Eggs Are Cheaper. Larvae Are the Ones That Arrive.

We sell green lacewing twice. Once as eggs and once as larvae — the same insect, a few days apart, at prices that are not a few days apart.

A pack of 250 eggs is $21. A pack of 250 larvae is $70. That is the same number of animals, from the same species, and one costs more than three times the other. Nobody in this industry explains the gap, so here it is.

What is actually in each container

Both products start as the same thing: eggs laid by the same insectary colony. The difference is what happens between the colony and you.

So this is not a comparison of two organisms. It is a comparison of when you take delivery of the risk. The eggs product hands it to you; the larvae product keeps it in the insectary and charges you for that.

What hatches is identical either way: a larva with three instars that feeds for two to three weeks, eats somewhere between 300 and 400 aphids in about a fortnight, and then pupates into an adult that eats no pests at all. The adult is not the product, and that surprises people.

What the price difference actually is

Per individual, across our own range:

Two things worth noticing. The multiple is not nine or ten times, which is what you get if you compare the smallest egg pack to the smallest larva pack — those are 250 and 50 respectively, and it is not a like-for-like comparison. At matched counts it is between two and a half and six and a half times.

And the gap widens with size. Eggs get dramatically cheaper in bulk; larvae get cheaper more slowly, because incubating and shipping a living, feeding, cannibalistic animal at volume does not scale the way shipping eggs does.

Where the eggs go

The price gap is an attrition gap, and the attrition has been measured — in a vineyard rather than a plant room, but measured.

A 1997 study released green lacewings against grape leafhoppers and tracked what happened to them. In the egg-release plots, there was about 70% egg mortality. In the larval-release plots, about 50% of the larvae survived to the third instar.

The same paper gives the cause, and it is the biology rather than the handling: egg hatch was about 60% in the bulk paper cups used for release, against about 91% when the lacewings were reared in individual cells. Their conclusion — “the poor egg hatch is attributed primarily to cannibalism.”

Which is what the stalks are for

A green lacewing does not lay her eggs on a leaf. She lays each one on the end of a fine silken stalk, standing the egg a few millimeters clear of the surface. Kansas State’s extension bulletin states the function plainly: “The stalks protect the eggs from being fed upon by newly emerged (eclosed) larvae.”

The mother is protecting her eggs from her own earlier offspring. That is how strongly this species cannibalises — it is not a failure mode, it is built into the animal, and the same bulletin notes that larvae “will eat (cannibalize) each other if no prey are available.”

A laboratory study puts a shape on it: larvae “commit low egg cannibalism when alone but express higher cannibalism in the presence of conspecific larvae in the neighborhood.” Second instars with eight neighbours ate roughly 1.8 times as many eggs as second instars alone. Density is the variable. A pile of eggs in one place is the worst arrangement there is; scattering them thinly is not fussiness, it is the whole technique.

And then the ants, and everything else

The stalks turn out to do a second job. An experiment on a related lacewing found that when colonies were exposed to ants, “almost all eggs with intact stalks were untouched, whereas 50–80% of eggs in which stalks had been severed at their bases were destroyed by ants.”

Which matters here for a specific reason: bulk eggs shipped loose in a carrier have mostly lost their stalks. That study is on naturally laid eggs of a different genus and it is not a measurement of what happens to a pack of loose eggs on your plant. It does mean the stalk is a real defense and not decoration, and that an ant-tended aphid colony is a bad place to scatter eggs.

Even where the eggs hatch, the neonates are vulnerable. A long-term field study of lacewings in cotton found eggs hatching at 69% and 76% and then a “sharp drop in densities from the egg to the first larval instar” — the losses were after hatch, to other predators. Its summary is the best single line on why lacewings underperform in the open: in isolation they suppress aphids consistently, and “the full community of predators when tested together exerts minimal aphid control.”

What has been compared, and what has not

Here is where we have to be careful, because this is a question the industry answers more confidently than the literature does — and we have been among them.

What the aphid literature does have is a set of single-stage trials, and read together they are less encouraging than the marketing for either product:

Two honest conclusions from that table. The first is that rate matters more than stage in the trials that worked — the apple result used a third of a million eggs per hectare. The second is that the stage question is genuinely open for aphids, and anyone telling you otherwise, including a product page of ours, is extrapolating from leafhoppers.

A trial that would settle it is running now. A USDA and Washington State project on lacewing releases in apples lists “compare species, life stages, and cards versus loose eggs” among its objectives, and runs to 2027. There is also a 2025 paper from that group on augmentative lacewing releases against aphids in apples which we could not get access to — so we do not know what it says, and we are not going to guess.

Which one to buy

Given all of that, the decision comes down to what you are actually doing, and the mechanism supports a clearer answer than the trials do.

Common questions

Are lacewing larvae really better than eggs?

For aphids specifically, nobody has published the comparison. The one head-to-head release trial was against grape leafhoppers, and there eggs did not reduce the pest while larvae did — with about 70% egg mortality against about 50% larval survival to third instar. The mechanism behind that, cannibalism, applies to aphid releases too, but the result itself is from a different pest and we are not going to present it as more than it is.

Why are eggs so much cheaper?

Because you are taking on the attrition. The eggs are the stage before the predator, and a substantial share of them never become a feeding larva — mostly by being eaten by their own siblings. Buying larvae means the insectary carried that risk under controlled conditions instead.

Is it three times or ten times the price?

Per individual, between about 2.6 and 6.4 times, depending on pack size, and the gap widens as the packs get bigger. The ten-times figure comes from comparing our smallest egg pack with our smallest larva pack, which are 250 and 50 — not a like-for-like comparison.

What are the little stalks the eggs sit on?

A defense against the larvae's own siblings. Kansas State's bulletin puts it as “the stalks protect the eggs from being fed upon by newly emerged … larvae.” They also defend against ants: in an experiment on a related lacewing, eggs with intact stalks were almost all untouched by ants while 50–80% of those with severed stalks were destroyed.

Nothing in my egg container is moving. Is it dead?

Non-incubated lacewing eggs are not supposed to be doing anything on arrival, and cold transit lengthens the window before they hatch. Beneficials shipped cold and still are a separate article and worth reading before you judge a shipment.

Can I just buy eggs and release more of them?

You can, and the trial where eggs worked used about 335,000 per hectare on dwarf apple trees. The catch is that piling on more eggs in the same area increases exactly the thing that kills them — cannibalism rises with the number of neighbours. More eggs spread wider is the version that helps; more eggs in the same spot is not.

Will lacewings clear an aphid outbreak on a big plant?

Expect help rather than a clearance. Across the published aphid trials, results range from significant reduction on dwarf apple at very high rates to no detectable effect on landscape plants. On a large established specimen, plan on lacewings as one part of a program rather than the whole of it.