 428-2072 for roe deer (Capreolus capreolus). These ranges of tick numbers are estimated to represent potential blood losses from individual hosts of approximately 0.2-65% for rodents, 0.2-13% for hares and 0.3-9.0% for roe deer. Within the populations of all host species examined, the distributions of all stages of I. ricinus were clumped, with most host individuals harbouring few ticks and only a few individuals harbouring many ticks. The data suggest that, even though a small proportion of tick hosts may be severely affected, the direct effects of feeding by I. ricinus are unlikely to play an important role on mammal population dynamics.     

Effect of coexistence of Penicillium frequentans (westling) with Globodera rostochiensis (Woll.) behrens on potato

The aim of two‐year‐long pot experiments was to investigate the influence of P. frequentans on the growth of over‐ground parts, the intensity of assimilation and transpiration of plants, as well as ths influence on the yield of potato bulbs. It was determined how the above fungus influenced the populaüon of G rostochiensis, the influence being characterized by the density change of cysts, eggs, and larvae in the soil. Experiments in vitro allowed to determine the wholesomeness of cysts, eggs, and larvae (J2) that were in direct contact with the mycelium ofP. frequentans.

It was stated that presence of P. frequentans intensified the development of plants and relevantly stimulated their growth, especially in the initial vegetation phase, as compared with the remaining combinations (Fig. 1). Positive effect of P. frequentans on the growth of potato yield was proved, in comparison with the control, and by co‐occurrence of the fungus with G. rostochiensis, also in comparison to the combination with nematodes only (Fig. 2).

Pot experiments confirmed the antagonistic effect of P. frequentans on the population of G. rostochiensis. Presence of P. frequentans in the ground caused namely a relevant diminution of density of cysts, eggs and larvae (Tab. II), as well as morphological changes by females, which was connected with size reduction of the cysts (Tab. III). Experiments in vitro confirmed the destructive effect of P. frequentans on the cysts of G. rostochiensis (Tab. IV).     

Tick infestation (Acari: Ixodidae) in roe deer (<Emphasis Type="Italic">Capreolus capreolus</Emphasis>) from northwestern Spain: population dynamics and risk stratification

During the 2007 and 2008 hunting seasons (April–October) the skin of 367 roe deer (Capreolus capreolus L.), hunted in different preserves from Galicia (Northwestern Spain), were examined for ticks (Acari: Ixodidae). The overall prevalence of infestation by ticks was 83.1%. The predominant species was Ixodes ricinus (83.1%), whereas a single Dermacentor marginatus specimen appeared in one roe deer. All developmental stages of I. ricinus were found parasitizing roe deer, the adults being the most frequent (82.2%), followed by nymphs (45.6%) and larvae (27.2%). The mean intensity of infestation by I. ricinus was 43.2 ± 49.85; most of them were adults (30.7 ± 31.64) and in a lesser extend nymphs (16.9 ± 24.74) and larvae (10.7 ± 29.90). Ixodes ricinus was present all over the study with percentages that oscillated between 100% in spring and 57.4% in autumn. CHAID algorithm showed the sex of roe deer as the most influential factor in tick prevalence, followed by the climatic area. The different developmental stages of I. ricinus were more frequent in males than in females, and the prevalence of adults and larvae were higher in roe deer from coastal areas than in those from mountainous and central areas, whereas nymphs were more frequent in mountainous areas. Host age and density were not determinants for tick infestation. Our results confirm that roe deer are important hosts for I. ricinus in northwestern Spain, serving as a vehicle for the geographic distribution of these ticks.     

Hypoderma actaeon: an emerging myiasis in roe deer (Capreolus capreolus)

Subcutaneous larvae of Hypoderma spp. (Diptera: Oestridae) were detected in the dorsal region in 10 roe deer, Capreolus capreolus (Artiodactyla: Cervidae), hunted in central Spain between January and March 2016. All larvae were found in the inner side of the hide during the skinning of the animals. The study of the morphological features of eight larvae of different stages collected from two animals allowed the identification of Hypoderma actaeon Brauer. The small size (4–5 mm) of some of the first instars suggests that the internal lifecycle of H. actaeon may be exclusively subcutaneous. This is the first confirmation of H. actaeon in roe deer; however, further studies to assess the spread of the parasite and to follow the evolution of this myiasis in roe deer are needed.     

