Description
These 2 mm. mini-wasps, like D. siberica, are best used for preventing the establishment of several leafminer species. They can also tackle minor infestations. And, if established, they can adequately protect a crop throughout the season.
D. isaea, which are shipped as pre-hatched, pre-fed adults, are the product of choice when leafminers are first seen, or soon expected to be seen, in a warmer area. They do best in warmer conditions.
Some of the several species which can be controlled with these parasitoids include the ones controlled by the preceding biocontrol agent. They can control 18 known species from four different genera, not just the genus Liriomyza
Life-style
These parasitoids, work by "stinging" (oviposition) the larvae of leafminers while they work in their mesophyll mines with their ovipositors (egg-laying apparati). The stinging conveys a paralyzing toxin to the pests. The toxin works right away, the larvae stop feeding. But these mini-wasps don't stop there. They will also feed on the hosts (host-feeding), as do many Chalcid (KAL-cid) wasps (a wasp family). They will then lay 1-5 eggs next to the paralyzed larvae, up to 50 eggs in their life. The wasps' larvae which hatch from the eggs, then consume the leafminer larvae from the outside-in (ectoparasitism). The parasitoids' larvae then construct pillars of fecal matter around the remains of the much deteriorated pests. These are thought to protect the beneficial larvae from leaf drying, etc., while they undergo pupation.
The life-span of these parasitoids is roughly 2 weeks in their immature stages, then 3 weeks as adults. The conditions for optimum performance will be between 75-90F with a relative humidity of around 80%. But these are optimum conditions, and not necessarily a prerequisite of successful implementation. Under optimum conditions, each female Diglyphus kills about 360 leafminer larvae. Please note, however, significantly cooler or warmer temperatures and humidity fluctuations may hamper reproduction and development a certain degree.
Benefits
The benefits are very much the same as those of Dacnusa siberica (see previous for details), with exception to the time of year for best use (spring and summer) and their temperature preferences.
D. isaea, also being shipped as adults, offer the benefit of fast oviposition or egg-laying.These tiny wasps parasitize leafminer larvae in the first and second stages of development. .
Release rate: 500-1,000/acre every 2 weeks, 2-3 releases.
Use in conjunction with
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