赤眼蜂屬

赤眼蜂屬（學名：）是膜翅目細腰亞目寄生蜂下目之下的小蜂总科赤眼蜂科的成員之一，其物種皆為的微小拟寄生物，寄生於其牠昆蟲的蟲卵中。赤眼蜂屬是赤眼蜂科約80個屬的其中一個，在全世界包括超過200個物種。成蟲大多小於1毫米，會產卵於宿主卵内，幼蟲取食卵黄、化蛹並引發宿主死亡。成蟲羽化後咬破寄主卵殼而出。

儘管現時在全世界有多種用於生物防治的物種，本屬物種仍然是研究得最詳盡的一類，有超過一千份相關的文獻與本屬物種相關，也是目前世上於生物防治中 最常用的物種。 Trichogramma spp. are unique in approaching the size limit of how small an insect can be, which would be determined by how few neurons they can fit in their central nervous systems, yet exhibiting a complex behavior to sustain their lives. These wasps have less than 10,000 neurons, which is 1/100th that of the next smallest insect.

寄生性
雌性成虫会通过化学和视觉信号来找到用来作为宿主的卵，比如卵大小和颜色。在她找到合适的卵后，其将会试图通过她的产卵器和对卵壳的敲击来判别这个卵是否之前已经被寄生过了。雌性赤眼蜂也会通过敲击来判别目标被寄生卵的大小和质量以决定赤眼蜂在被寄生卵内的产卵数量。一个雌性赤眼蜂一天最多可以在十个被寄生卵上产卵。

辨識
本屬物種體型細小，構造上亦單一，使物種間的分辨頗困難。由于雌性相对来说体型较小，分类学家一般通过辨别雄性触角和生殖器的方式来辨别不同物种。

Charles V. Riley在1871年于北美第一种对赤眼蜂属下的物种进行描述。他将从总督蝶卵中爬出来的小蜂称为Trichogramma minutum。在生物分类学中，首个采集的标本是十分重要的，因为其被用作继续描述这个物种的基础，但是它丢失了。Riley后来在1879年又描述了第二种叫做Trichogramma pretiosum的赤眼蜂，但是其样本也丢了。为了更正这些错误，昆虫学家返回了Riley原本找到这两个物种的地方并收集了新的范本。现在这些范本被完好地存放在美国史密森尼学会。当前赤眼蜂属的物种超过两百种，但是在1960年的时候只有大概40种赤眼蜂被描述。

赤眼蜂屬物種體內的沃尔巴克氏体
赤眼蜂屬物種體內有沃尔巴克氏体（Wolbachia），是一種分佈廣泛的細菌，專門感染昆蟲的內臟，特別是生殖系統的器官。這些沃尔巴克氏体在感染了昆蟲後，會改變其宿主交配時的成功率。
Through a series of manipulations, Wolbachia-infected hosts transmit this intracellular bacterium to uninfected individuals. These manipulations include male killing (increasing ratio of infected females that can reproduce), feminization (males become fertile females), 单性生殖, and . Horizontal transfer of parthenogenesis-inducing Wolbachia, which has been observed in Trichogramma wasps, causes infected females to asexually produce fertile females and nonfunctional males. The effects of this include potential speciation of Trichogramma, if Wolbachia is maintained long enough for genetic divergence to occur and for a new species of asexual wasps to become reproductively isolated.

Transmission of the bacterium through horizontal transfer has been observed within the same species and among different species of Trichogramma, including T. kaykai, T. deion, T. pretiosum, and T. atopovirilia; however, limitations to transmission exist. In vitro successful horizontal transfer is uncommon within Trichogramma, which suggests that the density of Wolbachia must be relatively high inside of the hosts' ovaries. Cytoplasmic incompatibility of the host and bacterium can also be the source of this unsuccessful transfer in-vitro. These limitations in vitro suggest that in nature, horizontal transfer by parthenogenesis-inducing Wolbachia may be a difficult and rare phenomenon. However, when looking at the Wolbachia-host associations, the Trichogramma-Wolbachia form a monophyletic group based on several Wolbachia-specific genes, which may be explained by horizontal transfer of Wolbachia between different species. Therefore, although interspecific horizontal transfer of Wolbachia is limited in vitro, it is likely to occur quite frequently in nature and is not well understood yet.

The effects of Wolbachia in Trichogramma have  several evolutionary implications. Commonly, uninfected wasps are unable to breed with infected wasps. Many generations of reproductive isolation of these different groups may result in speciation. In addition, some hosts can evolve with a dependency on Wolbachia for core reproductive functions, such as 卵子生成, so that eventually an infection is a requirement for successful reproduction. Finally, Wolbachia can influence gender determination in its hosts so that more females are successfully born. This results in a reversal in 性選擇, where females must compete for male mates, which has evolutionary implications as it exposes different phenotypes to natural selection.

Biological control 
Trichogramma spp. have been used for control of lepidopteran pests for many years. They can be considered the Drosophila of the parasitoid world, as they have been used for inundative releases and much understanding today comes from experiments with these wasps.