High resolution NMR for studying lipid hydrolysis and esterification in cod (Gadus morhua) gonads

High resolution NMR was applied to study biochemical changes of lipids in cod (Gadus morhua) gonads during 7 days storage at 4 degrees C. Changes were observed in the (13)C and (1)H resonances of cholesterol which were due to esterification of fatty acids at the hydroxyl position in roe and milt. Furthermore, the (13)C NMR spectra showed that the lipolytic changes in milt and roe where different. New resonances appeared during storage, due to formation of specific free fatty acids, with the corresponding changes in resonances of the esterified carbonyls and glycerols. The highly unsaturated n-3 fatty acids were hydrolysed from the sn-1 and sn-2 position of both phosphatidylcholine and phosphatidylethanolamine in milt. The lipolytical changes in roe were less prominent compared to the changes in milt, however significant levels of sn-1-lysophospholipids was detected both in roe and milt. The current data demonstrate that high resolution NMR may be a suitable method to non-destructively study hydrolysis and esterification reactions occurring in heterogeneous marine lipids in a one step procedure.     

The consequences for deer of ingesting oilseed rape (Brassica napus): feeding experiments with roe deer (Capreolus capreolus) and red deer (Cervus elaphus)

In two experiments, in the growing season March–May, freshly harvested double-low oilseed rape ( Brassica napus ) plants were fed ad libitum to penned roe deer ( Capreolus capreolus ) and red deer ( Cervus elaphus ). In Experiment 1, oilseed rape was fed to five roe and 12 red deer as 60% of their daily dry matter (DM) intake for four weeks, after a two-week dietary change-over period. The rest of the diet comprised cattle-rearing pellets (33%) and freshly cut heather ( Calluna vulgaris ) plants (7%). In Experiment 2, oilseed rape was fed to seven roe and eight red deer as 100% of the diet for up to six weeks, after a two-week change-over period.
In both experiments, Heinz bodies were found in roe deer blood 2–3 weeks after the start of the change-over period, with a fall in mean packed cell volume (PCV) and blood glutathione (GSH) concentration. In Experiment 2, after 5–8 days of feeding on 100% oilseed rape, four roe deer showed signs of inappetance and were changed to a diet of 80% oilseed rape. At the same time, the other three roe deer had very low PCV (< 60% of normal values) and oilseed rape feeding was discontinued for those animals. The red deer showed no symptoms of haemolytic damage nor any change in blood GSH concentration in either experiment, but showed a gradual fall in PCV in Experiment 2. No other ill-effects were observed in any of the animals.
Intakes of oilseed rape (gDM/kg^0–75/day) were lower for the roe deer than the red deer in both experiments. The severity of haemolytic anaemia in the roe deer was related to the proportion of oilseed rape in the diet, rather than the amount ingested. It was concluded that the health of roe deer ingesting oilseed rape may be affected if other foods are not available.     

Heterologous transmission with Dictyocaulus capreolus from roe deer (Capreolus capreolus) to cattle (Bos taurus)

Eight Swedish Red Breed cattle, about 2 months old, were experimentally infected with a Swedish isolate of Dictyocaulus viviparus (Dviv-Se) from cattle and D. capreolus from roe deer. The aims were to determine whether the roe deer lungworm is infective to cattle or if it can induce seroconversion in cattle against D. viviparus as measured with an ELISA. Four calves which were given 500 Dviv-Se infective larvae (L3) each by larval dosing for two successive days developed patent infection between days 23 and 25 post-inoculation (PI). Larval output varied among the calves and during the patent period. However, maximum recovery occurred between 28 and 56 days PI with peak shedding on day 37 PI. Shedding ceased at day 58 PI and adult worms were recovered from one calf at necropsy (day 67 PI). No immature worms were recovered from the lungs at necropsy. Seroconversion was detected on days 35-42 PI. One Dviv-Se infected calf became seronegative on day 67 PI whereas the other calves still remained seropositive during this period. Prepatency and patency periods of D. viviparus and serological findings in this study basically conform to previous studies. Each calf that was infected with 400 L3 of D. capreolus for two successive days, and about 800 L3 of the same species about 8 weeks later, did not develop to patency based on faecal and post-mortem examinations. Consequently, under the conditions of this study, D. capreolus was not infective to cattle. Two of the four calves that were infected with L3 from roe deer were challenged with L3 cultured from faeces of the Dviv-Se-infected calves. This infection did not develop to patency. Whether this was due to cross-protection as a result of the prior priming with L3 from roe deer is not clear. However, if it is so, it opens up the possibility of using D. capreolus L3 for preventing bovine dictyocauliasis.     

