Today we are going to talk about a type of parasitic wasps that belongs to the Hymenoptera order and to the Eulophidae family. It’s about the Diglyphus isaea. It is known mainly since it is capable of exercising its control over the miner is Liriomyza Brioniae, Liriomyza trifolii, L. huidobrensis, L. strigata besides the chrysanthemum miner Phytomyza syngenesia. In some characteristics that make them unique and are difficult to eliminate given their ability to adapt.
In this article we are going to tell you about all the characteristics, life cycle and application of the Diglyphus isaea.
The female of these Hymenoptera is capable of stinging and paralyzing the leafminer larva in the last nymphal stages. To do this, it lays an egg next to it from which the larva that feeds on the miner larva emerges. The advantage that this type of wasp has to reproduce compared to others is that it has a great reproductive capacity. It must be taken into account that if it has a great capacity to adapt to the environments and a high reproduction rate, it will be easier for it to spread throughout the territory and increase its abundance.
This ability makes the Diglyphus isaea can reach very high population levels in a short time. Although it has a high reproductive capacity, its early introduction into cultivation is recommended. The egg is quite difficult to see due to its very small size. The larvae change color as they develop and advance from stage to stage. The first color they go through is transparent. Once it grows into something else, they turn yellowish and finally bluish-green. The pupa acquires a dark metallic coloration when it begins to mature. The eyes of these insects are red.
When mature, they have short, jointed antennae and they develop into small wasps with a length of about 1.5 millimeters. The body is usually of a darker color and has some metallic reflections by which it can be recognized quite easily. The female is somewhat smaller than the male in general.
Biological cycle of Diglyphus isaea
This insect goes through various stages in its biological cycle. It begins with the egg, larva, upa and adult stage. The time they take to develop is shorter than that of the host. Therefore, it is usually a quite successful parasitic wasp. It should be noted that the biological cycle is very short and it only lasts about 10 days compared to 17 days for the miner. This biological cycle can be altered with room temperature. It turns out that those 10 days that it usually takes to reproduce completely, is as long as they have an approximate temperature of 25 degrees.
It is quite resistant since as an adult it can survive throughout the winter. However, most populations reach their peaks during the spring and summer season. The temperature thresholds that serve to develop the Diglyphus isaea They are set between 6 and 25 degrees. This means that, with this wide range of temperatures, it can develop faster than that of the dipteran it parasitizes. After 15 degrees is when this insect begins to grow much faster. For this reason, it is a type of wasp that is quite effective in this temperature range to be able to parasitize its host.
One of the negative aspects that can affect the reproduction of Diglyphus isaea is the low light. It is necessary to have a control during the spring and summer months since in those times such low light conditions do not occur. It is in the autumn and winter season when there are fewer hours of sunshine.
Activity of the Diglyphus isaea
We are going to mention now which one is the biological activity by which the Diglyphus isaea has become better known. It is an ectoparasite of leafminer larvae. The female has a high capacity to search and explore the leaf with her antennae. Once they have found the right larva to be parasitized, they immobilize it. The miner larva when paralyzed left to feed completely. Thus, the Diglyphus isaea stops blade damage immediately. Once it has done this, it makes a laying, rarely laying more than one egg, next to it. Usually this egg is placed inside the gallery.
When the eggs fan the larvae of Diglyphus isaea that are born between them they feed on the miner and consume them completely. Once we have passed to the last phase before starting the pupal phase, the larvae of the parasite is in charge of building between 6 and 8 vertical pillars with the excrement to keep the gallery walls separate and to be able to protect the future pupa. These pillars are usually very characteristic and have a black color. They are usually visible through the blade. The cycle and activity of the Diglyphus isaea it would end with the appearance of the adult emerging to the outside, piercing the gallery.
One of the quite important characteristics of the Diglyphus isaea What increases its value as a parasite is its predatory action. This insect kills miner larvae in order to feed, since the female usually bites these larvae repeatedly in order to absorb their juices and cause death. If this insect had to choose its primary food source, they would refer to the first and second larval stages.
You have to place a can in a horizontal position and remove the cap. While you want to spread the Diglyphus isaeathe most normal thing is to walk through the crop and give a few small taps at the base of the mount to facilitate the exit of the insect. The releases are advisable to do first thing in the morning and late in the afternoon. The introduction of Diglyphus isaea it is produced at the moment the first galleries are observed in the crop. The number of adult miners that exist in the pest can also serve as a reference. The introductions of this insect always come adapted to the level of attack that the miner has.
I hope that with this information you can learn more about Diglyphus isaea and their characteristics.