Sex ratios of the dryword termite Cryptotermes domesticus

为了解截头堆砂白蚁Cryptotermes domesticus(Haviland)群体中不同品级、不同虫态的雌雄性比,本文研究了该种白蚁自行配对室温条件下饲养4年巢龄的实验群体与采集的自然群体的各个品级和不同虫态的雌雄性比.结果表明:自行配对室温饲养4年巢龄群体与自然环境群体中原始繁殖蚁、幼蚁、若蚁、兵蚁都有雌雄之分,其中自行配对室温饲养群体的原始繁殖蚁雌雄比例为1:1,兵蚁雌雄比例为1:1.24,幼蚁和若蚁雌雄比例为1:1.46;自然环境群体原始繁殖蚁雌雄比例为1:1,兵蚁雌雄比例为1:1.15,幼蚁和若蚁雌雄比例为1:1.43.     

截头堆砂白蚁新群体的形成及发展

本文主要论述在广州室温及恒温27℃、相对湿度80%条件下,截头堆砂白蚁Cryptotermes domesticus(Haviland)新群体的形成、繁殖特性及其群体的发展、发育状况.(1)在广州6～7月室温下,截头堆砂白蚁原始繁殖蚁自行配对后,产卵前期7～16天,平均10.33±2.32天,卵期46～71天,平均55.13±6.42天,巢龄为1年、2年的新建群体,子代个体分别为3～8头、10～16头;3年巢龄群体,子代个体12～35头;4年巢龄群体,兵蚁开始出现,子代个体23～57头,其中兵蚁1～3头.该种白蚁新建群体经历7年才发育成熟,此时群体子代个体36～115头,其中兵蚁1～4头.(2)在恒温27℃、相对湿度80%条件下,截头堆砂白蚁原始繁殖蚁配对后产卵前期8～18天,平均11.6±2.66天,卵期50～73天,平均57.8±5.79天.1年巢龄群体,子代个体6～10头;2年巢龄群体,兵蚁出现,子代个体16～34头,其中兵蚁1～2头.新建群体经历2～3年发育成熟,此时群体内的子代个体18～44头,其中兵蚁1～2头.     

不同树种木材对截头堆砂白蚁初建群体的影响

收集了62种从东南亚进口的不同树种的木材,并作为截头堆砂白蚁Cryptotermesdomestictis(Haviland)的食料,让其原始繁殖蚁自行配对钻入这些木料中取食,建立新群体.观察该种白蚁对不同树种木材的取食状况,了解不同树种木材对该种白蚁初建群体的影响.结果表明,该种白蚁食性广泛,能取食多种在分类上差异很大的木材,除坤甸外,均被其取食.试验用的全部木材对该种白蚁原始繁殖蚁配对没有影响,均有原始繁殖蚁配对钻入洞内.在配对3个月后解剖群体发现,除坤甸、樟木、硬榄仁、柚木、子京、虫眼木、暗罗、硬椴、轻胭脂、胭脂、番龙眼外,其余树种的初建群体,雌雄繁殖蚁存活,子代发育正常.     

圆唇散白蚁补充生殖蚁的类型与建群能力

摘要: 【目的】为了探讨圆唇散白蚁Reticulitermes labralis补充生殖蚁对巢群稳定和发展的作用。【方法】对野外巢群进行调查研究, 及对婚飞成虫通过雌雄配对与补充生殖蚁隔离巢群进行人工饲养的对比研究。【结果】在野外巢群只发现1对原始蚁王蚁后, 而补充生殖蚁的数量最多可达到689头/巢。圆唇散白蚁有3种类型的补充生殖蚁, 即由工蚁转化来的无翅型补充生殖蚁、若蚁转化来的翅芽型补充生殖蚁和末龄若蚁羽化来的拟成虫型补充生殖蚁。实验室条件下婚飞配对群体和隔离群体建群1个月后的存活率分别为64%和96%。建巢初期婚飞配对群体的子代数目增长缓慢, 2个月时的群体数量为6.3±1.54, 10个月时的群体数量也仅为8.4±1.47; 而隔离建群补充生殖蚁2个月时的群体数量为52.4±6.44, 10个月时的群体数量为164.3±20.85, 都高于婚飞配对群体。 此外, 野外巢群的补充蚁后跟原始蚁后一样都具有发达的卵巢。【结论】在圆唇散白蚁中补充生殖蚁是白蚁巢群主要的繁殖力量, 也是建立新巢群的重要繁殖品级。     