The mitochondrial control region of Cervidae: evolutionary patterns and phylogenetic content

The mitochondrial control region (CR) sequence, also known as the D- loop, has been determined for six Cervidae (Artiodactyla, Ruminantia): the red and fallow deers (subfamily Cervinae), the brocket deer and two roe deers (subfamily Odocoileinae), and the Chinese water deer (Hydropotinae). These new sequences have been aligned with available cervid and bovid orthologues. Comparative analyses indicate that the 5'- peripheral domain exhibits a 75-bp length polymorphism near sequences associated with the termination of the H-strand replication. The New World Odocoileinae possess the longest cervid CR due to the presence of an additional 47-bp tandem repeat, located in the 3'-peripheral domain, downstream of the initiation site for H-strand replication (OH) and the first conserved sequence block (CSB-1). This insertion represents a duplication spanning the OH to CSB-1 region and constitutes an exclusive synapomorphy for New World Odocoileinae. Phylogenetic analyses of the complete CR support the paraphyly of antlered deers due to the nesting of the antlerless Hydropotes within Odocoileinae. Capreolus is the closest relative of Hydropotes, and the divergence of this Old World Odocoileinae clade may have occurred between 8.7 and 10.4 MYA. The conserved central domain of CR can be aligned across ungulates and indicates the Pecora monophyly, their close association with cetaceans, and the earlier emergence of suiformes.      

Biology of Campoletis chlorideae (Uchida) (Hym., Ichneumonidae) developing in Bt-treated, Bt-resistant Helicoverpa armigera (Hübner) (Lep., Noctuidae) larvae

Abstract:  Life history parameters in two generations of endoparasitoid Campoletis chlorideae (Uchida) were examined using Bacillus thuringiensis (Bt)-resistant Helicoverpa armigera (Hübner) larvae feeding on B. thuringiensis toxin Cry1Ac. In the laboratory, Bt toxin was fed to Bt-resistant host larvae continuously in case of Bt treatment and only before or after the host larvae were parasitized in Bt–P and P–Bt treatments, respectively. C. chlorideae pupae developed faster in Bt treatment than non-Bt treatment. The shortened pupal stage duration was mainly because of the feeding of host larvae on Bt-diet before being parasitized. Body length of adult male C. chlorideae developed inside Bt-treated Bt-resistant (Bt–Bt) H. armigera larvae significantly decreased, especially in host larvae feeding on Bt-diet after being parasitized. However, survival, pupal mortality and adult longevity of C. chlorideae were almost unaffected in Bt-resistant H. armigera larvae feeding on Bt-toxin. Furthermore, Bt-treated host larvae had the same effect on the F₁ progeny of C. chlorideae as the previous generation, and there was no significant difference between generations. This experiment suggests that there is very limited effect on the life history parameters in two generations of C. chlorideae parasitizing Bt–Bt H. armigera larvae. But both generations of C. chlorideae are affected when Bt-resistant H. armigera larvae fed on Bt toxin for different durations.     