Entomologists in the early 1900s began to rear Trichogramma spp. for biological control. T. minutum is one of the most commonly found species in Europe and was first mass reared in 1926 on eggs of . T. minutum has been investigated as a method of biological control of the Choristoneura fumiferana, a major pest of spruce and fir forests.

Nine species of Trichogramma are produced commercially in insectaries around the world, with 30 countries releasing them. Trichogramma wasps are used for control on numerous crops and plants; these include cotton, sugarcane, vegetables, sugarbeets, orchards, and forests. Some of the pests  controlled include cotton bollworm (), codling moth (Cydia pomonella), lightbrown apple moth (), and European corn borer ().

Trichogramma species vary in their host specificity. This can lead to nontarget hosts being parasitized. This, in turn, can cause problems by reducing the amount of parasitism of the target host, and depending on the rate of parasitism, nontarget effects could be significant on nontarget host populations. Research is being done on the use of Trichogramma wasps to control populations of spruce bud moth (), which damages white spruce trees.

Species used 
The most commonly used species for biological control are T. atopovirilia, T. brevicapillum, T. deion, T. exiguum, T. fuentesi, T. minutum, T. nubilale, T. platneri, T. pretiosum, and T. thalense.

T. pretiosum

T. pretiosum is the most widely distributed species in North America. It is a more generalized parasitoid, able to parasitise a range of different species. It has been the focus of many research studies and has been successfully reared on 18 genera of Lepidoptera. T. pretiosum was introduced into Australia in the 1970s as part of the Ord River Irrigation Area IPM scheme.

T. carverae

Trichogramma carverae is mainly used for light brown apple moth and codling moth control, and is predominately used in orchards.<ref name=llewellyn>Llewellyn R (2002) The good bug book: beneficial organisms commercially available in Australia and New Zealand for biological pest control.' (Integrated Pest Management Pty Ltd).</ref> In Australia, T. carverae is used for biological control of light brown apple moth in vineyards. Though Australia has its own native Trichogramma species, not much work has been undertaken to use them commercially for biological control within Australia.

Light brown apple moth is common throughout Australia and is polyphagous on more than 80 native and introduced species. The larvae cause the most damage, especially to grape berries, as their feeding provides sites for bunch rot to occur. Losses in the crops can amount up to $2000/ha in one season. It is very predominant in areas such as the 雅拉河谷. Insecticide use is not a choice method for most growers, who prefer a more natural means of controlling pests. As a result, Trichogramma wasps were considered a good candidate for biological control, even more so as the moth larvae are difficult to control with insecticide. Moreover, light brown apple moths are relatively vulnerable to egg parasitism, with their eggs being laid in masses of 20-50 on the upper surfaces of basal leaves in grapevines.

部分物種
以下譯名參照龐飛雄及陳泰魯 (1974)使用的名稱：
 Trichogramma aomoriense Trichogramma atopovirilia 澳洲赤眼蜂 Trichogramma australicum ：見於中国。
  Trichogramma brevicapillum Trichogramma carverae 螟黃赤眼蜂 Trichogramma chilonis 舟蛾赤眼蜂 Trichogramma closterae ：見於中国
 Trichogramma deion 松毛蟲赤眼蜂 Trichogramma dendrolimi ：見於中国。
 食胚赤眼蜂 Trichogramma embryophagum 
 暗黑赤眼蜂 Trichogramma euproctidis ：見於中国。
 廣赤眼蜂  ：見於中国。
 Trichogramma exiguum Trichogramma falx 暗褐赤眼蜂 Trichogramma fasciatum 
 Trichogramma fuentesi Trichogramma funiculatum 稻螟赤眼蜂  ：見於中国。
 Trichogramma jezoensis Trichogramma koehleri 
 粘虫赤眼蜂 Trichogramma leucaniae 
 Trichogramma luteum 舌突赤眼蜂 Trichogramma lingulatum 
 毛利赤眼鋒 Trichogramma maori 微小赤眼鋒 Trichogramma minutum 
 Trichogramma nubilale 玉米螟赤眼蜂 Trichogramma ostriniae 
 Trichogramma papilonis Trichogramma platneri Trichogramma pretiosum 微突赤眼蜂 Trichogramma raoi ：見於中国。
 窄突赤眼蜂 Trichogramma retorridum 
 顯棒赤眼蜂 Trichogramma semblidis 
 疏毛赤眼蜂 Trichogramma semifumatum 
 凤蝶赤眼蜂 Trichogramma sericini ：見於中国。
 Trichogramma siddiqi Trichogramma thalense Trichogramma valentinei Trichogramma vitripenne 
 Trichogramma yawarae''

參考文獻

外部連結

 Biocontrol-oriented Trichogramma Manual
 Trichogramma Article
 Trichogramma dropping by drones 

 
Insects acting as insect pest control agents
Biological pest control wasps
Chalcidoidea genera