Moths
The facts
Moth larvae can cause considerable damage to stored goods by feeding or by contamination with their own products, e.g. webbing and frass. Adult insects are not responsible for damage as they either feed on liquid food and water or do not feed at all. The larval byproducts, webbing and frass, are a particular problem. Webbing can entirely coat commodities and may be responsible for blocking machinery and ducts. The problem is exacerbated when webbing becomes mixed with frass, food and general debris. A major pest of warehouses and, more recently, retail premises. This species will infest cereals, fruit, shelled nuts, cocoa beans, fish, spices and tobacco. In the case of tobacco, "sweet" varieties are preferred and entire interveinal leaf areas may be destroyed. Moth infestations are especially serious where wheat and flour are stored in bulk, although they seldom infest goods which are stored in silos. The larvae themselves are unique and readily identifiable: well-developed head; clearly segmented body; three thoracic segments, each bearing a pair of five jointed legs; ten abdominal segments: numbers 3-6 bear false feet (prolegs), the tips of which are equipped with crochets; segment ten bears one pair of claspers. Within 4 days of emergence, the female produces 100-150 eggs which are laid in cracks and crevices. These hatch in 10-14 days to give larvae which are creamy-white with dark spots on their sides. They penetrate food, covering it with webbing as they feed. In colder climates larvae pass through 4-5 moults to attain full growth when they are 12mm long, whereupon they will leave the food and wander for 1-3 days, searching for a dark place in which to spin a silken cocoon. They may diapause in this state throughout the winter before pupating in April or May and emerging as adults in late spring. At room temperature development takes from 82-206 days.
Where do Moths live?
Moths live throughout the world, except in the oceans. They inhabit steamy jungles near the equator, and they have even been found on icecaps in the Arctic. Moths vary greatly in size. The largest moths are the Giant Hercules of Australia and the Giant Owl Moth of South America. They have a wingspread of about 12 inches (30 centimeters). The smallest moths have wingspreads of about 1/8 inch (0.3 centimeters). These moths belong to a group called leafminers.
Why keep Moths under control?
The reason Moths are considered a public health pest is chiefly because they consume and contaminate vast quantities of food, worldwide, intended for human consumption. With a 12mm wingspan; upper forewing: well defined, rather sinuate outer band on grey-buff background. Larval development is greatly influenced by the environmental conditions of temperature and food supply. Egg laying commences within 24 days of the adult's emergence, and up to 350 eggs are laid during the first 4 days. These hatch 3-17 days later. The larvae are dirty-white and may be tinged brown or have purple spots. At 25°C they will be fully grown in 25 days. The larvae do not diapause. Pupae develop in 12-17 days in the vicinity of food, and breeding is continuous. Where temperatures are low the moth overwinters as larvae.
Prevention & Control
The method and timing of control measures against moths depends upon the species involved. The larvae are frequently difficult to reach because they are concealed in foodstuffs or the fabric of buildings and may be obvious only when they migrate. This is important in order to avoid conditions suitable for the development of moth infestations. Warehouses should be constructed so as to ensure maintenance of correct storage conditions and allow easy cleaning. Cracks and crevices which might serve as harbourages should be kept to a minimum. Stacks of commodities should be neatly arranged above the floor on pallets, with a gap between stacks to allow for ventilation, regular inspection, cleaning and treatment with insecticides if necessary; Good packaging is particularly important to prevent entry of larvae. Spillages should be removed promptly, and infested goods dealt with immediately either by fumigation or destruction. Uncontaminated products should not be stored in the vicinity of infested materials. In the case of the house and clothes moths, fabrics should be regularly inspected and cleaned, and alternative breeding sites, for example birds' nests, removed if possible. It should be remembered that soiled fabrics make a more acceptable diet to these insects than clean ones. In order to obtain the best results, insecticidal control measures should be integrated with good hygiene.
Treatment
Contact Paramite Pest Solutions if you suspect you may have a problem and we can advise you on the best course of action. A visit by our pest control officer can be arranged. He will carry out a survey and suggest what action needs to be taken. Adhesive traps are used for trapping stored product moths. Attractant capsules containing a pheromone are attached to a sticky surface on which the moths are caught and which is partially protected from the environment. The trap is then suspended ca 2-3 m above the floor. They perform best in locations which are not dusty. Alternatively funnel traps may be used. These are usually constructed of plastic and incorporate a funnel system leading to a retaining chamber in which moths are trapped and killed using a toxicant strip, water or detergent. Paramite Pest Solutions will take all possible precautions in the placing of poison baits. Revisits will be made until the problem is cleared.