Influence of livestock,habitat type,and density of roe deer (<Emphasis Type="Italic">Capreolus capreolus</Emphasis>) on parasitic larvae abundance and infection seroprevalence in wild populations of roe deer from central Iberian Peninsula

Livestock farming is a common human activity that not only modifies natural habitat but also may lead to interactions with other wild animal species. We studied whether health status of roe deer (Capreolus capreolus) is influenced by density, livestock, and type of habitat. We analyzed 208 samples (120 fecal and 88 sera) from roe deer populations of central Iberian Peninsula to evaluate both presence and abundance of parasitic oocysts, eggs, and/or larvae, especially of gastrointestinal and bronchopulmonary parasites, as well as the prevalence of five infectious diseases (infectious bovine rhinotracheitis (IBR), pestivirosis (BVD/BD), paratuberculosis (PTB), bluetongue (BT), and brucellosis). Fecal samples were collected in transects in pine and oak forests and endoparasites were detected by means of coprological techniques. Serum samples were obtained from hunted individuals and the serological testing for the infectious pathogens was performed by ELISA and Rose Bengal tests. Livestock and habitat type were associated both with the presence and the number of bronchopulmonary nematode L1-larvae per gram of feces (lpg), which was higher in areas with livestock and in pine forests. However, roe deer density neither influenced parasite presence nor lpg values. Regarding infectious pathogens, only seropositive samples for PTB and pestivirus were obtained indicating a possible transmission between domestic and wild ungulates in the study area. The low prevalence found is consistent with other studies in the Iberian Peninsula suggesting that roe deer have little contact with the infectious agents studied. Our results highlight that both habitat type and livestock significantly mediate abundance of parasitic larvae in roe deer, being higher under competition scenarios and in habitats of lower quality, a valuable aspect to be considered in future management and conservation strategies.     

Microsatellite investigation of roe deer (Capreolus capreolus) in Scandinavia reveals genetic differentiation of a Baltic Sea Island population

After a decline in the early 19th century, a remnant population of the Scandinavian roe deer (Capreolus capreolus) was protected in southern Sweden around 1840. The roe deer quickly recovered and recolonized most of the Scandinavian Peninsula. In this study, I analyze microsatellite variation in 14 roe deer populations in Scandinavia to (1) investigate if all Swedish roe deer trace their ancestry to southern Sweden, (2) define other areas where roe deer may have remained during the population decline, and (3) examine if the large geographic distances during the expansion phase have influenced the degree and sorting of genetic variation. The results show that the mainland roe deer most likely trace their ancestry to southern Sweden, but interestingly, the two neighboring populations Övedskloster and Wittskövle in the south are significantly different from each other (p<0.01). Furthermore, the population in Wittskövle and roe deer from Köpingsvik at the Baltic Sea Island Öland are significantly different from all other populations (p<0.1). Thus, potentially, there are more than one founder population that contributed to the current Swedish population. The particular differentiation of roe deer from Öland might be an effect of random population genetic processes during the population expansion phase, potentially in combination with introductions of roe deer from other areas than the Swedish mainland. The results are discussed in relation to management of roe deer in Sweden.     

Functional response and predation of Nabis kinbergii （Hemiptera. Nabidae） to Plutella xylostella （Lepidoptera. Plutellidae）

The functional response of adult Nabis kinbergii （Hemiptera： Nabidae） to density of diamondback moth Plutella xylostella （Lepidoptera： Plutellidae） was investigated under laboratory conditions. Holling＇ s （1959） type Ⅱ model was found to be a good fit for the observed functional response of this predator. The numbers of P. xylostella consumed increased with temperature from 15℃ to 35℃. The maximum number of prey killed was observed at 35℃, with average of 10.3 and 8.3 forth instar larvae consumed by adult females and males of N. kinbergii, respectively. The predation of N. kinbergii on P. xylostella increased with successive immature stages. The number of prey consumed by predators decreased as the body size of prey increased. An average of 131 eggs or 95 larvae of P. xylostella were killed by a single of female adult in 24 hours at 24＂C. The pupae of P. xylostella were observed to be eaten by fifth instar nymphs and adults N. kinbergiiin numbers of less than an average of 0.7 pupae per predator in 24 hours at 24＂C. Predation preference by N. kinbergii was also investigated. The number of P. xylostella and Myzus persicae killed by female N. kinbergii was not significantly different, but males killed significantly more P. xylostella than M. persicae. Both eggs and larvae of P. xylosteUa were killed in significantly greater number than those of Pieris rapae in the same feeding arena.     