截头堆砂白蚁原始繁殖蚁形成的周期

采用马尾松(Pinusmassonianalamb)、东北松(PinusSpp.)、北美黄杉(花旗松)(Pseudotsugamenziesii)、青岗(CyclobalanopsisSpp.)、荷木(SchimaSpp.)作为截头堆砂白蚁Cryptotermesdomesticus(Haviland)的食料,研究其原始繁殖蚁配对后新建群体的形成和发展,从饲养的新建群体中培养产生了下一代的原始繁殖蚁,完成了1个世代的生活周期观察。试验证实,截头堆砂白蚁在广州市室温下,产生下一代原始繁殖蚁(完成1个生活周期)为7年;在湛江市室温下6、7年;而在恒温27℃,相对湿度80%的条件下只需2～3年。     

黑胸散白蚁的分飞成熟年龄及生殖蚁对子代个体分化的抑制作用

实验室配对饲养黑胸散白蚁Reticulitermes chinensis表明,黑胸散白蚁新群体在原始生殖蚁控制下,83.30%的群体在第9年分出了有翅成虫,16.70%的群体在第7年发生有翅成虫分飞,平均分飞成熟年龄为8.67年;由补充生殖蚁控制的群体在第6年即有53.85%的群体发生分飞,第7年有46.15%的群体分飞,平均分飞成熟年龄为6.38年,较原始生殖蚁控制的群体发生分飞平均提前2.29年。初次发生分飞时群体内个体数量前者明显多于后者。研究还发现,群体内补充生殖蚁的数量与分飞发生的早迟关系不大。作者认为在黑胸散白蚁中,原始生殖蚁对补充生殖蚁和若蚁的产生具有较强的抑制作用,而补充生殖蚁对上述品级的分化虽有一定抑制,但不如原始生殖蚁强。认为黑胸散白蚁群体发展速度在品级分化的调节上起到不可忽视的作用,但一定要在生殖蚁分泌外激素的能力开始减弱后才能发挥效应。     

黑胸散白蚁新群体的建立及发展规律

经十年的室内配对饲养观察,黑胸散白蚁 Reticulitermes chinensisSnyder初期群体配对后5—10天开始产卵,胚胎发育期36—46天,幼蚁经历两个龄期,各龄8—13天,工蚁是幼蚁经两次蜕皮后分化出来,具有上颚自如活动,头宽0.71mm以上;前兵蚁蜕一次皮发育为兵蚁需经历10—13天,触角14—15节,头宽0.81—0.82mm,大于2龄工蚁,初期巢群最早3个半月左右产生兵蚁.当年配对的产卵期3至4个半月,产卵量16—45粒.饲养7—8年后的群体开始出现若蚁(长翅成虫的幼期).9、10年群体发育成熟即产生长翅成虫.解剖三个成熟群体中一个巢原始蚁王、蚁后均存在,另两巢发现原始蚁王、蚁后均死亡,其中一巢由群体内自行补充上了翅鳞型母蚁1头,无翅补充型生殖蚁1头(较小,性别不清),翅芽型3头.另一巢补充上了无翅型大腹母蚁1头,翅芽型1头.通过室内长期连续饲养观察,对该种白蚁新建群体发育成熟年龄及其内在因素已有一定的了解.     

