Because the virus only infects L. dispar, it has proven safe for use with other insects including ants, bees and non-target lepidopteran species.

Studies of its safety have found no toxicity or mortality concerns, though ocular doses administered to rabbits did cause some irritation.

[11][12] The exact mechanism for how the virus induces the larva to climb to a high vantage point before dying has been linked to a gene in the virus that causes infected cells to produce an enzyme which inactivates the hormone that triggers molting behavior.

[11] Even if it does not reach the top of the tree, the infected larva will migrate to the exposed parts of the plant.

The infected larvae are consumed and the virus is viable after its passage as feces, facilitating its spread.

[14] The U.S. Forest Service studied LdMNPV for its potential use as a microbial insecticide due to a variety of reasons.

[16] In order to produce Gypchek, a laboratory strain of the spongy moth is reared and infected with the virus.

[17] The virus polyhedrals comprise 12% of Gypchek with larvae body parts and other inert solids making up the remaining 88%.

[18] Gypchek's toxicological and pathogenicity testing revealed no effects on laboratory animals, wild mammals, birds, and fish at field doses.

[18] The appearance is listed as, "dried insect body parts and virus polyhedral" and has a musty odor.

[18] LdMNPV has undergone numerous tests in regards to toxicity and mortality, all of which show no adverse effects except varying irritation for ocular doses administered to the eyes of rabbits.

LdMNPV was found to not infect other members of the order Lepidoptera, or Hymenoptera-order insects such as ants and bees.

[17]: 63 A study done on mice, shrews and two opossums showed no toxicity, no adverse effects or abnormalities, and the animals were sacrificed twelve days after last exposure.

[17]: 54  A study done on albino guinea pigs found no toxicity, mortality or irritation after dermal application of LdNPV.

[17]: 58  Irritation was reported in a study using 'LDP 53 air dried sample' lasting from 4 to 14 days; analysis found the presence of Staph epidermidis, Corynebacterium xerosis, Bacillus cereus, and Bacilius subtillis, but this was not labeled as significant.

Two oral studies, one on mallard ducks and the other on black-capped chickadees and house sparrows, had no adverse effects.

[17]: 64  Two field test studies found no significant difference on songbirds and caged quail populations at one to two months after application.

[17]: 66 Tests on Daphnia, backswimmers, midges and water boatmen found no significant effects on survival.

[19] In another study, protein tyrosine phosphatase (PTP) was found to have a crucial role in the virus's infection of brain tissue, but was not responsible for the enhanced locomotory activity associated with climbing to the top of the trees to die.

National Geographic described the gruesome effect of LdMNPV; "The virus forces the "zombie" caterpillars to climb trees, where the invader eventually liquifies its hosts' bodies into a dripping goo.

[4][22][23][24] These same stories often referred to the discovery of EGT as the driving force behind the behavior of the infected larvae.