Role of eosinophils in the destruction of schistosomula of Schistosoma mansoni in vivo (preliminary report)

Schistosoma mansoni cercariae mechanically transformed into schistosomula were injected, either dead or alive, into the tail vein (2.000 larvae/0,15 ml) of Balb/c mice which were either previously infected with S. mansoni (10 weeks/50 cercariae) or non-infected. Histological examination of the lungs 24, 48, 72 and 96 hours after injection revealed that inflammatory reaction around schistosomula occurred only in the groups injected with dead schistosomula (killed by freezing and thawing). In non-infected animals the reaction was predominantly macrophagic while in those infected many eosinophils appeared around the dead larvae. These results are at variance with those obtained in vitro and suggest that in vivo the participation of eosinophils in the schistosomulum induced reaction in sensitized animals is secondary to the death of the larvae.     

白蜡吉丁肿腿蜂对栗山天牛低龄幼虫的寄生作用

栗山天牛Massicus raddei（Blessig）是我国东北危害栎树的重要害虫。在对其进行生物防治研究中,通过功能反应实验方法探讨了利用寄生蜂白蜡吉丁肿腿蜂Sclerodermus pupariae Yang et Yao对栗山天牛低龄幼虫的寄生作用。结果表明：白蜡吉丁肿腿蜂在取食寄主补充营养的过程中,对栗山天牛1～2龄小幼虫的致死作用随着寄主密度的增加而显著提高,功能反应符合Holling Ⅱ型方程,平均每日最大致死量为0.53头。寄生作用功能反应符合Holling Ⅰ型方程,寻找时间21 d内的寄主密度阈限为4头。当该肿腿蜂密度固定为1头时,对栗山天牛致死作用和寄生作用的寻找效率均随寄主密度的上升而降低。当寄主密度固定不变时,随着寄生蜂密度的增加寄主的死亡数量线性升高,被寄生的寄主数量也上升,但该肿腿蜂对栗山天牛低龄幼虫致死作用和寄生作用的寻找效应均显著下降,表明白蜡吉丁肿腿蜂是防治栗山天牛低龄幼虫的良好天敌。研究结果对于合理评价白蜡吉丁肿腿蜂在生产上的控害能力和制定寄生蜂的林间释放应用技术规程提供了依据。     

Effect of entomopathogenic nematodes on Plectrodera scalator (Fabricius) (Coleoptera: Cerambycidae)

Entomopathogenic nematodes were screened for efficacy against the cottonwood borer, Plectrodera scalator (Fabricius). Steinernema feltiae SN and S. carpocapsae All killed 58 and 50% of larvae, respectively, in filter paper bioassays but less than 10% in diet cup bioassays. S. glaseri NJ, S. riobrave TX, and H. indica MG-13 killed less than 10% of larvae in both assays. H. marelata IN was ineffective in the diet cup bioassay and killed 12.9% of larvae in a filter paper bioassay. The nematode isolates we tested are not suitable for use as biological control agents against P. scalator.     

Effects of spatio-temporal intervals between newly-hatched larvae on larval survival and development inMonochamus alternatus (Coleoptera: Cerambycidae)

The effects of distance between hatching larvae on survival and development were investigated inMonochamus alternatus. Two newly-hatched larvae were inoculated intoPinus densiflora bolts at a distance of 2.5 cm or 10 cm, simultaneously or at an interval of 2 weeks. Some larvae were inoculated singly as a control. When larvae were inoculated simultaneously, mortality of the closely-inoculated larvae was significantly higher than that of distantly-inoculated larvae. Such high mortality was identified as due to conspecific bites. When the two larvae were inoculated asynchronously, the first-inoculated larvae killed some second-inoculated larvae but were never killed by them. Consequently, mortality was higher in second-inoculated larvae than in first-inoculated larvae. In particular, there was a significant difference in mortality between them when the larvae had been inoculated closely. The mortality of second-inoculated larvae was higher in the closely-inoculated group than in the distantly-inoculated group although there was no significant difference between them. In the case of two simultaneously-inoculated larvae, the initial distance between them had no significant effect on the development and growth in the early larval stage. When the larvae were inoculated asynchronously, the first-inoculated larvae grew more quickly than singly-inoculated control larvae.