保幼激素类似物对白蚁的作用研究进展

本文介绍了保幼激素类似物对白蚁的影响,包括诱导前兵蚁、兵蚁和一些中间品级(形态畸形)的产生、抑制白蚁的取食、减少或消除白蚁的共生原生动物群、对白蚁产生不同水平的急性和慢性毒性、抑制工蚁蜕皮以及繁殖蚁建立新群体等方面的影响,其中最主要影响是诱导前兵、兵蚁和一些中间品级的产生破坏了白蚁群体品级比例的平衡性或完整性.因此,保幼激素类似物可用于白蚁的防治,并在田问防治散白蚁和乳白蚁均取得了较好的防治效果,并探讨了应用保幼激素类似物防治白蚁的潜力与前景.     

乳白蚁不同品级的比例

乳白蚁Coptotermes在湖北宜昌地区每年11月～次年3月收集到的巢群,每年品级比例基本平衡。品级头比的数据一律来自1月份的巢群;品级重比是11月～次年3月的巢群。品级的比例分别为：工蚁占81．70％、干重比69．45％;兵蚁占7．50％、干重比7．69％;生殖蚁占10．80％、干重比26．76％。     

截头堆砂白蚁原始繁殖蚁行为特点研究

本文主要论述截头堆砂白蚁Coptotermes domestictis(Haviland)原始繁殖蚁行为特点以及利用其特点判断木材及木制品有该蚁存在的方法.原始繁殖蚁行为特点:1、刚分飞时有趋光性.2、雌雄蚁没有明显的追逐行为.3、脱翅后的原始繁殖蚁喜欢找隐蔽的场所营站.4、钻洞后的原始繁殖蚁封闭洞口,抗外界干扰.5、在洞内活动、取食、排泄、繁殖子代.6、原始繁殖蚁形成群体后把排泄物推出洞外.7、原始繁殖蚁形成群体后容易蔓延.判断有该蚁存在的方法:1、木材及木制品表面有0.3mm-1.5mm圆形封闭或未封闭洞口.2、洞口外有细砂粒状及不易碎的排泄物.     

Response to orphaning in two Neotropical termites: shape Armitermes euamignathus and shape Embiratermes festivellus

In this paper we examine the potential of the termites Armitermes euamignathus Silvestri: 1901 and Embiratermes festivellus (Silvestri, 1901) (Isoptera, Termitidae, Nasutitermitinae) to produce neotenics experimentally. Three nests of the mound-building termite A. euamignathus, from the Brazilian cerrado, had their primary queens removed in August 1994. After 12 months, only one mound survived; it had a normal appearance. In this healthy, orphaned colony we found the primary king, six physogastric nymphoid female replacement reproductives, two ergatoid female replacement reproductives, 46 nymphs, several presoldiers, soldiers, workers, larvae and many eggs. These data show that neotenics in A. euamignathus may originate from both workers and nymphs, but nymphoids are produced in larger numbers. The biometric study of nymphs and nymphoids suggests that these brachypterous neotenics were derived from third instar nymphs after a single moult or from four instar nymphs after a reduction of wing bud length. A piece of an E. festivellus nest with some third instar nymphs, soldiers and workers was kept under laboratory conditions. After 12 months, the whole experimental subcolony was examined and appeared to contain two pigmented nymphoid females, two pigmented nymphoid males, only one larva, seven nymphs of the same instar, 148 workers, five soldiers and many eggs. These results also indicate the capacity of the termite E. festivellus to produce nymphoid neotenics. These neotenic females were laying eggs, but they were not physogastric after a year, unlike some nymphoids of the same species collected from natural colonies.     

