Paecilomyces lilacinus

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Chemical Identification | General Product Information | Physical & Safety Data

Chemical Identification

Common Name

中文通用名

淡紫拟青霉

General Product Information

Category

Microbial pesticide > Fungal pesticide
Nematicides > Bionematicides

Activity

Unlike the most effective synthetic organic chemical nematicides, Paecilomyces lilacinus is non-systemic; it acts as a parasite. Spores of the fungus become attached to the cuticle of the ventiform stages of the nematodes as they pass through the soil. After germination, the fungus penetrates the cuticle of the nematode and feeds on it, thereby attacking the eggs too. The fungus also penetrates the nematode via the hyphae which enter through body openings such as the anus and vulva.

Research has shown that a serine protease from Paecilomyces lilacinus may play a role in penetration of nemotade eggs by the fungus. Experiments carried out with the purified protease showed the immature eggs to be highly vulnerable whereas those containing a juvenile were more resistant; the protease had no effect on hatched larvae.

The fungus is parasitic to all stages of development of common plant infecting nematodes, but does not affect beneficial entomopathogenic nematodes. In the laboratory, eggs from highly infected cysts were infected by Paecilomyces lilacinus when incubated at 26°C. Microscopic studies showed that the fungus infects excised Meloidogyne javanica females (and the eggs within), 3^rd and 4^th stage juveniles, and 1^st and 2^nd stage juveniles from egg masses. Infection of Radopholus similis eggs occurred only after prolonged exposure to the fungus. In pot trials carried out in Australia, Paecilomyces lilacinus was shown to infect 80% of white cysts (Heterodera avenae). In another test, all Radopholus similis adults were infected and immobilised within six days.

The mode of action of Paecilomyces lilacinus to the nematode, the crop and soil ecosystem is very different to synthetic organic chemical nematicides. Whilst the effectiveness of a particular chemical may decline after repeated applications due to the emergence of target pest resistance and increased populations of soil organisms capable of degrading the nematicide, Paecilomyces lilacinus is still successful when applied in successive cycles. Chemical nematicides are also affected by the weather - dry conditions or periods of heavy rain are non-ideal as these nematicides should be dissolved slowly; however, Paecilomyces lilacinus is effective under all weather conditions.

Trials with bananas found that the banana mat became more resilient and robust after several applications of the product. It is suggested that this is because beneficial soil organisms are unaffected and so a ‘natural’ root system develops. This can cope better with water stress during droughts (which means that the mean bunch weight does not decrease by as much as when the plant is treated with chemicals) and also reduces the interval between flower and harvest. In addition, plants treated with Paecilomyces lilacinus appear more resistant to disease; the product can suppress soil-borne pathogens such as Moko disease.

As Paecilomyces lilacinus poses a lower potential hazard than the conventional pesticides, it is classified as a biorational pesticide: it is non toxic, specific and has no adverse environmental affects. Tests exposing plant roots to approximately ten times the normal field dose of Paecilomyces lilacinus were carried out on banana, barley, capsicum, cotton, pineapple, potato, tomato and wheat to investigate the selectivity; no fungal hyphae were detected within the roots. A selection of invertebrates including 2 species of entomopathogenic nematodes, earthworms, ants, brine shrimp, termites, fly pupae and paper-nest wasps were also tested against a low dose (exposure expected in the field) and a high dose at 10 or 100 times that of the field rate. As only termites and ants exhibited high rates of mortality after two weeks at the 100 X dose, it is unlikely that Paecilomyces lilacinus will be harmful to the species tested, when used at low dose rates.

The product can be used as a pre-plant, transplant or post-plant treatment. Pre-plant treatment provides effective control because as the roots of the plant grow, the spores become concentrated around the tips where they can most readily infect the nematodes attracted to the developing roots. For effective control, the product should be applied frequently (six month intervals, compared to three months with other nematicides). It has no effect on subsequent crops.

PI Plus can be used in combination with chemical nematicides and other herbicides and pesticide, but not fungicides. Therefore it can form part of an overall pest management programme.

Pot trials on potato crops found that application of Paecilomyces lilacinus had an effect on the decline of viable eggs of the potato cysts nematodes Globodera rostochiensis and G pallida.

CropUse

CropUses:
Banana, black pepper, citrus, coffee, cotton, legumes, okra, ornamentals, papaya, peanut, pineapple, potato, ramie, strawberry, sugarcane, tea, tobacco, tomato, vegetables, wheat

Bananas

1 g/mat

Premix

Type	AI concⁿ
Wettable Powder (WP)	2 X 10⁹ spores/g
Water dispersible granule (WG)	2 X 10⁹ spores/g

Physical & Safety Data

Toxicology

Acute oral (rat)

LD₅₀ 2000 mg/kg <

Environmental Profile

Fish _{[96 h]}	LC₅₀ = 100 mg/L
Daphnia_{[48 h]}	LC₅₀ = 100 mg/L
Algae _{[72 h]}	LC₅₀ = 100 mg/L

Fate in :
Non-hazardous to honeybees or to relevant populations of beneficials.

Fate in soil:
Paecilomyces lilacinus undergoes biodegradation readily. It occurs naturally in the upper 60 cm of soil. Paecilomyces lilacinus is immobile in soil and so is unlikely to be washed through to lower less porous soil layers and enter ground water systems.