赤眼蜂屬

寄生性

To locate host eggs, adult females use chemical and visual signals, such as egg shape and colour. After she finds a suitable egg, an experienced female attempts to determine if the egg has previously been parasitized, using her ovipositor and antennal drumming (tapping on the egg surface). Females also use antennal drumming to determine the size and quality of the target egg, which determines the number of eggs the female will insert. A single female can parasitize up to 10 host eggs a day.

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。As females are all relatively similar, taxonomists rely upon examination of males to tell the different species apart, using features of their antennae and genitalia.
The first description of a Trichogramma species was in North America in 1871, by Charles V. Riley. He described the tiny wasps that emerged from eggs of the viceroy butterfly as Trichogramma minutum. In 生物分類學, original specimens are very important, as they are the basis of reference for subsequent descriptions of species. The original specimens, however, were lost. Riley also described a second species in 1879 as Trichogramma pretiosum, but these specimens were also lost. To correct these errors, entomologists returned to the areas where Riley originally found the species and obtained  specimens of T. minutum and T. pretiosum. These specimens are now preserved properly in the 史密森尼學會. Currently, the number of Trichogramma species is over 200, but as of 1960, only some 40 species of Trichogramma had been described.

赤眼蜂屬物種體內的沃爾巴克氏體

赤眼蜂屬物種體內有沃爾巴克氏體（Wolbachia），是一種分布廣泛的細菌，專門感染昆蟲的內臟，特別是生殖系統的器官。這些沃爾巴克氏體在感染了昆蟲後，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), 單性生殖, 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 (), 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. 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 . 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.