Evolution of eusociality and the soldier caste in termites: a validation of the intrinsic benefit hypothesis

In termites the evolution of reproductive altruism is not based on a particularly high relatedness between nestmates. For the evolution and maintenance of the ancestral sterile soldier caste, the benefits generated by the soldiers' presence must compensate the loss of the soldiers' reproductive potential. To study the impact of soldiers on colony's fitness, we manipulated the proportion of soldiers to nonsoldiers in colonies of the dry-wood termite Cryptotermes secundus.'Soldier-less' colonies were obtained by removing soldiers and inhibiting their development with an extract of soldier heads. The colonies were set up for 1 year in experimental nests in the field. 'Soldier-less' colonies produced fewer soldiers. The reduction of soldiers neither affected colony survival nor helper growth, but fewer dispersing sexuals were produced in 'soldier-less' than in control colonies. This confirms what was only supposed so far, that in termites soldiers are maintained for their intrinsic benefit to cost ratio.     

Preliminary studies on the control of caste formation in the harvester termiteHodotermes mossambicus (Hagen)

The control of caste formation in the harvester termiteHodotermes mossambicus (Hagen) was investigated.Normal laboratory colonies contained a primary reproductive pair, between 6.59 and 24.98% workers, 0.39 and 3.45% soldiers and 74.64 and 92.06% larvae. Supplementary reproductives did not develop in colonies deprived of their king and queen. Continuous removal of soldiers stimulated soldier production. We have suggested that a pheromone produced by the soldiers plays a major role in controlling the soldier population of a colony. A similar phermone system appreared to control the production of workers.Evidence was also obtained that the primary reproductive pair influenced the production of workers and soldiers.     

Proximate factors influencing soldier development in the basal termite <Emphasis Type="Italic">Cryptotermes secundus</Emphasis> (Hill)

Summary Regulation of soldier development in termites at the endocrinological and social scale was intensively studied in the 60s and 70s, but conclusive results are still scanty. In termites, the presence of soldiers inhibits further soldier differentiation, but the mechanism is not well understood. Secretions from the frontal glands seem to be important, but dry- and dampwood termites do not have frontal glands. We investigated the influence of precocene I, a JH-antagonist, and of soldier head extracts on the development of soldiers in the drywood termite, Cryptotermes secundus (Hill). Soldierless colonies produced fewer soldiers when treated with precocene I or soldier head extract than control colonies. Furthermore, colonies treated with precocene I had produced worker-nymph intercastes, last stage nymphs and alates by the end of the experiment (after six months) which were not present in control colonies. Hence, both treatments inhibited soldier development while precocene I simultaneously promoted the development of adult traits, probably by reducing (directly or indirectly) the JH level. The inhibition effect of the soldier head extract indicates that at least in termites without a frontal gland, other sources of material in the head have a regulatory function.     

家白蚁的生物学和群体发育

家白蚁Coptotermes formosanus Shiraki的生物学和初建群体的经过,显示有如下特性:(1)在广州室温条件下,成虫配对后5至10天开始产卵,产卵盛期集中在6天至7天。当年产卵期有5个月,每头雌虫平均产卵约为46粒。雌里产卵后,如果不断将卵取走,产卵量显著提高。这时,每头雌虫平均可产卵约96粒。(2)家白蚁卵要经过成虫或工蚁用口舐触和搬动卵粒才能孵化。孵化期在室温下为31至35天,32至33天为孵化高峰期。卵的孵化期随温度而变化。(3)初步测定幼蚁共有6个龄期。1—2龄幼蚁不活跃,要靠成虫或工蚁喂养,3龄后幼蚁非常活跃并能自己取食。4龄期间出现工蚁和兵蚁的分化,拟工蚁可以产生短翅补充型。(4)蚁巢成片叶状,由成虫唾液与食物及沙土等基质组成。配对后80天腔室内开始出现巢架。(5)家白蚁生活史漫长,需8年才能完成一个周期。     

Does lack of intraspecific aggression or absence of nymphs determine acceptance of foreign reproductives in <Emphasis Type="Italic">Macrotermes</Emphasis>?

The rejection or acceptance of a foreign reproductive by an alien colony may not always be as straightforward as cue recognition between worker termites. This paper aims to determine whether adoption of foreign reproductives is caused simply by lack of intraspecific aggression or is contingent on the reproductive status of the host colony. In the fungus-culturing termites, Macrotermes gilvus (Hagen) and Macrotermes carbonarius (Hagen), major workers showed low intraspecific aggression towards non-nestmates irrespective of geographic distance between source colonies. Our results indicated that workers were hardly aggressive towards non-nestmates. In royal cell-swapping experiments, both species responded in a similar way: (1) in host colonies with nymphs present, the foreign reproductives were rejected; while (2) in host colonies without nymphs the foreign reproductives were either accepted and breeding resumed or the host colonies died eventually. Workers from the host colonies preferentially maintained offspring nymphs from which adultoid replacement reproductives develop rather than accepting foreign reproductives. There is no fitness gain for the queenless workers in accepting foreign reproductives; however, there is overall benefit to the newly born population.     

Male or female soldiers? An evaluation of several factors which may influence soldier sex ratio in lower termites

In termites, the soldiers’ sex ratio is often biased toward one sex. Unlike in the Hymenoptera, this bias cannot easily be explained by relatedness asymmetries because termites are diploid. Matsuura proposed that when large body size is adaptive for colony defence (e.g. in case of phragmotic defence) then the larger sex (given sexual size dimorphism exists) should be more likely to reach a threshold size and develop into soldiers. This would explain biased sex ratios. Matsuura validated his hypothesis for four Reticulitermes species. Here, we tested his hypothesis for two species of Cryptotermes with phragmotic defence. These drywood termites have a life type that is thought to be ancestral in termite’s evolution, thus giving us potential insights into the evolution of the soldier caste. In one of these species, the sex ratio of soldiers was highly female biased, but we could not support Matsuura’s hypothesis. Both species lacked sexual size dimorphism in all castes. Additionally, in both species, the sex ratio of helpers and sexuals did not deviate from a 1:1 ratio, and hence can also not account for the bias observed in soldiers. However, this study showed that there were behavioural differences between the sexes in both species, which could shed some light on biased sex ratio in soldiers. Our findings also indicate that the developmental pathway taken by individuals reflects a ‘decision’ at the colony level. The discovery of behavioural differences between sexes in termites should open the way to similar studies in other taxa with helpers/ workers of both sexes, as it might reveal more task partitioning in colonies than previously thought and it raises questions concerning the selective pressures that acted on caste evolution in termites. Received 30 October 2007; revised 17 January and 27 February; accepted 4 March 2008.     

尖唇散白蚁的孤雌生殖行为及初建群体研究

为了证明尖唇散白蚁Reticulitermes aculabialis Tsai et Hwang是否存在孤雌生殖行为和探讨其初建群体的发育特征,本文对尖唇散白蚁分飞成虫进行雌雌配对（FF）和雌雄配对（FM）人工饲养对比研究。结果显示：FM和FF组的筑巢时间和筑巢活动相似;在建巢初期（配对第5天）FF配对组和FM配对组死亡率分别为11．33％和2．67％,FF配对组死亡率显著高于FM组;产卵前FM组的2只雌性个体和FF组的雌性个体卵巢发育程度一致,都有已经完成卵黄积累的成熟卵母细胞。6个月后,FF配对组有7组产生后代,FM配对组有17组产生后代;FF组子代数目显著低于FM组,分别平均为（7．00±1．58）个和（10．33±1．21）个;FF子代全为2～3龄工蚁,而FM组有由3-4龄工蚁分化的低龄兵蚁。最后,我们对新建群体分化出的第一只兵蚁与成熟巢群中的兵蚁进行了形态学比较。我们的结果表明,尖唇散白蚁具有孤雌生殖行为,并且分飞成虫通过雌雌配对和雌雄配对初建群体在发育模式上有显著差异,雌雌成虫配对采用孤雌生殖方式繁殖有可能是野外尖唇散白蚁建群的另一种方式。